As Doppler ultrasound has been proven to be an effective tool to predict and compress the optimal pulsing windows, we evaluated the effective dose and diagnostic accuracy of coronary CT angiography (CTA) incorporating Doppler-guided prospective electrocardiograph (ECG) gating, which presets pulsing windows according to Doppler analysis, in patients with a heart rate >65 bpm.119 patients with a heart rate >65 bpm who were scheduled for invasive coronary angiography were prospectively studied, and patients were randomly divided into traditional prospective (n = 61) and Doppler-guided prospective (n = 58) ECG gating groups. The exposure window of traditional prospective ECG gating was set at 30%–80% of the cardiac cycle. For the Doppler group, the length of diastasis was analyzed by Doppler. For lengths greater than 90 ms, the pulsing window was preset during diastole (during 60%–80%); otherwise, the optimal pulsing intervals were moved from diastole to systole (during 30%–50%).The mean heart rates of the traditional ECG and the Doppler-guided group during CT scanning were 75.0±7.7 bpm  and 76.5±5.4 bpm (range: 66–105 bpm), respectively. The results indicated that whereas the image quality showed no significant difference between the traditional and Doppler groups (P = 0.42), the radiation dose of the Doppler group was significantly lower than that of the traditional group . The sensitivities of CTA applying traditional and Doppler-guided prospective ECG gating to diagnose stenosis on a segment level were 95.5% and 94.3%, respectively; specificities 98.0% and 97.1%, respectively; positive predictive values 90.7% and 88.2%, respectively; negative predictive values 99.0% and 98.7%, respectively. There was no statistical difference in concordance between the traditional and Doppler groups (P = 0.22).Doppler-guided prospective ECG gating represents an improved method in patients with a high heart rate to reduce effective radiation doses, while maintaining high diagnostic accuracy. With the clinical application of multi-detector CT scanning for imaging the coronary arteries, coronary CT angiography (CTA) has emerged as an attractive noninvasive diagnostic modality for detecting coronary artery disease Until now, many methods have been developed and applied to reduce the radiation dose, among which prospective electrocardiograph (ECG) gating is one effective method that has demonstrated the obvious advantage of allowing for a decreased patient dose Numerous studies have mainly focused on the relationship between the heart rate and the optimal pulsing windows to guide the clinical utility of prospective ECG gating for patients with a high heart rate. The results, nevertheless, are contradictory, as the optimal pulsing window does not always change regularly with the heart rate. For example, Leschka et al. believed that the narrowest reconstruction window providing diagnostic image quality was 60–70% for a heart rate <60 bpm, 60–80% for a heart rate of 60–70 bpm, 55–80% for a heart rate of 70–80 bpm, and 30–80% for a heart rate >80 bpm (20), whereas Weustink et al. concluded the optimal exposure windows to be at 60–76%, 30–77%, and 31–47% for a heart rate ≤65 bpm, 66–79 bpm, and ≥80 bpm, respectively . The possible reason may be that the physiological phase is associated not only with heart rate but also with other factors, such as filling pressures and heart function A precise definition of an optimal ECG pulsing window is therefore required for prospective ECG gating scanning in patients with a high heart rate. Since Doppler ultrasound has been proven to be a helpful methodology with which to predict the physiological phase Our study protocol and radiation dose measurements were approved by the Ethics Committee of Jinan Military General Hospital . WrittenIn total, 1431 symptomatic patients who were scheduled for invasive coronary angiography (ICA) were prospectively studied. For patients with a heart rate >65 bpm, a β-blocker was traditionally applied in order to reduce the heart rate. Excluded from the study were 744 patients with a heart rate <65 bpm and 547 patients with a heart rate >65 bpm, whose heart rate could be brought under 65 bpm by the β-blocker. Among the 102 patients whose heart rate could not be brought under 65 bpm by the β-blocker as well as 38 patients with a heart rate >65 bpm and contraindications for β-blockers (asthma and severe chronic obstructive emphysema), the subjects were randomly divided into a traditional prospective ECG-gating group and a Doppler-guided prospective ECG-gating group. Patients who met the following criteria were excluded: refused to provide consent or withdrew for personal reasons (n = 2); demonstrated a heart rate variability of more than 20 bpm (n = 13); had undergone stent-graft and bypass surgery (n = 5); or were allergic to iodinated contrast agents (n = 1). Our final study cohort consisted of 119 patients, with 61 patients in the traditional prospective ECG-gating group and 58 in the Doppler-guided prospective ECG-gating group, respectively . No signAll CT examinations were performed using 320-detector CT  with a detector collimation of 320×0.5 mm. For CT coronary imaging, a 40–60 ml bolus of Iohexol  was injected into an antecubital vein through an 18-gauge catheter at an injection rate of 4–6 ml/sec, followed by 50 ml of saline solution.CT scanning parameters were set according to body mass index (BMI): 100 kV and 350 mA for BMI <18; 100 kV and 400 mA for BMI between 19–24; and 120 kV and 450–500 mA for BMI >24. For heart rates between 65–79 bpm, the two-heart-beat acquisition mode was used. For heart rates ≥80 bpm, the three-heart-beat acquisition mode was applied in order to increase the effective temporal resolution and obtain adequate imaging quality. Using the multi-heart-beat acquisition mode, the effective temporal resolution was able to reach 87.5–58.3 ms.The exposure window of traditional prospective ECG gating was adjusted at 30%–80% of the cardiac cycle according to previous studies of the optimal pulsing windows of CTA_ENREF_19  [14], [1Image reconstruction was performed with 0.5-mm slice thickness and 0.25-mm overlap. At the level of the middle right coronary artery (RCA), we used an absolute timing approach and reconstructed transverse images with a 10-ms step from the peak R-wave. When the interval with less motion artifact was determined, the whole-heart data were reconstructed. All reconstructed images were transferred to an independent workstation .Coronary segments were defined by a 15-segment model according to American Heart Association guidelines Cardiac angiograms were performed using the conventional Judkin technique −1×cm−1, which was calculated specifically for the 320-detector CT) 2) The dose length product (DLP) displayed on the dose report of the CT scanner was recorded. An effective dose was obtained using the equation: E = k×DLP . A P-value of less than 0.05 was considered statistically significant.Quantitative variables were expressed as mean ± SD, and categorical variables as frequencies or percentages. An inter-observer agreement for the determination of image quality was calculated with kappa statistics.The mean heart rate of the traditional-ECG gating group during CT scanning was 75.0±7.7 bpm , with 72.4% (42/58) of a heart rate of 65 ≤ heart rate <80 bpm and 27.6% (16/58) of a heart rate ≥80 bpm. Of the 1,785 coronary arterial segments in 119 patients (15 segments per patient), 53 segments were excluded because the segments did not exist and could not be visualized by ICA and CTA. A total of 1,732 segments were thus available for analysis. The inter-observer agreement for image quality assessment was high (kappa = 0.78). The image quality grades of these segments were as follows: grade 1—81.9% (1419/1732); grade 2—12.9% (224/1732); grade 3—4.3% (74/1732); and grade 4—0.9% (9/1732). There was no significant difference in image quality score between traditional and Doppler-guided prospective ECG gating (P = 0.42) .Overall, the effective dose in the Doppler-guided prospective ECG-gating group was significantly lower than that in the traditional prospective ECG-gating group , and the patient dose in ICA was significantly higher than that of CTA  . In addiA groups × imaging methodology interaction followed by separate ANOVAs for traditional and Doppler-guided prospective ECG gating revealed that, whereas the effective dose of ICA was similar for the two groups , the radiation dose of CTA in the Doppler-guided prospective ECG-gating group (5.2±3.4 mSv) was lower than that of traditional prospective ECG gating  . This inThe inter-rater concordance between the two radiologists for ICA was good (kappa = 0.82). In the traditional prospective group, there were 154 segments in 44 patients with stenosis ≥50%. Among the 154 stenotic segments proven by ICA, CTA diagnosed 147 cases accurately. Among the 733 unstenotic segments proven by ICA, CTA diagnosed 718 cases accurately. The sensitivity of CTA was 95.5% ; the specificity was 98.0% ; the PPV was 90.7% ; and the NPV was 99.0% , respectively. The McNemar test showed no significant difference in the diagnostic results between CTA and ICA (P = 0.13).In the Doppler-guided prospective ECG-gating group, 158 segments in 42 patients were diagnosed with stenosis ≥50% by ICA, among which 149 segments were detected by CTA. In the 687 segments with stenosis <50%, 667 segments were diagnosed accurately by CTA. For the 845 evaluated segments, the sensitivity of CTA was 94.3% ; the specificity was 97.1% ; the PPV was 88.2% ; and the NPV was 98.7% , respectively. The McNemar test showed no significant difference in the diagnostic results between CTA and ICA (P = 0.06) . The diaAlthough prospective ECG gating has been suggested as a useful procedure to reduce radiation dose, it only works when the heart rate is low. A β-blocker is therefore recommended before CTA to control the heart rate, but is ineffective in some patients Due to the consistent movement of the heart, it is critical to find a relatively tranquil duration in which to scan and reconstruct the coronary artery. Studies have confirmed that there are two durations suitable for image reconstruction. One corresponds to the diastasis in diastole, while the other takes place in systole The present study showed that Doppler-guided prospective ECG gating, which can analyze the true length of physiological phase, may offer the possibility of locating pulsing windows exclusively at systole or diastole and thus decrease radiation dose. Previous study has demonstrated that when the length of diastasis >90 ms, the optimal image quality could be obtained at diastole. Otherwise, when the length of diastasis <90 ms, the diastole is not suitable for optimal reconstruction, and the reconstruction windows should be set at systole It is worth noting that in our study, the effective dose of Doppler-guided prospective ECG gating was still higher than those of previous studies based on patients with a low heart rate (5.2mSv vs. 2.2–4.2mSv) Generally, three main factors influence the radiation dose in patients with a high heart rate. The first is the length of exposure window. As mentioned above, this new technique of Doppler-guided prospective ECG gating cardiac CT angiography has the ability to compass the pulsing windows from 30%–80% to 60%–80% or 30%–50%. The second is the temporal resolution, determined by the hardware of CT scanners. If the temporal resolution is not sufficient to reconstruct a diagnostic image in patients with a high heart rate, the multi-segment reconstruction method should be applied to improve the effective temporal resolution, which increases the exposure time and patient dose significantly. Although the exposure windows were compressed greatly by Doppler-guided prospective ECG gating in the present study, the multi-segment reconstruction was applied by 320-detector CT, which led to a redundant dose when the heart rate is high −1×cm−1 or k = 0.017 mSv×mGy−1×cm−1 as the conversion coefficient, which however is chest conversion factor. Recent studies have suggested that the conversion coefficient changes depending on organ, scanning mode, patient size, X-ray tube voltage, and other factors −1×cm−1−1×cm−1 for 320-detectors CT Another reason for the redundant dose of the study was the differing conversion factor in dose estimation. Previous studies usually applied k = 0.014 mSv×mGyIt is worth noting that the procedure of CTA with Doppler-guided prospective ECG gating was more time-consuming and costly than the traditional method. However, patients whose heart rate could not be brought to desired levels only made up 8.3% of the total patients and thus did not disturb the work routine significantly. With regard to individual protection from radioactivity, Doppler-guided prospective ECG gating may reduce the patient dose by nearly 44%. Further studies should be conducted to investigate the cost-effectiveness of Doppler-guided prospective ECG gating in order to prove that the 44% of radiation dose saved benefits long-term survival.There are two limitations to our study. First, patients with arrhythmia were excluded from this study, as it was difficult for Doppler to forecast the tranquil duration interval. Second, the study was performed by applying first-generation 320-detector CT. In the future, the advantages of Doppler-guided prospective ECG gating should be confirmed with other scanners.In conclusion, in terms of decreasing the patient dose, ECG gating for coronary CTA improves from retrospective without dose modulation to retrospective with dose modulation to prospective mode. The current study indicates that Doppler-guided prospective ECG gating, a new method of ECG gating, may reduce effective doses further, while maintaining high diagnostic accuracy, particularly in patients with an elevated heart rate.Protocol S1The Detailed Protocol Approved by the Ethics Committee of Jinan Military General Hospital.(DOC)Click here for additional data file.


