Background: Diffuse myocardial fibrosis is a common pathological process in many cardiovascular diseases. In order to determine disease, we must have standard normal imaging values. We investigated myocardial interstitial fibrosis of the left ventricle (LV) in a healthy population of Chinese adults and explored the impact of gender, age, and other physiological factors using a T1 mapping technique of cardiac magnetic resonance imaging (CMR).Materials and Methods: We recruited 69 healthy adult Chinese subjects . LV function and global strain were obtained from functional imaging. T1 mapping was performed using a modified look-locker sequence. Global and segmental native T1 and extracellular volume (ECV) were calculated using dedicated software. Gender, age, and segmental variation of both native myocardial T1 and ECV of the LV were analyzed.Results: The global myocardial native T1 and ECV of the LV in this Chinese adult healthy population was 1,202 ± 45 ms and 27 ± 3% at 3T field strength, respectively. Females had a higher myocardial native T1 and ECV of the LV compared to males . ECV in older group was higher than younger group . The multi-variate linear regression analysis showed that only gender  was independently related with global native T1 of LV while gender  and age  were independently related with global ECV of LV. From the base to apex of the LV, myocardial native T1 (P = 0.020) and ECV (P < 0.001) significantly increased. Within the same slice of the LV, there were significant segmental variations of both myocardial native T1 (P < 0.001) and ECV (P < 0.001) values.Conclusion: Gender and age have significant impacts on the imaging markers of myocardial interstitial fibrosis in healthy adult Chinese volunteers. Segmental variation of myocardial interstitial fibrosis was also observed. The myocardium is composed of myocytes and many different cell types including the fibrocytes that occupy the interstitium. Myocardial fibrosis is the remodeling of extracellular matrix in response to injury and is a common pathological process in many cardiovascular diseases  healthy Chinese volunteers age ≥18 years were prospectively recruited between 2014 and 2016. Exclusion criteria were: any known cardiovascular disease, hypertension, cerebrovascular disease, neurologic disease, chronic lung disease, diabetes, cancer, autoimmune disease, recent systemic infection (within a month), recent operation or severe trauma (within a month), any recent medications, or history of pacemaker or other metallic object in the body (a contraindication for magnetic resonance imaging). Subjects also were excluded for: a resting blood pressure equal to or >140/90 mmHg, abnormal complete blood count, abnormal liver and renal function tests, abnormal ECG, abnormal findings by echocardiography, incidental arrhythmias, claustrophobia, intolerance to breath-holding during scanning and poor image quality, any LGE found following CMR examination.Data acquisition was performed on a 3.0T MRI scanner  using a four-channel phased-array receiver coil combined with a four-channel spine coil. Images were acquired during breath-holds with retrospective ECG gating. Steady-state free precession (SSFP) cine images were acquired in consecutive short-axis views covering the LV from base to apex and three long-axis views . The parameters were as follows: repetition time (TR), 3.4 ms; echo time (TE), 1.3 ms; flip angle (FA), 50°; field of view (FOV), 320–340 mm; matrix size, 256 × 144; and slice thickness, 8 mm with no gap. Temporal resolution was around 42 ms. Reconstruction in plane spatial resolution was 1.4 × 1.3 mm.Native T1 measurements were acquired before injection of gadolinium by the motion-corrected modified Look-Locker inversion recovery sequence (MOLLI) . Measurements were acquired at the basal, mid, and apical slices on short axis (SAX) through ECG gating. This involved three inversion-recovery prepared inversion time (TI) scout experiments, with three heartbeats for recovery between each experiment. Parameters for MOLLI were as follows: TR 2.9 ms, TE 1.12 ms, FA 35°, bandwidth 930 Hz/pixel, TI of first experiment 100 ms, TI increment 80 ms, parallel imaging 2, matrix 192 × 144, in plane spatial resolution 2.4 × 1.8 mm, total acquisition time 17 heart beats. T1 measurements were repeated in the identical short-axis slices 15 min following administration of gadolinium [MOLLI protocol: 4(1)3(1)2]. Gadopentetate dimeglumine  was used with a bolus dose of 0.15 mmol/kg. Hematocrit (HCT) was tested within 24 h of Cardiac MR scanning for ECV calculation.3). Papillary muscles were excluded in the LV mass calculation. Left atrial maximal volume (LAVmax) was analyzed according to bi-plane Simpson method based on four- and two-chamber SSFP cine images, according to our previous report  by two trained observers with more than 2 years and 500-case experience in CMR image analysis. LV volume and mass were measured by manually tracing endocardial and epicardial borders at end-diastole and end-systole on successive short-axis cine images. End-diastolic volume (EDV) and end-systolic volume (ESV) were calculated by summation of the volume in consecutive short-axis slices. Ventricular stroke volume (SV) was formulated as: SV = EDV – ESV. Ventricular ejection fraction (EF) was calculated as: EF = SV/EDV. LV mass was derived by the summation of discs method by multiplying myocardial muscle volume  by its specific density  analysis . Radial or circumferential strain was quantified on short-axis view at mid-level of the LV. Longitudinal strain was quantified on a standard four-chamber view. LV endocardial and epicardial contours were drawn manually at end-diastole and consecutive contours at the other phases through the cardiac cycle were tracked automatically by the FT algorithm. Peak global systolic radial, longitudinal, and circumferential myocardial strains were included in the analysis.Native T1 calculation was based on the MOLLI images in the three LV short-axis slices. Endocardial and epicardial contours were traced manually on the pre- and post-contrast T1-mapping images. After fitting the T1 curve , mean myocardial native T1 values were obtained. Blood T1 was obtained by locating a region of interest (ROI) in the blood pool within the LV cavity (avoiding papillary muscle) in the pre- and post-contrast T1-mapping images. ECV was calculated as follows: ECV = (1-HCT) ×   were randomly selected from the cohort to test observer variability. For inter-observer variability, the two independent observers performed post-processing, blinded to each other's results. For intra-observer variability, one observer repeated the measurements using the identical method 8 weeks later.SD and the range from minimum to maximum values if the distribution was normal while we presented the data not normally distributed as median and interquartile range. Differences in continuous variables between two groups were analyzed using the Student's t-test if the distribution was normal. If the distribution was not normal, the differences were tested with Mann–Whitney U-test. Comparisons in continuous variables between three or more groups were analyzed using a one-way analysis of variance (ANOVA) if the distribution was normal while the Kruskal–Wallis test was used if the distribution was not normal. No adjustments were made for multiple testing. Differences in categorical variables between two groups were analyzed using the chi-square test. Linear regression was used for analysis of relationships between the parameters (native T1 and ECV) and physiological variables. Multiple linear regression was used to test the relationship between parameters (native T1 and ECV) and demongraphic and CMR parameters. Inter- and intra-observer variability were tested by calculating mean bias from Bland–Altman analyses, coefficient of variation , and inter-class correlation coefficient (ICC). P < 0.05 was considered statistically significant.Statistical analyses were performed using MedCalc  and GraphPad Prism version 6.0 . The Kolmogorov–Smirnov test was employed to check normal distribution of continuous variables. Continuous data are presented as mean ± Demographic data for the 69 subjects are displayed in Table n = 35) group compared with the older group . Females had higher global strains than males, including radial, circumferential, and longitudinal, while older group had higher radial strain. Indexed LAVmax showed no significant difference between age or gender subgroups.LV volume, systolic function, and strain parameters measured by FT-CMR are displayed in Table P < 0.001) and ECV (P = 0.027) was significantly higher in female group. There was no significant difference in myocardial native T1 value between older and younger groups, while ECV in older group was higher than younger group (P = 0.019). By linear regression, only gender was independently related with native T1 (P < 0.01). Besides, only age and gender were independently related with ECV  segments in 69 subjects were analyzed. Seven basal slices  and four apical slices  were excluded due to artifacts or poor image quality. Native T1 values and ECV are shown in Table P > 0.1). Furthermore, no correlation was found between either native T1 