Presence Of Dyssynchrony Research Articles

CRT should be recommended for all heart failure patients with mechanical dyssynchrony and a ventricular conduction delay regardless of the QRS morphology

Abstract Introduction Two recent meta-analyses displayed the heterogeneous effect of cardiac resynchronization therapy (CRT) in patients with a non-left bundle branch block (non-LBBB) and found an increased burden of ventricular arrhythmias after CRT (1,2). Careful patient selection is therefore paramount. Evidence suggests the assessment of mechanical dyssynchrony may guide decision-making to CRT in this challenging population. Purpose To assess the effect of CRT in patients with and without mechanical dyssynchrony compared to medication only, and in particular in patients with a non-LBBB morphology. Methods We retrospectively screened for symptomatic heart failure patients who presented between 2012 and 2018 at our clinic with a QRS duration ≥130ms and a left ventricular ejection fraction (LVEF) ≤35%. We identified 361 patients who received CRT and 1107 patients who could have been considered for CRT. Patients were excluded if echocardiographic data was unavailable, they received CRT after 2018, were 80 years or older, or had other significant co-morbidities. We enrolled the remaining 220 CRT patients ("CRT") and 124 patients treated with medication only ("Control") for analysis. Patients were categorized for the presence of mechanical dyssynchrony on echocardiography, defined as the presence of either septal flash, apical rocking, or both. Multivariable-adjusted Cox regression analyses, including stratification by the presence of dyssynchrony, was performed to compare the effect of CRT to medication only. Hazard ratios (aHR) were obtained after adjustment for age, sex, atrial rhythm, QRS duration, QRS morphology, ischemic disease, kidney function, medication and presence of a defibrillator. Sensitivity analysis was performed in patients with a non-LBBB morphology. Results The CRT and Control group were comparable except for the QRS duration (163±22ms vs 152±16ms, p<0.001), the proportion of patients on optimal medical therapy (64% vs 47%, p=0.001), patients with a defibrillator (81% vs 19%, p<0.001), and patients with a LBBB morphology (75% vs 47%, p<0.001). During an average follow-up of 6.0(±3.2) years, 162 patients (47%) died. In the overall cohort, CRT did not significantly improve survival (aHR: 0.66, p=0.065). There was, however, a marked survival benefit for CRT over medication only in patients with mechanical dyssynchrony (aHR: 0.37, p=0.001). In patients without dyssynchrony there was a trend towards harm due to CRT (aHR: 2.05, p=0.062). These results were consistent in the sub-cohort of patients with a non-LBBB morphology. Conclusion CRT significantly improves the life expectancy of patients with mechanical dyssynchrony, including patients with a non-LBBB morphology. These results add to the evidence that all heart failure patients with LVEF≤35%, QRS≥130ms and mechanical dyssynchrony should be recommended (Class I) for CRT regardless of QRS morphology, while awaiting the results of ongoing randomized controlled trials.

ХАРАКТЕРИСТИКА ПАЦИЕНТОВ-КАНДИДАТОВ НА АБЛЯЦИЮ АТРИОВЕНТРИКУЛЯРНОГО УЗЛА С ТАХИКАРДИОМИОПАТИЕЙ В СЛЕДСТВИЕ ФИБРИЛЛЯЦИИ ПРЕДСЕРДИЙ

Aim. To assess the functional status, the state of ECG parameters, parameters of cardiac hemodynamics and quality of life in patients candidates for ablation of the atrioventricular node with the implantation of pacemakers, resynchronization devices (CRT) due to tachyform of atrial fibrillation. Materials and methods: the study included 61 patients with a mean age of 59.4 ± 10.4 years, BMI 31.3 ± 5.8; test 6-min. walk 315 ± 173m. Group 1 pacemaker – patients with implanted pacemaker 19 people, group 2 CRT – 42 people. Quality of life according to the Minnesota questionnaire in the cohort – 49 [32; 65] points (unsatisfactory), CHF FC 2 in general and FC 3 in the pacing group and FC 2 in the CRT group, but no significant differences. The mean QRS duration was 115 [90.146], ms. no significant differences between groups. Only the ratio of R6/S6 and the value of (S1+R6)-(S6+R1) were significantly different in subgroups with different QRS widths, which may be a predictor of the effectiveness of electrocardiotherapy. Ejection fraction (EF) was 32.0 ± 7.6% due to tachycardiomyopathy. Signs of interventricular and intraventricular dyssynchrony were registered. Conclusion: patients with tachycardiomyopathy have signs of a significant decrease in the quality of life and cardiac function, however, these changes, apparently, are not due to the width of the QRS complex, the presence of dyssynchrony and the criteria for referring to CRT therapy, but primarily tachysystole and a decrease in the overall contractility of the myocardium.

