Retinal tears are the most common vitreoretinal (VR) emergency and retinopexy aims to reduce the risk of rhegmatogenous retinal detachment (RRD). Currently retinal laser is a required competence by the Royal College of Ophthalmologists for residents. We report 6-month detachment rate and repeat retinopexy rate of VR specialists compared with residents.A retrospective, consecutive study of 958 eyes undergoing primary laser retinopexy (slit lamp or indirect laser) from January 2017–2020 was divided into training level by operator: specialty training (ST) 2–3, ST4–5, ST6–7 and VR specialists.We report an overall 6-month RRD rate in 32/958 (3.3%) (ST2–3: 9/221 (4.1%), ST4–5: 15/373 (4.0%), ST6–7: 2/72 (2.8%) and VR specialists: 6/292 (2.1%)). We additionally report a repeat retinopexy rate of 189/958 (19.7%), (ST2–3: 44/221 (19.9%), ST4–5: 80/373 (21.4%), ST6–7: 16/72 (22.8%) and VR specialists: 49/292 (16.8%)]). Multivariable Cox survival regression analysis showed significant risk factors for developing RRD include male gender (p=0.018), high myopia , ST2–3 (p=0.022) and ST4–5 (p=0.040)  and by ST6–7, no significance was found (p=0.151). Significantly higher repeat retinopexy rates were associated with horseshoe tears  and high myopia (p=0.026) with no difference between different training levels.There was a decreasing trend in RRD rate following primary retinopexy with increase in training. Although junior residents had a higher RRD rate than VR specialists, it was still favourable relative to other large case series. While there was no difference in subsequent laser retinopexy rate between training levels, the retreatment rate was associated with the type of tear and high myopia. Existing large case series demonstrate a rhegmatogenous retinal detachment (RRD) rate following primary retinopexy performed by residents of between 6.9% and 8.8%.Senior residents have a comparable RRD rate following primary retinopexy to vitreoretinal (VR) specialists.Junior residents, although having a higher RRD rate then VR specialists, demonstrated an excellent safety profile of primary retinopexy compared with other large case series.Our findings encourage junior residents to undertake laser retinopexy with adequate supervision.Retinopexy outcomes can continue to improve over 6 years of surgical training.Retinal tears are the most common vitreoretinal (VR) ophthalmic emergency, with a primary aim of retinopexy to reduce the risk of rhegmatogenous retinal detachment (RRD). Laser retinopexy can be carried out in multiple forms: 1) slit lamp retinopexy and (2) indirect retinopexy. Currently retinal laser is a required competence by the Royal College of Ophthalmologists (RCO) for residents, from year 3 of their specialty training (ST) (second year of residency). slit lamThe National Ophthalmology Database group demonstrated how a reduction in posterior capsule rupture rate following cataract surgery could be achieved with increased level of training.We present a single centre, retrospective, continuous comparative study of all patients who had primary laser retinopexy from January 2017 to 2020 at Birmingham and Midland Eye Centre, in the UK. All data were extracted from electronic patient records . The research adhered to the tenets of the Declaration of Helsinki and all patient data extracted were anonymised for analysis.Our cohort of patients was divided into four groups: primary retinopexy performed by ST2–3, ST4–5, ST6–7 and VR specialists. VR specialists were defined as VR fellows and consultants. No VR associate specialists or non-fellows operate in our unit. The most junior residents, on completion of retinopexy, would typically have the application reviewed by a senior resident, otherwise follow-up in the VR clinic would be arranged. If a senior resident/clinician took over to complete the retinopexy, the most senior clinician would be labelled as the operator.Our primary outcome measure was to compare RRD rate within 6 months following primary retinopexy by training grade. We also assessed the requirement for further retinopexies following primary retinopexy by training grade as secondary outcomes. All patients who had prior VR surgery were excluded. RRD rate was defined as requiring RRD surgery within 6 months of having primary retinopexy in the same eye. Retinopexy of retinal breaks was achieved with laser, via a slit lamp or indirect method and consisted of surrounding retinal breaks with several rows of confluent white laser burns using either a contact lens or a non-contact condensing lens system. Indirect laser was generally used in patient’s intolerant of slit lamp retinopexy , small pupils, specific pseudophakic patients (due to the intraocular lens edge obstructing the view of the tear), anterior breaks requiring scleral indentation and retinal tears present with concurrent vitreous haemorrhage where indentation helped provide a view. All patients undergoing primary retinopexy were reviewed within 4 weeks, depending on clinical urgency, in a VR specialist clinic. If patients were subsequently found to have inadequate chorioretinal scar cover, further retinopexy was applied. Patients occasionally presented to our emergency eye clinic with deteriorating symptoms and could be clinically determined to require further retinopexy. All the cases that required retinal detachment surgery following primary retinopexy were performed with transconjunctival 23-gauge pars plana vitrectomy, vitreous-base trim and cryotherapy/laser retinopexy or cryotherapy and/or scleral buckling. As a tertiary referral centre, patients whose postcode was outside, our catchment area was excluded as these patients may have had further retinopexy or surgery at the referring unit. Preoperative data collection included indication for retinopexy: retinal break morphology (horseshoe tears (HST), operculated breaks, round holes), lattice degeneration, RRD , other), treatment modality (slit lamp and indirect laser) age, gender and presence of high myopia (≤−6.00 Dioptres). Postoperative data collection included the 6-month RRD rate and repeat retinopexy rate.2 test was used for nominal variables with three or more categories. There were multiple factors that could affect outcome , presence of high myopia) and selection bias of treatment modality. Therefore, a multivariable Cox regression survival analysis was performed analysing both repeat retinopexy and RRD rate. Time in days to repeat retinopexy and RRD were used, respectively, with training grade , gender, age, high myopia and treatment modality (indirect retinopexy compared with reference of slit lamp laser) and indication for treatment (HST vs hole), as covariates.Statistical significance was defined as p<0.05. Prior to analysis, normality of continuous variables was assessed using the Shapiro-Wilk test and found not to be normally distributed. Hence, data are primarily reported as medians and IQRs throughout. Kruskal Wallis test was used to compare three or more independent groups, respectively, for continuous variables. A χAll statistical analyses were performed using IBM SPSS Statistics for Windows, V.27.0 .A total of 958 eyes of 914 patients with primary retinopexy were analysed. Within the resident group, we included outcomes from 54 residents and 18 VR operators over 3 years . A summary of demographics and baseline clinical characteristics of primary retinopexy between the training groups are found in A summary of outcomes of primary retinopexy by training level is found in Although no significant difference was found between groups on univariate analysis, there were a high number of variable risk factors between groups. Therefore, two multivariable Cox survival regression analyses were performed on risk factors for RRD and further retinopexy following primary retinopexy to determine differences in training level as outlined in the Methods section. Our Cox regression survival analyses are found in In our study, we explored that the influence training has on retinal detachment following primary retinopexy, the repeat retinopexy rate and the type of retinopexy performed on primary retinopexy. Through a multivariable Cox survival regression analysis, we demonstrated that increasing experience among different training grades is linked to a trend of reduced risk of developing a retinal detachment following primary retinopexy . Our ove12et al, on 307 eyes, found no significant difference in progression to RRD between residents and VR specialists.et al found a 24% repeat retinopexy rate and a RRD rate of 8%  following primary retinopexy by resident ophthalmologists.et al, 10 years following Ghosh et al, found that 40% of eyes lasered by residents in our unit subsequently required further laser, with no patients developing a RRD.et al reported a 15% retreatment rate and a 1.2% RRD rate following retinopexy.Only a few papers investigated the effect of training on primary retinopexy in the past including a significantly lower number of patients compared with our series. In addition, none of the previous papers correlated the retinopexy outcomes to the stage of training. Unlike, in our cohort, the study by Lankry We also demonstrated a difference in mode of retinopexy performed between VR specialists and residents, with significantly less indirect retinopexy being performed by the latter group as already showed by Ghosh et al. almost 20 years ago.14Our study is retrospective in nature and so we had no standardised treatment protocol to follow. We used RRD surgery as a rate of failed primary retinopexy at 6 months. Although patients may have had their surgery at another eye unit, patients were excluded by postcode outside of our catchment area to minimise this probability. The presence of subretinal fluid (SRF) was not consistently reported and was not included as a risk factor in our analysis. However, tears with extensive SRF,  were all subcategorised and presented in Overall, we discovered a decreasing RRD rate following primary retinopexy with the increase in training grade and experience. Although junior residents had a higher RRD rate than VR specialists, this was still favourable compared with other large case series. We demonstrate an incremental reduction in detachment rate with increased training. Although VR specialists on multivariable analysis maintained the lowest detachment rate across the cohort, the most senior residents showed no statistical difference in RRD rate compared with VR specialists, relative to their more junior colleagues, demonstrating the effectiveness of the RCO training curriculum.