or ECV and LV strain . In addition, no association was found between LAVmaxi and myocardial native T1 or ECV .No significant correlation was found between either myocardial native T1 or ECV and cardiac functional parameters. Septal segments had the highest T1 and ECV values. Anteriorlateral walls had the lowest T1 and ECV values. Significant segmental inhomogeneity of T1 or ECV was found in the mid- and apical-slices (P < 0.05) except for ECV of the mid slice, shown in Figure All segmental T1 and ECV are shown in the bull's-eye figure, according to the AHA 16 segment model , while reproducibility in segmental T1 and ECV was moderate (ICCs > 0.6) (data in Supplementary Tables Our study investigated LV T1 and ECV values in a cohort of healthy Chinese adults using a CMR T1 mapping technique. We compared and showed that there are significant differences in myocardial native T1 and ECV values by gender or age subgroups. No other physiological parameters correlated significantly with native LV myocardial T1 or ECV. We also observed segmental variations across the LV for both native myocardial T1 and ECV.Native myocardial T1 and ECV in healthy populations has been reported in various populations (Supplementary Table Analysis of gender differences in myocardial native T1 and ECV gave inconsistent results in previous studies (Sado et al., In our study, we found a significant correlation between age and ECV. The relationship between age and native T1 or ECV were conflicting in previous studies (Liu et al., In the present study, no association between LV myocardial strain and native T1 or ECV was found. In addition, LAVmaxi did not correlate with either native T1 or ECV. This could be explained by small differences of T1 or ECV in healthy subjects. In studies with cardiovascular diseases, ECV was found to be significantly correlated with ventricular function (Ugander et al., In previous studies, segmental variations of myocardial T1 value or ECV were observed. von Knobelsdorff-Brenkenhoff et al. reported myocardial native T1 increased from basal slice to apex. This phenomenon was explained by partial volume effect of image acquisition at the apex (von Knobelsdorff-Brenkenhoff et al., The sample size of the present study is small. Large sample size studies are necessary to explore physiological changes of interstitial LV myocardial fibrosis evaluated by the T1 mapping technique. In addition, hormone and other serum biomarker were not available. Correlations between native T1 and ECV and biomarkers also need further exploration. Finally, T1 and ECV normal reference are magnetic field strength-, sequence-, and vendor-dependent. Therefore, the reference range in the present study provided only a reference for the same field strength and scanner.In summary, the present study showed that gender and age have different impact on myocardial interstitial fibrosis in a healthy adult Chinese population. Segmental variation of myocardial interstitial fibrosis was also observed. This finding may help us to understand physiological changes of myocardial interstitial fibrosis in the Chinese population.YD participated in the study design, contributed to data analysis and interpretation, performed the statistical analysis, and drafted the manuscript; DY carried out data acquisition and analyzed the imaging data and contributed to study design and review of the manuscript and he contributed equally to this manuscript; YC is the supervisor of this study and contributed to study design, contributed to preparation, editing and review of the final manuscript; YH contributed to study design and helped revise the manuscript; KW and HL analyzed the imaging data; JS and WC carried out subject scanning and performed data analysis and interpretation; GA and XZ provided technical support in carrying out the T1 mapping study. All the authors read, helped to revise and approved the final manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


A comprehensive cardiovascular magnetic resonance (CMR) in reperfused ST-segment myocardial infarction (STEMI) patients can be challenging to perform and can be time-consuming. We aimed to investigate whether native T1-mapping can accurately delineate the edema-based area-at-risk (AAR) and post-contrast T1-mapping and synthetic late gadolinium (LGE) images can quantify MI size at 1.5 T. Conventional LGE imaging and T2-mapping could then be omitted, thereby shortening the scan duration.Twenty-eight STEMI patients underwent a CMR scan at 1.5 T, 3 ± 1 days following primary percutaneous coronary intervention. The AAR was quantified using both native T1 and T2-mapping. MI size was quantified using conventional LGE, post-contrast T1-mapping and synthetic magnitude-reconstructed inversion recovery (MagIR) LGE and synthetic phase-sensitive inversion recovery (PSIR) LGE, derived from the post-contrast T1 maps.P = 0.72; R2 0.97; ICC 0.986 (0.969–0.993); bias −0.1 ± 4.2% LV). There were excellent correlation and inter-method agreement with no bias, between MI size by conventional LGE, synthetic MagIR LGE , synthetic PSIR LGE  and post-contrast T1-mapping . The mean scan duration was 58 ± 4 min. Not performing T2 mapping (6 ± 1 min) and conventional LGE (10 ± 1 min) would shorten the CMR study by 15–20 min.Native T1-mapping performed as well as T2-mapping in delineating the AAR  and acute MI size (using post-contrast T1 maps) in STEMI patients without major cardiovascular risk factors. This approach would shorten the duration of a comprehensive CMR study without significantly compromising on data acquisition and would obviate the need to perform T2 maps and LGE imaging. Cardiovascular magnetic resonance (CMR) is considered the gold standard imaging modality for quantifying myocardial infarct (MI) size . It can T2-weighted imaging in the first week following primary percutaneous coronary intervention (PPCI) has been used to delineate the AAR in STEMI patients , but hasConventionally, MI can be identified by late gadolinium enhancement (LGE) with inversion recovery (IR) T1-weighted sequences and manual adjustment of the inversion times (TI) to null the remote normal myocardium. Post-contrast T1-mapping has also shown promise to detect acute MI in a small cohort of predominantly non-reperfused acute MI patients and chronic MI , 10. RefA comprehensive CMR study in STEMI can be time-consuming. Therefore, the aims of this study were to investigate, firstly, whether native T1-mapping can accurately delineate the edema-based AAR at 1.5 T (using T2-mapping as the reference); and secondly, whether post-contrast T1-mapping and synthetic IR LGE images can quantify MI size . This may allow one to omit conventional LGE imaging and T2-mapping to quantify MI size and the edema-based AAR, respectively, thereby shortening the duration of the scan.Twenty-eight acute STEMI patients reperfused by PPCI were chosen from a cohort reported in previous studies –17 basedAll CMR scans were performed on a 1.5 Tesla scanner  using a 32-channel phased-array cardiac coil. The protocol included cine CMR images, T2 maps, native T1 maps, T2* maps, early gadolinium enhancement (EGE), conventional LGE and post-contrast T1 maps . Full LV short axis coverage was acquired for all sequences except for T2* maps . The T2* maps and EGE were not analyzed for this specific study but the time taken for each imaging sequence was recorded to the nearest minute to obtain representative duration of a comprehensive CMR study in these patients.T2 maps were acquired using 3 single-shot images at different T2 preparation times  as previously described . The imaT1 maps were acquired using a steady state free precession-based MOLLI prototype. A 5 s(3 s)3 s modified MOLLI sampling protocol was used as previously described . The acqConventional Mag-IR LGE imaging was acquired using predominantly a respiratory motion-corrected, free-breathing single shot steady state free precession averaged inversion recovery (MOCO-FB) LGE sequence in 22/28 patients  or a standard segmented ‘fast low-angle shot’ (FLASH) two-dimensional IR gradient echo sequence in 6/28 patients  at 10 min after the injection of 0.1 mmol/kg of Gadoterate meglumine . For both LGE sequences, the inversion times were progressively optimized to null the normal remote myocardium .Post-contrast MOLLI T1 maps were obtained in-line using the 4 s(1 s)3 s(1 s)2 s sampling protocol (to improve the accuracy of T1 s in the 200-600 ms range as previously described ) 15 min Both the native and post-contrast MOLLI T1-mapping automatically generated 2 sets of IR images (MagIR and PSIR) in-line by the scanner for the TI range between 200 to 975 ms (25 ms increments) as illustrated in Fig. All imaging analysis was performed using CVI42 software .The endocardial and epicardial borders were manually delineated on all the conventional LGE short-axis LV images and were copied to all corresponding images for analysis with minimal manual adjustments. All sequences were subsequently analyzed independent of each other. A reference region of interest (ROI) was drawn in the remote normal myocardium using the automated option available on CVI42  to minimize variability  and this was done for each imaging technique independently. MI size was