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BACKGROUND Leadless pacemakers have been introduced into the clinical practice as a breakthrough technology that could tackle most of the major sources of complication of traditional pacemakers (PM). The excellent safety profile and optimal electrical performance of Micra have been already largely described, nevertheless the impact on QRS duration has not been investigated so far. We aimed to compare changes in QRS duration after septal Micra implant in comparison to patients who received transvenous right ventricular leads in the same position. METHODS We enrolled all patients who underwent Micra implantation (group 1) at our Center from April 2017 to March 2019. A septal placement was attempted in all cases. Duration of spontaneous and paced QRS and their difference (delta QRS) were measured using a polygraph. To provide a comparison group, we analyzed the QRS duration in a matched group of patients (group 2) who received a traditional single chamber pacing system with a transvenously implanted lead at septal position in the same period. Confounding variables that were used to provide the control group were age, sex, left ventricle ejection fraction, and rhythm at implant. High pacing threshold was defined as ≥1.0 V at pulse duration of 0.24 ms. RESULTS Twenty-eight consecutive patients (mean age 78 ± 3 years; 71.43% males) who underwent successful Micra implant were enrolled. A septal position was achieved in all cases with a single device delivery in 17/28 patients (60.7%). Mean pacing threshold at implant was 0.56 ± 0.34V/0.24 ms with only 3/28 patients (10.7%) presenting a high pacing threshold. No significant differences in demographic, clinical characteristics and ventricular pacing site were observed between groups. QRS duration was slightly longer in group 1 compared to group 2 before implant (median 123 ms (IQR 104-146.5 ms) vs median 116 ms (IQR 90-125 ms); p = 0.09). Nevertheless, there was a significantly lower delta QRS after implant in Micra compared to the traditional pacing group (15.82 ± 31.77 ms vs 35.82 ± 22.13 ms, p = 0.008). CONCLUSION Right ventricular stimulation induces ventricular dyssynchrony, which is correlated with the amount of QRS enlargement after pacing. Micra implant, in a non-apical position, produces significantly smaller changes on the QRS duration in comparison with transvenous lead implanted at the same site, although larger studies are necessary to confirm these results.

Dietary restriction has been well-described to improve health metrics, but whether it could benefit pathophysiological adaptation to extreme environment, for example, microgravity, remains unknown. Here, we investigated the effects of a daily rhythm of fasting and feeding without reducing caloric intake on cardiac function and metabolism against simulated microgravity. Male rats under ad libitum feeding or time-restricted feeding (TRF; food access limited to 8 hours every day) were subjected to hindlimb unloading (HU) to simulate microgravity. HU for 6 weeks led to left ventricular dyssynchrony and declined cardiac function. HU also lowered pyruvate dehydrogenase (PDH) activity and impaired glucose utilization in the heart. All these were largely preserved by TRF. TRF showed no effects on HU-induced loss of cardiac mass, but significantly improved contractile function of cardiomyocytes. Interestingly, TRF raised liver-derived fibroblast growth factor 21 (FGF21) level and enhanced cardiac FGF21 signaling as manifested by upregulation of FGF receptor-1 (FGFR1) expression and its downstream markers in HU rats. In isolated cardiomyocytes, FGF21 treatment improved PDH activity and glucose utilization, consequently enhancing cell contractile function. Finally, both liver-specific knockdown (KD) of FGF21 and cardiac-specific FGFR1 KD abrogated the cardioprotective effects of TRF in HU rats. These data demonstrate that TRF improves cardiac glucose utilization and ameliorates cardiac dysfunction induced by simulated microgravity, at least partially, through restoring cardiac FGF21 signaling, suggesting TRF as a potential countermeasure for cardioprotection in long-term spaceflight.

Background In a Fontan candidate, univentricular pacing may cause delay in interventricular conduction, which induces asynchronous contraction. Cardiac resynchronization therapy is expected to be an effective mode of therapy in such a case. Case presentation A 7-month-old girl, diagnosed with dextrocardia, congenitally corrected transposition of the great artery [situs solitus, L-loop, and L-transposition], ventricular septal defect, infundibular and pulmonary valvular stenosis, and straddling of the tricuspid valve, was considered as a candidate for the Fontan procedure. She had undergone Blalock-Taussig shunt, and epicardial univentricular pacemaker implantation for persistent complete atrioventricular block. She underwent a bidirectional cavopulmonary shunt concomitant with ventricular lead translocation from the morphological left ventricle to the morphological right ventricle. After discharge, ventricular dyssynchrony was noted and cardiac failure persisted. She was converted to cardiac resynchronization therapy (CRT) at 13 months of age. Two-dimensional speckle tracking imaging was used by cardiologists to determine the most suitable pacing site. CRT rapidly corrected the heart failure; thus, she underwent the Fontan procedure after 1.5 years. Five years have passed since the cardiac resynchronization therapy; her interventricular synchrony is maintained well and the level of brain natriuretic peptide remains within normal range. Conclusion We describe the successful conversion from single ventricular pacing to CRT, in a case of congenitally corrected transposition of the great artery indicated for the Fontan procedure. The long-term prognosis of cardiac resynchronization therapy is undetermined in the pediatric population; therefore, further follow-up is required.