We assessed the prognostic importance of right ventricular (RV) involvement in patients with acute inferior myocardial infarction (MI).RV infarction contributes markedly to hemodynamic instability, atrioventricular conduction block and in-hospital mortality in patients with inferior MI. Cardiac magnetic resonance imaging (MRI) is the superior imaging technique for assessing RV involvement because of its high spatial resolution.th, 75th percentiles) of 6  months. We assessed the association of RV function with length of cardiac care unit (CCU) treatment as an index of short-term prognosis by using multiple regression analysis, and used Kaplan-Meier analysis to demonstrate the association of RV dysfunction with occurrence of heart failure (HF) after discharge as an index of long-term prognosis.We analyzed 20 consecutive patients  with first acute inferior MI due to proximal right coronary lesion. All patients were assessed with cardiac MRI after primary percutaneous coronary intervention and followed up for a median (25RV involvement was diagnosed with delayed enhancement MRI in 11 patients (55%). Patients with RV involvement had lower RV ejection fraction (EF)  and longer duration of CCU treatment  than those without RV involvement, although there were no significant differences regarding clinical, angiographic and the other MRI characteristics such as left ventricular parameters. By multiple regression analysis, RVEF was an independent predictor of length of CCU treatment . Kaplan-Meier analysis demonstrated that RVEF <30% was associated with increased occurrence of HF in chronic phase (p = 0.003).RVEF in patients with acute reperfused inferior MI is an important predictor of short-term prognosis and patients with lower RVEF had more occurrence of HF at long-term follow-up than those without lower RVEF. Evaluation of RV with cardiac MRI can improve risk stratification and patient management after acute inferior MI.


Different cardiac MR acquisition sequences have been used to obtain myocardial T1 values. Among which available techniques, MOdified Look-Locker Inversion-recovery (MOLLI) and inversion-recovery TrueFisp (TI scout) sequences are widely used in research and clinical settings. We compared myocardial T1 values derived from both MOLLI and TI scout techniques in the post gadolinium delayed enhancement experiments in a large-scale multicenter study . Our results indicated that myocardial T1 measurement using MOLLI is reproducible with TI scout.Different cardiac MR sequences have been used to obtain myocardial T1 values. The multipoint approach, as first described by Look and Locker (TI scout), has been widely used for estimation of the optimal TI in the assessment of myocardial delayed enhancement (DE). The other technique, MOdified Look-Locker Inversion-recovery (MOLLI) allows a rapid and highly reproducible T1 mapping of the heart with high levels of intra and inter-observer agreement. Even though each technique claims its own merit and reliability, the post-contrast myocardial T1 value is confounded by various factors that inhibit comparison of myocardial T1 between patients. In this work, we compared myocardial T1 values derived from both MOLLI and TI scout techniques in the post gadolinium (Gd) DE experiments in a large-scale multicenter study .All cardiac MRI studies were performed using Siemens 1.5T MR scanner. 390 MESA participants without finding of DE were included in the data analysis. Gd  was administrated as a bolus and single slice T1 determinations at the mid-ventricle short-axis view using MOLLI (11 images within 17 heartbeats) was performed at 12 minutes after injection and followed immediately by TI scout imaging. MOLLI was acquired again at 25 minutes post-Gd. All images were processed off-line using MASS research software with the Levenberg-Marquardt fitting algorithm. Region of interest was manually drawn from the same area in septum. We interpolated 12-minute MOLLI T1 linearly using T1 changes between two MOLLI acquisitions. The T1 value of the 12-minute MOLLI was then corrected based on the imaging time difference. Paired student t-test and Bland-Altman analysis were used to compare the T1 values .The mean T1 values between the post-contrast 12-minute MOLLI and TI scout were significantly different before correction  and was comparable after correction for the acquisition time difference . Figure Our results indicated that myocardial T1 measurement using MOLLI is reproducible with TI scout. This evaluation addresses an important issue in which comparison between myocardial T1 derived from different techniques, MOLLI and TI scout, could be possible provided other conditions that affect T1 values such as Gd type/dose and timing remain the same.This study is supported by N01 HC 95168, Multi-Ethnic Study of Atherosclerosis (MESA), National Heart, Lung, and Blood Institute (NHLBI).