Correlation of electrocardiographic criteria for left bundle branch block with intraventricular synchrony

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION About 30% of patients are nonresponders to cardiac resynchronization therapy. One of the reasons proposed is that these patients do not present a true left bundle branch block (LBBB) and for that reason they do not develop dyssynchrony in the left ventricle. New electrocardiographic criteria have been published to define a true LBBB. Synchromax is a non-invasive, simple and practical method that has been shown to have a high predictive value for detecting electrical dyssynchrony and a very good correlation with mechanical dyssynchrony. OBJECTIVE Correlate the electrocardiographic criteria of LBBB individually or grouped, with the presence of dyssynchrony. METHODOLOGY Patients with LBBB (Minnesota Code) were prospectively collected. Those with pacemakers were excluded. The following electrocardiographic criteria were analyzed individually and in association: a) QS image in V1; b) QRS duration: 120-149 ms, ≥150 ms; c) Monophasic complexes with Notching or Slurring in D1 and / or V6 (Notch / S); d) QRS axis in the frontal plane deviated to the left (≥ -30º). Synchromax curves and values were taken from all patients and classified according to the indices as Synchronous (<0.4), Intermediate (0.4-0.7) or Asynchronous (> 0.7). RESULTS Were included 46p; age 34-89 years; 27 men. Heart rhythm was sinus in 40p and atrial fibrillation in 6p. The underlying heart disease was: Ischemic: 20p, Dilated Cardiomyopathy: 4p, Valvular: 3p, Chagas: 1p, Hypertensive heart disease: 18p. The results can be seen in table 1. CONCLUSION Of the LBBB electrocardiographic criteria analyzed in this study, QRS duration ≥150 ms and left axis deviation were the best predictors of dyssynchrony individually and in association. Table 1: ResultsQRS120/149QRS ≥150QSV1Notch/SLeftAxisQSV1+≥150Notch/S+≥150LeftAxis+≥150Nº Patients2917272625131110Synchronous5(17%)2(16%)3(11%)5(19%)1 (4%)2(15%)1(9%)0Intermediate6(20%)1(8%)4(15%)2(7%)2(8%)1(8%)1(9%)0Asynchronous18(63%)14(82%)20(74%)19(74%)22(88%)10(77%)9(82%)10(100%)Abstract Figure. synchronous and asynchronous LBBB

Relationship between fragmented QRS and response to cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF) with a wide QRS. Fragmented QRS (fQRS) on a 12-lead electrocardiography (ECG) has been shown to predict cardiac events in several patient populations. We aimed to investigate the relationship between fragmented wide QRS (f-wQRS) and left ventricular dyssynchrony and response to CRT. Fifty-three patients with HF undergoing CRT were studied. The presence of fQRS was assessed using standardized criteria. Dyssynchrony was defined as interventricular mechanical delay (IVMD) ≥40 ms and tissue Doppler velocity opposing-wall delay ≥65 ms. Echocardiographic response to CRT was defined by a ≥15 % reduction in left ventricular end-systolic volume at 6 months follow-up. Fragmented wide QRS was present in 17 (32 %) patients. Interventricular and intraventricular dyssynchrony were highly prevalent in both patient groups with f-wQRS and nonf-wQRS (64.7 % vs 75 %, p = 0.44; 70.6 % vs 72.2 %, p = 0.25). Ischemic HF was significantly higher in patients with f-wQRS than patients with nonf-wQRS (64 % vs 33 %, p = 0.03). Reverse remodeling was developed in 32 (89 %) and 6 (35 %) of patients with nonf-wQRS and f-wQRS, respectively (p = 0.001). In multivariate analysis, significant associates of response to CRT were evaluated adjusting for etiology of cardiomyopathy, QRS width, IVMD, intraventricular delay, and f-wQRS. Lack of f-wQRS was the only predictor of response to CRT (OR 1.556, 95 % CI, 0.016-0.806, p = 0.028). Presence of dyssynchrony is necessary but not sufficient to select appropriate candidates for CRT. Presence of f-wQRS on baseline ECG may play a role in identifying patients who may not respond to CRT.