Right ventricular (RV) dyssynchrony has been related to outcome in pulmonary arterial hypertension. Prospectively, we performed echocardiography with measurement of right ventricular dyssynchrony and pressure–volume loop catheterization in 27 pulmonary arterial hypertension patients. Afterload and diastolic function emerged as determinates of wall stress, which results in dyssynchrony., SCOPUS: ar.j, info:eu-repo/semantics/published

Left ventricular assist devices (LVAD) provide cardiac support to patients with advanced heart failure. Methods that can directly measure remaining LV function following device implantation do not currently exist. Previous studies have shown that a combination of loading (LV pressure) and deformation (strain) measurements enables quantitation of myocardial work. We investigated the use of ultrasound (US) strain imaging and pressure–strain loop analysis in LVAD-supported hearts under different hemodynamic and pump unloading conditions, with the aim of determining LV function with and without LVAD support. Ex vivo porcine hearts (n = 4) were implanted with LVADs and attached to a mock circulatory loop. Measurements were performed at hemodynamically defined “heart conditions” as the hearts deteriorated from baseline. Hemodynamic (including LV pressure) and radio-frequency US data were acquired during a pump-ramp protocol at speeds from 0 (with no pump outflow) to 10 000 revolutions per minute (rpm). Regional circumferential (εcirc) and radial (εrad) strains were estimated over each heart cycle. Regional ventricular dyssynchrony was quantitated through time-to-peak strain. Mean change in LV pulse pressure and εcirc between 0 and 10 krpm were −21.8 mm Hg and −7.24% in the first condition; in the final condition −46.8 mm Hg and −19.2%, respectively. εrad was not indicative of changes in pump speed or heart condition. Pressure–strain loops showed a degradation in the LV function and an increased influence of LV unloading: loop area reduced by 90% between 0 krpm in the first heart condition and 10 krpm in the last condition. High pump speeds and degraded condition led to increased dyssynchrony between the septal and lateral LV walls. Functional measurement of the LV while undergoing LVAD support is possible by using US strain imaging and pressure–strain loops. This can provide important information about remaining pump function. Use of novel LV pressure estimation or measurement techniques would be required for any future use in LVAD patients.

Diastolic intraventricular pressure difference (IVPD) reflects left ventricular (LV) diastolic function. The relative pressure imaging (RPI) enables the noninvasive quantification of IVPD based on vector flow mapping (VFM) and visualization of regional pressure distribution. LV dyssynchrony causes deterioration of cardiac performance. However, it remains unclear how IVPD is modulated by LV dyssynchrony. LV dyssynchrony was created in ten open-chest dogs by right ventricular (RV) pacing. The other ten dogs undergoing right atrial (RA) pacing set at the similar heart rate with RV pacing were used as controls. Echocardiographic images were acquired at baseline and during pacing simultaneously with LV pressure measurement by a micromanometer. Pressure difference (ΔP) was computed between the apex and the base of the LV inflow tract during a cardiac cycle by RPI and ΔP during isovolumic relaxation time (ΔPIRT), a parameter of diastolic suction, and that during early filling phase (ΔPE) were measured. During RV pacing, stroke volume (SV) and ΔPIRT decreased significantly, while ΔPE did not change compared to the baseline. During RA pacing, SV, ΔPIRT and ΔPE did not change significantly. ΔPIRT tended to correlate with –dP/dtmin and end-systolic volume, and significantly correlated with ejection fraction. IVPD during isovolumic relaxation time was decreased by LV dyssynchrony, while IVPD during early filling phase was not. A reduction of diastolic suction is observed in LV dyssynchrony and is significantly related to a decrease in SV.

Background Heart failure is associated with ventricular dyssynchrony and energetic inefficiency, which can be alleviated by cardiac resynchronization therapy (CRT) with approximately one-third of non-response rate. Thus far, there is no specific biomarker to predict the response to CRT in patients with heart failure. In this study, we assessed the role of the blood metabolomic profile in predicting the response to CRT. Methods A total of 105 dilated cardiomyopathy patients with severe heart failure who received CRT were included in our two-stage study. Baseline blood samples were collected prior to CRT implantation. The response to CRT was defined according to echocardiographic criteria. Metabolomic profiling of serum samples was carried out using ultrahigh performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry. Results Seventeen metabolites showed significant differences in their levels between responders and non-responders, and these metabolites were primarily involved in six pathways, including linoleic acid metabolism, Valine, leucine and isoleucine biosynthesis, phenylalanine metabolism, citrate cycle, tryptophan metabolism, and sphingolipid metabolism. A combination of isoleucine, tryptophan, and linoleic acid was identified as an ideal metabolite panel to distinguish responders from non-responders in the discovery set (n = 51 with an AUC of 0.981), and it was confirmed in the validation set (n = 54 with an AUC of 0.929). Conclusions Mass spectrometry based serum metabolomics approach provided larger coverage of metabolome which can help distinguish CRT responders from non-responders. A combination of isoleucine, tryptophan, and linoleic acid may associate with significant prognostic values for CRT.

Background Fragmented QRS (fQRS) is postulated to be associated with ventricular dyssynchrony and might be able to predict a nonresponse to cardiac resynchronization therapy (CRT) implantation. In this systematic review and meta‐analysis, we aim to assess whether fQRS can be a marker of intraventricular dyssynchronies in patients with ischemic and nonischemic cardiomyopathy and whether it is an independent predictor of nonresponse in patients receiving CRT. Methods We performed a comprehensive search on topics that assesses fQRS and its association with intraventricular dyssynchrony and nonresponse to CRT up until September 2019. Results Fragmented QRS is associated with intraventricular dyssynchrony (OR 10.34 [3.39, 31.54], p