This study investigates the segmental myocardial strain of the early phase of intramyocardial hemorrhage (IMH) caused by reperfused myocardial infarction (MI) in rats by low-dose dobutamine (LDD) cardiovascular magnetic resonance (CMR) feature-tracking.Nine sham rats and nine rats with 60-min myocardial ischemia followed by 48-h reperfusion were investigated using CMR, including T2*-mapping sequence and fast imaging with steady-state precession (FISP)–cine sequence. Another FISP–cine sequence was acquired after 2 min of dobutamine injection; the MI, IMH, and Non-MI (NMI) areas were identified. The values of peak radial strains (PRS) and peak circumferential strains (PCS) of the MI, IMH and NMI segments were acquired. The efficiency of PRS and PCS  were calculated on the basis of the time of every single heartbeat.The PRS, PCS, EPRS, and EPCS of the sham group increased after LDD injection. However, the PRS, PCS, EPRS, and EPCS of the IMH segment did not increase. Moreover, the PRS and PCS of the MI and NMI segments did not increase, but the EPRS and EPCS of these segments increased. The PRS, PCS, EPRS, and EPCS of the IMH segment were lower than those of the MI and NMI segments before and after LDD injection, but without a significant difference between MI segment and NMI segment before and after LDD injection.LDD could help assess dysfunctions in segments with IMH, especially using the efficiency of strain. IMH was a crucial factor that decreased segmental movement and reserved function. Myocardial revascularization reduces the infarction size and the incidence of long-term adverse events in clinical practice. However, myocardial revascularization itself can also lead to intramyocardial hemorrhage (IMH), which has been recognized as a poor prognostic factor in myocardial infarction (MI) for the adverse effect of left ventricular (LV) remodeling . A limitFeature-tracking (FT) cardiac magnetic resonance imaging (MRI) is a post-processing technique that is increasingly being employed to assess global and regional myocardial stain and strain efficiency. Tomas et al. have confirmed the reproducibility of FT for strain analysis in small animals (mice) , but no We designed two groups, namely, the reperfused MI group and the sham group, and hypothesized that this MRI strain analysis at rest and with LDD could discriminate IMH, MI, and non-MI (NMI) segments in the reperfusion group and discriminate these segments in the sham group.All experimental procedures were approved by the experimental Animal Ethics Committee of West China Hospital, Sichuan University . Nineteen female Sprague–Dawley rats  with body weights ranging from 250 to 300 g were divided into two groups: the reperfusion (n = 10) and sham control groups (n = 9). Before surgery, the rats were intraperitoneally anesthetized using sodium pentobarbital, and respiration was maintained using a rodent ventilator. A real-time electrocardiogram (ECG) was monitored throughout surgery.Thoracotomy was performed to introduce the coronary occlusion. The chest was opened at the fourth intercostal space to expose the heart, the pericardium was opened using forceps, and a 6.0 suture was passed underneath the left anterior descending coronary artery at a location 2 mm proximal to the ostium of the coronary artery. Coronary occlusion was achieved by tightening the suture over a 3.0 suture. The success of occlusion was confirmed by the pale appearance of the myocardial apex area and immediate changes in the ECG profiles, including a significant increase in the amplitude of the QRS complex and ST-segment elevation .In the early reperfusion model, all occlusions were maintained for 60 min, followed by reperfusion . ReperfuMRI was performed 48 h after surgery in both groups . All MRIScout imaging was initially performed using a gradient-echo sequence to localize the short-axis images at the middle level of the LV. Multi-slice cine images were obtained to cover the entire heart for functional analysis. After maintaining the respiratory rate at 30–50 cycles per minute by altering the isoflurane concentration, more than five (depending on the size of the heart) single-slice multi-echo T2*-mapping images were acquired on the short-axis slices during the mid-diastolic phase and end-inspiratory period using both ECG and respiratory gating systems. The imaging parameters were as follows: late gadolinium enhancement (LGE) imaging was performed by fast imaging with steady-state precession –diethylenetriamine penta-acetic acid . Then, the same FISP–cine was repeated in identical planes after 2 min dobutamine  injection at a rate of 10 mg/kg/min. Heart rate was measured before MR scan; before LDD injection; and 2, 20, and 30 min after LDD injection. Figure The imaging parameters included: T2*-mapping: FA (Flip angle) = 30°, TR/TE = 1000 ms/3.5,7,10.5,14,17.5,21,24.5,28 ms, Matrix size = 192 × 192, FOV = 50 × 50 mm, and slice thickness = 1.5 mm without slice gap. LGE: TR/TE = 5.2 ms/1.8 ms, FA = 25°, matrix size = 256 × 256, FOV = 50 × 50 mm, slice thickness = 1.5 mm, 25 frames for each slice.Following MRI evaluation, the rats were euthanized using potassium chloride , and the hearts were rapidly excised. Each heart was cut into five or more transverse slices from the apex to the base; these slices measured approximately 1.5 mm in thickness to match the MRI slices. These slices were then incubated in 4% paraformaldehyde for hematoxylin and eosin staining.The strain data were analyzed using commercially available software . The peak global radial strains (PGRS), peak global circumferential strains (PGCS), peak radial strains (PRS), and peak circumferential strains (PCS) were derived using an FT analysis of the LV short-axis. The efficiency of PRS and PCS  were calculated using the following formula: PRS (PCS)/R-R interval. The analysis was based on the six segmentation created consisting of six hexahedral elements corresponding to the anteroseptal, anterior, anterolateral, posterolateral, posterior, and poster septal walls.T2* maps were calculated using custom-made software written in Matlab 7.1 . More than five slices  were selected to decide the regions of hemorrhage for each rat, which identified as a hypointense core within a hyper intense territory on T2* maps. In The hyperenhanced myocardium on LGE images was defined as an MI area; this was detected using a computer-aided threshold of > 5 standard deviations (SDs) from the remote myocardium and adjusted manually and quantified using the multiple short-axis slice view. NMI areas were defined as segments without IMH and MI  and compared using the Kruskal–Wallis test. MRI evaluations were successfully completed in 18 rats  of the segments in the sham group and 158 of 270 (58.5%) of the segments of the reperfusion group . Table The PGRS and PGCS increased after LDD injection in the sham group Table . In addiThe PGRS and PGCS did not increase after LDD injection in the reperfusion group Table . The PRSp < 0.05). No significant difference was observed between the strains and efficiency of strain of the MI and NMI segments .The strains and efficiency of strain of the IMH segment were lower than those of the MI and NMI segments both before and after dobutamine injection . Additionally, the PCS and EPCS of the MI segment were lower than those of the sham group both before and after dobutamine injection . No significant differences in the PRS and EPRS were found between the MI segment and the sham group before dobutamine injection (both p > 0.05), but differences were found after LDD injection (both p < 0.05). No significant differences in the strains and efficiency of strain were observed between the NMI segment and the sham group before dobutamine injection (both p > 0.05); however, differences were found after LDD injection (both p < 0.05).The strains and efficiency of strain of the IMH segment were lower than those of the sham group both before and after dobutamine injection (all Representative histopathologic images from animals with hemorrhagic infarctions sacrificed are shown in Fig. This is one of a few studies using the CMR-FT technique in small animal models. In particular, we applied this technique to evaluate the segmental strain dysfunction in myocardium with IMH and MI in a rat model of acute reperfusion injury by using the LDD stress, we found that LDD would increase the PGRS and PGCS in normal sham rats, but not those in rats with acute reperfusion MI. And EPRS, EPCS of the MI/NMI segments increased, whereas those of the IMH segment remained the same. Interestingly, no difference in the PRS and PCS was found between the MI and NMI segments.Dobutamine significantly increased the heart rate and the maximum circumferential strain even at low doses , which iIn this study, during anesthesia, the heart rate decreased from 310–380 to 250–270 bpm, and dobutamine was helpful in recovering the heart rate to normal ranges; therefore, promoting the efficiency of myocardial strain except for the strain value in normal rats. Furthermore, detecting the MI and NMI segments of the reperfusion group with the efficiency of myocardial strain became more sensitive than the strain value after dobutamine injection.Limited data exist on the relationship between IMH and regional function. Kidambi et al. studied the role of myocardial deformation using tissue tagging-derived strains in patients with acute reperfused MI . They deInterestingly, we found no difference in the PRS and PCS between the MI and NMI segments during LDD stress. Two possible explanations exist for this result: First, the deterioration of the strains in the MI segments may affect not only the segment itself but also neighboring segments. Second, strain parameters describe myocardial deformation, which is also determined by passive movement.Our study has some limitations. First, this study had a small sample size; however, a study demonstrated that myocardial strain parameters were highly reproducible even with a small number of animals . TherefoIn conclusion, this study demonstrated a method in which LDD could be useful in assessing the stain dysfunctions in segments with IMH, especially using the parameter of the efficiency of strain. IMH could be a crucial factor that decreased segmental contractility to a greater extent, thus further reducing the global function. A combination of LDD-CMR and LGE-CMR may be a powerful tool for identifying which segment with impaired LV function will benefit from revascularization.


