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Prevalence and prognostic value of diastolic and systolic dyssynchrony in patients with coronary artery disease (CAD) + heart failure (HF) or CAD alone are not well understood. We included patients with gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) between 2003 and 2009. Patients had at least one major epicardial obstruction ≥ 50%. We assessed the association between dyssynchrony and outcomes, including all-cause and cardiovascular death. Of the 1294 patients, HF was present in 25%. Median follow-up was 6.7 years (IQR 4.9-9.3) years with 537 recorded deaths. Patients with CAD + HF had a higher incidence of dyssynchrony than patients with CAD alone (diastolic BW 28.8% for the HF + CAD vs 14.7% for the CAD alone). Patients with CAD + HF had a lower survival than CAD alone at 10 years (33%; 95% CI 27-40 vs 59; 95% CI 55-62, P

Cardiac resynchronization therapy (CRT) is an important and effective therapy for end-stage heart failure. Non-response to CRT is one of the main obstacles to its application in clinical practice. There is no uniform consensus or definition of CRT “response.” Clinical symptoms, ventricular remodeling indices, and cardiovascular events have been reported to be associated with non-responders. To prevent non-response to CRT, three aspects should be thoroughly considered: preoperative patient selection, electrode implantation, and postoperative management. Preoperative selection of appropriate patients for CRT treatment is an important step in preventing non-response. Currently, the CRT inclusion criteria are mainly based on the morphology of QRS waves in deciding ventricular dyssynchrony. Echocardiography and cardiac magnetic resonance are being explored to predict nonresponse to CRT. The location of left ventricular electrode implantation is a current hot spot of research; it is important to identify the location of the latest exciting ventricular segment and avoid scars. Cardiac magnetic resonance and ultrasonic spot tracking are being progressively developed in this field. Some new techniques such as His Bundle pacing, endocardial electrodes, and novel sensors are also being investigated. Postoperative management of patients is another essential step towards preventing non-response; it mainly focuses on the treatment of the disease itself and CRT program control optimization. CRT treatment is just one part of the overall treatment of heart failure, and multidisciplinary efforts are needed to improve the overall outcome.

The goal of this study was to examine whether diastolic dyssynchrony, measured by using gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) in patients with coronary artery disease (CAD), is independently associated with adverse outcomes.Systolic left ventricular dyssynchrony is known to be associated with worse clinical outcome in patients with CAD.This study included patients who presented to Duke University for GSPECT MPI between 2003 and 2009. Patients had at least 1 major epicardial obstruction ≥50%. Dyssynchrony was assessed by using Emory Cardiac Toolbox software and compared with a control population without CAD. Abnormal degree of diastolic/systolic dyssynchrony was defined as values above 2 SDs above mean of mechanical dyssynchrony parameters. Using Cox proportional hazards modeling, the adjusted association between dyssynchrony and outcomes, including all-cause and cardiovascular death, was assessed.Among 1,310 patients with a median age of 64 years (interquartile range: 55 to 72 years), 69.7% were male and 2.6% had left bundle branch block. Overall, 241 (18.4%) and 238 (18.2%) patients had significant systolic and diastolic mechanical dyssynchrony, respectively, and 211 (16.1%) had both. After a median follow-up of 7.1 years, 543 deaths occurred. At 5 years, the mortality estimate was 21.2% among patients with a normal degree of diastolic left ventricular mechanical dyssynchrony (LVMD) and 41.7% among those with an abnormal degree of LVMD (p 0.001). When added to clinical comorbidities, electrical dyssynchrony, and systolic LVMD, diastolic dyssynchrony was incrementally associated with cardiovascular mortality (global chi-square statistic of 211.9 vs. 222.8; 2 degrees of freedom; p = 0.004). In a model that also includes left ventricular ejection fraction, the addition of diastolic dyssynchrony to systolic dyssynchrony maintained an incremental prognostic benefit (global chi-square statistic of 234.8 vs. 241.8; p = 0.030). Adjustment for baseline ischemia and scar burden did not change this relationship.Systolic and diastolic left ventricular dyssynchrony, as measured by using GSPECT MPI, were associated with adverse outcomes. Moreover, diastolic dyssynchrony appears to provide incremental predictive value to clinical history, electrical dyssynchrony, and left ventricular function.

Cardiac resynchronization therapy (CRT) has been established as a standard therapy for patients with heart failure (HF) and ventricular dyssynchrony. Previous prospective randomized studies have demonstrated that CRT not only improves quality of life and increases exercise capacity, but also reverses myocardial remodeling and decreases all-cause mortality.1, 2 CRT typically is attempted with biventricular pacing (BiVP). We are presenting a case of dilated cardiomyopathy and left bundle branch block (LBBB) with significant improvement in electrical and mechanical dyssynchrony, HF symptoms, and left ventricular ejection fraction (LVEF) after initiation of left ventricular septal pacing (LVSP) therapy.

Investigative works of the past 20 years have compiled extensive data on the effectiveness and implications of cardiac resynchronization therapy (CRT) in patients with heart failure. Since then, CRT has become a well-accepted and widely adapted adjunctive therapy for patients with heart failure with ventricular dyssynchrony. This overview discusses the updated knowledge on the benefits afforded with CRT and reviews the major clinical trials that have established CRT at its current practice. Based on the data, the indications of CRT and the timing of appropriate implant of CRT devices with respect to heart failure status will be presented.

Permanent His bundle pacing (PHBP) has shown significant clinical benefits in patients requiring ventricular pacing compared with conventional right ventricular pacing. There is an emerging role for PHBP in patients with interventricular dyssynchrony. This article reviews the mechanisms and the available data on the use of PHBP in overcoming dyssynchrony.

Background: Cardiac resynchronization therapy (CRT) is an effective treatment of heart failure (HF) with ventricular dyssynchrony, but not all patients respond to a similar extent. We investigated the efficacy and safety of exercise training (ET) in patients without response to CRT. Methods and Results: Thirty-four patients who participated in a 3-month ET program and underwent cardiopulmonary exercise testing at baseline and after the program were divided into 17 responders and 17 non-responders based on echocardiographic response criteria: either an increase in ejection fraction (EF) ≥10% or a reduction in left ventricular (LV) end-systolic volume ≥10%. Baseline characteristics including peak oxygen uptake (V̇O2) and isometric knee extensor muscle strength (IKEMS) were similar in both groups, but non-responders had lower EF and larger LV. During the ET program, neither group had exercise-related adverse event including life-threatening ventricular arrhythmia. Peak V̇O2 and IKEMS were significantly improved in both groups and there was no significant difference in change in peak V̇O2 or IKEMS between responders and non-responders. On multiple regression analysis, change in IKEMS was an independent predictor of change in peak V̇O2, whereas the response to CRT was not. Conclusions: In HF patients undergoing CRT implantation, ET safely improved exercise capacity regardless of response to CRT, suggesting that even advanced HF patients without response to CRT can possibly benefit from ET.