BACKGROUND Recent studies have demonstrated that angiotensin receptor neprilysin inhibitors (ARNIs) can reverse the cardiac remodeling effects that occur in heart failure with reduced ejection fraction (HFrEF). These studies have also suggested that ARNIs have favorable effects on ventricular dyssynchrony. We assessed the changes in QRS duration associated with ARNIs in patients with HFrEF. METHODS We retrospectively investigated patients with HFrEF (defined by a left ventricular ejection fraction [LVEF] ≤ 35%) who were treated with ARNIs for at least six months. We divided the patients into QRS shortening and non-QRS shortening groups according to their electrocardiogram (ECG) findings. We also compared changes in echocardiographic parameters between the groups. RESULTS A total of 68 patients with HFrEF were included (mean age: 62.5 years, 74.6% male). Twenty-one patients had significant ischemic heart disease (IHD). Thirty-five patients exhibited QRS-duration shortening on follow-up ECGs (mean change: -7.8 msec), and 33 patients showed no changes or increased QRS duration (mean change: 5.1 msec). The QRS shortening group exhibited significant improvement in LVEF (12.5 ± 15.3% vs. 1.7 ± 9.5%; p < 0.001) when compared with the non-QRS shortening group. The QRS shortening group also had significantly lower LV end-diastolic dimension (LVEDD), LV end-systolic dimension (LVESD) and LV mass index (LVMI) than did the non-QRS shortening group. The change in QRS duration was significantly correlated with the change in LVEF (r = -0.329, p = 0.011) and LVESD (r = 0.298, p = 0.022). CONCLUSIONS Among patients with HFrEF treated with ARNIs, the QRS shortening group showed favorable LV systolic function recovery, and reversal of cardiac remodeling compared to those of the non-QRS shortening group. Change in the QRS duration, which reflects LV synchrony, may be associated with response to ARNIs in patients with HFrEF.

Contains fulltext : 229186.pdf (Publisher’s version ) (Closed access) The adverse effects of ventricular dyssynchrony induced by right ventricular (RV) pacing has led to alternative pacing strategies, such as biventricular, His bundle (HBP), LV septal (LVSP) and left bundle branch pacing (LBBP). Given the overlap, LVSP and LBBP are also collectively referred to as left bundle branch area pacing (LBBAP). Although among these alternative pacing sites HBP is theoretically the ideal strategy as it maintains a physiological ventricular activation, its application requires more skills and is associated with the most complications. LBBAP, where the ventricular pacing lead is advanced through the interventricular septum to its left side, creates ventricular activation that is only slightly more dyssynchronous. Preliminary studies have shown that LBBAP is feasible, safe and encounters less limitations than HBP. Further studies are needed to differentiate between LVSP and LBBP with regard to acute functional and long-term clinical outcome.

Background the assessment of myocardial work (MW) by pressure-strain loops is a recently introduced tool for the assessment of myocardial performance. Aim of the present study is to evaluate the relationship between myocardial work and exercise tolerance in patients with dilated cardiomyopathy (DCM) Methods 51 patients with DCM (mean age 57 ± 13 years, left entricular ejection fraction : 32 ± 9%) underwent cardiopulmonary exercise test (CPET) to assess exercise performance. Trans-thoracic echocardiography (TTE) was performed CPET. The following indices of myocardial work (MW) were measured regionally and globally: constructive work (CW), wasted work (WW), and work efficiency (WE). Left ventricular (LV) dyssynchrony (DYS) was defined by the presence of septal flash or apical rocking at TTE. Results LV-DYS was observed in 16 (31%) patients and associated with lower LV ejection fraction (LVEF), GLS, global and septal WE, and higher global and septal WW (Table 1). In patients with LV-DYS, septal WE was the only predictor of exercise peak VO2max at multivariable analysis (Figure 1), whereas LVEF (β=0.47, p = 0.05) and age (β=-0.42, 47, p= 0.04) were predictors of exercise capacity in patients without LV-DYS. Conclusions In patients with DCM, LV-DYS is associated with an heterogeneous distribution of myocardial work. Septal WE is the best predictor of exercise performance in these patients. Table 1 All n = 51 No-dyssynchrony n = 35 (69%) LV-Dyssynchrony n = 16 (31%) p-value LVEF, % 32 ± 9 34 ± 10 28 ± 7 0.04 GLS, % -12 ± 3 -13 ± 3 -10 ± 3 0.001 GCW, mmHg% 1325 ± 398 1342 ± 354 1287 ± 491 0.65 GWW, mmHg% 201 ± 147 154 ± 95 304 ±191 Abstract P1779 Figure.

Heart Failure (HF) is a global epidemic characterized by significant morbidity and mortality. Cardiac resynchronization therapy (CRT) and cardiac contractility modulation (CCM) are two device-based therapies currently available for HF patients. CRT enables favorable remodeling and improves quality of life (QOL) and mortality in HF patients with systolic dysfunction and ventricular dyssynchrony. A significant minority of patients does not benefit from CRT, and considerable research efforts are dedicated to improving CRT response. CCM is an emerging technology which improves left ventricular energy dynamics and remodeling by delivering non-excitatory electrical signals during the absolute refractory period. Initial studies of CCM have shown improvements in QOL and functional capacity in HF patients with systolic dysfunction and intact ventricular synchrony. Larger studies with longer follow-up are required before CCM is adopted into routine practice. This chapter will review current applications of CRT and CCM as well as describe future directions and challenges.

Right ventricular myocardial pacing leads to nonphysiological activation of heart ventricles. Contrary to this, His bundle pacing preserves their fast activation. Ultra-high-frequency electrocardiography (UHF-ECG) is a novel tool for ventricular depolarization assessment.The purpose of this study was to describe UHF-ECG depolarization patterns during myocardial and His bundle pacing.Forty-six patients undergoing His bundle pacing to treat bradycardia and spontaneous QRS complexes without bundle branch block were included. UHF-ECG recordings were performed during spontaneous rhythm, pure myocardial para-Hisian capture, and His bundle capture. QRS duration, QRS area, depolarization time in specific leads, and the UHF-ECG-derived ventricular dyssynchrony index were calculated.One hundred thirty-three UHF-ECG recordings were performed in 46 patients (44 spontaneous rhythm, 28 selective His bundle, 43 nonselective His bundle, and 18 myocardial capture). The mean QRS duration was 117 ms for spontaneous rhythm, 118 ms for selective, 135 ms for nonselective, and 166 ms for myocardial capture (P.001 for nonselective and myocardial capture compared to each of the other types of ventricular activation). The calculated dyssynchrony index was shortest during spontaneous rhythm (12 ms; P = .02 compared to selective and P = .09 compared to nonselective), and it did not differ between selective and nonselective His bundle capture (16 vs 15 ms; P.99) and was longest during myocardial capture of the para-Hisian area (37 ms; P.001 compared to each of the other types of ventricular activation).In patients without bundle branch block, both types of His bundle, but not myocardial, capture preserve ventricular electrical synchrony as measured using UHF-ECG.