In recent years, several new technologies for small-animal imaging have been developed. In particular, the use of ultrasound in animal imaging has focused on the investigation of accessible biological structures such as the heart, of which it provides a morphological and functional assessment. The purpose of this study was to investigate the role of micro-ultrasonography (μ-US) in a longitudinal study on BIO14.6 cardiomyopathic hamsters treated with gene therapy.Thirty hamsters were divided into three groups (n = 10): Group I, untreated BIO 14.6 hamsters; Group II, BIO 14.6 hamsters treated with gene therapy; Group III, untreated wild type (WT) hamsters. All hamsters underwent serial μ-US sessions and were sacrificed at predetermined time points.μ-US revealed: in Group I, progressive dilation of the left ventricle with a change in heart morphology from an elliptical to a more spherical shape, altered configuration of the mitral valve and subvalvular apparatus, and severe reduction in ejection fraction; in Group II, mild decrease in contractile function and ejection fraction; in Group III, normal cardiac chamber morphology and function. There was a negative correlation between the percentage of fibrosis observed at histology and the ejection fraction obtained on μ-echocardiography .Although histological examination remains indispensable for a conclusive diagnosis, high-frequency μ-echocardiography, thanks to the high spatial and contrast resolution, can be considered sufficient for monitoring therapeutic efficacy and/or the progression of dilated cardiomyopathy, providing an alternative tool for repeatable and noninvasive evaluation. In recent years, several new technologies for small-animal imaging have been developed including micro-radiography (μ-XR), micro-computed tomography (μ-CT), micro-magnetic resonance imaging (μ-MRI), micro-positron emission tomography (μ-PET) and micro-ultrasonography (μ-US). These technologies have allowed for a better evaluation of the efficacy of diagnostic and therapeutic protocols in the field of pre-clinical research. In particular, the use of ultrasound in animal imaging has focused on the investigation of accessible biological structures such as the heart, of which it provides a morphological and functional assessment -3.Muscular dystrophies constitute a heterogeneous group of degenerative diseases characterized by a progressive wasting and weakening of skeletal muscle, of varying severity and distribution . The ethThe most frequent types of muscular dystrophy, Duchenne and Becker, are characterized by an X-linked pattern of inheritance, but less common forms also exist having both dominant and recessive autosomal transmission: limb-girdle muscular dystrophies (LGMD). The most severe forms of LGMD  are due to mutations of alpha-sarcoglycan (SG), beta-SG, gamma-SG and delta-SG, they typically arise in infancy and are often associated with the development of dilated cardiomyopathy .In order to facilitate the understanding of the etiological and pathophysiological mechanisms underlying the different forms of muscular dystrophy and to devise and test new treatment protocols, several animal models have been developed. The BIO 14.6 hamster faithfully reproduces the LGMD2F phenotype seen in humans. In this animal model, the absence of delta-SG from the membrane of skeletal and cardiac muscle results in a secondary deficiency of alpha-, beta-, and gamma-SG. These hamsters exhibit a gradual loss of muscle strength and the progressive development of dilated cardiomyopathy, with a mean lifespan of 11 months, in contrast to the 22 months of the wild type (WT) hamsters ,8. The uThis study aimed to define the role of μ-US in the longitudinal study of BIO 14.6 hamsters with dilated cardiomyopathy treated with gene therapy.All procedures performed on the animals received prior approval from our institutional ethics committee. Thirty male hamsters were used; they were maintained on light/dark cycles of 12/12 h and had free access to food and water.The hamsters were divided into three groups of 10 animals each:- Group I: untreated BIO 14.6 hamsters;- Group II: BIO 14.6 hamsters which received an intraperitoneal injection of AAV2/8-CMV-hSCGD  after 2 weeks of age and an intrajugular injection of AAV2/1(AAV2 serotype transcapsidated with AAV1 serotype)-CMV-hSCGD after 5 months of age. The AAV were transcapsidated to improve cellular targeting. A different AAV serotype was used in the second injection to prevent immune response against the viral capsid.- Group III: untreated WT hamsters;All hamsters were examined with μ-echocardiography and sacrificed with an intrapulmonary injection of 0.2 mg of Tanax at the time points and in the manner shown in Additional file Echocardiographic examinations were performed with a VisualSonics Vevo 2100 unit, capable of recording over 750 frames per second and equipped with a high-frequency (40 MHz) transducer.During each μ-imaging session the hamsters received inhalation anesthesia with isoflurane in oxygen (3-4% for induction and 1.5% for maintenance). Heart rate and body temperature were appropriately monitored and remained constant also throughout the examination. Eutermia was guaranteed by the use of a heating pad. In order to prevent imaging artifacts each hamster was immobilized and its chest hair was removed by applying a calcium thioglycolate depilatory cream. The transducer was fixed on a special arm. An appropriate amount of heated sonographic gel  was applied to the shaved skin. The echocardiographic study was performed in two-dimensional (B-mode) and one-dimensional mode (M-mode) in the following projections:- Parasternal long axisOnce the hamster had been prepared for imaging on the animal platform, the transducer was positioned longitudinally to its body, along the right parasternal line, with the index marker pointing to its head and rotated about 35° counterclockwise.The obtained B-mode image represents a section across the long axis of the left ventricle, which allowed visualization of the aortic root, outflow tract of the left ventricle, delimited anteriorly by the interventricular septum and posteriorly by the anterior flap of the mitral valve Figure .- Short parasternal axisThe B-mode parasternal short-axis view was obtained from the long-axis view by rotating the transducer 90° clockwise so that the scan plane was perpendicular to the long-axis of the left ventricle. By moving the transducer downwards, cross-sectional views of the left ventricle were obtained at various levels  along its long axis, which enabled an accurate assessment of cardiac morphometry and global and segmental contractility. On the basis of the B-mode cross-sectional images at the level of the papillary muscles, the following left ventricle measurements were acquired in M-mode: interventricular septum end-diastolic (IVSdt) and end-systolic thickness (IVSst); left ventricular diameter in end-diastole (LVIDd) and end-systole (LVISs); left ventricular posterior wall thickness in diastole and systole ; left ventricular mass (LVmass); left ventricular volume  Figure .- ApicalThe bi-dimensional apical view was obtained from the short-axis view, by tilting downwards as far as possible the extremity of the animal platform where the hamster's head was placed and angling the base of the transducer towards the operator. This provided a four-chamber view of the heart. By rotating the transducer clockwise a two-chamber apical view was obtained which is highly important in the study of cardiac contractility Figure .Left ventricular systolic function was evaluated by calculating the ejection fraction (%EF); this was derived from the left ventricular end-diastolic and end-systolic volumes which were automatically generated by the echocardiographic system software on the basis of the short-axis M-mode measurements - in turn based on the bi-dimensional images - according to the following formula: (LVEDv -LVESv)/LVEDv × 100. Cardiac mass was calculated with the following formula: 0.8 (1.04 ([LVEDd + PWDt + IVSDt]3- [LVEDd]3)) + 0.6.After sacrifice of the hamsters at the time points, the cardiac muscle was completely removed and 7-10-micron-thick cryosections were obtained.The sections were stained with haematoxylin-eosin to quantify the extent of necrotic areas; others were studied after staining with Masson's trichrome stain to assess for the presence of fibrotic areas.The data are reported as mean ± standard deviation.The correlation between percentage of fibrosis at histology and ejection fraction at echocardiography was analyzed with the Spearman rank test. Values of p < 0.05 were considered statistically significant.The results of the echocardiographic study are summarized in Additional file The morphological and quantitative data of the echocardiographic study of the hamsters of Group I (untreated BIO 14.6) revealed: dilation of the left ventricle with a change in heart morphology from the physiological elliptical shape to a more spherical shape, altered spatial configuration of the mitral valve and subvalvular apparatus, widening of the left atrium and right atrium and ventricle with severe reduction in ejection fraction at 8 months Figure .In the hamsters of Group II (treated BIO 14.6), echocardiography showed a mild decrease in contractile function and ejection fraction, in presence of a left ventricular wall thickness at the lower limits of normal and mild dilation of the cardiac chambers.In the hamsters of Group III (untreated WT), echocardiography revealed normal morphology and function of the cardiac chambers.There was a statistically significant negative correlation between the percentage of fibrosis found at histology and the ejection fraction   formulated in 1959, which consider the possibility of replacing [Replacement], where possible, the use and/or sacrifice of the animal with other equally effective methods, reducing [Reduction] the number of experiments, and refining [Refinement] techniques to minimize pain and distress of the animals ,12. ThisEchocardiography is widely used for the morphological and functional evaluation of the heart  as it peOnly few ultrasound systems to date have been able to provide high-quality echocardiographic studies on hamsters, because of inadequate image resolution and an inability to process quantitative data. In the present study, despite the high hamsters heart rate, the μ-echocardiographic examination allowed to obtain a precise estimation of heart function parameters thanks to high-frequency transducers (40 MHz).Indeed, μ-echocardiography is ideal for phenotyping and estimating left ventricular function; as a fast and noninvasive method, it can also be used in animals in suboptimal physical condition.The lack of the gene coding for delta-SG in these animals entails a loss of sarcolemmal integrity with necrosis of the cardiomyocytes; this promotes the development of an inflammatory response with fibrotic degeneration. By limiting myocardial elasticity, fibrotic replacement reduces contractile function with progressive stretching and thinning of the fibrotic regions, leading to progressive dilation.The increase in ventricular volume worsens the systolic dysfunction associated with mitral valve insufficiency, leading to low-output heart failure.Serial echocardiography successfully documented this evolution in the untreated BIO 14.6 hamsters, but not in the treated hamsters. Gene therapy was in fact able to almost completely preserve cardiac function in the dystrophic hamsters, which showed similar morphology, echocardiographic parameters and survival to the wild type hamsters.In order to confirm the role of this method in monitoring the evolution of cardiomyopathy, samples of myocardial tissue were studied by histological examination. The estimation of injury obtained at microscopic analysis correlated with that of the