Background Conventional complete left bundle branch block (CLBBB) criteria sometimes result in a false‐positive diagnosis that does not represent dyssynchrony. Recently, true CLBBB criteria have been proposed to detect responders to cardiac resynchronization therapy (CRT), although their correlation with severity of dyssynchrony or natural prognosis is unclear. Methods Ninety‐four consecutive patients (74 ± 9 years, 63 men) with conventional CLBBB during sinus rhythm underwent semiconductor SPECT. They were divided into two groups: patients with true CLBBB and others. True CLBBB was characterized by the mid‐QRS notching/slurring and wide QRS duration (male, ≥140 milliseconds; female, ≥130 milliseconds). Multivariate analysis was performed to detect left ventricular dyssynchrony (LVD), defined as bandwidth ≥145° and/or phase standard deviation (SD) ≥43°. Primary endpoints (hospitalization for heart failure or cardiac death) were evaluated. Results True CLBBB had wider bandwidth (145 ± 83° vs 110 ± 64°, P = 0.024) and higher phase SD (48 ± 26° vs 35 ± 19°, P = 0.007). Ejection fraction (EF), end‐diastolic volume (EDV), summed rest score (SRS), and the presence of ischemic heart disease (IHD) showed no differences between groups (P = 0.401, 0.591, 0.165, and 0.212, respectively). Multivariate analysis revealed that true CLBBB, EF, and EDV were significant predictors of LVD (odds ratio, 12.6, 0.90, 1.03; P = 0.003, 0.002, 0.022, respectively). At 3‐year follow‐up (median 667 days), primary endpoints were comparable in both groups (log‐rank, P = 0.92). Conclusions Patients with true CLBBB had more severe dyssynchrony on single‐photon emission computed tomography than patients with nontrue CLBBB. On the other hand, the two groups showed no differences in EF, EDV, the presence of IHD, hospitalization for heart failure, and cardiac death.

Idiopathic or iatrogenic left bundle branch block (LBBB) is a unique model of electro-mechanical ventricular dyssynchrony with concordant changes in electrical activation sequence and mechanical ventricle synchronization. In chronic animal models, isolated LBBB induces structural remodeling with progressive left ventricular (LV) dysfunction. Most abnormalities can be reverted after cardiac resynchronization therapy (CRT). In humans, 2 principal models of LBBB dyssynchronopathy can be observed: the chronic model of isolated LBBB and an acute iatrogenic model of new-onset LBBB after aortic valve interventions. Although epidemiological evidence and clinical data need to be strengthened, there is a strong presumption that they may lead to LBBB-induced cardiomyopathy and benefit from CRT to prevent progression to heart failure. A large cohort study with prospective follow-up would be required to better define actual incidence, evolution over time, and predisposing factors. Parallel randomized CRT clinical trials should be conducted in selected at-risk populations: namely, patients with persistent LBBB after transcatheter aortic valve replacement.

Patients with heart failure with left ventricular (LV) dyssynchrony often do not respond to cardiac resynchronization therapy (CRT), indicating that the pathophysiology is insufficiently understood. Intracardiac hemodynamic forces computed from four-dimensional (4-D) flow MRI have been proposed as a new measure of cardiac function. We therefore aimed to investigate how hemodynamic forces are altered in LV dyssynchrony. Thirty-one patients with heart failure and LV dyssynchrony and 39 control subjects underwent cardiac MRI with the acquisition of 4-D flow. Hemodynamic forces were computed using Navier-Stokes equations and integrated over the manually delineated LV volume. The ratio between transverse (lateral-septal and inferior-anterior) and longitudinal (apical-basal) forces was calculated for systole and diastole separately and compared with QRS duration, aortic valve opening delay, global longitudinal strain, and ejection fraction (EF). Patients exhibited hemodynamic force patterns that were significantly altered compared with control subjects, including loss of longitudinal forces in diastole (force ratio, control subjects vs. patients: 0.32 vs. 0.90, P < 0.0001) and increased transverse force magnitudes. The systolic force ratio was correlated with global longitudinal strain and EF ( P < 0.01). The diastolic force ratio separated patients from control subjects (area under the curve: 0.98, P < 0.0001) but was not correlated to other dyssynchrony measures ( P > 0.05 for all). Hemodynamic forces by 4-D flow represent a new approach to the quantification of LV dyssynchrony. Diastolic force patterns separate healthy from diseased ventricles. Different force patterns in patients indicate the possible use of force analysis for risk stratification and CRT implantation guidance. NEW & NOTEWORTHY In this report, we demonstrate that patients with heart failure with left ventricular dyssynchrony exhibit significantly altered hemodynamic forces compared with normal. Force patterns in patients mechanistically reflect left ventricular dysfunction on the organ level, largely independent of traditional dyssynchrony measures. Force analysis may help clinical decision making and could potentially be used to improve therapy outcomes.

Background: Normal Left Ventricular systolic function is present in nearly 50% of patients with congestive heart failure, the majority of such patients have systemic hypertension. Recent studies have demonstrated Left Ventricular dyssynchrony among patients with heart failure and normal systolic function. The co-existence between Left Ventricular dyssynchrony and hypertension with normal systolic function (with no clinical evidence of heart failure) is less well understood. Objective: To assess the Left Ventricular dyssynchrony among hypertensive patients with normal systolic function by using Tissue doppler imaging.To find out the associations between the LV dyssynchrony and other global echocardiographic findings like (LA volume index, LVmassindex , LV sephericity and LV filling pressure E/E`) Type of the study: Prospective case- control study Methods: The study conducted in Baghdad Teaching Hospital from 1st of June 2015 to 30th of May 2016 .Study included two groups of people, 40 patients, age_ matched healthy (control) group (group1) and 60 patients with established hypertension (group 2). A Complete 2-D and TDI echocardiography studies with simultaneous ECG were performed for all patients. Examination involved LV septal and posterior wall thicknesses, internal dimensions, left atrial size, ejection fraction and tissue doppler derived waves velocities E', E/E.' Dyssynchrony was determined by measuring T-P max ( the maximal time difference from the onset of QRS to peak systolic velocity on TDI between any opposing LV wall in 3 apical views) . Results: The study included 40 age –matched control people, 27males (67.5%) and 13 females (32.5%) with a male to female ratio was 1.8 :1, ranging from (42.4-58y) with mean age was (50.2 ±7.8y ) (group 1) and 60 hypertensive patients, 38 males (63.3%) and 22 females (36.7%) with a male to female ratio was 1.7 :1, ranging from (48.5- 66.5y) with mean age of (57.5± 9.0 y) (group 2) . Left Ventricular dyssynchrony was identified in 20 of 60 patients (33.3%) .Dyssynchrony had no significant association with age and BSA. But it was significantly associated with LA volume index (r = 0.61, p=0.001), LV mass index(r=0.52 ,p=0.001) , LV sphericity index (r= 0.5, p = 0.003) ) and LV filling pressure(r=0.6 , p value=0.001) . Dyssynchrony had significant negative correlation with ( E`) velocity (r= - 0.7 ,P =0.001) . Conclusion: Left Ventricular dyssynchrony is frequent among hypertensive patients with normal LV systolic function .The Left Ventricular dyssynchrony is significantly related to LA volume, LV mass, LV sphericity and LV filling pressure.