Incremental prognostic value of combining left ventricular lead position and systolic dyssynchrony in predicting long-term survival after cardiac resynchronization therapy

The efficacy of CRT (cardiac resynchronization therapy) can be affected by a number of factors; however, the prognostic significance of the LV (left ventricular) lead position has not been explored. The aim of the present study was to examine whether a PL (posterolateral) lead position has an additional value to systolic dyssynchrony in predicting a better survival after CRT. Patients (n=134) who received CRT were followed-up for 39+/-24 months. The LV lead position was determined by cine fluoroscopy, and baseline dyssynchrony was assessed by TDI (tissue Doppler imaging). The relationship between the LV lead position/dyssynchrony and mortality was compared using Kaplan-Meier curves, followed by Cox regression analysis. The all-cause and cardiovascular mortalities were 38 and 31% respectively. The presence of dyssynchrony and a PL lead position predicted a lower all-cause mortality (29 compared with 47%; log-rank chi2=5.38, P=0.02) and cardiovascular mortality (21 compared with 41%; log-rank chi2=6.75, P=0.009) than when absent. The all-cause mortality was as high as 62% when patients had neither dyssynchrony nor a PL lead position, but was reduced to 29% when both criteria were present, and was between 45 and 46% when only one criterion was present (chi2=6.79, P=0.01). The corresponding values for cardiovascular mortality were 62% when patients had neither dyssynchrony nor a PL lead position, 36-38% when patients had either dyssynchrony or a PL lead position, and 21% when patients had both criteria present (chi2=9.54, P=0.004). Combining dyssynchrony and a PL lead position independently predicted a lower all-cause morality {HR (hazard ratio), 0.496 [95% CI (confidence interval), 0.278-0.888]; P=0.018} and cardiovascular mortality [HR, 0.442 (95% CI, 0.232-0.844); P=0.013]. In conclusion, the placement of the LV lead at a PL position provides additional value to baseline dyssynchrony in predicting a lower all-cause and cardiovascular mortality during long-term follow-up after CRT.

Response to Letters Regarding Article, “Tissue Doppler Imaging in the Estimation of Intracardiac Filling Pressure in Decompensated Patients With Advanced Systolic Heart Failure”

We thank all the authors for their interest and insightful comments about our article1 and the tremendous contributions of the American Society of Echocardiography/European Association of Echocardiography Diastology Writing Group.2 We believe the many issues raised about the potential inaccuracies of our findings are precisely the factors that may directly influence the reliability of the ratio of early transmitral velocity to tissue Doppler mitral annular early diastolic velocity (E/Ea) to act as the single surrogate estimate of left ventricular filling pressures. In particular, the confounding factors that they addressed (such as the degree of ventricular remodeling, prevalence of mitral regurgitation, presence of dyssynchrony, or previous cardiac resynchronization therapy) are commonly observed in patients presenting with advanced decompensated heart failure. These are the exact patients in whom assessing intracardiac filling pressures may have a major impact on treatment decisions (such as initiation of diuretic therapy to relieve congestion). In essence, their salient points about the limitations of our findings are concordant with our observations on the …

Left Ventricular Systolic and Diastolic Dyssynchrony in Asymptomatic Hypertensive Patients