quantified using a signal intensity threshold of 5 standard deviations (SD) above the normal remote myocardium , 18 and For the synthetic MagIR LGE, the image with the optimal TI  was manually selected and the corresponding matching PSIR image was selected as the representative synthetic PSIR LGE image Fig. . A thresConv; MagIR synthetic LGE as MISynthMagIR; PSIR synthetic LGE as MISynthPSIR; post-contrast T1 MI size by 2-SD as MIT1Post2SD; and by Otsu as MIT1PostOtsu.For the post-contrast T1 maps, we used 2 semi-automated techniques, namely a threshold of 2-SD below the mean remote myocardial post-contrast T1 and the Otsu technique  . These 2T2Man, AART22SD, AART2Otsu and AART1Man, AART12SD, AART1Otsu respectively). The Otsu technique was not applied on maps that were visually normal based on the colored look-up table and with normal wall motion on cine MR images were manually selected as normal.The endocardial and epicardial borders were manually traced on the T2 maps and copied to the T1 maps with minimal manual adjustments. In the absence of established quantification techniques, we used manual contouring as reference (%LV) and compared against a threshold of 2-SD above the remote myocardium and the Otsu technique (expressed as AARAreas of hypo-intense core of microvascular obstruction (MVO) were included as part of the MI zone and edema-based AAR. Manual ROIs were drawn in MI zone and the remote myocardium to obtain representative native and post-contrast T1 and T2 values.2) and inter-method agreement was assessed using intra-class correlation coefficient (ICC) with 95% confidence intervals (95%CI) and Bland-Altman analysis (expressed as bias ±2SD for limits of agreement). All statistical tests were two-tailed, and P < 0.05 was considered statistically significant.SPSS version 22  was used for all statistical analysis. Shapiro-Wilk Test was used to assess for normality and our data was normal distributed. Continuous data were expressed as mean ± SD. Categorical data were reported as frequencies and percentages. Paired student t test was used for edema-based AAR and MI size comparison by different thresholding techniques and by different sequences. T1 and T2 values in the MI zone and remote myocardium were compared with unpaired student t-test. Inter-method correlation was performed using the squared Pearson’s correlation coefficient (RConv) in the STEMI patients was 25.1 ± 14.3%LV and the mean edema-based AAR by T2 (AART2Man) was 41.5 ± 12.0%LV. The myocardial salvage index in this cohort was 0.41 ± 0.28. Out of 448 AHA segments the TEI were as follows: no LGE: 262 (59%); 1–25%TEI: 32 (7%); 26–50%TEI: 60 (13%); 51–75% TEI: 45 (10%); and 76–100%TEI: 49 (11%). 5 patients had TIMI flow grade 3 and 3 patients had TMI flow grade 2 pre-PPCI. The MI size in these 8 patients was significantly smaller than those with TIMI flow 0/1 pre-PPCI (14.0(2.3–25.7)%LV versus 25.0(22.3–34.8)%LV, P = 0.04). All patients had areas of hyperenhancement on the LGE areas of high signal on the T1 and T2 maps.The CMR was performed at 3 ± 1 days post-PPCI. Baseline characteristics are listed in Table Figure P < 0.0001). Native T1 in the MI zone was also significantly higher than in the remote myocardium . Post-contrast T1 was significantly lower in the MI zone compared to the remote myocardium .T2 in the MI zone was significantly higher than in the remote myocardium  and agreement (ICC 0.983 and 0.996 respectively) between AART2Man and the 2 semi-automated techniques. AART2Otsu was similar to AART2Man  with no bias (0.2 ± 2.1%). However, AART22SD was significantly larger than AART2Man (42.2 ± 12.1%LV versus 41.5 ± 12.1%LV P = 0.011) with a bias of 1.0 ± 2.6%.  with no bias (−0.6 ± 4.2%), and AART12SD was significantly higher than AART1Manual  with a small bias of 1.0 ± 3.9%. ; bias −0.1 ± 4.2%LV). Table T2Otsu and AART1Otsu.Native T1-mapping performed as well as T2-mapping in delineating the edema-based AAR (AAR2 0.96 to 0.99) and inter-method agreement (ICC 0.964 to 0.996) between conventional LGE and the other techniques. There was minimal bias between MIConv and MISynthMagIR , MIConv and MISynthPSIR  and MIConv and MIT1Post2SD , with the latter having the narrowest limits of agreement. However, MIT1PostOtsu underestimated MI size when compared to MIConv . Figure Conv against the 4 other techniques and further details are summarized in Table There was an excellent correlation . The average scanning time for the T2 and T1 maps were 6 ± 1 min each and for LGE it was 10 ± 1 min. Figure The main findings from our study are as follows: firstly, the edema-based AAR can be accurately quantified using native T1-mapping when compared to T2-mapping at 1.5 T; secondly, the acute MI size can be accurately quantified from the post-contrast T1 maps (2-SD) and the synthetic LGE images when compared to conventional LGE imaging; and finally, using T1-mapping to quantify the edema-based AAR and MI size may allow one to omit T2 mapping and LGE image, thereby shortening the scanning time by 15–20 min.We have previously shown that native T1-mapping can accurately quantify the edema-based AAR at 3 T  when compared to T2-mapping , 21 haveMessroghli et al.  have preA comprehensive CMR study in a reperfused acute STEMI patient requiring data on the edema-based AAR, intramyocardial hemorrhage (IMH), MVO, MI size and ECV, would take on average, an hour to perform. Based on the results from this study, T2-mapping and conventional LGE could be omitted - this would substantially shorten the scanning time by 15–20 min see Fig.  and b wiThe appearance of the synthetic MagIR and PSIR is noisy in regions such as air or lungs where the signal to noise ratio is low and the T1 estimates are noisy. This appearance of increased noise in these non-tissue regions is similar to the appearance of PSIR LGE images that results due to correction of surface coil intensities. Surface coil correction is also known as normalization and is generally accompanied by noise amplification in non-tissue regions. Various schemes are often employed to improve the appearance by softening the normalization in these regions. However, these methods may result in some degree of error in tissue regions. This issue, albeit mostly cosmetic, was not addressed in this article and represents a potential impediment to acceptance by clinicians.The conventional LGE scan (acquired 10–15 min post contrast) and post-contrast-T1 maps (acquired 15–20 min post contrast) were acquired 5 min apart. But despite this, there was no difference in MI size. The TI range for the IR images generated in-line from the T1 maps was quite wide (200 ms to 975 ms and at 25 ms increments). But off-line post-processing was not necessary and synthetic MagIR LGE images  and acute MI size (using post-contrast T1 maps) in this select group of low-risk STEMI patients, obviating the need to perform T2 maps and LGE imaging, thereby shortening the duration of a comprehensive CMR study without significantly compromising on data acquisition. This approach would make the CMR scan more tolerable to acute STEMI patients.


Pulmonary arterial hypertension (PAH) mainly affects the right (RV). Due to ventricular interdependence, PAH may also affect the left ventricle (LV) leading to opposite adaptive changes with an LV-atrophy and diffuse fibrosis. Strain analysis detects ventricular dysfunction even in patients with preserved ventricular function. Cardiac magnetic resonance (CMR) mapping techniques with determination of T1 and T2 relaxation times (T1 resp T2) may allow for discrimination between healthy myocardium and diffuse fibrosis in PAH patients. This study was performed to evaluate the association between myocardial changes assessed by strain analysis, and by native T1 and T2 map in patients with PAH.17 Patients with PAH  and 18 healthy volunteers  were examined on a 1.5 Tesla MR system . Native T1s were assessed using the modified Look-Locker inversion recovery sequence and T2s were assessed using a GraSE sequence. Hematocrit-corrected extracellular volume fraction values (ECV) were calculated from pre- and post-contrast T1 values. RV and LV longitudinal strain was assessed during postprocessing of standard SSFP cine images by CMR feature tracking using a dedicated software . LV and RV function were assessed by volumetric analysis.LV ejection fraction did not differ between PAH patients and healthy volunteers . Left ventricular T1 s and ECV were significantly higher in patients with PAH . LV longitudinal strain was significantly lower in patients with PAH . RV longitudinal strain and RV-Ejection fraction were both significantly lower in patients with PAH. There were no significant differences in T2 relaxation times, age, body mass index, or sex.In patients with PAH subclinical changes in T1-relaxation time-derived parameters indicate cellular and molecular alterations with myocardial fibrosis and left ventricular atrophy leading to impaired LV-performance despite preserved LVEF. These findings may help to further evaluate the mechanisms responsible for left ventricular changes in PAH, and to identify future therapeutic strategies aimed at targeting the contractile impairment and atrophy in patients with pulmonary arterial hypertension.