The incidence of worsened clinical outcome due to high right ventricular (RV) pacing burden in patients with preserved left ventricular function remains controversial.To investigate the impact of RV pacing on several echocardiographic and spiroergometric parameters.In 60 pacemaker patients with preserved left ventricular ejection fraction (LVEF) serial echocardiographies and spiroergometries were performed over a time course of 12 months. Additionally, in 48 patients retrospective echocardiographic analyses of the LV- and RV function were carried out up to 24 months after pacemaker implantation.The patients were divided into two groups: The high RV pacing burden group (hRVP: ≥ 40%) and the low RV pacing group (lRVP < 40%) according to the definitions in previous randomized MOST and DAVID trials. After a period of 12-month pacemaker therapy no changes to left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), LVEF, E/A-ratio; E/E′-ratio and tricuspid annular plane systolic excursion (TAPSE) could be revealed, independently of the RV pacing burden. Additionally, after 24-month long term follow-up there were no differences in LVEF and TAPSE in both groups. Accordingly, no relevant changes of peak exercise capacity, ventilatory anaerobic threshold or maximal oxygen consumption could be demonstrated independently of the RV pacing.In pacemaker patients with preserved LVEF the burden of RV pacing has no adverse influence on several echocardiographic and spiroergometric surrogate parameters of pacemaker-induced cardiomyopathy after a follow-up of 12 to 24 month. Despite this, screening for pacemaker induced cardiomyopathy should be performed especially in the presence of new heart failure symptoms. The incidence of pacemaker induced cardiomyopathy as the cause of worsened clinical outcome due to high right ventricular (RV) pacing burden remains unclear, especially in patients with preserved left ventricular function . A previIn the present clinical registry we evaluated the influence of RV pacing burden on several echocardiographic parameters. In addition, serial spiroergometric examinations were performed to investigate the clinically functional outcome of the pacemaker patients. The aim was to complement the existing data in order better to evaluate the need for screening for pacemaker-induced cardiomyopathy and potentially verify the indication for biventricular pacing and HIS bundle pacing in patients with preserved LV function.The current study was a single-centre registry, divided into a retrospective and a prospective part, performed in compliance with the guidelines for good clinical practice and the Declaration of Helsinki. The study was approved by the institutional ethical review board. All data were collected, managed and analysed at the Heart Centre, University of Dresden (ethics votum University of Dresden: EK 28409202).primary endpoints of this study were the left ventricular end diastolic and end systolic diameter , the systolic left ventricular function (LVEF), the diastolic left ventricular function  and the systolic right ventricular function  in dependence of the RV apical pacing burden.The secondary clinical endpoints were the changes in maximal oxygen consumption (VO2max), maximal workload and ventilatory anaerobic threshold (VAT) in dependence of the RV apical pacing burden.The Eligible subjects were consecutive males or females > 18 years of age with an indication for permanent pacemaker therapy according to the European guidelines . The maiConsecutive patients who received a pacemaker from May 2010 to December 2011 and received all clinical routine follow-up visits in the study centre were included in the retrospective analysis.The study centre is the University Hospital Dresden Heart Centre. At the time of the study, approximately 250 pacemakers per year were implanted by the co-authors MG and SK. Of these 250 patients, approximately 50 patients per year were completely followed up as part of the routine clinical practice at the university outpatient clinic. From these patients, those who had normal baseline LVEF and no other cardiac cause of worsening cardiac function besides pacemaker therapy were selected consecutively for the registry.2max, peak exercise capacity, VAT).After the analysis of the 24-month follow-up data, the expansion to include the prospective part of the registry was done. Prospective inclusion in the registry was conducted from September 2014 to June 2015. The inclusion criteria were as follows: 1. Normal left ventricular ejection fraction > 55%, 2. Normal to mildly dilated left ventricular end diastolic diameter < 57 mm, 3. Normal right ventricular function TAPSE > 17 mm, 4. Exclusion of other cardiac causes of worsened LV function and spiroergometric parameters. If a patient fulfilled all inclusion criteria, primarily a retrospective evaluation of clinical routine echocardiographic parameters (LVEF and TAPSE) was conducted at the time of pacemaker implantation and after 24 months in 48 consecutive pacemaker patients. As there were no changes in this routine echocardiographic parameters in the retrospective analysis over 24 months, a prospective part was added to the registry in which the 6 and 12 month follow-up visits were expanded to include additional echocardiographic parameters  and spiroergometry  with a 2.5 MHz transducer was used. All acquired echocardiograms were reviewed by a core laboratory at the Heart Center Dresden. The LVEDD and LVESD was measured M-mode guided in the parasternal long-axis view. The LVEF was assessed using biplane Simpson’s rule with manual tracing of digital images . TAPSE wE′-ratio .2max), peak exercise capacity and ventilatory anaerobic threshold (VAT) at the time of enrollment, which was repeated at 6 and 12 months after pacemaker implantation.In all subjects a spiroergometry was performed to assess maximal oxygen consumption (VO2) and carbon dioxide production (VCO2) were quantified. Maximal oxygen consumption (VO2max) was defined as the highest VO2 obtained during the entire test and expressed in ml/min/kg [2 [After a 5-min rest period, the patients were subjected to an examination on a bicycle ergometer. During exercise a 12-lead ECG was recorded and the heart rate was continuously calculated based on R–R interval. The arterial blood pressure was measured at rest and at least once at a given resistance level. A ramp protocol was employed with continuously increasing resistance of 25 W every 2 min starting at 0 W. Subjects were exercised to fatigue or until one of the following termination criteria was met: chest pain or dizziness, potentially dangerous arrhythmias or ST-segment deviations, marked systolic hypotension or hypertension . During l/min/kg . The venin/kg [2 .p < 0.05. Categorical variables are presented as total number with comparison using chi-square statistics and Fisher exact test. If more than 2 groups were analyzed, a one-way ANOVA test was performed. Post hoc analyses were applied using Bonferroni method. Significance level was set to p < 0.05.Data were tested for normal distribution. Results of continuous variables are expressed as means ± standard error of the mean. Statistical analyses were done using the 2 tailed, unpaired Student’s t-test. Level of significance was set to Primary 48 patients were included in the retrospective analysis for the 24 month long time follow-up. In addition, 60 consecutive patients were included in the current prospective 12-month short time analysis for a more detailed echocardiographic and spiroergometric evaluation . Additionally, in the retrospective cohort notably more dual-chamber pacemakers were implanted in the lRVP patients. There were no relevant differences in gender, co-morbidities and concomitant medications in both groups.The patients were divided into two groups. The high RV pacing burden group (hRVP) was defined as subjects with a RV pacing ≥ 40% according to the definitions in previous randomized trials . In contThe RV pacing burden was registered at the following routine pacemaker checkups: 4 weeks after pacemaker implantation as well as 6, 12 and 24 months after implantation. No crossover patients from the hRVP to the lRVP group during the follow-up were identified. In the retrospective analysis the average RV pacing burden was 12.3% in the lRVP group versus 75.5% in the hRVP group. In the prospective part of the registry the RV pacing burden was 9.6% in the lRVP patients vs. 78.9% in the hRVP group.Further results are evaluated below separately for the retrospective and prospective parts of the registry.In the retrospective cohort 88.2% of patients in the hRVP group received a pacemaker due to an AV-block, 5.9% pacemakers were implanted because of a symptomatic sick sinus syndrome and 5.9% of patients suffered from syncope with bundle branch block. In contrast, only 9.7% of patients in the lRVP group suffered from an AV-block, 61.3% suffered from sick sinus syndrome and 29% from syncope with bundle branch block .The changes in the echocardiographic parameters over the course of 24 months depending on the RV pacing burden are shown in Fig. In the prospective cohort all patients suffered from AV-block in the hRVP group. In the lRVP group this was the case in 25.6% of patients whereas 74.4% had sick sinus syndrome Table .LVEDD:lRVP: baseline: 45.4 ± 0.64 mm, 6 months: 45.5 ± 0.58 mm, 12 months: 46.4 ± 0.51 mm, hRVP: baseline: 45.6 ± 1.4 mm, 6 months: 46.5 ± 1.1 mm, 12 months: 47.2 ± 1.0 mm; LVESD: lRVP: baseline: 32.2 ± 0.74 mm, 6 months: 32.6 ± 0.62 mm, 12 months: 32.8 ± 0.61 mm, hRVP: baseline: 31.7 ± 1.5 mm, 6 months: 32.6 ± 1.2 mm, 12 months: 32.4 ± 1.1 mm; LVEF:lRVP: baseline: 59.2 ± 1.0%, 6 months: 57.9 ± 0.93%, 12 months: 57.6 ± 0.77; hRVP: baseline: 59.7 ± 1.6%, 6 months: 58.5 ± 1.1%, 12 months: 58.8 ± 0.9%; TAPSE:lRVP: baseline: 23.7 ± 0.71 mm, 6 months: 23.5 ± 0.76 mm, 12 months: 23.4 ± 0.57 mm; hRVP: baseline: 26.0 ± 0.85 mm, 6 months: 24.2 ± 0.76 mm, 12 months: 23.3 ± 0.58 mm; E/A-ratio:lRVP: baseline: 1.01 ± 0.05, 6 months: 1.05 ± 0.05, 12 months: 0.98 ± 0.04, hRVP: baseline: 1.1 ± 0.07, 6 months: 1.1 ± 0.06, 12 months: 1.19 ± 0.08; E/E′-ratio:lRVP: baseline: 9.3 ± 0.5, 6 months: 8.6 ± 0.44, 12 months: 8.0 ± 0.31, hRVP: baseline: 10.2 ± 1.0, 6 months: 9.5 ± 0.77, 12 months: 8.8 ± 0.59).The changes in more detailed echocardiographic parameters over the course of one year depending on the RV pacing burden is shown in Fig. peak exercise capacity:lRVP: baseline: 105 ± 7 W, 6 months: 105 ± 6 W, 12 months: 114 ± 7 W, hRVP: baseline: 