Introduction Fifteen to thirty percent of patients with impaired cardiac function have ventricular dyssynchrony and warrant cardiac resynchronization therapy (CRT). While leadless pacemakers eliminate lead-related complications, their current form factor is limited to single-chamber pacing. In this study, we demonstrate the feasibility of multisite, simultaneous pacing using miniaturized pacing nodes powered through wireless power transfer (WPT). Methods A wireless energy transfer system was developed based on resonant coupling at approximately 200 MHz to power multiple pacing nodes. The pacing node comprises circuitry to efficiently convert the harvested energy to output stimuli. To validate the use of these pacing nodes, ex vivo studies were carried out on Langendorff rodent heart models (n = 4). To mimic biventricular pacing, two beating Langendorff rodent heart models, kept 10 cm apart, were paced using two distinct pacing nodes, each attached on the ventricular epicardial surface of a given heart. Results All ex vivo Langendorff heart models were successfully paced with a simple coil antenna at 2 to 3 cm from the pacing node. The coil was operated at 198 MHz and 0.3 W. Subsequently, simultaneous pacing of two Langendorff heart models 30 cm apart using an output power of 5 W was reliably demonstrated. Conclusion WPT provides a feasible option for multisite, wireless cardiac pacing. While the current system remains limited in design, it offers support and a conceptual framework for future iterations and eventual clinical utility.

ispartof: EXPERIMENTAL PHYSIOLOGY vol:106 issue:4 pages:797-800 ispartof: location:England status: published

Background Long-term RV pacing leads to ventricular dyssynchrony, in the form of LBBB-like morphology, with subsequent detrimental effects on LV structure and function. Three-dimensional echocardiography allowed early detection of volumetric changes associated with PICMP and provided more accurate assessment of mechanical dyssynchrony. Speckle tracking strain is able to identify LV dysfunction even before any reduction in LVEF. Our aim was to study pacing effects on LV function and hemodynamics using 3D echo and speckle tracking strain. Results This was a prospective study of 175 consecutive patients without structural heart disease (LVEF > 50%) presented for permanent pacing. Full-volume 3D echocardiography done before implantation, 1 week, and 6 months together with GLS. Patients were followed for 6 months to detect incidence of PIVD (defined as reduction in LVEF > 10% but still above 50%) and PICMP (defined as decrease in LVEF by 10% from baseline in absence of other known causes of cardiomyopathy resulting in EF< 50%). PIVD and PICMP predictors and risk factors were analyzed. Only 50 patients met study criteria. Twenty-five (50%) patients developed LV systolic dysfunction; of these, 19 (38%) developed PIVD and 6 (12%) developed PICMP. Pre-implantation GLS was significantly lower in the 6 patients who subsequently developed PICMP, compared to those who developed PIVD and the preserved EF group (mean GLS − 15.50 vs. − 21.0, − 20.0 respectively; p = 0.005, 0.033, respectively). At 1 week, GLS was significantly lower in the 25 patients who subsequently developed PIVD, compared to those who did not (GLS − 13.0 vs. − 18.0, respectively; p = 0.002). A reduction of baseline GLS by 15% or more at 1 week was associated with the development of PIVD and PICMP (p = < 0.001). A wider native QRS complex was associated with PIVD and PICMP (p = 0.008, 0.018, respectively). The other predictors were found non-significant. Conclusion PICMP may be more common than previously reported and it may occur shortly after implantation. Pre-implantation GLS is a sensitive parameter for PICMP. One-week GLS, pre-implantation QRS complex width are early predictors for PICMP and PIVD before any reduction in EF.

Background: Left bundle branch area pacing (LBBAP) has recently been introduced as a novel physiological pacing strategy. Within LBBAP, distinction is made between left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP, no left bundle capture). Objective: To investigate acute electrophysiological effects of LBBP and LVSP as compared to intrinsic ventricular conduction. Methods: Fifty patients with normal cardiac function and pacemaker indication for bradycardia underwent LBBAP. Electrocardiography (ECG) characteristics were evaluated during pacing at various depths within the septum: starting at the right ventricular (RV) side of the septum: the last position with QS morphology, the first position with r' morphology, LVSP and-in patients where left bundle branch (LBB) capture was achieved-LBBP. From the ECG's QRS duration and QRS morphology in lead V1, the stimulus- left ventricular activation time left ventricular activation time (LVAT) interval were measured. After conversion of the ECG into vectorcardiogram (VCG) (Kors conversion matrix), QRS area and QRS vector in transverse plane (Azimuth) were determined. Results: QRS area significantly decreased from 82 +/- 29 mu Vs during RV septal pacing (RVSP) to 46 +/- 12 mu Vs during LVSP. In the subgroup where LBB capture was achieved (n = 31), QRS area significantly decreased from 46 +/- 17 mu Vs during LVSP to 38 +/- 15 mu Vs during LBBP, while LVAT was not significantly different between LVSP and LBBP. In patients with normal ventricular activation and narrow QRS, QRS area during LBBP was not significantly different from that during intrinsic activation (37 +/- 16 vs. 35 +/- 19 mu Vs, respectively). The Azimuth significantly changed from RVSP (-46 +/- 33 degrees) to LVSP (19 +/- 16 degrees) and LBBP (-22 +/- 14 degrees). The Azimuth during both LVSP and LBBP were not significantly different from normal ventricular activation. QRS area and LVAT correlated moderately (Spearman's R = 0.58). Conclusions: ECG and VCG indices demonstrate that both LVSP and LBBP improve ventricular dyssynchrony considerably as compared to RVSP, to values close to normal ventricular activation. LBBP seems to result in a small, but significant, improvement in ventricular synchrony as compared to LVSP.

Gated myocardial perfusion SPECT (GMPS) provides a one-stop-shop evaluation for cardiac resynchronization therapy (CRT). However, conflicting results have been observed regarding whether the baseline left-ventricular (LV) mechanical dyssynchrony as assessed by phase analysis on GMPS was predictive of therapeutic response to CRT. Since dyssynchrony parameters by phase analysis spuriously increased by scarred myocardium, the purpose of this study was to explore the value of dyssynchrony after stripping off the scar region in correlation to mechanical response to CRT. Forty-seven patients following standard indications for CRT received GMPS with phase analysis as pre-CRT evaluation. A decrease of end-systolic volume (ESV) > 15% on follow-up echocardiography after CRT was considered as a mechanical response to CRT. Myocardial regions with less than 50% of maximal activity on GMPS were considered as a scar. The phase standard deviation (PSD) and histogram bandwidth (BW) without or with stripping off scar were assessed by phase analysis of GMPS and were used for evaluation of LV dyssynchrony of all myocardium or only the viable myocardium, respectively. No significant difference was noted between mechanical responders (31 of 47 patients, 66%) and nonresponders ( 16 of 47 patients, 34%) for PSD (48.6° ± 19.4° vs 43.9° ± 20.7°, p = 0.46) and BW (225° ± 91.1° vs 163.5° ± 94.6°, p = 0.38) of the entire myocardium. However, responders had significantly larger PSD (40.5° ± 15.7° vs 30.5° ± 13.2°, p = 0.03) and borderlinely larger BW (215° ± 91.2° vs. 139.5° ± 78.2°, p = 0.05) than non-responders after stripping off scar. Logistic regression analysis showed that scar area and PSD after stripping off scar were independent predictors of mechanical response. Our result showed that LV dyssynchrony of the entire myocardium did not predict response to CRT. However, LV dyssynchrony only in the viable myocardium was a significant predictor of CRT mechanical response.