Dispersion in the contraction of the normally coordinate ventricular system, referred to as left ventricular (LV) dyssynchrony, is constantly observed at different grades of severity after myocardial infarction (MI). We aimed to investigate the prognostic value of early dyssynchrony in adverse cardiac events after MI in a rat model using the quantified gated single photon emission tomography (SPECT; QGS) software. After thoracotomy, the left coronary arteries of 16 rats were occluded and reperfused. SPECT was performed with [99m Tc]methoxyisobutylisonitrile 3 days, 1 week, 2 weeks, 4 weeks, and 8 weeks after MI. The phase analysis parameters including mean phase standard deviation (PSD), bandwidth (BW), entropy, and LV function were analyzed by the QGS software. A receiver operating characteristic curve was used to explore the predictors for cardiac death and severe cardiac failure (ejection fraction [EF]

Recently, permanent His bundle pacing (HBP) has emerged as a viable pacing strategy for chronic ventricular pacing. It allows for recruitment of the native His Purkinje system thereby preventing pacing-induced ventricular dyssynchrony seen in traditional right ventricular pacing. Current tools allow for relatively good success rates for implantation. Understanding the various responses to HBP is crucial for long-term success. With better tools and unique pacing and sensing algorithms designed specifically for this form of pacing, HBP is likely to increase as a tool for long-term pacing therapy.

Permanent His bundle pacing prevents ventricular dyssynchrony in patients who depend on ventricular pacing and can provide an alternative means to implementing cardiac resynchronization therapy in patients with bundle branch disease and congestive heart failure. Adoption of His bundle pacing, however, has lagged in part due to perceived and real challenges in performing the procedure well and durably. This article focuses on what is required to get on the learning curve and developing technical competence.

Tetralogy of Fallot is the most common cyanotic congenital heart disease. Despite ongoing improvements in the initial surgical repair, there are lingering concerns regarding the long-term outcomes that may be complicated by right ventricular dysfunction, right ventricular dyssynchrony, and sudden cardiac death. The mechanisms leading to these late complications remain incompletely understood. Experimental animal models have been developed as preclinical steps to gain better insight into the pathophysiology of diseases and to develop new therapeutic strategies. This article summarizes the various types of experimental animal models of repaired tetralogy of Fallot published to date in the literature, with the aim of achieving a greater understanding of the deleterious mechanisms that may lead to these known late and sometimes lethal complications. In addition to analysing the type of animals that can be used according to a given study's objectives, needs, and constraints, the present review also evaluates the type of dysfunction that can be reproduced in our model according to the research objectives, as well as the different types of studies in which these models can be used. In view of all that, we propose a decision algorithm to create an animal model of repaired tetralogy of Fallot. This synthesis should furthermore help in the development of future studies and in the design of new experimental models, thus allowing greater insight into this disease, while not forgetting the ultimate goal of broadening future therapeutic measures to reduce the morbidity and mortality of this prevalent congenital heart disease.

Background The presence and extent of ventricular dyssynchrony are currently assessed from the QRS complex morphology and width. However, similar electrocardiography (ECG) pattern may be caused by variable ventricular activation sequence. This may then contribute to interindividually different response to cardiac resynchronization therapy (CRT). Methods Electroanatomical mapping and magnetic resonance imaging scan were performed in 11 patients with left bundle branch block (LBBB, QRS 170 ± 14 ms) and heart failure of ischemic (coronary artery disease (CAD), n = 2) and nonischemic (dilated cardiomyopathy (DCM), n = 9) etiology. Ventricular activation sequence was studied during LBBB and final CRT programming. Presence and extent of scarring were analyzed in the 17-segment left-ventricular (LV) model. Results Regardless of etiology, presence of typical LBBB was associated with diffuse prolongation of impulse conduction with right-to-left activation sequence. Basal lateral wall was constant site of late activation. This activation pattern was present in "true LBBB," but also in LBBB-like pattern (persistent S wave in V5-6) and left axis deviation. Activation started in right vetricular (RV) apex in patients with left axis deviation at RV free wall in normal axis. Individuals with CAD and DCM patient displayed focal scar. Despite that they exhibited typical LBBB and activation sequence mirrored findings in other LBBB individuals. Reverse remodeling (∆LVESV > 15% after 6 months) was evident in 10 patients. Conclusions Both typical LBBB and LBBB-like pattern might be associated with constant activation sequence regardless of etiology and scar localization. Activation initiation in RV apex, not LV activation sequence can be surrogate for left axis deviation. CRT caused inter- and intraventricular LV resynchronization without significantly changed RV activation sequence and duration.

Background: Most diabetic patients have silent ischemia and cardiac dysfunction that is usually observed in the late phase of the disease when it becomes clinically obvious. We hypothesized that left ventricular dyssynchrony (LVdys) (or dispersion) is an early marker of myocardial involvement in asymptomatic early type 2 diabetes mellitus (T2DM) patients. Therefore, we aimed to detect early markers of myocardial dysfunction in early T2DM using LVdys and left ventricular mechanical reserve (LVMR). Methods: We examined 91 consecutive subjects with early T2DM with speckle tracking imaging to evaluate LVdys and with dobutamine stress to evaluate LVMR (defined as left ventricular mechanical reserve global longitudinal strain [LVMRGLS] ≥2%). Our patients were divided into two groups according to LVdys: group 1 with LVdys (n = 49), and group 2 without LVdys (n = 42). Results: We found that 49 (54%) subjects in our cohort had resting LVdys (standard deviation of tissue synchronization of the 12 left ventricular segments [Ts-SD-12] ≥34.2 ms). GLS and strain rate were comparable at rest between patients with and without LVdys. On the other hand, LVMR was blunted in those with LVdys (p < 0.001). We found that HbA1c, high-sensitivity C-reactive protein, and left atrial volume index were inversely correlated with LVMR. Multivariate analysis showed that LVdys was the strongest predictor (p < 0.001) of blunted LVMR. Using receiver operating characteristic curve analysis, we found that a Ts-SD-12 ≥36.5 ms was the best cutoff value to predict blunted LVMR (area under the curve = 0.89, p < 0.001). Conclusion: The LVdys (Ts-SD-12) cutoff ≥36.5 ms was the optimal value for prediction of impaired LVMR and might be an early marker of subclinical cardiac dysfunction and risk stratification of subjects with asymptomatic early T2DM with preserved left ventricular ejection fraction.