In this study we designed a modified method of abdominal aortic constriction (AAC) in order to establish a stable animal model of left ventricular hypertrophy (LVH). We also evaluated cardiac structure and function in rats with myocardial hypertrophy using echocardiography, and provide a theory and experimental basis for the application of drug interventions using the LVH animal model. We hope this model will provide insight into novel clinical therapies for LVH.The abdominal aorta of male Wistar rats (80–100 g) was constricted between the branches of the coeliac and anterior mesenteric arteries, to a diameter of 0.55 mm. Echocardiography, using a linear phase array probe, combined with histology and plasma BNP concentration, was performed at three, four and six weeks post AAC.The acute (24-hour) mortality rate was lower (8%) than in previous reports (15%) using this modified rat model. Compared with shams, animals who underwent AAC demonstrated significantly increased interventricular septal (IVS), LV posterior wall (LVPWd), LV mass index (LVMI), crosssectional area (CSA) of myocytes, and perivascular fibrosis; while the ejection fraction (EF), fractional shortening (FS) and cardiac output (CO) were consistently lower at each time interval. Notably, differences in these parameters between the AAC and sham groups were significant by three weeks and reached a peak at four weeks. Following AAC, plasma B-type natriuretic peptide (BNP) level was gradually elevated, compared with the sham group, between three and six weeks.This modified AAC model induced LVH both stably and safely by week four post surgery. Echocardiography was accurately able to assess changes in chamber dimensions and systolic properties in the rats with LVH. The development of left ventricular hypertrophy (LVH) is an adaptive response to pressure overload. Clinically, sustained hypertrophy is correlated with an increase in incidence of cardiovascular disease (CVD)-mediated mortality, and is often the initial step in the progression to congestive heart failure. Cardiac hypertrophy is also a risk factor for arrhythmia and sudden cardiac death. In order to develop therapeutic approaches to prevent LVH, it is important to elucidate the precise mechanisms and time course of the development of LVH.Animal models of hypertrophy are critically important for studies on the pathogenesis of LVH, its pathological processes and therapeutic strategies for treatment and/or prevention of LVH. Abdominal aortic constriction (AAC) is the most widely used strategy to induce pressure overload leading to compensatory myocardial hypertrophy.Several important factors may affect the time course and progression of myocardial hypertrophy caused by pressure overload, such as species and age of animals, anatomical sites of constriction, overload duration, and the degree of stenosis.In this study, we modified the traditional methods of AAC to evaluate banding severity, banding location, age and time course. We also explored an optimal method to induce myocardial hypertrophy in rats. To date, most studies have used small-animal echocardiographic systems or clinical echocardiography instruments coupled with miniature transducers to detect ventricular structural and functional changes in rats. This specialised equipment increases the cost of experiments.BNP is a circulating hormone produced in the heart, primarily by ventricular cells. This hormone is mainly secreted in response to increases in ventricular wall stress, such as ventricular hypertrophy, and it is detectable at high concentrations in a number of circumstances, including cardiac ischaemia and severe heart failure.The primary goals of this study were to modify the AAC procedure in order to establish a safer and more stable LVH model in rodents, evaluate the utility of standard human ultrasound probes to detect structural and functional changes in rats with cardiac hypertrophy, and provide a theoretical and experimental foundation for the application of novel drug interventions aimed at interfering with clinical LVH.ad libitum and housed in stable conditions at 22°C with a 12-hour light/dark cycle for one week prior to AAC surgery. All procedures were performed in accordance with institutional guidelines for animal research.Fifty male Wistar rats (80–100 g) were used in all experiments. They were allowed standard laboratory chow and tap water After a one-week acclimatisation, the AAC surgery was performed. All experimental rats were weighed prior to surgery, and at three, four and six weeks post surgery. Echocardiographic studies were conducted at three, four and six weeks post surgery. For LV weight and histological measurements, rats were sacrificed following echocardiography, and blood samples were collected from the right carotid artery for enzyme-linked immunosorbent assay (ELISA) analyses of plasma BNP concentrations.AAC was induced in outbred male rats, as previously described.n = 8); (2) sham for four weeks (n = 8); (3) sham for six weeks (n = 8); (4) AAC for three weeks (n = 8); (5) AAC for four weeks (n = 8); (6) AAC for six weeks (n = 10).Following surgery, 50 mg/kg, i.m. ampicillin was administered once daily for three days after surgery to prevent infection. The day following surgery, the sham and AAC animals were randomly divided into six groups as follows: (1) sham for three weeks  for anaesthesia. The IE 33 echocardiographic system  was used to perform two-dimensional (2D) guided M-mode echocardiography and pulse-wave Doppler echocardiography with a linear-phase array probe , which was placed on the shaved left hemithorax. 2D images of the heart were obtained in the parasternal long-axis view, followed by the short-axis and apical four-chamber views.M-mode echocardiography is useful for assessing LVH, allowing accurate measurements of wall thickness and LV dimensions during systole and diastole. For M-mode recordings, the parasternal long-axis view was used to image the heart in 2D, with a depth setting of 2 cm. M-mode recordings were then analysed at a sweep speed of 66 mm/s, with the axis of the probe aligned near the posterior leaf mitral valve.The following parameters were measured: LV posterior wall (LVPW) dimensions during both diastole and systole , interventricular septal (IVS) dimensions during both diastole and systole , LV internal dimensions (LVID) during both diastole and systole , LV end-diastolic volume (EDV), LV end-systolic volume (ESV), percentage LV fractional shortening (FS), LV ejection fraction (EF), cardiac output (CO), and heart rate (HR). LV mass (LVm) was obtained from echocardiography and derived from the cubic equation at the end of diastole:3 – LVIDd3] × 0.8 + 0.14.10LVm = 1.04 × [(LVIDd + LVPWd + IVSd)All data are means of three consecutive cardiac cycles. 2D guided M-mode recordings were obtained from the parasternal short-axis view of the left ventricle at the level of the papillary muscles. The angle of the M-mode beam was focused on the middle of the LV, and aligned at the anteroposterior axis, perpendicular to the LV walls. Parameters and methods were the same as in the parasternal long-axis view, except that the thickness of the LV anterior wall (LVAW) was obtained instead of IVS. To assess inflow and outflow of the left ventricle, Doppler recordings were acquired in the apical four-chamber view to obtain inflow values parallel to the sample volume.Pulse-wave Doppler (PWD) recordings were acquired with the sample volume placed midway between the mitral and aortic valves to determine the velocity of mitral inflow and aortic outflow. PWD spectra of mitral inflow were recorded with the sample volume placed at the tips of the mitral valve leaflets and adjusted to the position at which velocity was maximal, with the sample volume set to the smallest size available (1 mm). Due to the high heart rates of rodents, which caused fusion of the E and A waves, diastolic function was not evaluated using Doppler imaging.LV outflow velocity was recorded from the apical long-axis view, with the sample volume positioned just below the aortic valve. The Doppler beam was set within 30° of the incident angle, to the aortic direction. Values for statistical analyses were averaged data collected from three to five cardiac cycles.Colour-flow Doppler images were obtained by centering the sampling area in the region of interest, thus making it possible to evaluate valvular dysfunction. The same method was used to measure diameters of the abdominal aorta via the aortic longaxis view.All measurements were performed in accordance with the leading-edge method of the American Society of Echocardiography.Rat hearts were harvested by cardiectomy and perfused in 30 ml of ice-cold phosphate-buffered saline to wash out any remaining blood. The total mass of the hearts and mass of the right and left ventricles were obtained. Heart mass index (HMI) and LV mass index (LVMI) were determined as the ratio of LVm (in mg) to body weight (in g).The left ventricle was then cut into four pieces along the longitudinal axis. Three sections were immediately frozen in liquid nitrogen and one was fixed in 10% formalin for histological analysis. Tissues were dehydrated through serial alcohol immersions, cleared in xylene and embedded in paraffin. They were then cut into three to five 5-μm-thick sections for each animal. For cardiomyocyte size measurements, the samples were stained with haematoxylin/eosin (HE) and Masson trichrome (MT), as previously described,To quantify cardiomyocyte hypertrophy, about 30 myocytes were selected randomly per section, at 400 × magnification, and digitally imaged. The cross-sectional area of the cardiomyocytes was measured using Image Pro Plus software . Quantitative measurement of the perivascular fibrosis area was calculated as the ratio of the fibrosis area surrounding the vessel wall to the total vessel area using Image Pro Plus software. At least 10 arterial cross sections were examined per heart. The area of interstitial fibrosis was identified, after excluding the vessel area from the region of interest, as the ratio of interstitial fibrosis to the total tissue area. At least three sections were examined per heart.For ELISA analyses, blood was collected into tubes containing heparin from the right carotid artery of the rats and immediately centrifuged at 1 000 × g for 15 minutes. The plasma supernatant was collected and maintained at −80°C for BNP concentration determinations, using ELISA assays with a specific BNP kit (Cusabio).t-test was applied for multiple comparisons. Linear regression analysis was used to evaluate correlations between LVm by echocardiography and the actual weights from sacrificed rats. SPSS V19 was used for statistical analyses. A probability value of p < 0.05 was considered statistically significant.All data are expressed as mean ± SD. One-way analysis of variance (ANOVA) was performed to compare the AAC and sham groups. When the probability value was statistically significant, a least-significant-difference (LSD) Fifty rats were initially enrolled in this study. After the surgery (same day as surgery), the mortality rate for the experimental pressure overload was 8% (two rats died), and there were no fatalities in the sham groups. Three days after surgery, 41 rats remained in the study, including 22 sham controls and 19 AAC rats. No additional fatalities occurred over the duration of the experiment.Following AAC surgery, the abdominal aortas were constricted in diameter by 37% (~ 0.06 ± 0.01 cm) relative to the aorta, measured using echocardiography In the AAC rats, IVS and LVPWd were significantly increased at all time points, reaching a maximum at four weeks. At six weeks post AAC, IVSd and LVPWd were decreased to 177% and 141% of the sham values, respectively. IVSs remained at the same level at four and six weeks post AAC, which was 137% of the control values. In the AAC rats, LVPWs were significantly increased  four weeks post surgery, a trend that continued to six weeks. Subsequently, the AAC rats had no marked chamber dilatation; however, some time points showed statistically significant yet marginal increases in ESV and IVIDs (at four weeks), and EDV and LVIDd were decreased significantly at three weeks post AAC.CO was measured in order to differentiate between highand low-output failure Using Doppler echocardiography, as shown in p < 0.01). By four weeks post AAC, the ratio of LVMI and HMI were markedly increased, reaching 201 and 191% of the sham values, respectively. At all time points, the AAC model caused no significant difference in body weight compared to their respective sham controls. In this pressure overload model, LVm values obtained using echocardiography were consistent with the actual tissue weights, with a correlation coefficient of 0.997 , and the constriction site relative to these branches could impact on the progression to myocardial hypertrophy, as describe above. Therefore, development of myocardial hypertrophy in our study was more stable than in traditional methods.For monitoring changes in hearts subjected to dynamic pressure overload, we used echocardiographic measurements. Echocardiography is a non-invasive method routinely used to investigate changes in cardiac structure and function in various disease states. Echocardiography allows repetitive, non-invasive