Background Few therapies improve outcomes in patients with heart failure with preserved ejection fraction (HFpEF). If left bundle-branch block (LBBB) is associated with left ventricular dyssynchrony and impaired cardiac performance in HFpEF, cardiac resynchronization therapy could be a promising treatment. Methods We performed a cross-sectional analysis of selected patients with HFpEF (ejection fraction ≥50%) with and without LBBB (normal conduction, NC) and patients with HFrEF and LBBB who were suitable cardiac resynchronization therapy candidates to describe and contextualize the mechanical phenotype of LBBB in HFpEF. Systolic and diastolic isovolumic times, ejection time(ET), and diastolic filling time(DFT) were measured on spectral tissue Doppler echocardiographic images and indexed to the heart rate. Dyssynchrony pattern was assessed using speckle-tracked longitudinal strain patterns. Comparisons were performed using analysis of variance and χ2 test with posthoc pairwise comparisons as indicated. Results Eighty-two HFpEF (50 with NC, 32 with LBBB) and 149 HFrEF (all with LBBB) patients met criteria. Overall, 84.4% with HFpEF/LBBB and 91.3% with HFrEF/LBBB had demonstrable mechanical dyssynchrony compared to 0% with HFpEF/NC. Compared to HFpEF/NC, HFpEF/LBBB had significantly prolonged isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and total isovolumetric time and significantly shorter ET (all indexed). LBBB/HFrEF patients, compared to LBBB/HFpEF patients, had increased ICT and IRT with decreased DFT but similar ET. Conclusions Patients with HFpEF and LBBB frequently have an LBBB dyssynchrony phenotype, prolonged ICT and IRT, and reduced ET compared to HFpEF patients with NC. The electromechanical dyssynchrony and disordered cardiac timing of HFpEF with LBBB are similar to HFrEF with LBBB.

Background QRS duration and morphology including left bundle branch block (LBBB) are the most widely used electrocardiogram (ECG) markers for assessing ventricular dyssynchrony and predicting heart failure (HF). However, the vectorcardiographic QRS area may more accurately identify delayed left ventricular activation and HF development. Objective We investigated the association between QRS area and incident HF risk in patients with LBBB. Methods By crosslinking data from Danish nationwide registries, we identified patients with a first-time digital LBBB ECG between 2001 and 2015. The vectorcardiographic QRS area was derived from a 12‑lead ECG using the Kors transformation method and grouped into quartiles. The endpoint was a composite of HF diagnosis, filled prescriptions for loop diuretics, or death from HF. Cause-specific multivariable Cox regression was used to compute hazard ratios(HR) with 95% confidence intervals(CI). Results We included 3316 patients with LBBB free from prior HF-related events (median age, 72 years; male, 40%). QRS area quartiles comprised Q1, 36–98 μVs; Q2, 99–119 μVs; Q3, 120–145 μVs; and Q4, 146–295 μVs. During a 5-year follow-up, 31% of patients reached the composite endpoint, with a rate of 39% in the highest quartile Q4. A QRS area in quartile Q4 was associated with increased hazard of the composite endpoint (HR:1.48, 95%CI:1.22–1.80) compared with Q1. Conclusions Among primary care patients with newly discovered LBBB, a large vectorcardiographic QRS area (146–295 μVs) was associated with an increased risk of incident HF diagnosis, filling prescriptions for loop diuretics, or dying from HF within 5-years.

Contains fulltext : 238836.pdf (Publisher’s version ) (Open Access) NEW FINDINGS: What is the central question of this study? Right ventricular dyssynchrony is a marker of function that is elevated in healthy individuals exposed to acute hypoxia, but does it remain elevated during sustained exposure to high altitude hypoxia, and can it be normalised by augmenting venous return? What is the main finding and its importance? For the first time it is demonstrated that (i) increasing venous return in acute hypoxia restores the synchrony of right ventricular contraction and (ii) dyssynchrony is evident after acclimatisation to high altitude, and remains sensitive to changes in venous return. Therefore, the interpretation of right ventricular dyssynchrony requires consideration the prevailing haemodynamic state. ABSTRACT: Regional heterogeneity in timing of right ventricular (RV) contraction (RV dyssynchrony; RVD) occurs when pulmonary artery systolic pressure (PASP) is increased during acute hypoxia. Interestingly, RVD is not observed during exercise, a stimulus that increases both PASP and venous return. Therefore, we hypothesised that RVD in healthy humans is sensitive to changes in venous return, and examined whether (i) increasing venous return in acute hypoxia lowers RVD and (ii) if RVD is further exaggerated in sustained hypoxia, given increased PASP is accompanied by decreased ventricular filling at high altitude. RVD, PASP and right ventricular end-diastolic area (RVEDA) were assessed using transthoracic two-dimensional and speckle-tracking echocardiography during acute normobaric hypoxia ( FiO2 = 0.12) and sustained exposure (5-10 days) to hypobaric hypoxia (3800 m). Venous return was augmented with lower body positive pressure at sea level (LBPP; +10 mmHg) and saline infusion at high altitude. PASP was increased in acute hypoxia (20 ± 6 vs. 28 ± 7, P

Contains fulltext : 241430.pdf (Publisher’s version ) (Open Access) The purpose of this study was to investigate left ventricular contraction patterns in asymptomatic Childhood cancer survivors (CCS) using two-dimensional speckle tracking echocardiography (2DSTE). Left ventricular longitudinal and circumferential myocardial parameters were assessed using 2DSTE, in asymptomatic CCS and age matched healthy controls. Time to peak (T2P) systolic strain was quantified. Dyssynchrony index (DI) was measured by calculating the standard deviation of T2P systolic strain of six segments in each view. Difference between T2P systolic longitudinal strain of septal and lateral wall was also assessed as a parameter for dyssynchrony. We included 115 CCS with a median age of 17.2 years (range 5.6-39.5) and a median follow up of 11.3 years (range 4.9-29.5) and 119 controls. Conventional echocardiographic parameters and global longitudinal strain were significantly decreased in CCS compared to controls (p

Introduction. The relationship between ventricular pre-excitation and left ventricular dysfunction has been described in the absence of sustained supraventricular tachycardia in a series of case reports. However, there have been no systematic studies about the effect of ventricular pre-excitation on cardiac function in adult patients with different accessory pathway locations. Methods and Results. Patients were divided into four groups based on the type and location of their accessory pathway: septal, right free wall, left free wall, and concealed. N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, electrocardiogram recordings, electrophysiological properties, and transthoracic echocardiographic data (septal-to-posterior wall motion delay (SPWMD) and interventricular mechanical delay (IVMD) indicating intraventricular and interventricular dyssynchrony) were compared before and after successful ablation. Before radiofrequency catheter ablation, left ventricular ejection fraction (LVEF) was significantly lower in patients with septal and right free wall accessory pathways. Within three months after radiofrequency catheter ablation, NT-proBNP levels decreased, left ventricular function improved, and intraventricular left ventricular dyssynchrony disappeared. There was a negative correlation between initial LVEF with initial QRS duration and initial SPWMD. Notably, SPWMD had a stronger correlation with LVEF than initial QRS duration. Conclusions. Anterograde conduction with a septal or right free wall accessory pathway may cause left ventricular dyssynchrony and impair left ventricular function. Intraventricular left ventricular dyssynchrony seems to be responsible for the pathogenesis of left ventricular dysfunction. Radiofrequency catheter ablation results in decreased NT-proBNP levels, normalized QRS duration, mechanical resynchronization, and improved left ventricular function.