μ-echocardiographic study.Our experience showed that μ-US imaging applied to the study of cardiomyopathy in BIO 14.6 hamsters, thanks to the high spatial and contrast resolution, provides an estimation of morphological changes which well correlate with the histological findings, and may help to reduce the animals sacrifice.Even though histology remains indispensable for a definite diagnosis, echocardiography can be used to monitor the efficacy of treatment and/or the progression of dilated cardiomyopathy and constitutes an alternative tool for a repeatable and noninvasive assessment.The implementation of power and color Doppler imaging, the use of contrast media and higher-frequency transducers will help to refine the characterization of sonographic patterns of disease also reducing both the time and cost of longitudinal studies.The authors declare that they have no competing interests.MPB, DB and FI performed the research and wrote the manuscript, CR and MC contributed to the conception and design of the study; GN and ILR contributed to the acquisition and interpretation of the data; SC and SC revised the article critically for important intellectual content; AR and RG designed the research and approved the final version for publication. All authors read and approved the final manuscript.Timing and modality of examination of the hamsters. "Arrow" indicates the timing of gene therapy administration; "heart" represents the time points at which the μ-US examination was performed in each animal; "block" corresponds to the sacrifice of animals to proceed with the histological examination. For each time point, two animals were sacrificed in each group. Point: natural death  the data are reported as mean ± standard deviation.Click here for fileResults of the echocardiographic measurements. IVSs, d - interventricular septum thickness during diastole and systole; LVIDs, d - left ventricular internal diameter during diastole and systole; LVPWs, d - left ventricular posterior wall thickness during diastole and systole; EF% - ejection fraction percentage; LV mass - left ventricular mass; LVvols, d - left ventricular volume during systole and diastole).Click here for fileCorrelation between percentage of fibrosis and ejection fraction. The graph shows a significant negative correlation between the percentage of fibrosis and the ejection fraction Click here for filePercentage of total fibrosis at histological examination and ejection fraction at micro-echocardiography evaluation.Click here for file


ECG -gated myocardial perfusion imaging is a sensitive test for diagnosis of ischemia as well as scarred myocardium. It provides additional information on global and regional myocardial contractile function. A number of methods are available to calculate left ventricular volumes and ejection fractions, which depends on various technical and patients specific factor.This study was carried out to measure effect of reconstruction filter in calculations of left ventricularend diastolic volume (EDV) and end systolic volume (ESV) and left ventricular ejection fraction (LVEF) from 99mTc-sestamibi myocardial perfusion imaging.99mTc-sestamibi-gated SPECT myocardial perfusion imaging was performed in 90 patients. Studies were reconstructed with Butterworth and Metz filters.Mean ejection fraction with Butterworth and Metz filter are 64.3 and 64.2, respectively. Mean EDV is for Butterworth and Metz filters are 77.3 and 78.5 ml, respectively. While ESV was 36.49 and 36.63 ml, stroke volume calculated was 41.54 and 42 ml for Butterworth and Metz filters, respectively. Pearsons’s correlation coefficients between results calculated with Metz and Butterworth filters were 0.994 for ESV, 0.996 for EDV, 0.966 for LVEF and 0.925 for SV. Student ‘t’ test was applied on the data and no significant difference was noted between parameter estimated by Butterworth or Metz filter.This study shows that difference of filter application has no significant effect in computing left ventricular function parameters. Myocardial perfusion imaging is a sensitive test for diagnosis of ischemia as well as scarred myocardium. Electrocardiography (ECG)-gated imaging providesadditional information on global and regional myocardial contractilefunction, and alloA number of methods are available to calculate left-ventricularvolumes and ejection fractions.4 Various899mTc-sestamibi myocardial perfusion imaging.It has been emphasized that the effect of changing filter may invalidate the clinical parameter. This study was carried out to measure effect of reconstruction filter in calculations of left-ventricularEDV and ESV and LVEF from 99mTc-sestamibi-gated SPECT myocardial perfusion imagingwas performed in 90 patients.Patients 99mTc-sestamibi. SPECTacquisition was carried out on a dual-head large field of view γ-camera (DXTXL SMV). Sixty-four projections (32per head) were obtained in 64×64 matrices using a step andshoot acquisition over a 180° arc from right anterior obliqueto left posterior oblique position. Acquisition zoom was 1.33, giving a pixel size of 6.7 mm. All studies were acquired with 16 framesper cardiac cycleusing an R-wave trigger and a 40% acceptance window.Myocardial gated SPECT was carried out 1 hourafter intravenous injection of 400 MBq Studies were processed on a Xeleris version 1.330. Images werepre-filtered, and then reconstructed by filtered back-projectionwith a ramp filter. Two filters recommended by the manufacturerfor reconstruction of gated SPECT studies, Butterworth order10, cut-off frequency 0.394 cycles/pixel and Metz order 3.25, full-width half-maximum 2.35 mm, were compared. The former is a lowpass filter, while the latter is an edge-enhancement filter. Both these types of filter have been shown to be effectivein reconstructing SPECT studies. Myocardial EDV (ml) and ESV (ml), SV (ml) and LVEF (%) weredetermined using a commercial semi-automatic gated SPECT processingsoftware, Emory toolbox. Processing was performedby a single operator for each study using thetwo filters concurrentlyt-test.Statistical analysis was performed with the SPSS program version13 for Windows. The Spearman rankcorrelation coefficient was used to test for correlations. Theindividual differences for each patient between filtering withMetz and Butterworth filters were calculated, and statisticaldifferences were tested for using a paired The ESV and EDV, SV and LVEF are shown in t’ test was applied on the data and no significant difference was noted between parameter estimated by Butterworth or Metz filter [Student ‘z filter .During processing of ECG gated Myocardiac perfusion imaging quantification starts with thedetection of the LV endocardial and epicardial boundaries. Mostalgorithms first estimate the location of the midmyocardium, which corresponds to the maximal myocardial count. From themidmyocardial points, endocardial and epicardial boundariescan be extracted either by using a fixed number of SDs of gaussianfitting to the myocardial count profile12 or usiAs endocardial edge is found fromthe maximum slope of the profile between the cardiac centerand the wall center, which woet al,[et al, which have shown that smoother reconstruction filters lead to lower volumes and higher ejection fractions. Although excellent correlation was noted between the filters but the difference was significant statistically. Number of patients was 30 and 40 in these studies. Mean difference of ejection fraction was -3.5 ± 0.9 (Metz and Butterworth) and 2.55 ± 3.10% (Butterworth and Hann filter). This difference may be statistically significant but unlikely to be clinically significant.The result of this study is in contrast with that of observed by Vakhtangandze et al, and Wriget al, et al, wet al, also focusing on patients with recent myocardial infarction demonstrated that besides LVEF, left ventricular volumes are important in the prediction of survival. Progressive increments of 25 ml in ESV augmented the relative risk of cardiac death in an exponential fashion: as compared to patients with a normal ESV (30-55 ml), patients with an ESV of 75 ml and 125 ml had a 2.5-fold and a 5-fold higher relative risk of cardiac death, respectively.[LVEF is a has been established as an indicator of prognosisafter myocardial infarction and hearectively.99mTc-sestamibi SPECT may help differentiateMI from artifact since fixed defects with decreased function probably represent MI, whereasattenuation artifacts either have normal function or at leastdo not demonstrate markedly reduced function.[Gated cardiac scan has one additional advantage of increasing specificity of myocardiac perfusion imaging. As perfusion-scan fixed defects may result from soft tissue attenuation, decreasing test specificity for coronary disease and myocardialinfarction (MI). Gated function.There were no statistically significant mean differences in EDV, ESV, LVEF and SV measured using Butterworth and Metz filters. The differences found in our study are dissimilar to those from previous studies comparing reconstruction with different filters.17 The coThese results show that difference of filter application has no major effect on left ventricular function parameter.


Left ventricular (LV) remodeling and activation of sympathetic nervous system (SNS) are cardinal features of heart failure. We previously demonstrated that enhanced central sympathetic outflow is associated with brain toll-like receptor 4 (TLR4) probably mediated by brain angiotensin II type 1 receptor in mice with myocardial infarction (MI)-induced heart failure. The purpose of the present study was to examine whether silencing brain TLR4 could prevent LV remodeling with sympathoinhibition in MI-induced heart failure.MI-induced heart failure model rats were created by ligation of left coronary artery. The expression level of TLR4 in brainstem was significantly higher in MI-induced heart failure treated with intracerebroventricular (ICV) injection of hGAPDH-SiRNA than in sham. TLR4 in brainstem was significantly lower in MI-induced heart failure treated with ICV injection of TLR4-SiRNA than in that treated with ICV injection of hGAPDH-SiRNA. Lung weight, urinary norepinephrine excretion, and LV end-diastolic pressure were significantly lower and LV dimension was significantly smaller in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks.Partially silencing brain TLR4 by ICV injection of TLR4-SiRNA for 2 weeks could in part prevent LV remodeling with sympathoinhibition in rats with MI-induced heart failure. Brain TLR4 has a potential to be a target of the treatment for MI-induced heart failure. It has been demonstrated that activation of sympathetic nervous system (SNS) is one of the hallmarks of heart failure state, and the activation of SNS contributes to the worsening of mortality and left ventricular (LV) dysfunction Inflammatory response is usually associated with the activation of innate immunity Considering these backgrounds, in the present study, we examined whether silencing brain TLR4 by ICV injection of TLR4-SiRNA could prevent LV remodeling with sympathoinhibition in MI-induced heart failure or not.vivo study. vivo. The degree of the increases in the expression of TLR4 in MI-induced heart failure treated with hGAPDH-SiRNA was similar with that in MI-induced heart failure mice treated with no virus examined in our previous study vivo  was significant higher, and highest rate of decline in LV pressure  was significantly lower in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks. 24-hour urinary norepinephrine excretion was significantly lower in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks  content, because LV -dP/dtmax is directly linked to SERCA2 content Abnormal activation of SNS is associated with the prognosis of heart failure and beta-blocker therapy has significant benefits on the survival of heart failure We did ICV injection