Several trials are investigating the delivery of stem cells to treat ischemic cardiomyopathy. The aim of this study was the echocardiographic evaluation of the effectiveness of isolated coronary artery bypass graft (CABG) combined with bone marrow mononuclear cells (BMMNC) delivered through the graft vessels to improve left ventricular dyssynchrony in patients with previous myocardial infarction and chronic heart failure.42 patients with previous myocardial infarction and chronic heart failure were randomly allocated to either the CABG only group (n = 18) or the CABG with BMMNC graft group (n = 24group). We used 2D strain imaging to measure the absolute difference in time-to-peak radial strain between the earliest and the latest activated segments on LV short-axis images at the apical (RSTa), at the mitral annulus (RSTb), and at the papillary muscle (RSTm) level.The effective rate of LV dyssynchrony improvement was significantly higher in the CABG + BMMNC than in the CABG only group (RSTb: 91.7% vs 50%, P .05; RSTm: 78.6% vs 35.7%, P .05; RSTa: 92.3% vs 50%, P .05). The deterioration rate of LV synchrony was significantly lower in the CABG + BMMNC than in the CABG only group for RSTb (8.3% vs 70%, P .05;) and RSTm (0 vs 50%, P .05), but not for RSTa (18.2% vs 37.5%, P .05).Combining CABG with BMMNC delivering provided a better improvement of left ventricular dyssynchrony than CABG only.

Background Right ventricular apical pacing with the resultant left ventricular dyssynchrony often leads to depressed systolic function and heart failure. This study aimed at investigating the relation between various septal locations guided by ECG and fluoroscopy and the intermediate term functional capacity of the patients. Results Fifty patients who received a single lead pacemaker with assumed > 90% pacemaker dependency. Patients were randomized according to RV pacing site RV into group 1 “high septum” (n = 15), group 2 “mid septum” (n = 25), and group 3 “low septum” (n = 10) using QRS vector and duration as well as fluoroscopic parameters. Their clinical status was assessed 6 months after device implementation using 6-min walk test (6MWT). The study showed that paced QRS complex duration itself has no significant difference between the different septal pacing locations (P-value 0.675), although its combination with the paced QRS complex vector can signify the optimal pacing site and 6MWT showed a significant difference among the groups in favor of group 1; group 1 (413.3 ± 148.5), group 2 (359.8 ± 124.6), and group 3 (276.0 ± 98.5) P value 0.04. Conclusion There was a significant difference found between the three septal pacing sites concerning the patient functional capacity with superiority of high septal location. By contrast, different septal sites showed no significant difference of the paced QRS complex duration. To optimize the pacing site in the septum, assessment of the paced QRS vector in leads I and III is of a great benefit especially when combined with paced QRS complex duration assessment.

BackgroundThe aim of this study was to compare Philips and TomTec two-dimensional speckle tracking echocardiography (2D-STE) software measurements of strain and dyssynchrony values in healthy fetuses.MethodsThis was an explorative observational study in which the echocardiographic data of 93 healthy fetuses between the 20th and 38th week of gestation were determined from a four-chamber view using 2D speckle tracking. The global and segmental longitudinal strain values of both ventricles, inter-ventricular and left intra-ventricular dyssynchrony were analyzed using QLab version 10.8 (Philips Medical Systems, Andover, MA, USA) and TomTec-Arena version 2.30 (TomTec, Unterschleißheim, Germany).ResultsTomTec showed persistently lower values for all of the assessed strain and dyssynchrony variables. For all variables, the bias between vendors tended to increase with gestational age, though not to a significant extent. Left ventricular dyssynchrony and longitudinal strain within the mid segment of the septum correlated best between vendors; however, the limits of agreement were wide in both cases. None of the variables assessed in the two-chamber view compared well between QLAB and TomTec.ConclusionSpeckle tracking software cannot be used interchangeably between vendors. Further investigations are necessary to standardize fetal 2D-STE.

OBJECTIVE We investigated the impact of alternative locations of right ventricular (RV) pacing on left ventricular function and its relation to exercise capacity. METHODS Fifty patients who received a single lead pacemaker were divided according to RV pacing site into group 1 "high septum" (n = 15), group 2 "mid-septum" (n = 25), and group 3 "low septum" (n = 10) using a documented fluoroscopic method. Dyssynchrony parameters were obtained using different echocardiographic parameters. Their exercise tolerance was evaluated after 6 months of pacemaker implantation using 6 minutes walk test (6 MWT). RESULTS We found a lesser degree of dyssynchrony in mid-location and high location compared with low location pacing (radial dyssynchrony: P