Diastolic and systolic dyssynchrony are common in patients with heart failure. However, the presence of dyssynchrony in asymptomatic patients with hypertension who are susceptible to the development of heart failure is not well understood. The aims of this study were (1) to evaluate the prevalence of systolic and diastolic dyssynchrony and (2) to identify the main determinants of left ventricular (LV) dyssynchrony in asymptomatic patients with hypertension. One hundred ten patients with hypertension consecutively enrolled were compared with 55 age-matched and gender-matched normal control subjects. Comprehensive echocardiography was performed, including conventional and Doppler tissue imaging parameters. LV end-systolic wall stress was calculated using a hemodynamic and echocardiographic M-mode data set. For the assessment of LV dyssynchrony, both the standard deviation of the time from QRS onset to peak systolic velocity and the maximal difference of the time from QRS onset to peak systolic velocity from 6 basal segments at the apical views were used and were compared between the two groups. Both systolic and diastolic dyssynchrony indexes were significantly higher in patients with hypertension than in the normal controls (P < .001), with no significant correlation between the systolic and diastolic dyssynchrony indexes. The proportions of patients with hypertension who had LV systolic and diastolic dyssynchrony were 24% and 21%, respectively. Multivariate analysis showed that the E/E' ratio (P < .001) was independently associated with LV systolic dyssynchrony, whereas LV mass index (P = .001) and E/E' (P < .001) were major determinants of LV diastolic dyssynchrony. LV systolic and diastolic dyssynchrony are not uncommon in asymptomatic patients with hypertension and are significantly associated with LV filling pressure. The determinants of LV systolic dyssynchrony are not the same as those of diastolic dyssynchrony, implying that different mechanisms are involved in the development of LV systolic and diastolic dyssynchrony in asymptomatic patients with hypertension.

Relation of mechanical dyssynchrony with underlying cardiac structure and performance in chronic systolic heart failure: implications on clinical response to cardiac resynchronization

The aim of this study is to describe the relationship between ventricular mechanical dyssynchrony (VMD) and echocardiographic indices of cardiac remodelling. We evaluated 219 ambulatory patients with chronic systolic heart failure [left ventricular ejection fraction (LVEF) <or= 35%, New York Heart Association functional classes II-IV] who underwent echocardiographic evaluation. The presence of dyssynchrony was defined by Bader criteria (intra-VMD > 40 ms and/or inter-VMD > 38 ms). In our study cohort, 59% of patients had evidence of dyssynchrony (including 44% with intra-VMD and 38% with inter-VMD, and 20% with both). Inter-VMD correlated with QRS width (r = 0.48, P < 0.0001) better than intra-VMD (r = 0.24, P < 0.001). Higher inter-VMD was associated with less restrictive filling patterns (rank sums P = 0.012) and larger left ventricular end-diastolic dimension (LVEDD, rank sums P = 0.020), but intra-VMD values were similar across diastolic stages and LVEDD tertiles. In chronic systolic heart failure, evidence of mechanical dyssynchrony is prevalent but the underlying cardiac structure and performance may influence the degree of inter-VMD more so than intra-VMD. Our data suggest that the extent of inter-VMD is directly related to the degree of dilatation of the heart but inversely to diastolic dysfunction.

Abstract 697: Dyssynchrony in Duchenne Muscular Dystrophy Demonstrated by Tagged MRI Analysis is Independent of Ejection Fraction

Patients with Duchenne Muscular Dystrophy (DMD), a dystrophinopathy, universally develop dilated cardiomyopathy, which is associated with abnormal myocardial strain, as well as heterogeneous development of fibrosis as demonstrated by pathology and more recently by cardiac MRI methods. We sought to determine the presence of systolic dyssynchrony in this population using cardiac MRI tagging methods. We analyzed tagged MRI images for the presence of dyssynchrony in 61 males (age 12.5 ± 4.4 y) with a dystrophin mutation undergoing clinical cardiac MRI. Tagged MRI images were analyzed using HARP® analysis of regional strain and strain-time curves. The mid-myocardial slice was specifically analyzed, by dividing it into 6 coronary perfusion regions. Dyssynchrony was defined by the presence of either of 2 previously published indexes modified for use with MRI data: 1) time difference of 1 st to last regional peak strain &gt; 100 ms; 2) standard deviation of time differences to peak strain for each of the six regions &gt; 33 ms. Additional indexes evaluated included heart rate, LV ejection fraction, mid-myocardial composite circumferential strain, and presence of delayed myocardial hyperenhancement (MDE). Among the 61 subjects analyzed, 28 (46%) exhibited dyssynchrony indexes 1 and 2, while 8 additional subjects met dyssynchrony index 2 but not index 1. Only 4 subjects, all of whom met both dyssynchrony criteria, had positive MDE and abnormal EF &lt;55%. The regions of slowest activation were highly dispersed and not clustered to the areas of positive MDE. One additional subject with dyssynchrony by either of the critieria also had abnormal EF but did not have MDE. There was no statistically significant difference between mean EF (61 vs 62%), age (12.58 vs 12.63 yrs), heart rate (105 vs 108 bpm) or mid-myocardial composite circumferential strain (−13.3 vs −12.9%) between those subjects with dyssynchrony (by either criteria) and those without. DMD patients frequently exhibit systolic dyssynchrony even in the presence of normal EF. However, the dispersed nature of the dyssynchrony suggests that resynchronization therapy once EF becomes abnormal is unlikely to be of benefit in DMD cardiomyopathy.