114 ± 12 W, 6 months: 118 ± 14 W, 12 months: 127 ± 15 W; VO2max:lRVP: baseline: 22.5 ± 0.8 ml/min/kg, 6 months: 22.8 ± 0.8 ml/min/kg, 12 months: 23.1 ± 0.9 ml/min/kg, hRVP: baseline: 21.4 ± 1.4 ml/min/kg, 6 months: 22.9 ± 1.9 ml/min/kg, 12 months: 24.4 ± 2.0 ml/min/kg; VAT:lRVP: baseline: 88.2 ± 6 W, 6 months: 85.8 ± 6 W, 12 months: 86.2 ± 6 W, hRVP: baseline: 82.0 ± 14 W, 6 months: 80.9 ± 14 W, 12 months: 85.0 ± 14 W).Figure The present pacemaker registry represents a detailed observational study regarding the influence of RV pacing on various echocardiographic and spiroergometric parameters in patients with preserved left ventricular function over a period of 12 and 24 months of pacemaker therapy. The main findings of this pacemaker registry were as follows: in the first retrospective part of the registry no relevant worsening of the LVEF and TAPSE could be observed within 24 months either in patients with a low RV pacing burden (< 40%) or in subjects with a high RV pacing burden with (> 40%). In the second prospective part of the current registry more detailed echocardiographic parameters including LVEDD, LVESD, LVEF, TAPSE, E/A-ratio and E/E′-ratio were measured 6 and 12 months after pacemaker implantation in order to reveal changes in the LV geometry and diastolic function in relation to RV pacing. Similarly, in the prospective study the comparison between subjects with low (> 40%) and high (< 40%) right ventricular pacing burden yielded no significant differences with regard to the echocardiographic parameters. These results were also reflected in the clinical short term outcome of the current registry, which was determined by spiroergometry. Accordingly, no relevant changes of peak exercise capacity, ventilatory anaerobic threshold and maximal oxygen consumption could be recorded independently of the RV pacing burden in the short term follow-up up to 12 months.Controversial data exist concerning the long-term effect of chronic RVA pacing on the systolic LV function of patients with preserved LVEF. On the one hand the results of the current registry are in line with different previous studies. A large cohort study of pacemaker recipients with predominantly normal LVEF was also unable to demonstrate a clinically relevant decrease in LVEF due to RV pacing even after 44 months of follow-up . MoreoveIt has been discussed that the location of the RV lead plays a role in the development of pacemaker induced cardiomyopathy. Some registries, nevertheless, have shown that non-apical RV pacing site does not offer any benefit in terms of incidence of pacemaker-induced cardiomyopathy over apical lead position . FurtherIn addition to all the above-mentioned contributing factors, baseline LVEF appears to be one of the most important predictors for the development of a pacemaker-induced cardiomyopathy in various previous studies , 23. ThiThe LVEF also appears to play a critical role in the clinical outcome of RV pacing. Thus in the DAVID trial patients with standard indications for ICD therapy and an LVEF of 40% or less, RV pacing increased the combined end point of death or hospitalization for heart failure . FurtherFurther, the incidence of atrial fibrillation as a sign of pacemaker-induced cardiomyopathy was significantly higher in patients with a high RV pacing burden compared to atrial-only pacing . In the There are several therapeutic approaches to reduce the incidence of the pacemaker-mediated cardiomyopathy. In this context, the BLOCK-HF study suggests that patients with LVEF < 50% and AV block may benefit from biventricular pacing compared to RV pacing in terms of heart failure .Similarly, in the long-term follow-up from the PACE study, HF hospitalizations were significantly increased among those receiving RV pacing compared to the CRT group . FurtherInspired by an excellent editorial written by Dr. Israel about his “top 10 excuses” with regard to unexpected results in prospective pacemaker studies, this study has several surmountable limitations as well . First, In summary, the current pacemaker registry regarding changes in echocardiographic and spiroergometric surrogate parameters of heart failure depending on RV pacing burden supports previous studies showing that pacemaker induced cardiomyopathy is a rare complication especially in patients with preserved LVEF in short term follow-up over 24 months. Despite this, screening for pacemaker induced cardiomyopathy should be performed particularly in the presence of new heart failure symptoms.


Cardiac magnetic resonance imaging (MRI) has been largely dependent on retrospective cine for data acquisition. Real-time imaging, although inferior in image quality to retrospective cine, is more informative about motion dynamics. We herein developed a real-time cardiac MRI approach to temporospatial characterization of left ventricle (LV) and right ventricle (RV) wall motion. This approach provided two temporospatial indices, temporal periodicity and spatial coherence, for quantitative assessment of ventricular function. In a cardiac MRI study, we prospectively investigated temporospatial characterization in reference to standard volumetric measurements with retrospective cine. The temporospatial indices were found to be effective for evaluating the difference of ventricular performance between the healthy volunteers and the heart failure (HF) patients . The HF patients and healthy volunteers were well differentiated in the scatter plots of spatial coherence and temporal periodicity while they were mixed in those of end-systolic volume (ESV) and ejection fraction (EF) from volumetric measurements. This study demonstrated the potential of real-time cardiac MRI for intricate analysis of ventricular function beyond retrospective cine. Due to imaging speed limitation, however, cardiac MRI has been largely dependent on retrospective cine for data acquisition. Retrospective cine can collect data from several cardiac cycles with breath-holding and sort them into a virtual cardiac cycle in reference to electrocardiogram (ECG) gating during post processing4. This technique provides a set of single-cycle multi-phase images for quantitative analysis with an assumption that the heartbeat variation be minor across different cardiac cycles. Owing to its reliable performance, retrospective cine has been used as a primary tool for cardiac MRI data acquisition. Volumetric measurements with retrospective cine have become a clinical standard for quantitative assessment of ventricular function in the practice of clinical cardiology1.Magnetic resonance imaging (MRI) is an essential tool for clinical diagnosis of cardiovascular diseases7, real-time MRI has been demonstrated to be feasible13. It has also been evidenced in cardiology that this technique can provide volumetric measurements comparable to those with retrospective cine14. Although real-time cardiac MRI gives worse image quality than retrospective cine due to the use of data undersampling for imaging acceleration, it offers several advantages including less logistical challenges associated with breath-holding and ECG gating15, more reliable images in arrhythmia patients16, and the ability to investigate cardio-respiratory coupling17. In addition, real-time images are more informative because they permit visualization of the temporal and spatial behaviors of cardiac motion over a series of sequential cardiac cycles. This multi-cycle temporospatial information, although potentially beneficial to ventricular function assessment, has not been investigated extensively in cardiac MRI studies.Recently with the development of parallel imaging and compressed sensing18 and correlation analysis19, two temporospatial indices, temporal periodicity and spatial coherence, were calculated to evaluate ventricular performance. For proof-of-concept, a cardiac MRI study was conducted with healthy volunteers and heart failure (HF) patients. Temporospatial characterization with real-time cardiac MRI was investigated prospectively in reference to conventional volumetric measurements with retrospective cine. This study was to demonstrate that temporal periodicity and spatial coherence would offer the ability to detect the difference of ventricular performance between the healthy volunteers and HF patients.The presented work was therefore to develop a real-time cardiac MRI approach to temporospatial characterization of ventricular wall motion for quantitative assessment of ventricular function. This approach sought to image a series of sequential cardiac cycles instead of a single cardiac cycle like in conventional retrospective cine for volumetric measurements. By characterizing time-series signals related to ventricular wall motion with Fourier transformA total of 12 healthy volunteers and 12 HF patients were recruited in the presented work. The healthy volunteers included 7 females and 5 males with ages ranged from 22 to 72 years (average age 56 years). The HF patients included 4 females and 8 males with ages ranged from 29 to 74 years (average age 51 years). These patients had reduced systolic function either in the left ventricle (LV) or in the right ventricle (RV). The MRI assessment results from cardiologists are provided by Table 12: Because heartbeats would be unstable during exercise, there was considerable inconsistency in retrospective data collected from different cardiac cycles. As a result, retrospective cine suffered more performance degradation during exercise than real-time imaging.The healthy volunteers were scanned both at rest and during exercise. The HF patients were scanned only at rest. Figure P > 0.2). A t-test was used to compare volumetric index measurements in different subject groups.Volumetric indices, including end-diastole volume (EDV), end-systole volume (ESV), stroke volume (SV), and ejection fraction (EF), were measured with retrospective cine and real-time images in the LV and RV. The volumetric measurements with retrospective cine images provided a clinical standard for quantitative assessment of cardiac function. This clinical standard served two purposes: First, a comparison between the volumetric measurements with real-time images and the clinical standard provided validation on whether real-time images offered sufficient quality for cardiac MRI quantification. Second, the clinical standard provided a reference for evaluating the ability of temporospatial characterization to quantitatively assess ventricular function in HF patients. In volumetric measurements, the normality of data distribution