of TLR4-SiRNA twice in 2 weeks (10 and 17 day after coronary ligation), because the effective time of TLR4-SiRNA used in the present study continued for around 4 days. As shown in vivo and vitro study. In the aspects of cardiac echocardiography, there are discrepancies between the parameters of LV function in the present study. We consider that the discrepancies would be made because of the methodological limitations of echocardiography in rats. ICV injection of TLR4-SiRNA improves LV dP/dt and LVEDP, not infarct size and LV fractional shortening. We consider that infarct size and LV fractional shortening are varied data, and the benefits on LV dP/dt and LVEDP are meaningful to a greater extent than infarct size and LV fractional shortening. Moreover, we demonstrated that ICV injection of TLR4-SiRNA improves LVEF and cardiac output. Taking all, we consider that ICV injection of TLR4-SiRNA could improve LV performance in MI-induced heart failure.We should discuss about the mechanisms in the prevention of LV remodeling by partially silencing of brain TLR4 and implications of the results in echocardiography, because both of silencing brain TLR4 and benefits on LV remodeling were partial and superficial, and there is a discrepancy between several parameters of LV function. With regard to the mechanisms, we could not clearly demonstrate and determine the relationship between the effects of systemic and brain TLR4. We could propose just only the potential relationship between TLR4 in brainstem, sympathetic nerve activity, and LV remodeling in MI-induced heart failure. In addition, we did not check the effects of silencing brain TLR4 in sham. To examine these issues, in a future we should do chronic and brain-specific knockdown of TLR4 in sham and MI-induced heart failure, for example by Cre-Lox P system. Moreover, previously we demonstrated that ICV injection of angiotensin II type 1 receptor blocker prevent LV remodeling associated with sympathoinhibition and decreased TLR4 in brainstem of MI-induced heart failure mice There are several limitations in the present study. First and the most important limitation is that we could not do the really “silencing” of TLR4 in brainstem by ICV injection of TLR4-SiRNA in the present study. Although we tried to do the silencing of TLR4 by TLR4-SiRNA in higher doses, the expression of TLR4 in brainstem could not really silenced (data not shown). Because the aim of the present study was to decrease TLR4 in brainstem, we accepted ICV injection of TLR4-SiRNA. However, it is not really “silencing”. Second, we did not identify the area in the brain where the activation of TLR4 is occurred, and we also did not do the cite-specific silencing TLR4 for a longer period, especially at the nucleus involved in the cardiovascular regulation. Because of these limitations, we could not determine the benefits of silencing brain TLR4 on the survival. To clarify these issues, we should do really silencing brain TLR4 for several months by other methods in a future. Finally, we still did not find direct ligands for brain TLR4 in heart failure. Further studies are needed to clarify these important questions.The present study suggests that brain TLR4-mediated inflammatory cascade, probably not in plasma and heart, might in part exacerbate LV remodeling with sympathoexcitation in MI-induced heart failure. Although the prevention of LV remodeling and/or sympathoinhibition are necessary in the treatments for MI-induced heart failure and previous many studies have already revealed the pharmacological benefits of several agents, it is also true that we could not prevent MI-induced heart failure via LV remodeling sufficiently. The role of TLR4 in maladaptive MI-induced LV remodeling has been considered to be via inflammatory cytokine production and matrix degradation in heart The study was reviewed and approved by the Committee on Ethics of Animal Experiments, Kyushu University Graduate School of Medical Sciences, and conducted according to the Guidelines for Animal Experiments of Kyushu University. Male Sprague-Dawley (SD) rats  were purchased from SLC Japan .2, in 10% Dulbecco’s Modified Eagle Medium (DMEM) with 10% fetal bovine serum (FBS), 50 U/ml penicillin and 50 µg/ml streptomycin. For experiments, cells were plated on polystyrene cell culture dishes at a density of 3×106 cells per 6-cm plate in 3 ml 10% FBS DMEM.Rat cell-lines were cultured under conventional conditions. C6 cells  were cultured at 37°C and 5% CO5′-GACTTACAGTTTCTACGT-3′; 2: 5′-GAAGCTATAGCTTCACCAA-3′; 3: 5′-GCAGTTTCAATCGCATAGA-3′; hGAPDH: 5′-CGGGAAGCTTGTCATCAAT-3′. Plasmids were purified on columns with a Qiagen kit and quantified by A260 measurements. We used the plasmid vector at a concentration, 1 µg/µl in vitro and vivo.Three different SiRNAs were made against TLR4 of rat sequence (TLR4-SiRNA), and human GAPDH sequence for the negative control . The pBAsi vector was a plasmid vector containing a RNA polymerase III (pol III) promoter for expression of SiRNA. By inserting synthesized oligo DNA sequence for hairpin RNA into the downstream of the pol III promoter, SiRNA expression vector was constructed. The sequences are as follows: 1: 6 cells in 6-cm plates. Transfection with SiRNA expression vector that is specific for TLR4 or hGAPDH gene was performed.Before transfection, the cells were plated at a density of 3×10SD rats were induced MI by ligating left coronary artery as described previously At 10 day after MI or sham operation, we divided rats into two groups, treated with ICV injection of TLR4-SiRNA or hGAPDH-SiRNA for 2 weeks. Prior at 10 day after coronary ligation, we could not do ICV infusion safely because the surgical procedures of the ICV infusion, involving anesthesia, are too hard for rats with MI-induced heart failure. In addition, we did ICV infusion again at 17 day after MI or sham operation. The rats were anesthetized with sodium pentobarbital  and placed in stereotaxic instrument, and a small hole was drilled in the skull for ICV injection of TLR4-SiRNA using glass microsyringe in the right lateral ventricle . 10 µg SiRNA dissolved in 10 µl water was administered for 5 minutes.To evaluation of LVDS, LVDD, LVEF, and %FS, cardiac echocardiography was performed at the end of the protocol under light sodium pentobarbital anesthesia  with spontaneous respiration. An echocardiography system  with a dynamically focused 7.5 MHz linear array transducer was used. LVDD amd LVDS were obtained in M-mode tracings from the short-axis view at the level of the papillary muscle. LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) were obtained in two-dimensional mode by taking the measurement of short-axis cross sectional areas (A) and LV length (L)  max, LV -dP/dtmax, and heart rate, at the end of the protocol, rats were anesthetized with sodium pentobarbital  under mechanical ventilation to avoid the interference of the impairment of ventilation due to lung edema and anesthesia with hemodynamic condition. A Miller catheter was inserted into the right carotid artery for measurement of mBP and heart rate, and then was advanced across the aortic valve into the LV for measurement of LVEDP, LV dP/dtmax, and LV -dP/dtmax.To measure mean BP (mBP), LVEDP, LV dP/dtAs described previously, we measured the 24-hour urinary norepinephrine excretion as a parameter of the activity of SNS Western blot analysis was performed to determine the expression levels of the TLR4  and MyD88 in brainstem as described previously Total RNA from brainstem was isolated using the ISOGEN (NIPPON GENE). cDNA was generated using the ReverTra Ace qPCR RT Kit (TOYOBO). Gene specific primers are as follows: TLR4: forward primer, 5′CTCACAACTTCAGTGGCTGGATTTA3′; reverse primer, 5GTCTCCACAGCCACCAGATTCTC’3′; TNF-α: forward primer, 5′ATACACTGGCCCGAGGCAAC3′; reverse primer, 5′CCACATCTCGGATCATGCTTTC3′; IL-1β: forward primer, 5′CTACCTATGTCTTGCCCGTGGAG3′; reverse primer, 5′GGGAACATCACACACTAGCAGGTC3′; IL-6: forward primer, 5′ATTGTATGAACAGCGATGATGCAC3′; reverse primer, 5′CCAGGTAGAAACGGAACTCCAGA3′; GAPDH: forward primer, 5′GGCACAGTCAAGGCTGAGAATG3′; reverse primer, 5′ATGGTGGTGAAGACGCCAGTA3′. These primers were purchased from Takara Bio . Real-time PCR was performed using the ABI prism 7500 Sequence Detection System . All data ware subsequently normalized to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA level and expressed as mRNA relative fold change.t test when comparing data between the 2 groups. A one-way analysis of variance (ANOVA) for the multiple group of ICV injection of SiRNA experiments was performed. Differences were considered to be statistically significant at a P value of <0.05.Data are expressed as mean ± SEM. The statistical analyses were performed by nonpaired


An abundance of evidence exists in support of primary and secondary prevention for tackling the scourge of cardiovascular disease. Despite our wealth of knowledge, certain deficiencies still remain. One such example is the association between sleep disordered breathing (SDB) and cardiovascular disease. A clear body of evidence exists to link these two disease entities (independent of other factors such as obesity and smoking), yet our awareness of this association and its clinical implication does not match that of other established cardiovascular risk factors. Here, we outline the available evidence linking SDB and cardiovascular disease as well as discussing the potential consequences and management in the cardiovascular disease population. Sleep disordered breathing (SDB), encompassing both obstructive and central sleep apnoea, has been associated with increased cardiovascular morbidity and mortality. It occurs in half of all heart failure patients and is linked to hypertension, arrhythmia, impaired glucose tolerance, cerebrovascular disease, and ischaemic heart disease –3. DespiAn abundance of evidence exists in support of primary and secondary prevention for tackling the scourge of cardiovascular disease. Despite our wealth of knowledge, certain deficiencies still remain. One such example is the association between SDB and cardiovascular disease. A clear body of evidence exists to link these two disease entities (independent of other factors such as obesity and smoking) yet our awareness of this association and its clinical implication does not match that of other established cardiovascular risk factors , 5. HereSleep apnoea can be defined as the cessation of breathing during sleep which lasts for at least 10 seconds, on five or more occasions per hour, and which leads to tiredness during the daytime . PresentThe severity of sleep apnoea is assessed using the apnoea-hypopnoea index (AHI), which represents the number of apnoeic or hypopnoeic  episodes per hour of sleep. Sleep apnoea can be classified as mild (AHI = 5–15), moderate (AHI = 15–30), or severe (AHI ≥ 30) . Sleep aA combination of the two apnoeic pathologies can occur in some patients, defined as mixed sleep apnoea. Obstructive apnoeas can lead to an impaired homeostatic response to hypercapnia and the subsequent development of central apnoeas. This happens primarily in heart failure patients with the exact mechanism not fully understood. Obstructive and central apnoea can also combine to produce complex sleep apnoea. This occurs when patients with OSA treated with continuous positive airway pressure (CPAP) convert to central apnoeic episodes; again believed to be a consequence of impaired homeostatic mechanisms .The prevalence of SDB in the general population is estimated to be between 5 and 10% , 6, 9. TNormal sleep physiology involves a reduction in sympathetic nervous system activity combined with an increase in parasympathetic tone. The combined effect is a decrease in heart rate, stroke volume, and systemic vascular resistance so reducing cardiac output, blood pressure, and myocardial workload during sleep. In SDB, this usual cardiovascular quiescence is disrupted through the mechanisms outlined below  5]..5].