evaluation in a single live animal, as well as serial determination of cardiac structure and function to follow disease progression and response to therapeutic interventions. This method is far superior and more physiologically relevant than invasive techniques that require open-chest procedures and intubation of vessels, offering no opportunity for time-course studies, since they require time-consuming surgeries, with subsequent euthanasia.The Sonos 5500 echocardiographic system,Concentric myocardial hypertrophy is a hallmark of chronic pressure overload. Increased ventricular wall thickness induced by overload pressure is initially beneficial to maintain normal cardiac function. However, the heart could convert to heart failure with LV dilatation if the hypertrophic stimulus is maintained. In our study, significant increases in LVPW and IVS with only small decreases in LVIDs were indicative of pure concentric hypertrophy, which is often observed during the early stages of pure pressure overload. Most previous studies have shown late-stage chamber dilatation, signifying the end of the compensatory response and the start of heart failure.FS and EF are commonly used parameters to evaluate systolic function, which is determined by measuring LV end-diastolic and end-systolic diameters with M-mode echocardiography. Since increased afterload may depress stroke volume (SV) in AAC rats, FS and EF were lower in the AAC rats compared to sham rats from three to six weeks. Accordingly, significant decreases in CO were observed in AAC rats, especially at the four-week time point, since CO may be affected by HR and EF (both reduced in the AAC groups).In this study, we measured PFVA and E waves using echocardiography to evaluate ventricular relaxation and diastolic function. Significant decreases in PFVA and E-wave values in the AAC rats suggested restrictive filling, which may result from the combined effect of elevated ESV and impaired compliance due to wall thickening and/or fibrosis.17et al.Although E/A ratio is a marker for ventricular relaxation, it could not be obtained in this study since the E and A waves were fused in the rats due to their extremely fast heart rates. To distinguish E and A waves, Kokubo et al.In rats, the heart generally gains ~ 1 g in weight with each 2-mm increase in LV wall thickness. Progressive increases in heart weight, HMI and LVMI, and increased cross-sectional areas of the myocytes  were observed in the ACC rats. Elliott Fibrosis is a common response to pressure overload or infarction, to overcome elevated ventricular wall stress. Excessive fibrotic deposits around the small vessels may reduce oxygen and nutrient exchange rates between the blood supply and the surrounding myocardium. Additionally, extensive interstitial fibrosis impedes myocardial relaxation, increasing stiffness in the ventricular wall and reducing LV compliance.Our data suggest that hypertrophic indices decline from four to six weeks post surgery, with myocardial hypertrophy reaching its peak at four weeks in rats. This observation may be associated with acute pressure overload within four weeks post surgery, and then LV pressure decreases slightly (data not shown), leading to alleviation of myocardial hypertrophy, as previously shown.18As an important biological marker, BNP concentrations in the plasma may increase in line with increased haemodynamic stress, or ventricular cavity expansion in the case of cardiac hypertrophy and heart failure.Some limitations of this study should be considered. E and A waves were not isolated due to the high heart rates of rodents. In addition, the longest time point studied (six weeks) was not long enough to observe the transition from concentric to eccentric hypertrophy. Echocardiographic measurements were performed under anaesthesia, which is known to alter cardiac and respiratory function, even if the doses used were the minimum necessary.This study demonstrated that constriction of the abdominal aorta between the branches of the coeliac and anterior mesenteric arteries, to a diameter of 0.55 mm in young rats represents an excellent experimental animal model of pressure overload-induced myocardial hypertrophy. This model induces hypertrophy that occurs at three weeks or earlier, developing to a peak at four weeks, and recovering slightly at six weeks. Changes in cardiac structure and function during the development of cardiac hypertrophy were monitored using a standard ultrasound probe. LVm was determined using echocardiography and was consistent with the actual tissue weights. By using this animal model, we aim to provide a theoretical and experimental foundation for the application of novel drugs, for example, highspecificity and high-affinity receptor antagonists or agonists to intervene in the pathogenesis of clinical LVH.


HF). We evaluated cardiac function in 142 patients using conventional echocardiography and the phased tracking method (PTM), which was measured using the minute vibration and the rapid motion components, neither of which is recognized in standard M‐mode nor in tissue Doppler imaging. For systolic function comparison, we compared left ventricular ejection fraction (LVEF) in conventional echocardiography with the average velocity of ventricular septum myocytes (Vave) in the PTM. The Vave of 12 healthy volunteers was 1.5 (m/s)/m or more. At baseline of 99 patients, there was a positive correlation between LVEF and Vave in all patients. There were no significant differences in baseline cardiac function between patients with and without HF. There was a negative correlation between the cumulative anthracycline dose and LVEF or Vave among all patients. We determined that Vave 1.5 (m/s)/m was equivalent to LVEF 60%, 1.25 (m/s)/m to 55%, and 1.0 (m/s)/m to 50%. During the follow‐up period, there was a pathological decrease in LVEF (<55%) and Vave (<1.25 m/s/m) in patients with HF; decreases in Vave were detected significantly earlier than those in LVEF (P < 0.001). When Vave declined to 1.5 (m/s)/m or less, careful continuous observation and cardiac examination was required. When Vave further declined to 1.0 (m/s)/m or lower, chemotherapy was postponed or discontinued; thus, serious drug‐induced cardiomyopathy was avoided in patients who did not relapse. The PTM was superior to echocardiography for early, noninvasive detection and intermediate‐term monitoring of left ventricle systolic function associated with anthracycline chemotherapy, among patients with hematologic malignancies. The PTM was an effective laboratory procedure to avoid the progression to serious cardiomyopathy.Anthracyclines are among the most effective and widely used anticancer drugs; however, their use is limited by serious cardiotoxicity. Early detection is necessary to prevent the high mortality rate associated with heart failure ( Anthracycline treatment significantly improves the survival of patients with cancer, but can result in serious cardiotoxicity; therefore, effective monitoring of anthracycline‐induced changes in cardiac function could detect changes early enough to implement treatment strategies to significantly reduce or prevent such life‐threatening complications The aim of this study was to compare changes in left ventricle cardiac parameters detected using the PTM with those obtained using conventional echocardiography in order to evaluate whether the PTM is superior for the detection of early anthracycline‐induced changes in cardiac function in patients with acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), and malignant lymphoma (ML). We had experienced a case on the basis of the PTM measurement data, by adjusting the chemotherapy schedule as the development of serious cardiomyopathy was prevented Twelve healthy volunteers and 142 patients with hematologic malignancies were eligible for the PTM and conventional echocardiography. Between August 1998 and August 2014, 128 consecutive patients underwent echocardiography and PTM to evaluate cardiac function. An additional 14 AML patients were examined after completion of chemotherapy in 2009. Patients were grouped according to the absence or presence of clinical heart failure (HF), no HF group and HF group, respectively  and a SSD‐500SV ultrasound scanner  in accordance with recognized standards. Left ventricular ejection fraction (LVEF) was calculated using modified Teichholz.v ‐ } of each heart beat on the tracked points {xi ‐ (t)} on IVS during six heartbeats. The vertical axis of these figures was inverted so that the negative value of the velocity, which is shown above the baseline, corresponds to the situation in which the object moves in the direction of the ultrasonic transducer on the chest wall. The resultant velocity signals are sufficiently reproducible for six heartbeat periods. The results were immediately visualized and output as shown in Figure The ultrasound scanner was switched to the phased tracking mode. By referring to the M‐mode image, which was constructed from the analog/digital (A/D) converted data, we manually preset two points, in the heart wall, between which, the ultrasonic beam was directed, as illustrated in Figure t‐tests were used to compare parameters between the groups using the JMP11 statistical software .The results are presented by the mean and median values. Paired and nonpaired two‐tailed Student's ave) using the following equation:The contractile force and contraction synchrony of myocardial cells was measured using the PTM. We analyzed the period between aortic valve opening and closing . Vave also significantly decreased 2–3 years after the completion of chemotherapy (P = 0.01); however, among patients who survived more than 5 years after the completion of chemotherapy, those in no HF group had recovered cardiac function, whereas cardiac function remained depressed in HF group. In no HF group, LVEF was not shown the reduction but Vave showed decreased (0.001), also, in HF group, Vave was shown a significant declined than LVEF (0.01) after completion of chemotherapy.Table ave 1.5 (m/s)/m was comparable to LVEF 60%, Vave 1.25 (m/s)/m to LVEF 55%, and Vave 1.0 (m/s)/m to LVEF 50%, at 1 and 12 months before the onset of HF ave declined significantly earlier than did LVEF. Figure ave during the courses of chemotherapy. The value of the linear slope in Fig. ave than the LVEF.In accordance with the historical proposal of cardiotoxicity definition ave was 2.503 (m/s)/m, with maximum and minimum values of 5.117 (m/s)/m and 0.99 (m/s)/m, respectively).In Table ave ≤ 1.5 (m/s)/m and 2.5% had Vave ≤ 1.0 (m/s)/m  with Vave ≤ 1.0 (m/s)/m developed HF, and 14 of these patients with Vave ≤ 0.5 (m/s)/m soon developed severe HF.10% had V)/m Fig. A. Figureave. Powerful and effective action of the heart is sustained by synchronization of cardiac myocytes. In Figure Table ave values fell to ≤1.5 (m/s)/m, the rest period was extended to allow recovery of at least Vave 1.5 (m/s)/m, then the following treatment was initiated. For cases in which Vave decreased <1.0 (m/s)/m, we canceled additional chemotherapy treatment. Even if myocardial damage is expressed, it is possible to long‐term survival if not experienced recurrence (P = 0.0001) in Table When VThe summary of the aforementioned results and our proposal for clinical treatment of patients in each group are shown in Table Anthracyclines were originally introduced in the late 1960s as chemotherapeutic agents. They are extremely effective drugs for the treatment of leukemia and a wide variety of solid tumors. In patients undergoing anthracycline therapy, dose‐dependent myocardial impairment has been described in 23–74% of cases, with a high incidence of HF or fatal complications in 5–19% of cases ave during systolic time at the left ventricular septum, we hypothesize that the development of more detailed myocardial damaging process becomes clear by analyzing the continuous temporal relationship with Vave, Vmax, and color image. The nature of cardiac tissue that exhibits low levels of antioxidative enzymes, such as superoxide dismutase and catalase, make it more susceptible to redox oxidative stress (ROS) generation and accumulation of oxidative stress. The major mechanism of chemotherapy‐induced cardiotoxicity involves the generation of ROS. In turn, elevated ROS causes cellular damage and alternation responses The PTM, which was employed in this study, has been applied to clinical studies by many researchers, that is, noninvasive evaluation of the myocardial property of contraction and relaxation Careful observation is required to detect decreases of more than 1.0 (m/s)/m in such patients to consider treatment delay or cancelation in order to avoid lethal cardiotoxicity. To circumvent the development of HF, early detection of drug‐induced changes in cardiac function is essential for preventive intervention. Careful surveillance using the PTM could ensure early detection and timely management of such cardiotoxicity.The PTM was superior to echocardiography for early, noninvasive detection and intermediate‐term monitoring of left ventricle systolic function associated with anthracycline chemotherapy in patients with hematologic malignancies. We found that the PTM is a valid laboratory procedure that may help avoid progression to serious cardiomyopathy.The authors declare no conflicts of interest.