Aims. LBBB is rare in healthy young adults, and its long-term prognosis is uncertain. Methods. 56 subjects (aged 60 years at the end of follow-up, we cannot establish the prognosis in older age-groups.

Background Phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy provides a measure of left ventricular dyssynchrony and may have applications for identifying patients suitable for cardiac resynchronisation therapy. Phase analysis is typically described in degrees of cardiac cycle, less intuitive to cardiologists familiar with ECGs. We assessed the relationship between time and degrees, to determine whether they are interchangeable. Methods and results 399 patients underwent normal stress-only SPECT myocardial perfusion imaging using Technetium-99m-tetrofosmin. Data analysis used QGS software (Cedars Sinai) calculating bandwidth and standard deviation. Heart rate, age, gender, stress modality, and ejection fraction were analyzed for their relation to phase variables. 13 patients were excluded for conduction abnormalities including right and left bundle branch block and ventricular pacing. Heart rate was strongly correlated to bandwidth and standard deviation measured in time, but unrelated when measured in degrees. Although bandwidth measured by time and degrees were strongly correlated with each other this relationship was not perfect (correlation coefficient 0.87, P

Background: Right ventricular (RV) pacing causes delayed activation of remote ventricular segments. We used the UHF-ECG to describe ventricular depolarization when pacing different RV locations. Methods: In 51 consecutive patients, temporary pacing was performed at the RV apex, anterior and lateral wall, and at the RV septum with (cSp) and without direct conductive tissue engagement (mSp) (further subclassified as RVIT and RVOT for septal inflow and outflow positions). The timing of UHF-ECG electrical activations were quantified as: left ventricular lateral wall delay (LVLWd; V8 activation delay), RV lateral wall delay (RVLWd; V1 activation delay), and LV lateral wall depolarization duration (V5-8d). Results: The LVLWd was shortest for cSp (11 ms (95% CI; 5;17), followed by the RVIT (19 ms (11;26) and the RVOT (33 ms (27;40), (p

Cardiac resynchronization therapy (CRT) is an effective therapy for patients who suffer from heart failure and ventricular dyssynchrony such as left bundle branch block (LBBB). When it works, it reverses adverse left ventricular (LV) remodeling and the progression of heart failure. However, CRT response rate is currently as low as 50-65%. In theory, CRT outcome could be improved by allowing clinicians to tailor the therapy through patient-specific lead locations, timing, and/or pacing protocol. However, this also presents a dilemma: there are far too many possible strategies to test during the implantation surgery. Computational models could address this dilemma by predicting remodeling outcomes for each patient before the surgery takes place. Therefore, the goal of this study was to develop a rapid computational model to predict reverse LV remodeling following CRT. We adapted our recently developed computational model of LV remodeling to simulate the mechanics of ventricular dyssynchrony and added a rapid electrical model to predict electrical activation timing. The model was calibrated to quantitatively match changes in hemodynamics and global and local LV wall mass from a canine study of LBBB and CRT. The calibrated model was used to investigate the influence of LV lead location and ischemia on CRT remodeling outcome. Our model results suggest that remodeling outcome varies with both lead location and ischemia location, and does not always correlate with short-term improvement in QRS duration. The results and time frame required to customize and run this model suggest promise for this approach in a clinical setting.

Introduction: Asymptomatic patients on active surveillance for degenerative mitral regurgitation are at risk of ventricular arrhythmia and sudden death. Hypothesis: Abnormal myocardial mechanics may precede ventricular remodeling and may help identify at-risk patients. Methods: Multi-directional myocardial mechanics and LV dyssynchrony were assessed in 204 consecutive patients awaiting surgical mitral repair for severe degenerative MR in a quaternary mitral reference center. Results: The mean age was 58 ±12.5 years and 40% were females. The mean EF was 63% ± 6% and 92% had compensated LV function (EF>60% and LVESD2 ). The median LV mechanical dispersion was 40msec (IQR 30.7-56.5) but increased significantly with ventricular ectopy (65msec, P Conclusions: Left ventricular dyssynchrony manifested by increased mechanical dispersion and imbalanced interpapillary mechanics are observed prior to overt chamber remodeling in significant degenerative MR and is associated with ventricular ectopy. Further studies are needed to assess the related clinical implications and potential impact on risk stratification in this patient group.

Cardiac resynchronization therapy (CRT) is an ef-fective therapy for patients who suffer from heart failure and ventricular dyssynchrony such as left bundle branch block (LBBB). When it works, it reverses adverse left ventricular (LV) remodeling and the progression of heart failure. How-ever, CRT response rate is currently as low as 50-65%. In theory, CRT outcome could be improved by allowing clinicians to tailor the therapy through patient-specific lead locations, timing, and/or pacing protocol. However, this also presents a dilemma: there are far too many possible strategies to test during the implantation surgery. Computational models could address this dilemma by predicting remodeling outcomes for each patient before the surgery takes place. Therefore, the goal of this study was to develop a rapid computational model to predict reverse LV remodeling following CRT. We adapted our recently developed computational model of LV remodeling to simulate the mechanics of ventricular dyssynchrony and added a rapid electrical model to predict electrical activation timing. The model was calibrated to quantitatively match changes in hemodynamics and global and local LV wall mass from a canine study of LBBB and CRT. The calibrated model was used to investigate the influence of LV lead location and ischemia on CRT remodeling outcome. Our model results suggest that remodeling outcome varies with both lead location and ischemia location, and does not always correlate with short-term improvement in QRS duration. The results and time frame required to customize and run this model suggest promise for this approach in a clinical setting.

Fragmented QRS is an abnormal sign in an ECG resulting from ventricular dyssynchrony. The presence of fragmented QRS (fQRS) is related to mortality in patients with repaired tetralogy of Fallot (rTOF). This study aimed to analyze the correlations between fQRS and ventricular function parameters from cardiac magnetic resonance (CMR) images. A total of 54 patients with rTOF or repaired DORV, TOF type who had been investigated by CMR at Songklanagarind Hospital from January 2012 to August 2019 were retrospectively reviewed. Most of the patients (47 patients, 87%) were diagnosed with TOF and most of these (57.4%) were treated with a transannular patch (TAP) on the right ventricular outflow tract (RVOT). Forty-four patients (81%) had fQRS. The median time interval between EKG and CMR was 4.2 months (IQR 1.1, 6.9). Patients with fQRS had significantly higher RVEDVi (145.6 [IQR 121.1, 173.1) vs. 115.9 [IQR 96.2, 146.9] mL/m2, p = 0.037), higher RVESVi (82.5 [IQR 62.9, 100.8] vs. 58.6 [IQR 46, 77.2] mL/m2, p = 0.032) and higher RVEDV/LVEDV ratio [1.6 (IQR 1.4, 1.9) vs. 1.4 (IQR 1.3, 1.5), p = 0.026]. The extent of fQRS was significantly associated with an increase in RVEDVi (r = 0.39, p = 0.004) and RVESVi (r = 0.45, p