was confirmed with in each subject group an Anderson–Darling test  and a significant increase of EF . No significant differences were found between the resting- and exercising-state measurements of EDV  and SV . In comparison to the healthy volunteers, the HF patients presented a higher EDV , a higher ESV , and a lower EF . No significant differences were found in the SV measurements between the healthy volunteers and the HF patients .Figure P = 0.031 for LV and P = 0.012 for RV) while retrospective cine could not. This performance difference, as suggested in a previous study12, was because real-time imaging gave a smaller standard deviation in volumetric measurements than that given by retrospective cine, especially during exercise . Figure In every subject, a region of interest (ROI) was defined for the ventricle (LV or RV). Within each ROI (LV-ROI or RV-ROI), a reference wall-motion signal was generated for calculating temporal periodicity with Fourier transformP > 0.5). Figure P < 0.001) and lower in the resting-state HF patients .The normality of temporal periodicity measurements was confirmed in each subject group with an Anderson–Darling test , generating two correlation maps respectively for LV wall motion and RV wall motion. The spatial coherence was calculated from each correlation map for LV or RV wall motion. Figure P > 0.3). Figure P > 0.4). In contrast, the HF patients presented significantly lower spatial coherence .Correlation analysisFigure We recorded the post-processing time for measuring temporal periodicity and spatial coherence in real-time images. The most time-consuming procedure was image segmentation for ROI determination in the LV and RV. This manual procedure required 10–20 min for each subject depending on the quality of real-time images. After ROI determination, the time cost of automatic index computation was ~ 2 s on a computer with Intel (R) Core (TM) i7-6700 CPU 3.40 GHz and 32 GB memory. In comparison, volumetric measurements with retrospective cine required 5–10 min for image segmentation and ~ 0.5 s for automatic index computation on the same computer.The presented work proposed a real-time cardiac MRI approach to measuring temporal periodicity and spatial coherence of LV and RV wall motion in a series of sequential cardiac cycles. It was experimentally found that the temporospatial indices detected the difference of ventricular performance between the healthy volunteers and the HF patients. This demonstrated the potential of temporospatial characterization with real-time cardiac MRI for quantitative assessment of ventricular function.Intuitively, ventricular wall motion may be characterized by tracking ventricular wall anatomy spatially along the time with real-time images. Practically, the direct tracking is difficult because the ventricular walls give low SNR in the images. For this reason, temporospatial characterization seeks to identify the high-SNR blood pool regions, and define two ROIs (LV-ROI and RV-ROI) that give an estimate of the spatial range of ventricular wall motion in every cardiac cycle. The MRI signals within an ROI arise primarily from the ventricular walls. In addition, they can be affected by the surrounding tissues such as pericardium, lumen and blood that may move into the ROI with systolic contraction and diastolic relaxation. However, as these surrounding tissues always move together with the ventricular walls, the dynamic changes of MRI signals within the ROI are dependent primarily on ventricular wall motion. The ROI-based temporospatial characterization thus provides an indirect approach to analyzing ventricular wall motion with real-time cardiac MRI.24, allowing the ventricular wall motion to be synchronized at different spatial locations. Due to the synchronization, there should exist a common motion pattern along the ventricular walls. This common motion pattern can affect the dynamic changes of MRI signal at every spatial location and may be estimated from the spatial averaging of time-series signals. Accordingly, the reference wall-motion signal, which is calculated by spatially averaging the time-series signals within an ROI, gives an estimate of the common pattern of ventricular wall motion in LV or RV. This estimate can be used as a reference in correlation analysis for measuring how well ventricular wall motion is synchronized at different spatial locations, i.e., spatial coherence. As the measurements of temporal periodicity and spatial coherence are both based on the reference wall-motion signal arising from spatially averaged ventricular wall motion, they provide quantitative assessment of global ventricular function.Temporospatial characterization relies on the calculation of a reference wall-motion signal from spatial averaging in each ROI Fig. . The rat18. If a time-series signal is periodic, its Fourier transform has a non-zero magnitude only at the frequency corresponding to its temporal period. In this ideal case, the temporal periodicity  with EF and ESV, moderately (0.5 > R > 0.3) with EDV, and weakly (R < 0.3) with SV  MRI; measurement of left atrial functional performance parameters; assessment of LV diastolic function; and assessment of the RV function in various disease states . They may also have the potential to allow effective assessment of therapeutic response in patients with cardiomyopathy.In conclusion, real-time cardiac MRI enables an approach to characterizing temporospatial behaviors of ventricular wall motion with two quantitative indices, temporal periodicity and spatial coherence, which may provide quantitative assessment of the LV and RV function beyond conventional volumetric measurements with retrospective cine.A cardiac MRI study with healthy volunteers and HF patients was conducted under the approval of the Institutional Review Board . The study followed the principles of the Declaration of Helsinki and the regulations of the St. Francis Hospital human ethic committee. Informed consent and medical history questionnaires were obtained from all the subjects. The study exclusions included metallic hazards, pacemaker/defibrillator device, claustrophobia and conditions not appropriate for exercise. In addition, the subjects with a resting heart rate greater than 90 bpm or a systolic blood pressure greater than 180 mmHg were excluded.A healthy volunteer was recruited if there was no history of cardiovascular disease and no major risk factor. In addition, the 12-lead ECG and echocardiography examination were normal. A HF patient was recruited if there was a history of hospitalized heart failure. The healthy volunteers were scanned at rest and during exercise. The HF patients were scanned at rest only. All the scans were run with a balanced steady state free precession sequence and a 12-channel coil array on a 1.5 T clinical scanner . In the exercising-state scans, an MRI-compatible exercise supine bicycle  was mounted on the scanner table. The imaging data were acquired while a volunteer was exercising inside the scanner. During exercise, the volunteer's heart rate and rhythm, and oxygen saturation were monitored continuously. The blood pressure was measured every 3 min. The intensity of exercise was adjusted by the bike resistance, which was increased by 25 Watts every 3 min until the heart rate was consistently in the range of 100–110 bpm.ECG-gated retrospective cine: FOV 340 × (220–250) mm, voxel 1.5–1.9 mm, segments 5–8, iPAT factor 2, ECG-synchronized phases 30, TR/TE 2.6/1.3 ms, FA 50°–75°, slice thickness 8 mm, slice gap 2 mm, bandwidth 1420 Hz.Real-time imaging with radial sampling: FOV 230–250 mm, voxel 1.5–1.9 mm, TR/TE 2.2–3.0/1.1–1.5 ms, FA 50°–75°, slice thickness 8 mm, slice gap 2 mm, bandwidth 1510 Hz, time frames 384, a total of 3072 radial views.Retrospective cine and real-time imaging data were both collected. The ventricular anatomy was covered by 10 short-axis slices. The retrospective cine scan was run with breath-holding and ECG gating. The real-time imaging scan was run using radial sampling during free-breathing and without ECG gating. In addition, the following acquisition parameters were used:13. Each series of the real-time images included 7–16 cardiac cycles with a temporal resolution of 18–30 ms in a time window of ~ 7 s. There were 33–48 phases in every cardiac cycle at rest and 24–32 phases during exercise.Retrospective cine images were reconstructed online with the system software provided by the MRI manufacturer. Each series of the retrospective images included 30 phases in a single cardiac cycle, providing a temporal resolution of 30–40 ms. Real-time images were reconstructed from the raw data offline in MATLAB . The reconstruction was performed with a lab-developed algorithm based on the real-time imaging works previously published by several different research groups31 that sought to delineate the LV and RV borders based on both image contrast between the blood pool and the myocardium and prior information about ventricular geometry and structures. The segmented end-diastole and end-systole images for all the short-axis slices were used to measure LV and RV volumes as in previous studies34. The measurements were manually reviewed and corrected if necessary. In temporospatial characterization with real-time cardiac MRI, the end-diastole and end-systole images were manually selected and segmented for ROI definition  represents the Fourier transform at an arbitrary frequency fn with n = 0, 1, 2, …, and S(fc) represents the Fourier transform at the cardiac frequency fc. In this equation, the numerator gives the root sum square of the cardiac frequency components and the denominator is the root sum square of all the frequency components. It should be noted that, as real-time images are complex, the frequency spectrum of the reference wall-motion signal is not conjugate symmetric and the calculation must take into account the spectral components at both positive and negative frequencies. Equation  is the Pearson correlation coefficient between the LV or RV reference wall-motion signal and the time-series signal at a spatial location , VA represents the ventricular anatomy defined by LV and RV segmentation at the end of diastole, and M gives the total number of voxels within the ventricular anatomy. Equation (A Pearson correlation coefficientt-test35_ENREF_33_ENREF_33: First, the t-test was run to compare the exercising- and the resting-state measurements of each index in the healthy volunteers. This was to investigate whether an index would be effective for detecting the exercise-induced increase of ventricular performance. Second, the t-test was run to compare the resting-state measurements of each index in the HF patients and those in the healthy volunteers. This was to investigate whether an index would be effective for detecting the disease-related decrease of ventricular performance. In addition, we evaluated the correlation between temporospatial indices and volumetric indices with a Pearson correlation coefficient19.Volumetric and temporospatial indices were investigated statistically with a one-tailed 36 was used to assess data normality before the t-test. The statistical results were presented with box plots that provide the median, 25th and 75th percentiles of the index measurements. The data summary was shown as mean ± standard deviation. The values of P < 0.05 were considered to be statistically significant. All the statistics were carried out in MATLAB.In the statistical investigation, an Anderson–Darling test