(1) Hypoxia. Hypoxic episodes may directly impair cardiac contraction and diastolic relaxation by reducing oxygenation and hence cardiac efficiency. In addition, intermittent hypoxia may create oxygen-free radicals and activate inflammatory pathways so causing hypertension by direct effects on vascular endothelium, independent of sympathetic tone [tic tone .(2) Repeated Arousals during Sleep. In SDB, termination of apnoeic episodes is accompanied by a sudden and brief arousal from sleep, with an accompanying increase in sympathetic activity, reduction in vagal tone, and resultant peripheral vasoconstriction [triction , 12. Thitriction . Therefo(3) Exaggerated Negative Intrathoracic Pressure. In OSA there is ineffective inspiration due to attempts to inspire against a fully or partially collapsed pharynx, so increasing the inspiratory negative intrathoracic pressure. The resultant greater venous return to the right side of the heart increases cardiac preload and work [and work .consequence of heart failure, and once present, may further exacerbate cardiovascular disease progression [The causative mechanisms of obstructive and central type sleep apnoea differ, but the physiological and hence cardiovascular sequelae can be considered in unison . Howevergression , 4. Secogression , 4, 13. gression .The repeated arousals that occur with apnoeic episodes result in an increase in heart rate and blood pressure, typically 5–7 seconds following an apnoea , 14. EviA cross-sectional analysis of 6,132 subjects who underwent polysomnography at home showed a definite association between OSA and hypertension with the prevalence of hypertension increasing in proportion to the AHI . A furthOSA may also predispose to resistant hypertension defined as a blood pressure persisting above 140/90 mmHg despite lifestyle intervention and the use of three or more pharmacological agents, one of which should be a diuretic . GreaterThere is accumulating evidence in support of CPAP in the management of resistant hypertension. The use of nightly CPAP for a two-month period can produce significant reductions in both systolic and diastolic BP in patients with resistant hypertension and, similarly, compliance with CPAP may normalise nocturnal blood pressure patterns , 22. HowAs well as systemic hypertension, pulmonary hypertension is associated with sleep disordered breathing. This is likely to be via similar mechanisms as described for systemic hypertension including the effects of increased sympathetic activity. Additionally, negative intrathoracic pressure during apnoeic or hypopnoeic episodes amplifies venous return to the right heart accentuating pulmonary artery blood flow. Alongside preload, increased afterload due to pulmonary arteriolar remodelling and increased reactivity to hypoxia is also thought to contribute .Pulmonary hypertension, which tends to be mild, may have a prevalence of up to 40% in the OSA population with evidence to support using nocturnal CPAP for reducing pulmonary artery pressures . A studyThe link between SDB and coronary artery disease (CAD) is primarily derived from studies of OSA. Following correction for confounding factors such as age, sex, BMI, hypertension, hypercholesterolaemia, diabetes mellitus, and current smoking, the prevalence of CAD is still higher in patients with OSA. The prospective Sleep Heart Health Study revealed that subjects with a moderate to high AHI (>11) were 1.42 times more likely to develop CAD when compared with patients in the lowest AHI quartile. Likewise, there is a significantly higher prevalence of OSA in patients with angiographic evidence of CAD when compared to control patients with normal coronary arteries. The overall prevalence of OSA in the CAD population is estimated to be in the region of 30 to 58% compared with 2–4% for the general population –29.Patients with SDB are more likely to have cardiac events during nocturnal hours . Acute cThe effect of hypoxia on the cardiac function is not as straightforward as it may first appear. Significant research data advocates exposing the heart to repeated episodes of hypoxia to protect it from ischaemic damage through preconditioning of the myocardium. This process aids to regulate critical transcription factors within the cardiac endothelium and also promotes development of coronary collaterals, a phenomenon well-documented in patients with chronic myocardial ischaemia , 36.superoxide release from neutrophils depleting nitric oxide bioavailability,increased catecholamine levels promoting platelet activation and aggregation,hypertension induced hypercoagulability.The development of hypertension, of which SDB may be a causative factor, along with LV hypertrophy which is also associated with SDB may further accentuate the relationship between CAD and SDB; both conditions act as risk factors for ischaemic events. In addition, hypoxia induces the release of inflammatory mediators such as C-reactive protein, fibrinogen, interleukin-6, and adhesion molecules, all of which have a postulated role in the development of CAD , 5. Coroconsequence of heart failure [Current evidence strongly supports an association between heart failure and SDB. Studies consistently report SDB prevalence of 50% or higher in the chronic heart failure population , 37. Bot failure . CSA dev failure . Once ca failure .Heart failure, in turn, may worsen as a consequence of SDB. Right ventricular (RV) preload is increased (as discussed earlier) and hypoxia induced pulmonary arterial vasoconstriction produces increased RV afterload; the combined effect results in RV distension, a leftward shift of the interventricular septum, and a subsequent impedance to LV filling and diminution of stroke volume. Similarly, increased systemic vascular resistance may impair LV function .Outcomes are worse in heart failure patients with SDB. The 3-year mortality rate in heart failure patients with untreated SDB is double that of non-SDB subjects, even when allowing for age, LV ejection fraction, and New York Heart Association functional class . SimilarThe effect of cardiac resynchronisation therapy (CRT) in patients with severe heart failure and SDB has also been studied. CRT decreases the number of apnoea-hypopnoea episodes, reduces the maximum apnoea-hypopnoea duration, and results in higher minimal oxygen saturations. These physiological benefits are not seen in the OSA or patients without SDB. The benefit seen in CSA appears to be dependent on a good clinical and haemodynamic response to CRT , 44.Apnoeic episodes have a tendency to induce bradycardias through increased vagal activity, whilst the subsequent postapnoea period can be associated with tachycardic episodes due to hyperventilation and sympathetic stimulation , 13. Then = 26) and without SDB (n = 19) demonstrated significantly more appropriate ICD therapies for patients with SDB (73% versus 47%). This was solely due to an increase in arrhythmias occurring between midnight and 6 a.m. with no difference in ICD therapies during waking hours [The risk of ventricular arrhythmias increases with SDB. Polysomnograms have shown an almost 18-fold increase in the relative risk of arrhythmias within 90 seconds of a respiratory disturbance compared with normal breathing, with nonsustained ventricular tachycardia making up 76% of the arrhythmic episodes . Also, Sng hours .Chronic intermittent hypoxia can contribute to endothelial dysfunction independent of other risk factors –52. EndoOSA is an independent risk factor for stroke. Patients presenting following a stroke or transient ischaemic attack are 3 to 4 times more likely to have OSA than matched control subjects, and silent infarction (infarction in the absence of stroke symptoms) occurs in 25% of OSA subjects compared with only 6.7% of control subjects , 57.transient alterations in cerebral blood flow velocity during apnoeic episodes, changes in autoregulation may produce a more permanent impairment of cerebral blood flow velocity. This is associated with a higher incidence of stroke as well as poorer outcomes after stroke. An impaired cerebral blood flow response to changes in arterial pressure, particularly the sharp decrease in blood pressure following apnoea, can leave the brain vulnerable to ischaemia [The brain requires a steady and continuous supply of oxygen in order to function. Measurements of cerebral blood flow velocity  in subjects with OSA during apnoeic episodes demonstrate an increase in flow during the apnoea itself with a resultant decrease below baseline velocity on termination of the apnoea, which typically persists for one minute before return to baseline. During these hypoxic episodes, levels of brain adenosine triphosphate have been shown to decrease whereas inorganic phosphate levels increase . These tschaemia , 63.In addition to changes in cerebral blood flow velocity and autoregulation, the cerebral vasculature will also be exposed to the same cascade of events that have been discussed regarding the peripheral vasculature: prothrombotic and inflammatory changes, vasoconstriction, and endothelial dysfunction. Therefore, the cerebral vascular system is also predisposed to atherosclerotic processes in the same way as the peripheral system. Specific to the obstructive form of sleep apnoea, there is evidence to suggest that physical vibration of the carotid arteries during snoring can also contribute to endothelial damage and atherosclerosis .Current evidence is largely based on observational studies with a dearth of robust randomised control trial data.CPAP is a recognised treatment for the symptoms of OSA and has a clear role in the management of acute heart failure. Fixed pressure CPAP has consistently resulted in improved left ventricular ejection fraction (LVEF) and a decrease in sympathetic nervous system activation in patients with OSA . A one-mCPAP also appears to improve patient outcomes. Long-term >5 years) prospective observational studies of middle-aged and elderly patients with OSA suggest increased mortality and risk of cardiovascular events in patients untreated with CPAP compared to those on treatment. The risk of cardiovascular events is not increased in patients with OSA treated with CPAP when compared to patients without OSA, so implicating a cardioprotective role for CPAP  years pr, 69. TheCSA has been identified as a poor prognosticator in heart failure. There is less data to support CPAP in the context of CSA but application of CPAP can reduce the frequency of central apnoeic episodes and improve quality of life. A randomised controlled trial of CPAP for 66 heart failure patients (29 with and 37 without CSA) over a five-year period demonstrated a significantly reduced mortality and cardiac transplantation rate for patients with CSA receiving CPAP. CPAP did not affect mortality or the cardiac transplantation rate in subjects without CSA . These fDespite the lack of evidence for using positive airway pressure treatment to improve long-term outcomes in heart failure patients with CSA, the reduction in apnoeic episodes and improvement in symptoms merit continued CPAP usage. A 2012 meta-analysis of the available literature for the treatment of CSA recommends the use of CPAP as well as positive airway pressure delivery using an adaptive servoventilator (ASV) . ASV is The prevalence of SDB is increased throughout the cardiovascular disease spectrum when compared to the general population and its presence is associated with poor prognostic outcomes. Despite the growing body of evidence illustrating this point, SDB is still underdiagnosed; research indicates that over 85% of individuals with clinically significant and treatable SDB have never been diagnosed and its relationship with cardiovascular disease states is poorly recognised , 5, 12.