Visual LV motion and invasive LVdP/dtmax for selection and optimisation of cardiac resynchronisation therapy

Echocardiography shows that multiphasic septal movement and a septal to lateral apical systolic left ventricular (LV) motion have a high predictive value for dyssynchrony and the response to cardiac resynchronisation therapy (CRT). Presence of dyssynchrony is also the major marker for CRT response in the presence of scar tissue, provided the interventricular (V-V) pacing interval is optimalised. For atrioventricular (AV) interval optimisation, the velocity-time integral of the transmitral flow has an excellent correlation with invasive LVdP/dt(max). In acute haemodynamic measurements, LVdP/dt(max) shows strongly the effect of AV and V-V optimisation. It also illustrates that the haemodynamic effect of LV pacing when associated with intrinsic conduction over the right bundle is equal to or better than biventricular pacing. We found that once AV and V-V interval were optimised, QRS morphology could be used as a template for optimal therapy. Automated continuous optimisation of the pacing intervals will be the big challenge for the future. (Neth Heart J 2008;16(Suppl1):S32-S35.).

Abstract 3076: Effects of Exercise on Ventricular Mechanical Dyssynchrony in Patients with Heart Failure Currently not Recommended for Resynchronization - Results from the Dyssynchrony Induced by Ventricular Exertion in Heart Failure (DIVE-HF) Study.

Background. Resynchronization therapy has been proven to improve exercise tolerance only in heart failure (HF) patients (pts) with profoundly impaired left ventricular ejection fraction (LVEF). Whether it could be useful to other spectrum of HF pts may depend on the existence of ventricular dyssynchrony, either at rest or exercise-induced. Methods. We studied clinical features, ECG, and echocardiography coupled with tissue Doppler imaging (TDI) in 70 pts (38 men and 32 women, mean age 62±13 years). Among them, 60 pts with compensated HF (functional class II–III) for at least 3 months were grouped into systolic HF (SHF; EF=35–50 %, N=30) and diastolic HF (DHF; EF=50 % plus diastolic dysfunction, N=30) groups. The other 10 pts had no systolic or diastolic dysfunction are the control group. Six-minutes (stage 2) treadmill exercise tests were performed for SHF pts by modified Bruce protocol and for DHF and control pts by Bruce protocol. Dyssynchrony index (DI) represented by standard deviation of electromechanical delays of 12 LV segments was measured before and immediately after exercise. Results. Except for diverse clinical features and conventional echo-parameters as expected, the QRS duration was similar (mean: 93±16 ms) between the 3 groups. TDI studies showed that baseline synchronized LV contraction remained unchanged after exercise (DI: 12.4±3.6 vs. 11.8±2.9 ms, p =ns) in control group. With regard to the DHF group, the preexisting ventricular dyssynchrony got significantly exacerbated (DI: 52.4±10.0 vs. 62.4±12.8 ms, p&lt; 0.001) including 21 pts (70%) with a ≥ 10% increase of DI after exercise provocation. With a more complex response to exercise, the DI in SHF pts didn’t worsen significantly (27.0±19.2 vs. 32.8±20.6 ms, p&lt; 0.06). However, the proportion of DI&gt;33 ms, considered as presence of dyssynchrony, increased from 37% at baseline to 50% after exercise, including 6 pts (20%) with post-exercise new development and 2 pts (7%) with post-exercise disappearance of ventricular dyssynchrony. Conclusions. Exercise-exacerbated ventricular dyssynchrony in DHF pts, and a 50% incidence of post-exercise dyssynchrony in SHF pts with LVEF between 35 to 50% may support the potential utility of resynchronization therapy to these non-indicated HF groups.