Nowadays, severe symptomatic tricuspid regurgitation (TR) affects millions of persons worldwide. However, the benefit of surgical correction of isolated secondary TR remains controversial because of the increased risk of periprocedural mortality and morbidity. In recent years, novel transcatheter tricuspid valve interventions (TTVI) were developed to treat TR, so that TTVI is currently considered in symptomatic, inoperable, anatomically eligible patients. TTVI can be divided into these five domains: edge-to-edge leaflet repair, tricuspid annuloplasty, caval implants, spacer, and total valve replacement. Each transcatheter intervention needs specific imaging protocols for assessing the anatomical feasibility and consequentially predicting the procedural success. This review summarizes the available multimodality imaging tools for screening patients with TR, and identifies anatomical characteristics to choose the best option for the patient. Interest in the tricuspid valve (TV) has increased over the past two decades, because of the recognition of the progressive nature and clinical impact of secondary tricuspid regurgitation (TR) on outcomes , 2. FurtIn recent years, novel transcatheter tricuspid valve interventions (TTVI) were developed for treating TR, so that the current european society of cardiology (ESC) and the european association for cardio-thoracic surgery (EACTS) guidelines for the management of valvular heart disease consider TTVI in symptomatic and inoperable patients who met anatomical criteria for eligibility . NumerouThis article reviews the TV anatomy and the available imaging tools for a comprehensive assessment of the valve. Finally, it identifies favorable and unfavorable anatomical conditions that can guide the operator to choose the best option for the patient.2 and the most apically located valve. Its functional anatomy consists of four elements named annulus, leaflets, papillary muscles, and chords  reconstruction of the tricuspid annulus showed a non-planar saddle-shaped pattern with two high points, corresponding to the AS and post-erolateral segments, and two low points corresponding to the anterolateral and PS segments . The annIn patients with functional TR, the tricuspid annulus is flatter, which reduces the saddle shape. Compared with normal subjects, patients with functional TR have a more circular annulus, and greater enlargement in the AP than in the mediolateral distance, because the greater dilation occurs along the free-wall side of the annulus. In presence of TR, the percent reduction of the tricuspid annulus size during the systole is also significantly decreased. Therefore, the minimum systolic annular dimension is almost twice larger than in normal subjects .Characterization of the anatomy of the RV and TV is the first step in the evaluation of patients with functional TR, candidates for TTVI. While historically the anatomical knowledge of TV was derived from cadaveric specimens or open, today non-invasive imaging techniques represent helpful instruments to understand the anatomy of cardiac structures. Currently, echocardiography, CT, and cardiac magnetic resonance (CMR) are available instruments to study the TV anatomy, guide in the decision-making process, and support the development of novel transcatheter therapies. In addition, the current ESC/EACTS guidelines for the management of valvular heart disease recommend transesophageal echocardiography (TEE) and cardiac CT for detailed anatomical evaluation owing to higher spatial resolution .Echocardiography is undoubtedly the first step in assessing the etiology and severity of TR and the size and function of the RVs. Moreover, this is the only imaging technique available for intraprocedural TTVI guiding. But the anterior location can pose challenges for the transesophageal approach. CMR is the gold standard for assessing right ventricular size and function and can help in quantifying TR when echocardiographic doubt exists. However, the reduced availability and contraindications limit the routine application of CMR in this setting of patients. On the other hand, CT provides complete morphologic imaging of the heart structures, thanks to a high spatial resolution with excellent capacity to define the endocardial border. However, disadvantages are the need for radiation and iodinated contrast injection.Transthoracic echocardiography (TTE) is the first-line approach for studying the anatomy and function of TV and right-side chambers . Due to Transesophageal echocardiography is the second-line imaging modality for the assessment of TV anatomy in patients with TR, even if the anterior position of the valve can limit the examination. Nevertheless, TEE allows obtaining imaging from several depths  and multiplane angles. The four-chamber view (0–0°) and the alternative four-chamber view (160–180°) permit the visualization of the septal and typically the anterior leaflet; the posterior leaflet can also be visualized by changing probe angulation. Simultaneous biplane imaging may clarify which leaflet is imaged because the anterior leaflet is usually adjacent to the aorta, whereas the coronary sinus is the marker for the posterior leaflet. Other useful information for a comprehensive TV assessment may be achieved by a mid/deep esophageal RV inflow/outflow view in multiplane (60–100°), which crosses the coaptation between the septal and the posterior leaflet  and the septal and anterior leaflet (near the aorta)  Figure .Then, advancing the TEE probe into the stomach results in transgastric views, which enables to obtain optimal view settings to :Identify all tricuspid leaflets and commissures. The transgastric short-axis view is the only 2D view that can simultaneously visualize all three TV leaflets;Visualize zones of coaptation and all coaptation gaps;Analyze the distribution of the TV regurgitation;Align the view parallel to the annulus of the TV and focus on the leaflets tips at closure, using the biplane modality.Three-dimensional echocardiography has greatly improved the accuracy of TV visualization and identification of all anatomical components, eliminating the need for mental reconstruction starting from multiple 2D planes . However2 as the most sensitive cutoff value for severe TR   (r = 0.97)  >0.75 cmy 82.1%) , whereasity 84%) . This vaity 84%) –20. More = 0.97) .2 RA and ventricular dimensionsanatomic relationships with surrounding structuresthe device landing zoneprediction of optimal fluoroscopic projections for device implantationvascular access route.A short-axis plane can be reconstructed on the annular level using multiplanar reconstruction starting from RV two- and four-chamber views. Cross-sectional area, perimeter, septolateral, and AP diameters can be obtained with excellent intra- and interobserver reproducibility . The croOnce the annulus has been manually or automated traced, commissures can be located, taking into account their unique anatomical findings. The fan-shaped chords can help in commissural identifications. Precisely, the AS commissure is placed anteriorly, just below the first right coronary tract and the anterior aortic valve cusp. At this site, it is possible to observe a short fan-shaped chorda, arising directly from the septal band of the crista supraventricularis or from a small papillary muscle on that band . The PS In the two- and four-chamber views, it is possible to obtain additional planes parallel to the TV for optimizing the visualization of the tricuspid leaflets. The grade of leaflet tethering, including tenting height, angle, and area can be obtained with a good to excellent intra- and interobserver variability . The degAdditionally, helpful information obtained by CT analysis is the AROA measurement, which may be used as a potential flow-independent anatomic parameter of TR severity, supplementing and enriching the traditional echocardiographic parameters , 36. ForMeasurements of the right chambers obtained with CT imaging may also be valuable in assessing the anatomic feasibility of a transcatheter therapy and planning the procedure.In a complete transfemoral approach, the RA must allocate the delivery catheter and have adequate space to permit safely catheter's movements. In case of transcatheter TV replacement, RV volume, as well as the distance between the annular plane and the RV apex and location of the papillary muscles are of interest with regard to the protrusion of the prosthesis into the RV. For quantification of RV volumes and function, semiautomated software can be used.Furthermore, assessment of the RCA course and its distance to the annulus, simulation of virtual device implantation, and prediction of an optimal projection angle are part of a comprehensive CT-based pre-procedural assessment  34)..34).Finally, the measurements of the inferior vena cava (IVC) along the vessels and at the transition level with the RA, as well as the anatomical relationship of the IVC and the annulus must be examined to plan the procedure. In the case of heterotopic caval valve implantation, additional measurements are obtained in regards to the first hepatic vein. Dedicated semiautomated software can be helpful in IVC analysis.Cardiac magnetic resonance is particularly well-suited for assessing cardiac morphology and function. It offers an excellent spatial resolution with the advantage of not using ionizing radiation and iodinate contrast agents. On the other hand, limitations in obtaining high-quality imaging and clear interpretation of reconstructions can occur in the presence of cardiac arrhythmias