Test-retest reproducibility is of utmost importance in follow-up of right ventricular (RV) volumes and function; optimal slice orientation though is not yet known. We compared test-retest reproducibility and intra-/inter-observer variability of right ventricular (RV) volumes and function assessed with short-axis and transverse cardiovascular magnetic resonance (CMR).t-test, Bland-Altman plots, intra-class correlation coefficient (ICC) and 2-way ANOVA, SEM and minimal detectable difference calculations.Eighteen volunteers underwent cine CMR for RV assessment obtaining ventricular coverage in short-axis and transverse slice orientation. Additional 2D phase contrast flow imaging of the main pulmonary artery (MPA) was performed. After complete repositioning repeat acquisitions were performed. Data sets were contoured by two blinded observers. Statistical analysis included Student’s P = 0.1) and MPA flow  did not differ between imaging sessions. EDV and ESV demonstrated an inter-study bias of 0.4 % and 2.1 % for short-axis and 1.1 % and 0.8 % for transverse orientation, respectively. There was no significant interaction between imaging orientation and interstudy reproducibility (p = 0.395–0.824), intra-observer variability (p = 0.726–0.862) or inter-observer variability (p = 0.447–0.706) by 2-way ANOVA. Inter-observer agreement by ICC was greater for short axis versus transverse orientation for all parameters . Minimal detectable differences for short axis and transverse orientations were 10.1 mL/11.5 mL for EDV, 8.3 mL/8.4 mL for ESV and 4.1 % vs. 4.7 % for EF, respectively.Heart rates (65.0 ± 7.4 vs. 67.6 ± 9.9 bpm; Short-axis and transverse orientation both provide reliable and reproducible measures for follow-up of RV volumes and global function. Therefore, additional transverse SSFP cine CMR may not necessarily be required if performed for the sole purpose of quantitative volumetric RV assessment. Accurate and reproducible quantification of right ventricular volumes and function plays a crucial role in the diagnosis of various cardiac diseases. It also guides clinical decision-making and monitoring of therapy in many conditions. These include pathologies primarily affecting the right ventricle (RV) such as arrhythmogenic right ventricular cardiomyopathy (ARVC), tricuspid regurgitation, pulmonary hypertension as well as congenital heart disease (CHD) entities such as Tetralogy of Fallot (ToF), Ebstein’s and shunt diseases –6.Various studies have established cardiovascular magnetic resonance (CMR) as the standard of reference in assessment of RV dimensions and function –10. FurtWhile the acquisition of cine steady state free prcession (SSFP) data in short axis orientation (SAO) is the accepted standard for assessment of the left ventricle (LV) in CMR, both, transverse as well as short axis slice orientations have been applied for analysis of the RV. However, acquisition of an additional transverse stack for the sole purpose of RV volumetric assessment not only lengthens the total examination time and as such effects imaging workflow and capcities but also may negatively impact patients’ comfort and compliance.Several studies have demonstrated that transverse cine orientation has better intra- and inter-observer reproducibility than SAO cine in patient populations with various anatomies , 14–17.Additionally, longitudinal follow-up examinations using CMR and identification of changes and pattern of changes over time have gained attention especially in CHD , 18. CMRWe hypothesize that SAO is not inferior to transverse orientation cine SSFP in respect to the overall variability of longitudinal comparison for RV volume and function assessment.The aim of our study therefore was to evaluate test-retest variability of cine SSFP applied in both orientations approaches in addition to intra- and inter-observer variability in a cohort of healthy volunteers undergoing two serial CMR exams.Twenty-one healthy volunteers aged 18 or older with no personal or family history of cardiovascular disease were recruited. The following exclusion criteria were applied: contraindication to MRI, claustrophobia, possible pregnancy in female candidates.Data from three participants  were excluded from the study because of either the short axis or transverse cine SSFP data sets were missing or affected by substantial motion artifacts. The age of the final cohort of 18 participants  ranged from 22.2 to 45.6 years (33.0 ± 6.7 years).2 (matrix 224). With the acquisition of 13 lines/segment and parallel acquisition using GRAPPA (R = 2) the temporal resolution was 40 ms. In addition, a transverse stack of cine SSFP slices provided coverage from the main pulmonary artery (MPA) to the infracardiac diaphragmatic surface. Identical parameters of spatial and temporal resolutions were applied as detailed above. Further details were: flip angle 75°, repetition time 3.1 ms, echo time 1.3 ms, bandwidth 930Hz/Px.All CMR was performed at 1.5 T  using body surface arrays for optimized signal reception. After localization of cardiac axes, ECG retrogated cine SSFP was applied for analysis of ventricular function. This included a stack of parallel short axis cine SSFP acquisitions with coverage from the atrio-ventricular plane to the apex with a slice thickness of 6 mm (2 mm gap) and an in-plane resolution of 1.35 × 1.35 mm2 (matrix 256) with a slice thickness of 5 mm. With the acquisition of 2 lines/segment the achieved temporal resolution was 26.9 ms. Further sequence details included: flip angle 30°, repetition time 13.5 ms, echo time 3.5 ms, bandwidth 391Hz/Px.Additional phase contrast (PC) flow imaging was performed in the main pulmonary artery (MPA) serving as an independent standard of reference for the RV stroke volume. After multiplanar localization of the MPA for perpendicular slice prescription, an ECG retrogated through-plane velocity encoded PC spoiled gradient recalled echo (sGRE) technique measurement was performed in free-breathing with two averages. Spatial resolution was 1.56x1.56 mmFor both retrogated techniques, cine SSFP and PC flow measurements, the number of phases reconstructed per RR cycle was chosen to match the temporal distance between phases to the acquired temporal resolution.In order to test for interstudy variability all above measurements were repeated after a 5–8 min biobreak with the volunteer getting off the table (at home position) and exiting the scan room. After the break the volunteers were repositioned on the table with acquisition of new localizers and re-planning/re-scanning of above described cine SSFP stacks and PC flow measurements.Semi-automated segmentation of the RV volume in transverse and short axis cine SSFP data of all volunteers was performed by two observers  using a commercially available post-processing software  Fig. . Both obAnonymized image data was presented to observers in a random fashion in order to avoid back to back segmentation of transverse and short axis data sets in the same patient. First, end-diastolic and end-systolic frames were chosen for the RV segmentation followed by drawing of the endocardial RV contours at end-diastole and end-systole. Trabeculations were excluded from the mass and included in the RV blood pool. Following finalization of the RV contouring ventricular parameters, such as end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were recorded. One observer (L.D.) repeated all contouring with a time interval of >10 days between both contouring sessions blinded to results of any previous contouring.Available PC flow data sets for the MPA were analysed by a third observer (B.J.W.) blinded to results of RV volumetric measurements. Flow data quantification was performed using semiautomated postprocessing tools . After initial automated contour seeding within the MPA and propagation across the entire series, contours were subsequently checked on all individual frames and modified whenever necessary. Furthermore, the stationary pixel based background correction was applied in order to correct for potential offsets. The forward volume, reverse volume and net forward volume per heartbeat were recorded for further analysis. In addition, this observer also visually evaluated the available cine SSFP data sets for possible tricuspid regurgitation which would affect the comparability of RV stoke volumes to the MPA forward flow volume.For the purpose of analysis of potential heart rate variation between both scanning session, the average RR interval during the retrogated MPA PC flow acquisition was recorded.t-test was applied for comparison of individual volumetric results as well as for comparison with recorded MPA flow data. Statistical analysis also included Bland-Altman analysis for the recorded RV volumetric and functional data, intra-class correlation coefficient (ICC) for inter-observer variability analysis and 2-way ANOVA to assess for the effect of slice orientation on interstudy as well as intra-/inter-observer variability of volumetric RV results.All continuous data is presented as mean ± standard deviation unless otherwise stated. Student’s p < 0.05 with Bonferroni corrections applied for multiple repeated testing when required.In addition, the standard error of the measurement (SEM) for EF and each volumetric parameter was evaluated by calculating the square root of the mean square error for each slice orientation performed based on one-way ANOVA. In this analysis the parameter or interest was used as the dependent variable, while patient ID was used as fixed factors. Subsequently the minimal required change between two separate examination time points required for each parameter beyond which a real change could be assumed by a chosen cine MRI slice orientation  was calculated as 2x SEM . A