Background Prognostic value of stress induced left ventricular (LV) dyssynchrony has not been fully understood. The aim of this study was to evaluate the possible impact between cardiovascular events and stress induced worsening LV dyssynchrony. Methods and results One hundred and eighty consecutive subjects with known or suspected coronary artery disease (CAD) (142 men, mean age 68±12 years) underwent both gated myocardial single photon emission computed tomography (SPECT) with 99mTc-sestamibi or tetrofosmin according to a standard same day stress-rest protocol and coronary angiography or coronary computed tomography. The summed difference score (SDS) was calculated in every subjects. LV ejection fraction (EF) and phase Entropy at after stress and rest were determined by cardioREPO software. We determined %ΔEntropy = (stress Entropy - rest Entropy)/rest Entropy x100, as an indicator of stress-induced LV dyssynchrony. In the study population, the mean SDS was 2.7±3.9 and LVEF was 58±16%, stress and rest Entropy were 0.62±0.15 and 0.57±0.13, respectively. %ΔEntropy was higher in patients with CAD than in those without CAD (3.3±11.5 vs. 10.2±15.0, respectively). Moreover, there was a strict correlation between the presence of CAD and %ΔEntropy, indicator of stress induced LV dyssynchrony (non-CAD vs. CAD and/or 1 vessel disease vs. multivessel disease: 4.3±12.5 vs. 8.8±15.6 vs. 12.7±14.3, respectively. p We examined all study subjects and they were divided into 2 groups by cut off value of the %ΔEntropy constructed with receiver operating characteristic curve (=15.4). Kaplan-Meier analysis revealed that future cardiovascular event rate was significantly higher in %ΔEntropy >15.4 group (20/57) than in %ΔEntropy However, SDS was higher in patients with future cardiovascular event than in those without cardiovascular event (4.4±5.4 vs. 2.2±3.2, respectively. p=0.001). Conclusion In patients with known or suspected CAD, stress-induced worsening LV dyssynchrony may predict the presence of CAD and future cardiac events. Acknowledgement/Funding None

Background Frequent right ventricular pacing causes ventricular dyssynchrony and adverse outcomes. His bundle pacing (HBP) offers a physiological alternative. HBP electrical performance characteristics with cardiac conduction system abnormalities are not well established. Purpose To compare HBP implant procedure related parameters in patients with abnormal atrioventricular (AV) conduction versus those with intact AV conduction. Methods Patients prospectively enrolled in the IMAGE-HBP study undergoing implant attempt with a SelectSecure 3830 lead placed at the putative His-bundle location were included in the analysis. Patients were divided into groups based on AV conduction status. Implant characteristics and electrical performance of the pacemaker were tabulated and compared between the two groups with formal statistical tests. Results Among 60 patients (age 74.7 years old and 60% male), 29 patients (48%) had abnormal AV conduction at or below the AV node (18 with AV block of which 5 also had bundle branch block (BBB), 6 with SND and BBB, and 5 with AV node ablation). The remaining 31 patients (52%) had intact AV conduction. Procedure times were not significantly different between the groups (P=0.26). Selective HBP was achieved in 20.7% of abnormal AV conduction patients and 45.2% of intact AV conduction patients (P=0.06); the remaining patients had non-selective HBP. There were no differences detected in pacing characteristics at implant and paced QRS durations by AV conduction status. Patient with intact AV conduction (N=31) Patients with abnormal AV conduction at or below AV node (N=29) Procedure time in minutes (mean ± SD, Median, IQR) 99±38; 87 [43, 180] 108±32; 108 [65, 182] Fluoroscopy time in minutes (mean ± SD, Median, IQR) 15±12; 11 [3, 50] 16±9; 13 [4, 36] Number of fixation attempts 3.0±2.2 2.2±2.0 sHBP PCT N=14 N=6 V at 0.5ms 1.8±0.9 1.7±1.2 V at 1.0ms 1.6±1.2 1.2±0.8 nsHBP PCT N=17 N=22 V at 0.5ms 2.2±1.9 1.7±1.3 V at 1.0ms 1.5±1.1 1.3±1.1 His signal recorded, number 30 (96.8%) 28 (96.6%) H-QRS interval, ms 46±7 48±13 His Injury of Current, N (%) 23 (74.2%) 18 (62.1%) Baseline Intrinsic QRS, ms 96±16 107±22 Paced QRS duration, ms (from HBP at 1.0ms) 119±23 121±19 Conclusions Selective and non-selective HBP are achievable in bradycardic patients with abnormal and intact AV conduction, including those with BBB. There were no major differences in HBP implant parameters between patients with abnormal AV conduction and those with intact AV conduction.

Idiopathic pulmonary arterial hypertension is a progressive disease with high mortality with an increasing burden of right ventricular. Right ventricular dyssynchrony was observed in idiopathic pulmonary arterial hypertension, but the association with mortality is unclear. This study aimed to investigate the impact of right ventricular dyssynchrony on the survival of idiopathic pulmonary arterial hypertension. A total of 116 patients with idiopathic pulmonary arterial hypertension were enrolled in this study. All these patients underwent comprehensive clinical evaluation. Right ventricular dyssynchrony was assessed by two-dimensional speckle-tracking echocardiography. The time to peak strain (T peak ) of right ventricular segments were obtained. Right ventricular dyssynchrony was quantified by the standard deviation of the heart rate-corrected T peak of right ventricular four segments. All patients were followed up and the primary endpoint was all cause of death. Results found patients with significant right ventricular dyssynchrony present with advanced World Health Organization functional class, worse hemodynamic status and right ventricular function. Right ventricular dyssynchrony was an independent predictive factor for the survival of idiopathic pulmonary arterial hypertension. Kaplan–Meier survival curves showed patients with right ventricular dyssynchrony had worse prognosis. In conclusion, right ventricular dyssynchrony analyzed by speckle-tracking echocardiography provided added value to hemodynamic and echocardiographic parameters in evaluating the survival of patients with idiopathic pulmonary arterial hypertension.