Cardiac and vascular anatomy of patients with congenital heart disease (CHD) is often complex and accurate evaluation mandates MR image acquisition in several non-standard planes. This requires significant patient involvement while multiple additional breath-holds are required. For these reasons, the utility of self navigated isotropic 3D-free-breathing whole-heart MRI (SN-3D) was assessed for the visualization of heart, coronary arteries (CA) and great vessels in CHD patients.3, matrix 1923, acquired voxel size (1.15 mm)3. The scan was performed over 377 or 610 heartbeats, depending on the patient's heart rate. The isotropic image data were reformatted offline.Twelve patients (>10 years old) with CHD were studied. Data acquisition was performed during free breathing on a 1.5T-MRI scanner  with a previously described 3D-radial trajectory [The mean duration of the acquisition was 6.3±1.2 min. 3D-isotropic datasets allowed the assessment of the arrangement of cardiac chambers and great vessels, the anatomy of pulmonary Figure  and systThe SN-3D methodology enables time-efficient whole-heart coverage during free breathing. The high isotropic resolution supports multi-planar offline reformatting in any plane orientation and allows quickly planning targeted additional flow or cine images, which is particularly useful in CHD patients with complex anatomy. The only determinant for scanning time is the heart rate, while the need for breath-holding is entirely removed. Self-navigation and the absence of fold-over artifacts with the 3D-radial acquisition enhance the ease of use of this sequence and favor a fast acquisition planning. Even small anatomical structures could be precisely identified illustrating the potential of this methodology to assess the anatomy of the proximal course of CA.No funding


Growing evidence exists for soluble Angiotensin Converting Enzyme-2 (sACE2) as a biomarker in definitive heart failure (HF), but there is little information about changes in sACE2 activity in hypertension with imminent heart failure and in reverse remodeling.Patients with systolic HF  were compared to hypertensive patients (n = 239) and to a healthy cohort (n = 45) with preserved ejection fraction (EF>50%) in a single center prospective clinical study. The status of the heart failure patients were checked before and after CRT. Biochemical  and echocardiographic parameters  and end-systolic diameter (ESD) and dP/dt) were measured.sACE2 activity negatively correlated with EF and positively with ESD and EDD in all patient's populations, while it was independent in the healthy cohort. sACE2 activity was already increased in the hypertensive group, where signs for imminent heart failure (slightly decreased EF and barely increased NT-proBNP levels) were detected. sACE2 activities further increased in patients with definitive heart failure (EF<50%), while sACE2 activities decreased with the improvement of the heart failure after CRT (reverse remodeling). Serum angiotensin converting enzyme (ACE) concentrations were lower in the diseased populations, but did not show a strong correlation with the echocardiographic parameters.Soluble ACE2 activity appears to be biomarker in heart failure, and in hypertension, where heart failure may be imminent. Our data suggest that sACE2 is involved in the pathomechanism of hypertension and HF. The renin–angiotensin system (RAS) is a central regulator of cardiovascular and renal functions and plays an important role in the pathophysiology of heart failure In the heart, sACE2 is expressed in various cell types including fibroblasts, cardiomyocytes and endothelial cells Opposite to the AngI-ACE-AngII-AT1R pathway sACE2 may provide a vasoprotective/antiproliferative mechanism resulting in the counter-regulation of the RAS In contrast to hypertension, sACE2 has already been studied in animal and human HF suggesting a protective role for this enzyme Epelman et al. showed that increased sACE2 activity is associated with more advanced HF and that elevated sACE2 activity could predict adverse cardiac events Growing evidence exists for irrefutable importance of sACE2 in the pathophysiology of HF, however there is little information about changes in sACE2 activity during the progression of the disease as well as about reverse changes under medical therapy such as Cardiac Resynchronization Therapy (CRT).Here we report a single center, prospective clinical study to establish a relationship between circulating ACE, sACE2 and clinical parameters, such as hypertension or cardiac performance. Considering that use of terms related to ACE enzyme-activity and enzyme-level occurs inconsistently in the literature, we performed parallel ACE enzyme activity and enzyme concentration measurements. We have studied these relationships in patients with severe remodeling and during reverse remodeling when improved systolic function was achieved by biventricular pacemaker device therapy. sACE2 activity was measured in hypertensive patients for the first time, and sACE2 was identified as a biomarker of imminent heart failure, when cardiac ejection fraction is above 50%, but deterioration of cardiac performance is expected (e.g. in patients with hypertension).Written informed consent has been obtained from the patients and all clinical investigation has been conducted according to the principles expressed in the Declaration of Helsinki. The study has been approved by the Regional and Institutional Ethics Committee, Medical and Health Science Center, University of Debrecen, (UDMHSC REC/IEC number: 3261–2010) and by the Medical Research Council of Hungary.A single center, prospective clinical study was performed at the Institute of Cardiology of the University of Debrecen to investigate the relationship between serum sACE2 activity and cardiovascular pathologies, among other parameters.There were three study groups. Healthy individuals (n = 45) without any cardiovascular pathology or medication were recruited with normal cardiac morphology and left ventricular ejection fraction above 50%.A second group of 239 hypertensive patients (systolic blood pressure above 140 mmHg and/or diastolic blood pressure above 90 mmHg at the time of the diagnosis of the disease) was established. This group was characterized by preserved ejection fraction (above 50%) besides optimal antihypertensive therapy according to the national guidelines .A third group of 100 patients with severe left ventricular systolic dysfunction with indication of cardiac resynchronization therapy  were also enrolled into the study (HF - CRT before). Patients were selected for CRT according to the current ESC guideline related to pharmaceutical and device therapy of systolic heart failure Examinations were performed at the enrollment , at regular visits (hypertensive group) or just before (HF - CRT before group) and between 6 and 9 months after CRT device implantation (HF – CRT after group). Each visit included physical examination with assessment of New York Heart Association (NYHA) functional stage, echocardiographic measurements and blood sample collection for biochemical measurements. Cardiovascular risk assessment comprised age, sex, hypertension, hypercholesterinaemia, diabetes mellitus or ischaemic cardiomyopathy . NYHA clTransthoracic echocardiography was performed using an Accuson Sequoia  echocardiograph. Two dimensional and Doppler imaging was performed in standard parasternal and apical views. The left ventricular ejection fraction (EF) was measured by M mode left ventricular dimensional method. Preserved EF cutoff was >50%. Values for dP/dt  were determined in patients with severe mitral regurgitation. Two experienced cardiologists unaware of the biochemical data performed the echocardiographic measurements.Blood samples were collected by using a standard aseptic technique. Native blood was incubated for 60 minutes at room temperature. Serum fractions were separated by centrifugation  and kept in a freezer (−20°C) until the measurements.The sACE2 activity measurement was performed using a specific quenched fluorescent substrate as previously described with some modifications 2, 75 mM TRIS HCI, pH 6.5. All chemicals were from Sigma  if not stated otherwise.The reaction buffer contained a protease inhibitor cocktail 10 μM Bestatin-hidrochloride, 10 μM Z-prolyl-prolinal , 5 μM Amastatin-hidrochloride, 10 μM Captopril and 5 mM NaCI, 100 μM ZnCIThe reaction was performed in black 96-well microtiter plates . The assay was monitored continuously by measuring the increase in fluorescence  upon substrate hydrolysis using a fluorescence microplate reader . Initial enzyme activities were determined from the linear rate of fluorescence increase over the 0–120 min time course. The increase in fluorescence was plotted as a function of reaction time and fitted with a linear regression.sACE2 activity was calculated by the equation:sACE2 activity = (S/k)*DS is the rate of observed increase in fluorescence intensity, k is the change in fluorescence intensity upon the complete cleavage of 0.1 nmol of Mca-APK(Dnp), and D is the dilution of the serum. 1 unit of fluorescence (UF) corresponds to the quantity of enzyme which can degrade 0.1 nmol Mca-APK(Dnp) in 1 hour at 37 °C. The specificity of the sACE2 enzyme activity assay was tested by the specific human sACE2 inhibitor DX600, on a single test sample, where DX600 resulted in a complete inhibition of Mca-APK(Dnp) cleavage *D,ACE activity = −, k is the change in optical density upon the complete cleavage of 1 nmol of FAPGG, and D is the dilution of the serum. One unit (U) of ACE activity represents 1 nmol of FAPGG hydrolysis per minute at 37 °C.where 2O2 and 50 mM acetic acid (incubation time was about 20 minutes). Reaction was terminated by addition of 0.5 M HCl and was evaluated by measuring absorbance at 450 nm. ACE concentration was calculated using a calibration curve. The ACE concentration in the samples were measured at least three times to achieve a standard deviation of at most 15%. Serum ACE concentration was given as ng/mL of serum.ACE concentration was determined using a Human ACE enzyme-linked immunosorbent assay (ELISA) Development System  according to the manufacturer's instruction, with minor modifications NT-proBNP levels were measured in serum using a commercially available kit .Unpaired echocardiographic values were analyzed by the nonparametric Kruskal-Wallis test  patients had significantly enlarged initial left ventricular dimensions  before cardiac resynchronization therapy (HF - CRT before) compared to healthy individuals . Severe A remarkable elevation of sACE2 activity was present in CRT patients before pacemaker implantation (HF – CRT before) compared to healthy people and to the hypertensive patients with preserved left ventricular EF  expression was generally lower in heart failure patients before CRT  do not have identifiable cause . It is important to note, that there are effective treatments for hypertension, making it a relatively easily manageable disease, but there is no cure for it, which is probably related to the issue, that the very cause of the disease is not known. As a result, patients are treated and their blood pressure is kept at an acceptable level (target blood pressure is reached by medication), but their background pathology causing the hypertension may be unaffected.Here we found for the first time that serum ACE2 activities are increased in hypertensive patients  compared to healthy individuals. Nonetheless, these hypertensive patients already had a barely decreased ejection fraction compared to the healthy population and also featured slightly elevated NT-proBNP levels, suggesting that this