standEvaluation of RV volumes and function based on cine SSFP was successful in the entire study cohort of 18 healthy volunteers with a total of 36 cine SSFP volume stacks to be contoured . In all but one volunteer MPA PC flow assessment was successfully analysed for both sessions. A single volunteer demonstrated a significant variation in RR interval (1039 ± 422 ms) in one session of the MPA PC flow data related to transient arrhythmia making this flow measurement unreliable as a reference for the RV output. This volunteer’s MPA flow data was therefore not used for any comparison of flow related data between both measurement sessions. All other flow and volumetric data of this individual were not affected by any arrhythmia and as such included in respective subsequent data analysis.P = 0.12).In the 17 volunteers where reliable heart rate recording was available, no significant differences between the recorded heart rates between scan session 1 and 2 was observed  without any significant difference in forward flow (Table P = 0.1).Quantification of the MPA flow for measurement sessions 1 and 2 demonstrated strong correlation between both sessions (P > 0.05)  and SAO . For both observers the transverse orientation RV SV strongly correlated to SAO derived RV SV data  without significant differences in pairwise comparison   Table . In addiFor inter-observer agreement the ICC demonstrated higher values in short-axis vs. transverse orientation for SV measures  , inter-observer  and intra-observer  variability of SV results.No significant interaction between imaging orientation was demonstrated for interstudy . Results for EDV demonstrated a bias of 0.4 %  for short axis and 1.1 %  for transverse orientation between both sessions  as well as inter-  and intra-observer  variability for EDV results.2-way ANOVA did not demonstrate significant interaction between imaging orientation and interstudy . Bland-Altman analysis revealed a bias of 2.1 %  and 0.8 %  between both studies for short axis and transverse orientation, respectively , inter-observer  and intra-observer  variability of ESV results.No significant interaction between imaging orientation was demonstrated for interstudy , inter-observer  and intra-observer  variability of ESV results.Again, no significant interaction between imaging orientation was demonstrated for interstudy  volumetry utilizing transverse cine SSFP orientation in a population of repaired tetralogy of Fallot (rToF) patients . SimilarIn addition to intra- and inter-observer variability few studies have also demonstrated differences in ventricular volumes between both slice orientations. In the work by Alfakih et al. short axis slice orientations resulted in significantly larger results for RV EDV (4.7 % difference) and RV ESV (10.7 % difference) while no differences were found for SV . Fratz e2 or an RV ESV of <80–85 ml/m2 a normalization of RV size after PVR has been demonstrated [In therapy guidance and longitudinal follow-up of various cardiac pathologies that affect ventricular volumes and function a high test-retest reproducibility is of utmost importance. For example, various investigators have proposed cut-off values for timing of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot and chronic pulmonary valve regurgitation. With an RV EDV of <160–165 ml/mnstrated , 5, 6. Gnstrated . Few stunstrated . Howevernstrated . Using bnstrated . They renstrated . Most renstrated . While nnstrated . While aDespite the fact that this study provides the first direct comparison of test-retest reproducibility between transverse and short axis slice orientation for RV volumes and function, the following limitations apply.The study is composed on a relatively small number of individuals included, however as opposed to previous test-retest investigations we included MPA PC flow measurements as an independent reference standard. Furthermore, our study only recruited cooperative healthy volunteers without relevant arrhythmia and a high level of compliance to scanning instructions. In a symptomatic patient population the test-retest reproducibility therefore might be lower than reported above.This first report on direct comparison of short axis and transverse cine SSFP slice orientation with respect to test-retest reproducibility of RV volumes and function demonstrate equally high performance of both orientations. While there were comparable levels of intra- and interobserver variability and similar volumetric results of both slice orientations, volumetric analysis of transverse slice orientation cines did not demonstrate a significant advantage over short axis ventricular coverage. With standard coverage using SAO for LV assessment, this single data set also provides adequate assessment of RV size and function. As such, transverse cine SSFP imaging may be omitted for the sole purpose of RV volumetric assessment resulting in shortened scan protocols for improved workflow and patient comfort.However, assessment of complex vascular and cardiac anatomy may still require the application of transverse cine SSFP as a non-oblique and reproducible orientation for insight into spatial relationships.


Left ventricular (LV) phase dyssynchrony parameters based on gated myocardial perfusion imaging varied among software programs. The aim of this study was to determine normal ranges and factors affecting phase parameters.n = 69). The programs were Emory Cardiac Toolbox with SyncTool (ECTb), Quantitative Gated SPECT (QGS), Heart Function View (HFV), and cardioREPO (cREPO); parameters of phase standard deviation (PSD), 95% bandwidth, and entropy were compared with parameters with ECTb as a reference.Normal databases were derived from the Japanese Society of Nuclear Medicine working group (P < .0001), 5.4 ± 2.5 for HFV (P < .0001), and 10.3 ± 3.2 for cREPO (P = n. s.) compared with 11.5 ± 5.5 for ECTb. Phase bandwidth with three programs differed significantly from ECTb. Gender differences were significant for all programs, indicating larger variation in males. After adjustment of LV volumes between genders, the difference disappeared except for QGS. The phase parameters showed wider variations in patients with the lower ejection fraction (EF) and larger LV volumes, depending on software types.PSD (degree) was 5.3 ± 3.3 for QGS (Based on normal ranges of phase dyssynchrony parameters in four software programs, dependency on genders, LV volume, and EF should be considered, indicating the need for careful comparison among different software programs. In nuclear cardiology, phase analysis of timing of contraction has been used since the 1980s in a gated blood-pool study.Since several software packages are now available in Japan, the purpose of this study was to determine the normal values of each software program, including cardioREPO  and Heart Function View  in comparison with ECTb. The normal database was prepared from the Japanese Society of Nuclear Medicine (JSNM) working group database 2007.99mTc-methoxy-isobutylisonitrile (MIBI) or 99mTc-tetrofosmin studies at resting condition with 16 frames per cardiac cycle were used.The JSNM working group created normal databases for MPI in 2007, and the electrocardiographic gated Parameters for baseline cardiac function included left LVEF, end-diastolic volume (EDV), and end-systolic volume (ESV). All the analyses were performed using standard software settings of ECTb, QGS, HFV, and cREPO. Regarding ventricular edge detection, ECTb used an anatomically based 3-dimensional model for ventricular edge detection assuming that at end-diastole, LV myocardial thickness is 1 cm.fi*log(fi)]/Log(n)], where f and n are frequency in the ith bin and number of bins, respectively.Fourier analysis was applied to extract the phase and amplitude of the fundamental frequency of the regional time-activity curves.In addition, cREPO provided 17-segment-based regional time-activity curves and its regional variations similar to the “cardioGRAF” software , which has been used for heart failure and resynchronization therapy.P value <.05 was considered significant.All the data are expressed as mean and standard deviation (SD). Mean values were compared by the analysis of variance. Scatterplot matrix was calculated for all combinations of the four software programs, and pairwise correlation coefficients and p values were calculated. Gender difference was also calculated for all phase parameters. Linear regression line was calculated with the least square method. To compare parameters for gender differences in the small and larger LV, non-parametric Wilcoxon test was used for the four groups, and only males with the smaller LV and females with the larger LV were compared. Statistical analysis was performed using JMP 10.0 software . A P < .0001 for all combinations).The mean EF was 69.2 ± 6.5%, 77.1 ± 6.3%, 73.2 ± 5.3%, and 71.7 ± 6.4% for QGS, ECTb, cREPO, and HFV, respectively . The PSD was comparable for ECTb and cREPO (P = n. s.), which was higher than that of QGS (P < .0001) and HFV (P < .0001). Phase entropy was higher in cREPO than that in QGS (P < .0001).Regarding phase parameters Table , the banr = 0.38, 95% confidence interval (CI) = 0.16-0.57, P = .0012]    , and ECTb also showed higher tendency in males (P = .078). The PSD was consistently higher (P = .002-.043) in males than in females. The phase entropy parameter was also higher in males, indicating larger disorder in the male database (P < .0001). When phase bandwidth and PSD were plotted versus EDV, positive correlations were obtained for QGS, HFV, and cREPO  and HFV . The relationship between PSD and LVEF showed that correlation coefficients ranged from −0.24 to −0.53 (P < .0001 to .048)  in QGS and −0.31 (P = .009) in cREPO. However, the relationship between