and intracardiac leads, which create significant artifacts.The RV size and function can be fully assessed using dedicated RV views from multiple planes. Moreover, CMR allows an accurate estimation of TR grade, in terms of regurgitant volume and regurgitant fraction, using direct (by right and left ventricular stroke volume) and indirect methods (by phase-contrast imaging). However, CMR quantification of TR severity is less established than for other regurgitant valves, and there are no specific cutoff values for severe TR , 37. AlsFurther studies are needed to evaluate the utility of CMR parameters, in defining the timing and predicting the response to TTVI.The TTVI can be divided into these five domains: edge-to-edge repair, tricuspid annuloplasty, caval implants, spacer, and total valve replacement . HoweverThe choice of the most suitable transcatheter therapeutic option in a single patient remains challenging , 39. ThiConsequently, a multimodality cardiac imaging focusing on the anatomy and function of TV apparatus, right-side chambers, and adjacent structures is mandatory for diagnosis and prognosis and the planning of transcatheter therapy.Indeed, specific imaging techniques for each transcatheter procedure are required to assess anatomic feasibility and select the correct procedure for an individual patient .Edge-to-edge repair devices act on tricuspid leaflets with the aim to improve the coaptation in the regurgitant valve. Currently available devices include the Triclip system , which grasps and coaptates leaflets , and theDuring the pre-procedural examination for edge-to-edge repair, a complete assessment of the TV anatomy is mandatory, including where the largest coaptation gap is located and which leaflets are more tethered. The echocardiographic 3D en-face view of the TV, the transgastric short axis, and the mid/deep esophageal RV inflow/outflow with simultaneous biplane view permit accurate assessment of the leaflets and commissures, as well as the largest coaptation gap. Preoperative CT imaging is not routinely performed for screening patients with TR who are candidates for edge-to-edge valve repair .Data from published experiences demonstrate that the best results occur by attaching the anterior and/or posterior leaflet to the septal leaflet, which can also reduce annular dimensions without distorting the valve . This zoThe favorable and unfavorable anatomical conditions for the edge-to-edge repair are listed in Annuloplasty devices aim to reduce the annular size in functional TR using a transfemoral ring- or suture-based approach. Precisely, the Cardioband (Edwards Lifesciences) consists of a flexible ring with multiple anchors attached to the annulus . The TriDetailed measurements of the tricuspid annulus are obtained by CT images. But the major concern related to annuloplasty devices is the risk of RCA injury as it runs closely and parallel to the tricuspid annulus. Therefore, it is imperative to routinely assess the course of the RCA and the distance between the vessel and the annulus by CT reconstruction. In addition, valve tethering should be assessed with both CT and echocardiography.The favorable and unfavorable anatomical conditions for the annuloplasty are listed in Heterotopic implantation of valves in the caval veins aims to reduce blood backflow and prevent systemic venous congestion. The technique counts balloon-expandable transcatheter aortic valve prostheses  implanted in the inferior (and superior) caval veins ; the TriThe most important parameters to consider in cardiac imaging for heterotopic implants include:Systolic backflow reversal in the inferior caval vein on echocardiography.Accurate measurement of the diameters of caval veins using CT. The IVC is measured at the level of the cavoatrial junction and at the level of the first hepatic vein. In addition, the distance between the cavoatrial junction and the most superior hepatic vein is measured to avoid obstruction of this vein during valve implantation. The superior vena cava is measured at the cavoatrial junction. In case of large RA, the cavoatrial junction may have a funnel shape, increasing the valve migration risk.Measurement of the RA is required for the Tricento device.Assess whether RV function is preserved because RA pressure increases and increased RV and atrial volume overload persist after the procedure, leading to further adverse remodeling and RV failure and preventing symptomatic benefit.The favorable and unfavorable anatomical conditions for the caval implant are listed in The Forma spacer device (Edwards Lifesciences) aims to minimize the leaflet coaptation gap caused by tricuspid annular dilatation and leaflet tethering, through a foam-filled polymer balloon (spacer) deployed at the level of the TV and an anchoring system placed in the RV septal free wall groove , 52.The pre-procedural imaging checklist includes:Measurement of the largest vena contracta or coaptation gap by echocardiographyMeasurement of the TV annulus, preferably from CTMeasurement of RV dimensions and distance between the annulus plane and RV septal free wall groove, using CT or CMRCT imaging of the proposed anchor site for possible obstruction to the passage of the rail and anchor systemDimensions of the left subclavian and axillary veins, which will be used to introduce the system. The CT is recommended to assess these measurements.The favorable and unfavorable anatomical conditions for the space technique are listed in Transcatheter TV replacement is a promising therapeutic tool that is still in its infancy. However, the procedure presents significant technical challenges due to the anatomical peculiarities of the TV annulus, which is enlarged, dynamic during the cardiac cycle, and without calcifications in the landing zone for the prosthesis. This can result in incomplete apposition of the prosthesis in the native annulus with consequent possible significant paravalvular regurgitation. Moreover, the anatomical relationship with surrounding cardiac structures  poses the risk of potential procedural complications. The NAVIGATE  is a self-expanding bioprosthesis for orthotopic replacement implanted through a transjugular or transatrial 42-Fr approach and consists of three xenogeneic pericardial leaflets, seated in a tapered nitinol stent with atrial winglets and ventricular graspers to anchor the tricuspid annulus and leaflets without protruding into the adjacent chambers. However, the short series published so far have shown the feasibility and safety of this procedure , 54. RecSpecific CT measurement protocols are needed for pre-procedural planning, including a comprehensive assessment of valvular and subvalvular anatomy, prosthesis sizing, vascular access route, and prediction of fluoroscopic angles. This study can be additionally supported by virtual prosthesis placement to predict implantation depth, prosthesis selection, and anchoring possibilities.Specifically, the pre-procedural imaging checklist should include :dimensions and morphology of the TV annulusRA and ventricular dimensionsdistance between the RV apex and the annular plane and location of the moderator band and prominent trabeculae with regard to the protrusion of the prosthesis into the RV during implantationanatomic relationships with surrounding structuresanalysis of vascular access route and relationship between caval veins and TV plane.On the other hand, in case of transcatheter TV-in-valve and valve-in-ring procedures, the measurements should be routinely assessed by a dedicated CT analysis rather than the nominal size documented in the surgical report.The favorable and unfavorable anatomical conditions for the orthotopic valve replacement are listed in With the ongoing rise in transcatheter TV interventions, procedural success extremely depends on precise and comprehensive pre- and periprocedural imaging. Multimodality imaging, including 2D and 3D echocardiography, as well as CT, is crucial in the complete anatomic evaluation of the right heart and TV, which are the target for current TTVI. On the other hand, the rapid growth and promising success of these procedures have been accompanied by advances in imaging techniques that have helped to accurately visualize the TV and its anatomic relationships, allowing appropriate selection of patients for the various techniques of transcatheter tricuspid repair.VC contributed with design and drafting of the manuscript. MC, MB, and SM contributed with revision of the content. GU contributed with conception, revision, and final approvement of the manuscript. FG contributed with conception of the paper. All authors agree to be accountable for the content of the work.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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Left ventricular (LV) global function index (LVGFI) has been introduced as a volume-based composite metric for evaluation of ventricular function. The definition formula combines stroke volume (SV), end-systolic volume (ESV), end-diastolic volume (EDV) and LV mass/density. Being a dimensionless ratio, this new metric has serious limitations which require evaluation at a mathematical and clinical level. Using CMRI in 96 patients we studied LV volumes, various derived metrics and global longitudinal strain (GLS) in order to further characterize LVGFI in three diagnostic groups: acute myocarditis, takotsubo cardiomyopathy and acute myocardial infarction. We also considered the LVGFI companion (C), derived from the quadratic mean. Additional metrics such as ejection fraction (EF), myocardial contraction fraction (MCF) and ventriculo-arterial coupling (VAC), along with their companions (MCFC and VACC) were calculated. All companion metrics  showed sex-specific differences, not clearly reflected by the corresponding ratio-based metrics. LVGFI is mathematically coupled to both EF (with R = 0.86) and VAC (R = 0.87), which observation clarifies why these metrics not only share similar prognostic values but also identical shortcomings. We found that the newly introduced LVGFIC has incremental value compared to the single use of LVGFI, EF, or GLS, when characterizing the three patient groups. The left ventricular (LV) global function index (GFI) has been introduced by Mewton et al. as a novel metric that integrates LV structure with global function, and was shown to be a powerful predictor of incident heart failure and hard cardiovascular events . It is swhere LVmass is normalized to myocardial density (q), so that the term (LVmass/q) carries the