population is at imminent heart failure. At this stage of the disease serum ACE2 activity was already elevated although it did not correlate with NT-proBNP levels. It appears therefore, that serum ACE2 activity is another biomarker of imminent heart failure in hypertension. Importantly, sACE2 may also be related to the cause of the disease. It can regulate (decrease) local angiotensin II levels, affecting vascular diameter (vascular smooth muscle located angiotensin receptors) and sympathetic tone . It may also contribute to the synthesis of angiotensin peptides which may activate the Mas receptor, believed to be beneficial in hypertension. This hypothesis is supported by recent findings suggesting that serum ACE is a rate-limiting step in RAAS: endogenous inhibitors Although this is the first time when increased sACE2 activity was shown in hypertension in human, the potential connection between sACE2 and regulation of blood pressure is not a new concept. Previous animal data have shown that transgenic sACE2 overexpression in the vessels of SHRSP rats normalizes (reduces) high blood pressure The sACE2 was also implicated as a biomarker of definitive heart failure in animal models where absence of sACE2 caused severely impaired cardiac function There is a wealth of information in human heart failure. Myocardial sACE2 gene expression increased in patients with left ventricular dysfunction including thinning of the left ventricle and severe reduction in cardiac contractility Here we made an effort to directly address the relationship between serum ACE2 activity and cardiac function. Changes in serum ACE2 activity were measured in severe heart failure when cardiac resynchronization therapy (CRT) is indicated In HF people serum ACE2 activity also correlated with the NT-proBNP concentration, which is the most widely used molecular marker of systolic HF with a reasonably high predictive and prognostic value. It has been suggested that soluble ACE2 levels are independent predictors of a composite end-point consisting of all-cause mortality, cardiac transplantation and heart failure hospitalization Elevated circulating ACE2 level in systolic HF raise the question whether serum ACE2 concentration is elevated due to a general increase in sACE2 expression or the increasing soluble ACE2 activity represent a re-distribution of sACE2 from the tissues to the serum. Higher rate of release from the cells may lead to lower tissue sACE2 levels in parallel with increasing serum ACE2 activities in this latter case.Data from animal models suggest that sACE2 shedding is stimulated by the tumor necrosis factor-α convertase ADAM17. Moreover, TACE/ADAM17 is upregulated in HF A considerable part of currently used biomarkers are related to a specific disease indirectly. Here we tested the soluble ACE2 activity for the first time when cardiac function is being improved, but no change in drug therapy occurs. We found that soluble ACE2 activity correlated well with the improvement of cardiac function after implantation of a biventricular pacing device (CRT). In particular, improving EF after CRT correlated negatively with serum ACE2 activities , improveAn effort was also made to correlate the soluble ACE levels to cardiovascular disease. ACE expression changed with the improvement of cardiac function. In particular, soluble ACE concentration was lower before pacemaker implantation than in the healthy individuals and in patients with hypertension with preserved ejection fraction and it increased in parallel with the improvement of cardiac function . In spitThere is a significant interest about HF biomarkers. Many candidates were proposed, including peptides, enzymes, receptors of inflammatory system, changes in the extracellular matrix of myocytes, oxidative stress and neurohormones Based on these data we hypothesize that redistribution of ACE and in particular sACE2 contribute to the pathomechanism of HF. We found that soluble ACE concentration decreases, while soluble ACE2 concentration increases in systolic HF suggesting an opposite change in the tissue located forms of these enzymes. These changes promote AngII formation in the tissues, contributing to AngII related pathologies. Therapeutical interventions leading to improvement of cardiac function reverse the changes in soluble enzyme concentrations . It is nHaving said that we have to point out that this hypothesis is limited by the lack of the direct measurement of tissue ACE and sACE2 expression. It may also be possible that changes in the serum concentrations of ACE and sACE2 represent changes in the expression level of these proteins, rather than their redistribution. This issue needs to be clarified by further clinical studies.Figure S1Specificity of Mca-APK(Dnp) hydrolysis as a measure of sACE2 activity. Mca-APK(Dnp) was incubated with a single test human serum sample for 120 min in the presence of 0–3 μM sACE2 inhibitor DX600, as detailed in the methods. DX600 completely inhibited Mca-APK(Dnp) hydrolysis in a concentration dependent manner in accordance with its inhibitory activity on sACE2.(TIFF)Click here for additional data file.


Assumptions about LV shape are often used to estimate LV volumes in ultrasound and x-ray angiography, which are not necessary for CMRI.Using CMRI as the gold standard, we sought to systematically evaluate the performance of commonly used models, and a linear combination of the models, to estimate LV volumes of children.198 children  who provided written informed consent, in the context of a screening study for causes of sudden cardiac death, were enrolled in this IRB approved study.2, and an acquired temporal resolution < 50 ms for all subjects.Breath held CMRI cine images were acquired in standard orientations (4-chamber (4Ch), Left-Ventricular Outflow Tract (LVOT), and Short Axis (Sax)) were acquired using a vendor provided stock SSFP sequence at 1.5 T  with an in-plane resolution < 2 x 2 mmAn expert observer drew contours in end-diastole (ED) and in end-systole (ES) to estimate LV volumes on CMR images acquired in all orientations . In 4Ch and LVOT views, longitudinal length , and the transverse width  of the LV were recorded.w) using a linear combination of any two of the six geometric models  were evaluated.The performance of six geometric models  of all 21 models were calculated.EDV = 0.4, βEDV=0.7; αESV = 0.9, βESV=0.2) respectively.Commonly used biplane and tripIn this group of young children, our results show that the estimation of LV volumes of conventional bi-plane and triplane models can be significantly improved by using a linear weighted model of bi-plane and parabolic models. These findings have to be confirmed in a larger study.The study was partly funded by Texas Heart Institue.


Depression of left ventricular (LV) intrinsic contractility is constant in patients with septic shock. Because most parameters of cardiac function are strongly dependent on afterload, especially in this context, the cardiac performance evaluated at the bedside reflects intrinsic contractility, but also the degree of vasoplegia. Recent advances in echocardiography have allowed better characterization of septic cardiomyopathy. It is always reversible providing the patient's recovery. Unlike classic cardiomyopathy, it is not associated with high filling pressures, for two reasons: improvement in LV compliance and associated right ventricular dysfunction. Although, it is unclear to which extent it affects prognosis, a hyperkinetic state is indicative of a profound and persistent vasoplegia associated with a high mortality rate. Preliminary data suggest that the hemodynamic response to a dobutamine challenge has a prognostic value, but large studies are required to establish whether inotropic drugs should be used to treat this septic cardiac dysfunction. Reversible myocardial depression in patients with septic shock was first described in 1984 by Parker et al. using radionuclide cineangiography . In a caMany factors may contribute to cardiac depression during sepsis. Studies performed in humans have ruled out coronary hypoperfusion requiring coronary intervention as a cause of LV systolic dysfunction in sepsis ,7. Of coOn the other hand, the role of cytokines has been strongly advocated in the genesis of septic cardiomyopathy. In 1985, Parrillo et al. demonstrated in vitro that myocardial cell shortening is reduced by exposure to the serum of septic patients , even thThe first characteristic of septic cardiomyopathy is that it is acute and reversible, providing the patient recovers. In 90 patients during a 5-year period, Jardin et al. reported that LV ejection fraction is normalized in a few days , as alsoThe second characteristic, which is crucial to full understanding, is that depressed LV systolic function is associated with normal or low LV filling pressure, unlike the "classic" pattern of cardiogenic shock where LV pressures are elevated Figure . This maTwo mechanisms may explain this absence of elevated LV pressures. The first relates to the frequent association with right ventricular (RV) dysfunction. Vincent et al. in a group of 93 patients with septic shock reported a decreased RV ejection fraction compared with a "control" group . SimilarThe second mechanism relates to LV compliance alteration, which usually occurs. In their original work, Parker et al. suggested a huge increase in LV compliance; they found a dilatation of the left ventricle of more than 100% ,20,22. IThe reported incidence of LV systolic dysfunction varies significantly Table . This isIt is very difficult to establish whether septic cardiomyopathy independently affects the prognosis of patients with septic shock, because many other variables are involved, such as age, patient history, type of microorganisms, and time to resuscitation. Initially, Parker et al. suggested that development of septic cardiomyopathy was "protective" . Ten of Three therapeutic interventions must be discussed. The first is volume expansion. Parker et al. suggested that "massive" fluid infusion maintains a normal cardiac index, despite a significantly impaired LV contractility, through LV preload adaptation . However2 increase in LV stroke index in response to dobutamine correctly categorized the outcome in 21 of 23 patients [The second therapeutic option is the infusion of an inotropic drug, such as dobutamine, a beta-agonist agent. We and others reserve this treatment for patients with persistent shock, lactic acidosis, and oliguria ,29. In tpatients . Levosimpatients ,34. BarrFinally, a few words should be mentioned about norepinephrine administration. As explained above and shown in Figure Depression of LV intrinsic contractility is constant in patients with septic shock. Because most parameters of cardiac function are strongly dependent on afterload, especially in this context, cardiac performance evaluated at the bedside reflects intrinsic contractility but also the degree of vasoplegia. Recent advances in echocardiography have allowed better characterization of septic cardiomyopathy. Unlike classic cardiomyopathy, it is not associated with high filling pressures for two reasons: increased LV compliance and frequently associated RV dysfunction. It is always reversible. Although it is unclear how septic cardiomyopathy affects outcome, a hyperkinetic state is indicative of profound and persistent vasoplegia associated with a high mortality rate. Preliminary data suggest that the hemodynamic response to dobutamine challenge has a prognostic value, but large studies are required to establish whether inotropic drugs should be used to treat this septic cardiac dysfunction.The author declares that they have no competing interests.