Item does not contain fulltext Synchronous ventricular electrical activation is a prerequisite for adequate left ventricular (LV) systolic function. Conduction abnormalities such as left bundle branch block, and ventricular pacing lead to a dyssynchronous electrical activation sequence, which may have deleterious consequences. The present review attempts to connect the various processes involved in the development of 'dyssynchronopathy', and its correction by cardiac resynchronization therapy (CRT). Abnormal electrical impulse conduction leads to abnormal contraction, characterized by regional differences in timing as well as shortening patterns and amount of external work performed. Early activated regions may show 'wasted work', which leads to inefficient action of the entire left ventricle. Moreover, both the development of heart failure (HF) in general and the regional differences in mechanical load lead to structural, electrical, and contractile remodelling processes. These have been demonstrated at the level of the myocardium (asymmetric hypertrophy, fibrosis, prolongation of activation and reduction in repolarization forces, decrease in LV ejection fraction), cell (gap junctional remodelling, derangement of the T-tubular structure), and molecule (under or overexpression of ion channels and contractile proteins subtypes and abnormal calcium handling). The myocardial adaptations to dyssynchrony are 'maladaptive'. This also explains why CRT, unlike most pharmacological treatments, continues to increase its therapeutic effect over time. Finally, better understanding of all processes involved in dyssynchrony and CRT may also lead to new pharmacological agents for treating HF and to novel pacing strategies.

Two-dimensional speckle tracking echocardiography represents a novel, simple, and reproducible technique for the estimation of left ventricular myocardial deformation (strain) and the evaluation of left ventricular twist mechanics. During the last few years, its clinical and prognostic implications in cardiomyopathies and hypertrophic cardiomyopathy (HCM), in particular, have been rapidly increasing. Reduced global longitudinal strain is associated with more severe disease and confers an increased risk for major cardiac events, independently of other clinical and echocardiographic risk factors. Left ventricular dyssynchrony also seems promising as a risk factor for sudden cardiac events. With respect to left atrial mechanics, left atrial reservoir, conduit, and contractile strain may also confer an increased prognostic value for atrial fibrillation, major cardiac events, and even sudden death. Although right ventricular global longitudinal strain is impaired in HCM compared with healthy controls and individuals with physiological hypertrophy, its prognostic significance is currently unknown. Conclusively, 2-dimensional speckle tracking imaging seems promising for HCM. However, future studies are needed to incorporate this new imaging technique in the standard evaluation of an HCM individual.

Guidelines for cardiac resynchronization therapy (CRT) have been established, but there may be a subgroup of patients not identified in these guidelines who may benefit from this therapy. We report a patient with a dynamic left ventricular dyssynchrony and severe mitral regurgitation caused by exercise successfully treated with CRT. Exercise testing should be considered in patients with left ventricular ejection fraction

The right ventricular (RV) apex has been considered to be the primary site for ventricular lead implantation since the original descriptions of permanent pacing. However, long-term RV apical pacing has been shown to have negative effects on ventricular function and hemodynamics as a result of ventricular dyssynchrony. Alternative sites of ventricular pacing, particularly the RV septum and His bundle, have been evaluated for patients with a need for long-term ventricular pacing. In this article, we review the available data on the use of these alternative sites for RV pacing.

Background Transcatheter aortic valve replacement (TAVR) is a minimally invasive approach to aortic valve replacement. However, critical cardiovascular collapse can occur during the procedure for various reasons. Case presentation A 90-year-old man with severe aortic stenosis and left circumflex artery stenosis developed acute torrential mitral regurgitation (MR) during TAVR. The valve deployment process induced left ventricular dyssynchrony due to left bundle-branch block and myocardial ischemia in the left circumflex artery region with torrential MR. Transesophageal echocardiography clearly demonstrated the mechanisms of MR, which was successfully bailed out by left ventricular pacing and intra-aortic balloon pumping. Conclusions MR can be seriously exaggerated by various and complicated mechanisms during TAVR and should be rapidly assessed and appropriately managed depending on its mechanisms. Electronic supplementary material The online version of this article (10.1186/s40792-018-0446-z) contains supplementary material, which is available to authorized users.

His bundle pacing (HBP) prevents ventricular dyssynchrony and its long-term consequences by preserving normal electrical activation of the ventricles. Since the original description of permanent HBP in 2000, the adoption of HBP has increased over the past several years. However, the reporting of procedural and clinical outcomes to date is not uniform. This article is a collaboration between several implanters with significant experience in HBP to establish a uniform set of definitions encompassing the different forms of HBP as well as define a standardized approach to gathering data end points to ensure consistency in reported outcomes.

Congenital absence of aortic valve cusps is a rare congenital heart malformation, which is commonly associated with other cardiac defects. Isolated absence of aortic valve or one leaflet is extremely rare and has not been described antenatally. We present the first case of a fetus with isolated congenital severe aortic regurgitation from absent aortic cusp and pathological specimen of this rare entity. On fetal echocardiography at 19 weeks of gestation, there were dilated aortic root and severe aortic regurgitation causing ‘to and fro’ colour flow signals across left ventricular outflow. This caused severe LV systolic dysfunction, significant ventricular dyssynchrony and cardiomegaly. On fetal autopsy, aortic root was dilated. Left coronary cusp was absent while other cusps showed mild thickening. Left ventricle was dilated and hypertrophied. Pulmonary valve leaflets were normal.

Background: Intra ventricular mechanical dyssynchrony may play an important role in ventricular arrhythmogenesis in chronic ischemic patients.Aim of the Study: To detect the prevalence of ventricular arrhythmia in chronic ischemic patients in association with left ventricular dyssynchrony assessed by left ventricular longitudinal strain.Methods: The study included 50 patients with ischemic heart disease confirmed by coronary angiography. Speckle tracking echocardiography was performed. Patients were divided into 2 groups according to presence or absence of left ventricular mechanical dyssynchrony, considering difference in time to peak ³130ms by longitudinal strain between any two opposing segment at basal and mid level in LV 12 segments positive for mechanical dyssynchrony. Every patient in both groups underwent 24 hours holter monitoring for detection of ventricular arrhythmia.Results: The study results showed that there were 45 males and 5 females. Mean age ±SD was 51.00±7.06 years. Mean heart rate was 76.92±13.29 beat/minute. Patients were divided into 2 groups. Group I included 40 patients with left ventricular dyssynchrony and mean time to peak SD was 102.5±34.16m sec and Group II included 10 patients without left ventricular dyssynchrony and mean time to peak SD was 82.3±45.1msec. 24 hours ECG Holter monitoring data showed that there was higher incidence of ventricular runs in Group I with positive dyssynchrony patients (47.5%) than those in Group II with negative dyssynchrony patients (20%).Conclusion: Left ventricular dyssynchrony assessed by left ventricular longitudinal strain could be a predictor for increased risk of ventricular arrhythmia.