dimension of volume. As a result, the expression for LVGFI refers to a metric without any physical dimension. The ratio is not unique, as several LV volume combinations yield the same outcome, e.g., the pair with ESV = 50 and EDV = 100, as well as the combination ESV = 80 and EDV = 140 mL, lead to an LVGFI value of 28.6 % when LVmass/q is kept at 100. This fact implies that LVGFI, in order to be meaningful, requires consideration of a companion (C), denoted as LVGFIC . In thisA further problem with LVGFI resides in the fact that within the denominator the contribution by LVmass/q cannot be distinguished from the (ESV+EDV)/2 component, i.e., if LVmass/q increases, then a balanced decrease of (ESV+EDV)/2, realized while keeping SV unaltered, makes that the denominator and therefore LVGFI remain unchanged. For example:State 1: LVmass/q = 100, ESV = 50, EDV = 100, (ESV+EDV)/2 = 75, denominator = 175 mLState 2: LVmass/q = 110, ESV = 40, EDV = 90, (ESV+EDV)/2 = 65, denominator = 175 mL,while, of course, the two states are cardiomechanically different .The limitation as mentioned for the sum of LVmass/q and (ESV+EDV)/2, does not apply to the constant value of the sum of ESV and EDV, as any change of ESV and EDV (while keeping their sum constant) would be visible in the numerator SV. Some of these difficulties are eliminated in the myocardial contraction fraction (MCF) definition , where tAn attractive feature of C is the fact that it carries a physical dimension, namely volume. It is now evident that the newly introduced C metric plays a central role in the evaluation of LV function. This study explores the impact of LVGFIC in three diagnostic groups of patients with acute cardiac problems. Additionally, we will analyze the mathematical aspects of the definition formula, as various terms included are not independent, e.g., SV = EDV–ESV, while the term (ESV+EDV) correlates with the traditional metric ejection fraction (EF).This study included 96 patients consecutively admitted to the hospital because of suspected ST-segment elevation with myocardial infarction (STEMI). All patients presented with prolonged oppressive chest pain at rest (>30 min) with an ST-elevation >0.2 mV in two or more contiguous precordial leads and/or >0.1 mV in other leads, and elevated serum troponin level. All patients underwent invasive coronary angiography (ICA) performed using radial artery puncture. In patients with normal coronary arteries, CMRI was performed 72–96 h following the ICA, after ruling out acute kidney injury due to the use of iodinated contrast. Patients with previous myocardial infarction, other known heart disease or contraindications for CMRI were excluded from the study. The local Ethics Committee of Reñaca Clinic approved this study, and written consent was obtained from all patients.The CMRI studies were performed on a SIGNA Excite 1.5-Tesla resonator  with a multi-element phased-array coil. All patients were placed in a supine position, and images were acquired at an end-expiratory breath hold with ECG gating. Initial scout images were acquired to locate the heart. Studies involved two-dimensional fast imaging using steady-state acquisition sequences for cine-CMRI, which were used to assess segmental and global contraction of the heart according to the American Heart Association classification . To deteThe cine-CMRI, T2-STIR, and LGE sequences were obtained in the short-axis view covering the LV from the base to apex in the two-, three- and four-chamber views. The slice thickness was 8 mm with no slice gap, and the in-plane resolution was typically 1.5 mm × 1.5 mm. The temporal resolution of the cine-CMRI sequences was 20–30 frames per cardiac cycle.Patients with subendocardial and transmural LGE were diagnosed with acute myocardial infarction (AMI). Patients who had subepicardial and/or intramyocardial DCE were diagnosed with myocarditis. Finally, Takotsubo cardiomyopathy (TCM) was diagnosed in patients exhibiting high T2-STIR sequences  with absence of LGE in the late post-gadolinium sequences. CMRI studies were evaluated by two experts in this diagnostic technique. In case of disagreement, the differences were resolved by reaching consensus with a third expert observer.A fully automated volumetric analysis of LV volumes, mass and function was performed using a novel deep learning-based algorithm within a dedicated commercially available software package . Global myocardial LV strain (GLS) was measured from integrated long and short-axis and axis cine images, using feature tracking. All strain parameters were quantified offline by an experienced observer blinded to all patient data. LV endocardial and epicardial borders in short and long axis views were automatically determined. The right ventricular (RV) insertion points and mitral annular plane were specified. An automated tracking algorithm was applied and tracking of LV segments, as well as the mitral annular plane, was confirmed. Manual adjustments were performed as needed to optimize LV wall tracking. Basal, mid-ventricular, and apical short-axis images, as well as LV long-axis images were analyzed for global circumferential, radial and longitudinal strain measurements.P < 0.05 is considered statistically significant.Data are presented as mean value, along with the corresponding standard deviation, and analyzed using IBM SPSS version 22 . Comparison of means is based on t-statistics. The Fisher z-transform or the William's test is used to compare R-differences between groups, as appropriate. A one-sided In the definition formula LVGFI = SV / [LVmass/q + (ESV+EDV)/2] (see equation 1) we discern three components (apart from q): SV, LVmass and average LV volume. Note that the term (LVM/q) with q as myocardial density, has the physical dimension of volume, as q is expressed as 1.05 mL/g. As emphasized before, LVGFI is not unique and requires consideration of its companion metric, defined as the quadratic mean:More in general, the companion of any data pair x and y is calculated as the quadratic mean of x and y, where in our case for convenience the constant √(1/2) = 0.7071 has been omitted. This procedure yields the size of the hypotenuse for the perpendicular line segments x and y, as given by the familiar Pythagorean theorem . ObviousN = 96), indicating that each component offers information that is to a large extent not generated by the other.In this study we will apply the companion concept not only to LVGFI, but also to EF, ventriculo-arterial coupling (VAC) and MCF. Essentially, the LVGFI refers to the ratio of SV and average overall LV size . On a beat-to-beat basis LVmass may be assumed to be fairly constant for a particular heart, implying that LVmass is a minor modulating factor in the denominator.N = 96).In our data set R = 0.55 for (ESV+EDV)/2 (range 49 to 196 mL) vs. LVmass (range 62 to 203 g), indicating that the two components in the denominator (equation 1) are far from entirely independent in this patient population (P = 0.021) and EDV (P = 0.005) in 42 patients with heart failure with reduced EF and type 2 diabetes or prediabetes, compared with a matched placebo group (N = 50), while LVmass, EF, GLS, and LVGFI did not change significantly  in women, but women also constitute the majority (91%) in the takotsubo group.The mathematical characteristics of LVGFI are theoretically analyzed for the population averaged SV and (ESV+EDV) values in dependence of variation of LVmass for the entire range encountered in this study, i.e., from 62 to 203 grams. Results are shown in We have dissected the definition formula of LVGFI by separately considering its components. First inspection reveals that the definition includes redundant elements, as SV is the difference between EDV and ESV, which pair returns again as their sum (ESV+EDV)/2. Part of this duplication is then mixed by considering their ratio, which construct introduces another problem, namely the complete removal of physical dimensions. The route followed here would be equivalent to dividing pulse pressure by mean pressure in case of hemodynamics, where the latter variable in fact is known to correspond with the companion to pulse pressure itself . Thus, aP = 0.38), although being a predictor of major adverse cardiac events (MACE). However, also in a group of STEMI patients treated with primary percutaneous coronary intervention Eitel et al. (Considering the fact that the (ESV+EDV) term in LVGFI is associated with EF , it is cl et al.  found thObviously, a single component may dominate the ratio depending on the type of patients studied, e.g., LVmass was higher in HF patients compared to those with no events in the study by Nwabuo et al. . Likely P < 0.0001 in our P = 0.0005 in our 2 + ((ESV+EDV)/2)2], as e.g., D = 200 may result from LVmass/q is 100 and (ESV+EDV)/2 is 100, or the combination 80 and 120, etc. For those combinations the DC would be 141.4 and 128.1 mL, respectively.Sex-specific differences also deserve attention. In equation 1 the smaller SV generally found in women  in order to derive RV effective GFI (eGFI) . This exSpecific applications have been reported, e.g., Huang et al.  found thMCF = SV.q/LVmass, introduced by King et al. , is alsoMost studies on EF report on population-based volumetric data, while only a few publications present the dynamic behavior of volume regulation for a single heart. However, sequential data collection in individuals is common practice following heart transplantation, and a recent case report documents the superiority of ESV above ratios (such as EF or VAC) when evaluating the long term course of these patients . Interescombination of EF and EFC, or being superior to the combination of ESV and EDV. In case LVmass is selected as a precious addition, it may in the future be relevant to consider ESV, EDV and LVmass in a 3-dimensional framework.The bottom line is that the creation of any novel ventricular function index that includes more than what is embodied by EF itself , will one way or the other demonstrate (some) incremental value, just because EF is by definition incomplete see . The chaThe raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the local Ethics Committee of Reñaca Clinic. The patients/participants provided their written informed consent to participate in this study.RD-N and PK contributed to conception and design of the study and organized the database. PK performed the statistical analysis and wrote the first draft of the manuscript. RD-N wrote sections of the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.