Background PR prolongation is associated with poor hemodynamic performance and may contribute to heart failure (HF). There is some evidence that in HF patients, normalization of atrioventricular (AV) coupling can attenuate HF. Purpose To investigate acute hemodynamic effects of restoration of AV coupling by atrio-biventricular (BiV) pacing in patients with HF and PR prolongation, but without evident ventricular dyssynchrony. Methods Nineteen patients underwent BiV pacemaker implantation. An invasive hemodynamic pacing protocol was performed during BiV and right ventricular (RV) pacing with four paced AV delays (100, 75, 50 and 25% of patient's PR interval during baseline AAI pacing). All patients had symptomatic HF, left ventricular ejection fraction (LVEF) 150 ms or left bundle branch block. Acute hemodynamic response was assessed by invasive left ventricular (LV) stroke work measurements (conductance catheter technique). Results At baseline, PR interval was 255±22 ms, QRS duration 122±19 ms and LVEF 29±6%. Reducing AV delay to 50% of patient's intrinsic PR interval by BiV pacing resulted in a median 25% increase (p Conclusion In patients with HF and PR prolongation, BiV pacing can be used to improve AV coupling that leads to hemodynamic improvement. These results suggest that BiV pacing may also be beneficial in this subset of HF patients that are currently not indicated for CRT. ReachPR Trial Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Abbott funded a part of this study.

Background Nonselective pacing of the distal His bundle is practically just another way of right ventricular septal pacing. It leads to the concomitant activation of the His bundle and septal myocytes with unknown impact on ventricular synchrony. Ultra-high frequency ECG (UHF-ECG) is a novel tool for ventricular depolarization imaging. Purpose To describe ventricular depolarization patterns during nonselective pacing of a ventricular aspect of His bundle and myocardial captures from different locations in the right ventricle by using the UHF-ECG. Methods Consecutive patients with an indication for permanent pacing due to bradycardia were included. During pacemaker implantation, the pacing lead was temporarily placed in prespecified locations of the right ventricle (mid-septum, anterior, lateral wall, and the para-hisian area of the RV). When pacing from mentioned locations, myocardial activation time under each specific lead (Vd), and ventricular dyssynchrony (e-DYS) indexes were calculated from UHF-ECG maps, for each particular type of pacing. The demonstration of UHF-ECG maps during pacing from different locations of the right ventricle is shown in the figure. Results Two hundred and fifty UHF ECG recordings were performed in forty-six patients. The calculated mean e-DYS parameter was significantly shorter during non-selective capture of the distal His bundle (14±8 ms) compared to each of myocardial captures of the right ventricle (pure myocardial para-hisian; 35±12 ms, mid-septal; 28±11 ms, anterior wall; 51±16 ms and lateral wall; 62±19 ms (p Conclusion Pacing of the basal interventricular septum with the engagement of the His bundle produced a superior depolarization pattern in both heart ventricles compared to other types of right ventricular myocardial capture, as assessed using UHF-ECG. Figure 1. Examples of UHF-ECG depolarization maps of different types of ventricular activation in the same patient. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Charles University in Prague

Background In pulmonary arterial hypertension (PAH) patients, the right ventricle (RV) stiffens due to hypertrophy, fibrosis and intrinsic (sarcomeric) stiffness. In these patients, end-diastolic elastance (stiffness, Eed) is associated with parameters of disease severity and predicts mortality. However, the effect of RV stiffness on RV filling and the effect of increased filling pressures on right atrial (RA) function remain elusive. Purpose To examine the relationship between RV diastolic stiffness and RA phasic function and the effect of diastolic dysfunction on ventricular filling in PAH patients. Methods Using single-beat pressure-volume analyses we determined Eed in controls (n=31) and baseline, treatment naive PAH patients (63 idiopathic, 9 hereditary and 25 connective tissue disease associated). We also measured RA reservoir, conduit and active strain by tissue tracking on cardiac magnetic resonance images. Furthermore, interventricular dyssynchrony was defined as a right to left difference in time to peak circumferential strain >52ms (97.5th percentile in controls). Results End-diastolic pressure was higher in PAH patients (16±7 mmHg) than in controls (8±4 mmHg; p Passive filling time of the RV (end-systole until start of atrial contraction) was shorter in patients than in controls (244±136ms vs. 365±103ms; p Conclusion Stiffening of the RV in PAH patients is accompanied by increased filling pressures and decreased RA conduit strain, while there is no correlation between Eed and RA active strain. Higher heart rate and ventricular dyssynchrony lead to shorter passive filling time of the RV, which in turn leads to lower passive filling volume. In contrast, the active filling volume is preserved in these patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Netherlands Organization for Scientific Research

Right ventricular apex (RVA) is still the most common implanted site in the world. There are a large number of RVA pacing population who have been carrying dual-chamber permanent pacemaker (PPM) over decades. Comparison of left ventricular dyssynchrony, morphology and systolic function between RVA pacing population and healthy population is unknown.This case-control study enrolled 61 patients suffered from complete atrioventricular block (III°AVB) for replacement of dual-chamber PPM. Then, 61 healthy controls matched with PPM patients in gender, age, follow-up duration and complications were included. The lead impedance, pacing threshold and sensing were compared between at implantation and long-term follow-up. Left ventricular (LV) dyssynchrony, morphology and systolic function were compared between RVA pacing population (RVA group) and healthy population (healthy group) at implantation (baseline) and follow-up. And clarify the predictors of LV systolic function in RVA group at follow-up.After 112.44 ± 34.94 months of follow-up, comparing with parameters at implantation, atrial lead impedance decreased significantly (690 ± 2397 Ω vs 613 ± 2257 Ω， p = 0.048); atrial pacing threshold has a increased trend and P-wave amplitude has a decreased trend, but there was no statistical differences; while, RVA ventricular lead threshold increased significantly (0.50 ± 0.23 V vs 0.91 ± 0.47 V， p 0.001), impedance (902 ± 397 Ω vs 680 ± 257 Ω，p 0.001) and R-wave amplitude (11.71 ± 9.40mv vs 7.00 ± 6.91 mv， p 0.001) decreased significantly. Compared with healthy group, long-term RVA pacing significantly increased ventricular dyssynchrony (mean QRS duration, 156.21 ± 29.80 ms vs 97.08 ± 15.70 ms， p 0.001), left atrium diameter (LAD, 40.61 ± 6.15 mm vs 37.49 ± 4.80 mm，p = 0.002), left ventricular end-diastolic diameter (LVEDD, 49.15 ± 5.93 mm vs 46.41 ± 3.80 mm，p = 0.003), left ventricular hypertrophy (LVMI, 121.86 ± 41.52 g/m2 vs 98.41 ± 25.29 g/m2，p 0.001), significantly deteriorated degree of tricuspid regurgitation (p 0.001), and significantly decreased left ventricular ejection fraction (LVEF, 61.38 ± 8.10% vs 64.64 ± 5.85%, p = 0.012), but after long-term RVA pacing, the mean LVEF was still more than 50%. Long-term RVA group LVEF was negatively correlated with preimplantation LVMI (B = -0.055，t = -2.244，p = 0.029), LVMI at follow-up (B = -0.081，t = -3.864，p = 0.000) and tricuspid regurgitation at follow-up (B = -3.797，t = -3.599，p = 0.001).In conclusion, although long-term RVA pacing has significantly effects on left ventricular dyssynchrony, morphology and systolic function in III°AVB patients, the mean LVEF is still50%. High preimplantation LVMI can predict the decline of LVEF.