phase parameters and body weight were not significant in all software programs. Parameters of TES using a 17-segment model were given only with cREPO  and entropy (P = .020) showed significant difference between genders with QGS. A slightly higher tendency (P = .05 to .010) was observed in males than females regarding PSD by ECTb, bandwidth by QGS, and bandwidth and PSD by HFV.To evaluate the effect of small hearts on phase parameters, male subjects with the lower LV volume  and female subjects with the higher LV volumes  were compared . When the same acquisition and processing filters were applied in both genders, the overall effects may become smoother images in the female condition. Phase parameters showed larger variation in patients with either lower LVEF or larger LV volumes in four software programs. The difference in phase parameters became smaller between genders after adjustment of volumes, but a slight difference still remained. Generally, the higher exercise level in male subjects than in female subjects may also be a concern. Physiologically, it is not a plausible explanation that male hearts contract more dyssynchronously and disorderly than female hearts, but the gender difference actually existed in the routine acquisition and processing conditions.Several factors may influence the distribution of phase depending on gender, total accumulated count or noise, amount of injected radionuclide, stress or rest, and number of frames per cardiac cycle. The perfusion pattern in addition to post-stress and resting conditions were also determinants of phase values.Based on the results of this study, phase parameters cannot be interchangeably used among four software programs. However, when we analyzed normal values, there seem to be similarities between ECTb and cREPO, and between QGS and HFV. The ventricular models used for detecting myocardial walls significantly influence EF and volumes as well as measured pixel-based counts. The calculated phase parameters might have been influenced by the count detection algorithm on the myocardial walls, filtering of the images, number of angular sampling, filtering of time-activity curves, and so on. In general, images with smoothing or low-pass filtering, either temporal or spatial domain, result in the lower noise and hence the smaller bandwidth and PSD. Although we could not strictly define the effect confounding factors on phase values in each software program, we should carefully deal with the differences in software in clinical applications.There are some limitations in this study. Since the JSNM working group database was prepared as the short-axis images from multiple institutions, we could not strictly define acquisition and processing conditions. However, the database reflects clinically acceptable image quality with optimal gating, and the selection criteria of the normal database were clearly defined.All normal values for phase dyssynchrony with currently available software programs were given in this study. Phase analysis parameters derived from MPI depend on software programs, due to their specific algorithms for calculating phase bandwidth, PSD, and entropy. Gender differences were observed in all software programs, and the values showed higher variations in males than in females and, in addition, in patients with the larger LV volumes and the lower LVEF. Although the results of phase analysis cannot be interchangeably used in the same subjects, such dependency on gender and functional conditions should be considered.


In patients with triple valve replacement developing third-degree atrioventricular block (AVB), the most appropriate approach for permanent pacemaker implantation remains questionable.In this case presentation, we first described the approach of implantation of the cardiac resynchronization therapy pacemaker (CRT-P) via one bipolar pacing lead in middle cardiac vein (MCV) and one quadripolar pacing lead in anterior interventricular vein (AIV) in a patient developing complete AVB, who had been previously diagnosed with rheumatic valvular heart disease with triple valve replaced. After the CRT-P implantation, the two pacing leads in coronary sinus (CS) provided a dual-site ventricular pacing from the anterior septum and posterior septum, which resulted in a narrow QRS complex and an increased ventricular synchrony. During the long-term follow-up, no deterioration of heart function was documented and pacing parameters remained good.In this patient developing complete AVB with triple valve replaced, our approach of CRT-P implantation provides an effective and reliable ventricular pacing, and is an alternative option when transvenous right ventricular pacing, transseptal left ventricular pacing and transpericardial epicardium pacing are not possible. Further prospective randomized trials are required to confirm the efficiency of our approach of dual-site ventricular pacing by CRT-P in this kind patients. In rheumatic heart disease patients with triple mechanical valve replacement and complete atrioventricular block (AVB), the most appropriate and beneficial method of pacemaker implantation remains questionable. With the tricuspid mechanical valve replaced, endocardial pacing of the right ventricle is not possible because such a manipulation may cause disastrous damage to the prosthetic valve . In addiA 42-year-old woman with a history of rheumatic valvular heart disease and permanent atrial fibrillation underwent open triple valvotomy 14 years ago and routinely took the warfarin to anti-coagulate since then. The international normalized ratio of prothrombin time (PT-INR) was monitored every 2 weeks to keep it range between 2.5 and 3.5 s. She complained of persistent abdominal distension and repeated exertional dyspnea for 2 years at admission. Physical examination showed obvious body signs of right heart failure, including jugular vein distention, lower limb pitting edema. The 12-lead surface ECG showed atrial fibrillation rhythm with narrow QRS complex. The transthoracic echocardiography indicated a normal ventricular size of 35 mm with left ventricular ejection fraction (LVEF) of 65% and a moderate stenosis of tricuspid valve with the pressure gradient across the tricuspid valve of 8 mmHg. Laboratory examination revealed the NT-pro-BNP of 1780 ng/ml. Due to progression of heart failure from her valvular heart disease, she underwent tricuspid valve replacement again (Medtronic bileaflet prosthesis). On the second day after surgery, the patient developed sudden cardiac arrest with bedside electrocardiographic monitor recording atrial fibrillation, complete third-degree AVB with repeated episodes of torsade de point secondary to the long QT interval (0.6 s). Thus, a permanent pacemaker was required to oppose this malignant arrhythmia.After taking full consideration of the patient’s basic situations, the CRT-P implantation via two pacing leads in cardiac venous system to provide dual-site ventricular pacing was primarily planned. As the patient with triple mechanical valve replaced had a relatively higher risk for thrombosis, the oral warfarin was not interrupted before operation. The instant blood test prior to operation showed a PT-INR of 2.42 s. The intravenous unfractionated heparin was used during the procedure to keep an activated clotting time (ACT) range between 250 and 300 s. Electric surgical knives were applied to stop bleeding of the incision during the whole procedure. A guiding catheter was delivered via left subclavian vein puncture to access the coronary sinus ostium, which was located between the inferior vena cava and the mechanical tricuspid valve on the inferior aspect of the atrial septum. A retrograde occlusion venogram was then performed to evaluate the anatomy of the cardiac venous system. As the lateral cardiac vein was too thin and the posterolateral vein was too tortuous for pacing leads to access, the MCV and the AIV were selected as target vessels for pacing leads placement. A quadripolar pacing lead  was introduced into the AIV, while bipolar pacing lead  into the MCV, both leads were secured to the pectoral muscle fascia and attached to a CRT-P , Fig. In this case, we first described the method of implantation of CRT-P with two pacing leads in coronary venous system, which provided an effective dual-site ventricular pacing in a patient developing complete atrioventricular block after triple mechanical valves replacement.In this patient, as the mechanical tricuspid and mitral valves implanted, placing pacing lead in right ventricular endocardium across the tricuspid valve was forbidden because of underlying risk of valve damage and failure, in addition, delivering pacing lead to left ventricular endocardium via the atrial septum puncture was also contraindicated due to the potential damage to the mitral valve , 2. The In this patient, due to a relatively higher thrombotic risk associated with triple mechanical valve replacement, the oral anticoagulant therapy of warfarin was not interrupted and a bridging therapy with low-molecular-weight heparin (LMWH) was not initiated. Though this protocol was some different from the standard anticoagulation protocol at the time of pacemaker implantation, which required stopping oral anticoagulation therapy and initiating a bridging therapy with subcutaneous LMWH, no pocket hematoma and thromboembolic events was found in this patient. Our observation further confirmed the safety of anticoagulation protocol proposed by the POCKET study .CRT-P implantation with two pacing leads in coronary sinus can provide an effective and reliable dual-site ventricular pacing. Further prospective randomized trials are required to confirm the efficiency of our approach of dual-site ventricular pacing by CRT-P.