The aim of the study was to evaluate systemic right ventricular (RV) dyssynchrony in patients with congenitally corrected transposition of the great arteries (CCTGA) and transposition of the great arteries (TGA) with New York Heart Association functional class (NYHA FC)

Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF) patients with an electrical substrate pathology causing ventricular dyssynchrony. However 40-50% of patients do not respond to treatment. Cardiac modeling of the electrophysiology, electromechanics, and hemodynamics of the heart has been used to study mechanisms behind HF pathology and CRT response. Recently, multi-scale dyssynchronous HF models have been used to study optimal device settings and optimal lead locations, investigate the underlying cardiac pathophysiology, as well as investigate emerging technologies proposed to treat cardiac dyssynchrony. However the breadth of patient and experimental data required to create and parameterize these models and the computational resources required currently limits the use of these models to small patient numbers. In the future, once these technical challenges are overcome, biophysically based models of the heart have the potential to become a clinical tool to aid in the diagnosis and treatment of HF.

Epicardial Cardiac pacing may lead to severe Mitral Regurgitation by one of the following mechanisms: 1) Inappropriate Atrioventricular interval. 2) Myocardial ischemia due to fast heart rate may cause transient papillary muscle dysfunction. 3) Right Ventricular apical pacing may lead to Left Ventricular dyssynchrony in the presence of optimal Atrioventricular synchrony. Acute severe Mitral Regurgitation leading to acute severe hemodynamic deterioration is a reported complication of Permanent Pacemaker insertion. Our case demonstrated acute severe MR as a consequence of RV Pacing leading to acute hemodynamic deterioration, which was relieved on withdrawal of pacing. Left Ventricular dyssynchrony can be relieved by reducing the peacemaker rate or changing to biventricular pacing, this reduces the severity of Mitral Regurgitation and improves the hemodynamics due to simultaneous activation of left and right ventricles. This case illustrates the acute and potentially dramatic effects of intra-Left Ventricular dyssynchrony upon Mitral Valve function. Informed consent was obtained from the patient to report the case. Thus right ventricular pacing can cause left ventricular dyssynchrony leading to worsening of Mitral Regurgitation. It is important to pay attention to mode of pacing when evaluating Mitral Regurgitation in patients with Right Ventricular pacemaker and unstable hemodynamics after initiation of pacing.

Inadvertent lead malpositioning into the left ventricle (LV) is an uncommon complication of pacemaker lead implantation. It can have implications on clinical outcome due to ventricular dyssynchrony, and result in further complications such as thrombus formation with subsequent embolisation. This case study reports the clinical, electrocardiographic, plain film and echocardiographic findings of an 82-year-old male in whom the intravenous lead of a dual chamber pacemaker was unintentionally passed into the LV via an atrial septal defect. Inadvertent placement was discovered incidentally following the onset of atrial fibrillation (AF) 17 years later.

Anatomical, functional, and pathophysiologic mechanisms of ischemic mitral regurgitation (IMR) are markedly different from the primary mitral regurgitation. The older and ubiquitous cutoff of EROA (effective regurgitant orifice area) and Rvol (regurgitant volume) for IMR has been reinstated in the new guideline after a brief hiatus. There had always been a lack of good-quality evidence for its introduction for guiding IMR severity in the previous guideline, and we still do not have quality evidences that could justify its reintroduction. Unlike primary MR, IMR is usually associated with reduced ejection fraction. Therefore, it appears unrealistic to keep the similar cutoff for primary MR and IMR. The cutoff of severity can be modified according to projected values of Rvol normalized to ejection fraction and EROA normalized to Rvol. In addition, the treatment outcome in these patients is determined by factors (left ventricular dyssynchrony, annular dilatation, tenting area, tenting height, tenting volume, and myocardial viability) other than the simple grading. In this review article, a series of graph have been constructed from the numerical data derived from the literatures on IMR to depict the relationship between EROA, Rvol, left ventricular end diastolic volume, and ejection fraction in order to obtain a reasonable projection formula for EROA and Rvol. Furthermore, a management algorithm has been proposed for patients with IMR undergoing coronary artery bypass grafting based on echocardiographic predictors that influence the postoperative outcome.

Left ventricular (LV) ejection fraction (EF) has poor predictive value for ventricular tachyarrhythmia (VT). Other parameters such as LV dyssynchrony (LVD), and LV scar burden have also been individually associated with VT, but the interplay of these factors in the genesis of VT has not been explored. This retrospective study sought to evaluate the relationship between LVD and imaging characteristics of the myocardial substrate in predicting VT.We identified 183 patients (150 men; mean age: 64 ± 14 years and mean LVEF: 23% ± 7%), who received an implantable cardioverter defibrillator (ICD) for primary prevention and who underwent a gated single-photon emission computed tomography (GSPECT) myocardial perfusion scan prior to ICD implantation. LVD was determined by phase analysis of the GSPECT images. Occurrence of VTs was established through routine ICD interrogations and review of electronic medical records.LVD was present in 136 (74%) patients. VT occurred in 48 (26%) patients. Ninety-eight percent of patient who experienced VT had LVD. Patients without LVD had a significantly better survival free of both sustained and non-sustained VT (HR, 95% CI 4.90, 2.12-11.20; P 0.0001). The combination of LVD and myocardial scar occupying 6% of LV myocardium accounted for 83% of all VT events.LVD assessment by GSPECT is strongly associated with incident VT in patients with low LVEF. The combination of LVD and scar burden predicted the majority of VT events.