Right ventricular (RV) dysfunction is the most important determinant of survival in patients with pulmonary hypertension (PH). The manifestations of RV dysfunction not only include changes in global RV systolic function but also abnormalities in the pattern of contraction and synchrony. The effects of PH on the right ventricle have been mainly studied in patients with pulmonary arterial hypertension (PAH). However, with the demographic shift towards an aging population, heart failure with preserved ejection fraction (HFpEF) has become an important etiology of PH in recent years. There are significant differences in RV mechanics, function and adaptation between patients with PAH and HFpEF (with or without PH), which are related to different patterns of remodeling and dysfunction. Due to the unique features of the RV chamber, its connection with the main pulmonary artery and the pulmonary circulation, an understanding of the mechanics of RV function and its clinical significance is mandatory for both entities. In this review, we describe the mechanics of the pressure overloaded right ventricle. We review the different mechanical components of RV dysfunction and ventricular dyssynchrony, followed by insights via analysis of pressure-volume loop, energetics and novel blood flow patterns, such as vortex imaging. We conduct an in-depth comparison of prevalence and characteristics of RV dysfunction in HFpEF and PAH, and summarize key outcome studies. Finally, we provide a perspective on needed and expected future work in the field of RV mechanics.

Purpose The aim of this study was to evaluate right ventricle (RV) dyssynchrony and its relation with mortality using speckle-tracking echocardiography (STE) in patients with acute inferior myocardial infarction (IMI). Methods One hundred and fifty-eight consecutive patients with acute IMI treated with primary percutaneous coronary intervention, and 44 healthy subjects were included. RV myocardial involvement (RVMI) was defined as an elevation >1 mm in V1 or V4R and/or the presence of a culprit lesion at the proximal portion of the first RV marginal branch after reviewing coronary angiography. Patients were followed for 3 years to determine the cardiovascular mortality. Results Overall, 70 patients with IMI had RVMI. IMI patients had significantly higher RV peak systolic longitudinal strain dyssynchrony (PLSSD) index, lower peak longitudinal systolic strain (PLSS), longer time to PLSS, and time to PLSS differences compared to healthy controls while the patients with RVMI had significantly worse values compared to patients without RVMI and healthy controls. Twenty-seven patients (17.1%) died within 2 years. RVMI was more prevalent in mortality group, and they had significantly higher RV PSSD index, whereas they had lower RV free wall PLSS and longer time to PLSS differences. Receiver operating characteristics (ROC) analysis revealed that a RV PLSSD index > 65 ms predicted mortality with a sensitivity of 88.9% and specificity of 71.8% in IMI patients. Conclusions Intra- and inter-ventricular dyssynhcrony may develop in patients with acute IMI, especially in those with RV involvement, which might have a negative effect on the prognosis of these patients.

La estimulacion apical permanente del ventriculo derecho (VD) puede producir asincronia del ventriculo izquierdo (VI) desde los puntos de vista electrico y mecanico. Este fenomeno es efecto de una alteracion de la activacion normal del VI que lleva al deterioro de la funcion sistolica y la aparicion de insuficiencia cardiaca y sus efectos deletereos relacionados. Para el estudio de la asincronia electrica del VI se ha propuesto en fecha reciente el nuevo sistema electrocardiografico no invasivo Synchromax, que puede cuantificar el grado de asincronia electrica que causa una subsecuente asincronia mecanica. Esta ultima se ha estudiado casi siempre mediante la ecocardiografia transtoracica bidimensional (ETT2D) a traves del Doppler tisular y la deformacion miocardica y ahora con la ecocardiografia tridimensional transtoracica en tiempo real (E3DTR). La relacion entre estos fenomenos ha sido motivo de estudio a fin de identificar a los pacientes que se benefician de la transicion a un tratamiento de resincronizacion cardiaca. Conclusiones: La estimulacion artificial permanente del VD produce asincronia electrica del VI que puede cuantificarse mediante el nuevo sistema electrocardiografico Synchromax y desencadenar asincronia mecanica estudiada mediante la ecocardiografia transtoracica para reconocer a los pacientes que pueden beneficiarse de un tratamiento de resincronizacion cardiaca. Permanent apical pacing of right ventricle (RV) can produce dyssynchrony of the left ventricle (LV) from an electrical and mechanical point of view. This phenomenon is caused by an alteration in the normal activation of LV leading to a deterioration of systolic function and the appearance of heart failure and its associated deleterious effects. For the study of the electrical asynchrony of the LV, a new noninvasive electrocardiographic system Synchromax has recently been proposed, being able to quantify the degree of electrical asynchrony that leads to a subsequent mechanical dyssynchrony. Th e latter has been traditionally studied by two-dimensional transthoracic echocardiography (2DTTE) through tissue Doppler and myocardial deformation and lately by real-time 3-dimensional echocardiography (RT3DE). The relationship between these phenomena has been the subject of study to predict those patients who benefit from an “upgrade” to cardiac resynchronization therapy. Conclusions: Permanent apical pacing of the RV produces electrical dyssynchrony of the LV that can be quantified using a new electrocardiographic system Synchromax and trigger mechanical asynchrony studied through transthoracic echocardiography allowing to predict those patients who benefit from cardiac resynchronization therapy.

Background Nonfluoroscopic 3-dimensional (3D) electroanatomic mapping systems (EAMs) have been developed to guide cardiac catheter navigation and reduce fluoroscopy. Selective right ventricular (RV) septal pacing could prevent pacing-induced left ventricular (LV) dysfunction. Objective The purpose of this study was to determine whether EAM-guided selective RV septal pacing preserves LV contractility/synchrony in pediatric patients with complete atrioventricular block (CAVB) and no other congenital heart defects. Methods Prospective analysis of children/adolescents who underwent EAM-guided selective RV pacing was performed. A 3D pacing map guided ventricular lead implantation at septal sites with narrow paced QRS. Serial echocardiograms were obtained after pacemaker implantation to monitor for function (volumes, ejection fraction [EF], global longitudinal/circumferential strain) and synchrony (interventricular mechanical delay, septal to posterior wall motion delay, systolic dyssynchrony index). Data are reported as median (25th–75th percentile). Results Thirty-two CAVB patients (age 9.8 [7.0–14.0] years; 11 with a previous pacing system) underwent selective RV septal pacing (13 DDD, 19 VVIR pacemaker; midseptum 22, parahisian 7, RV outflow tract 3) with narrow paced QRS (110 [100–120] ms) and low radiation exposure. Follow-up over 24 (5–33) months showed preserved LV function and synchrony, without significant differences between pacing sites (midseptum–parahisian) and mode (VVIR-DDD). EF decreased after implantation in patients without previous pacing, although values were mainly within normal limits. Three parahisian patients underwent early lead repositioning. Conclusion EAM-guided selective RV septal pacing is a feasible technique associated with preserved LV systolic function and synchrony and low radiation exposure in pediatric patients with CAVB.

Cardiac resynchronization therapy (CRT) response assessment relies on the QRS complex narrowing criterion. Yet one third of patients do not improve despite narrowed QRS after implantation. Electromechanical wave imaging (EWI) is a quantitative echocardiography-based technique capable of noninvasively mapping cardiac electromechanical activation in three dimensions. The aim of this exploratory study was to investigate the EWI technique, sensitive to ventricular dyssynchrony, for informing CRT response on the day of implantation.Forty-four patients with heart failure with left bundle branch block or right ventricular (RV) paced rhythm and decreased left ventricular ejection fraction (LVEF; mean, 25.3 ± 9.6%) underwent EWI without and with CRT within 24 hours of device implantation. Of those, 16 were also scanned while in left ventricular (LV) pacing. Improvement in LVEF at 3-, 6-, or 9-month follow-up defined (1) super-responders (ΔLVEF ≥ 20%), (2) responders (10% ≤ ΔLVEF 20%), and (3) nonresponders (ΔLVEF ≤ 5%). Three-dimensionally rendered electromechanical maps were obtained under RV, LV, and biventricular CRT pacing conditions. Mean RV free wall and LV lateral wall activation times were computed. The percentage of resynchronized myocardium was measured by quantifying the percentage of the left ventricle activated within 120 msec of QRS onset. Correlations between percentage of resynchronized myocardium and type of CRT response were assessed.LV lateral wall activation time was significantly different (P ≤ .05) among all three pacing conditions in the 16 patients: LV lateral wall activation time with CRT in biventricular pacing (73.1 ± 17.6 msec) was lower compared with LV pacing (89.5 ± 21.5 msec) and RV pacing (120.3 ± 17.8 msec). Retrospective analysis showed that the percentage of resynchronized myocardium with CRT was a reliable response predictor within 24 hours of implantation for significantly (P ≤ .05) identifying super-responders (n = 7; 97.7 ± 1.9%) from nonresponders (n = 17; 89.9 ± 9.9%).Electromechanical activation mapping constitutes a valuable three-dimensional visualization tool within 24 hours of implantation and could potentially aid in the timely assessment of CRT response rates, including during implantation for adjustment of lead placement and pacing outcomes.

The aims of this study were to explore the effect of high-altitude (HA) exposure on the incidence, determinants, and impacts of right ventricular dyssynchrony (RVD). In our study, 108 healthy young men were enrolled, and physiological and echocardiographic variables were recorded at both sea level and 4,100 m. By using two-dimensional speckle-tracking echocardiography, RVD was evaluated by calculating the R–R interval-corrected standard deviation of the time-to-peak systolic strain for the four mid-basal RV segments (RVSD4) and defined by RVSD4 > 18.7 ms. After HA exposure, RVSD4 was significantly increased, and the incidence of RVD was approximately 32.4%. Subjects with RVD showed lower oxygen saturation (SaO2) and RV global longitudinal strain and higher systolic pulmonary artery pressure than those without RVD. Moreover, myocardial acceleration during isovolumic contraction was increased in all subjects and those without RVD, but not in those with RVD. Multivariate logistic regression revealed that SaO2 is an independent determinant of RVD at HA (odds ratio: 0.72, 95% CI: 0.56–0.92; P = 0.009). However, the mean pulmonary artery pressure was linearly correlated with the magnitude of RVD in the presence of Notch. No changes were found in RV fractional area change, tricuspid annular motion, or tricuspid s’ velocity between subjects with and without RVD. Collectively, we demonstrated for the first time that HA exposure could induce RVD in healthy subjects, which may be mainly attributed to the decline in SaO2 as well as RV overload; the incidence of RVD was associated with reduced RV regional function and blunted myocardial acceleration.

Aims: A prolonged PR interval may adversely affect ventricular filling and therefore cardiac function. AV delay can be corrected using right-ventricular-pacing (RVP) but this induces ventricular dyssynchrony, itself harmful. Therefore, in intermittent heart-block, pacing-avoidance algorithms are often implemented. We tested His-bundle pacing (HBP) as an alternative. Methods: Out-patients with a long PR interval(>200ms) and intermittent need for ventricular pacing were recruited. We measured within patient differences in high-precision haemodynamics between AV-optimized RVP, and HBP, as well as a pacing-avoidance algorithm [Managed Ventricular Pacing (MVP)]. Results We recruited 18 patients. Mean left ventricular ejection fraction was 44.3±9%. Mean intrinsic PR interval was 266±42ms and QRS duration was 123±29ms. RVP lengthened QRS duration(+54 ms, 95%CI 42 to 67ms, p

OnBehalf Alexandria EPS Unit Background During recent years there was a focus on the negative effects associated with long term right ventricular (RV) pacing. It was shown in both experimental and clinical studies that RV pacing leads to ventricular dyssynchrony, similar to that of left bundle branch block (LBBB) with subsequent electrical, mechanical and anatomical changes leading to detrimental effects on left ventricular structure and function. During the last two decades, 3D echocardiography developed from a time-consuming method to a routine clinical approach. At present, evidence suggested that 3D echocardiography provided improved accuracy and reproducibility over 2D methods for LV volume and function calculation. There is a growing number of literature signifying that speckle tracking strain is able to identify left ventricular (LV) dysfunction even before any reduction in LV ejection fraction (LVEF). Methods This was an observational study of fifty consecutive patients without structural heart disease and preserved ejection fraction (LVEF > 50%) presented with high grade atrioventricular block for permanent pacing. Complete 2D and a full volume 3D echocardiography was done before implantation, one-week and 6-months after implantation together with global longitudinal strains analysis (GLS). Patients were followed for 6 months to detect the incidence of PIVD (defined as a reduction in LVEF >10 percentage points but still above 50%) and PICMP (defined as a decrease in LVEF by 10 percentage points from baseline in the absence of other known causes of cardiomyopathy resulting in EF Results At six months, 25 (50%) patients developed PIVD; of these, 6 (12%) developed PICMP. Pre-implantation, GLS was significantly lower in the 6 patients who subsequently developed PICMP, compared to those who developed PIVD and the preserved EF group (mean GLS -15.50 vs. -21.0, -20.0 respectively; p = 0.005, 0.033 respectively). At one week, GLS was significantly lower in the 25 patients who subsequently developed PIVD, compared to those who did not (GLS -13.0 vs. -18.0 respectively; p = 0.002). A reduction of baseline GLS by 15% or more at one week was associated with the development of PIVD and PICMP (p = Conclusion PICMP may be more common than previously reported and it may occur shortly after implantation. This rise in its incidence is due to the application of new sensitive tools like 3D echocardiography and speckle tracking strain. Pre-implantation GLS is a sensitive parameter for the development of PICMP. One-week GLS is an early predictor for the development of PICMP and PIVD before any reduction in EF develops.

Aims A prolonged PR interval may adversely affect ventricular filling and, therefore, cardiac function. AV delay can be corrected using right ventricular pacing (RVP), but this induces ventricular dyssynchrony, itself harmful. Therefore, in intermittent heart block, pacing avoidance algorithms are often implemented. We tested His‐bundle pacing (HBP) as an alternative. Methods Outpatients with a long PR interval (>200 ms) and intermittent need for ventricular pacing were recruited. We measured within‐patient differences in high‐precision hemodynamics between AV‐optimized RVP and HBP, as well as a pacing avoidance algorithm (Managed Ventricular Pacing [MVP]). Results We recruited 18 patients. Mean left ventricular ejection fraction was 44.3 ± 9%. Mean intrinsic PR interval was 266 ± 42 ms and QRS duration was 123 ± 29 ms. RVP lengthened QRS duration (+54 ms, 95% CI 42–67 ms, p