Ventricular Dyssynchrony Research Articles

Prognostic significance of phase analysis using SPECT myocardial perfusion imaging in heart failure: a systematic review and meta-analysis.

Left ventricular mechanical dyssynchrony (LVMD) is an important prognostic factor for heart failure (HF). Phase analysis of myocardial perfusion SPECT is actively being researched to evaluate LVMD. We performed a systematic review and meta-analysis on the prognostic significance of LVMD using gated SPECT in HF patient. PubMed, Embase, and the Cochrane library were searched until January 10, 2024, for studies reporting the prognostic value of LVMD in HF patients using gated SPECT for outcomes of all-cause death, cardiac death, or major adverse cardiovascular event (MACE). Hazard ratios (HRs) along with their corresponding 95% confidence intervals (CIs) were combined through meta-analysis employing a random-effects model. Funnel plots and Egger's tests were utilized to evaluate publication bias, and trim-and-fill method were applied where bias was identified. Ten studies (2585 patients) were included; six on MACE and five on all-cause or cardiac death. Prognoses were worse in patients with LVMD assessed by SPECT than in those without LVMD, with the overall pooled HR for MACE being 2.05 (95% CI, 1.65-2.54). The pooled HR for all-cause or cardiac death was 2.08 (95% CI, 1.10-3.94); however, publication bias was present (p = 0.0024), and after adjustment, the prognostic value of LVMD was not statistically significant (HR, 1.24; 95% CI, 0.68-2.23). Assessing LVMD through myocardial perfusion SPECT proves to be a significant indicator of subsequent adverse cardiac events in HF patients. Utilizing phase analysis of SPECT could offer valuable insights for risk assessment and decision-making regarding therapy in HF patients.

Abstract 4137695: Bundle Branch Block(BBB) is Independently Associated With Adverse Cardiovascular Outcomes in Patients With Heart Failure With Preserved Ejectionfraction(HFPEF): A Propensity Score Matched Analysis

Background: Ventricular dyssynchrony due to BBB can cause adverse cardiovascular(CV) outcomes in HF with reduced EF and is known to occur in HFpEF but its independent impact on is unclear. Objective: To determine if BBB is an independent risk factor for adverse HF outcomes in HFpEF and the impact of atrial fibrillation (AF).. Methods: We studied the impact of BBB in HFpEF utilizing propensity score(PS) matched cohorts without and with BBB from the TOPCAT Americas trial to account for confounding by other co-morbidities. Outcomes analyzed included the TOPCAT primary outcome, CV death&hospitalization (CVH), sudden death, pump failure death (PFD), HF hospitalizations(H), and progression of HF. The impact of concomitant AF ( defined as any AF or AF on ECG) on these outcomes with and without BBB was analyzed. Results: 329 pts with HFpEF&BBB were PS matched for 24 demographic&disease state variables, BNP strata and AF status with a cohort of 329 pts with HFpEF without BBB. BBB was associated with increased risk of the TOPCAT primary outcome (Hazard ratio{HR} 1.44, 95% confidence intervals {CI} 1.10-1.89, p=0.008), increased risk of HF hospitalizations by 41%(HR 1.41 95% CI 1.04-1.91 p=0.0248) but not CVH (HR 1.18, 95% CI 0.93-1.49, p=..169), but not sudden death (HR 1.40, 95% CI 0.70-2.82, p=0.342) or CV death (HR 1.26, 95% CI 0.84-1.89, p=0.257). Risk of pump failure death (PFD) with BBB was significantly higher in HFpEF subjects without a history of AF (Figure left panel .Kaplan Meier Log rank p=0.0478, HR: 4.22, 95% CI: 0.89 to 19.87, p=0.0689) but not in AF (p=0.138). PFD risk was markedly higher in AF subjects without BBB ( Figure right, Kaplan Meier Log rank p=.0012, HR:7.99, 95% CI:1.80 to 35.41,p = 0.0063) than those with BBB (p=0.91) Conclusion: Ventricular dysynchrony induced by BBB independently worsens HFH risk in HFpEF. Its adverse impact on PFD iis seen in the absence of AF. Increase in PFD risk with AF in HFpEF subjects is most prominent in those with normal intraventricular conduction. Mechanical dyssynchrony induced by BBB may have a role in HFpEF subgroups with preserved atrioventricular filling, leading to these adverse HF outcomes

The mechanistic interaction between mechanical dyssynchrony and filling pressure in cardiac resynchronization therapy candidates.

Both left ventricular (LV) mechanical dyssynchrony and filling pressure have been shown to be associated with outcome in heart failure patient treated with cardiac resynchronization therapy (CRT). To investigate the mechanistic link between mechanical dyssynchrony and filling pressure and to assess their combined prognostic value in CRT candidates. Left atrial pressure (LAP) estimation and quantification of mechanical dyssynchrony were retrospectively performed in 219 CRT patients using echocardiography. LAP was elevated (eLAP) in 49% of the population, normal (nLAP) in 40%, and indeterminate (iLAP) in 11%. CRT response was defined as %-decrease in LV end-systolic volume after 12±6 months CRT. Clinical endpoint was all-cause mortality during 4.8 years (interquartile range: 2.7-6.0 years). To investigate the mechanistic link between mechanical dyssynchrony and filling pressure, the CircAdapt computer model was used to simulate cardiac mechanics and hemodynamics in virtual hearts with LBBB and various causes of increased filling pressure. Patients with nLAP had more significant mechanical dyssynchrony than those with eLAP. The combined assessment of both parameters before CRT was significantly associated with reverse LV remodeling and post-CRT survival. Simulations revealed that mechanical dyssynchrony is attenuated by increased LV operational chamber stiffness, regardless of whether it is caused by passive or active factors, explaining the link between mechanical dyssynchrony and filling pressure. Our combined clinical-computational data demonstrate that in patients with LBBB, the presence of mechanical dyssynchrony indicates relatively normal LV compliance and low filling pressure, which may explain their strong association with positive outcomes after CRT.

Dyssynchronous Fetal Heart Failure in Maternal Diabetes: Evaluation with Speckle Tracking Echocardiography and Novel M-Mode Software

ObjectivesThis study aimed to investigate dyssynchronous heart failure in fetuses of mothers with diabetes mellitus (FDM) and fetal controls (FC) using two-dimensional speckle tracking echocardiography (2D-STE) and novel M-mode prototype software (PS). MethodsIn this cohort study 174 fetuses were analyzed, 87 in the FDM-cohort and 87 gestational age-matched fetuses in the FC-cohort. A subgroup of 38 fetuses formed the final case group, with a high median frame rate of approximately 160 frames/s. Using 2D Cardiac Performance Analysis software (TOMTEC, Unterschleissheim, Germany) we measured global longitudinal strain (GLS). TOMTEC PS detected annular displacement by assessing an artificial M-mode on the previously generated tracking. Dyssynchrony (DYS) was calculated as the inter- and intraventricular difference in time to peak GLS or annular displacement. ResultsGreater DYS was observed in all basal myocardial measurement sites and software between FDM-cohort compared to FC-cohort and no significant correlation was found between DYS measurements and gestational age. Intraventricular DYS between the basal segments was statistically significant (all p ≤ 0.036, Wald test of univariate regression models). The PS performed best in DYS measurements identifying right ventricular DYS as potentially predicting FDM (FDM: median, 18.5 (interquartile range [IQR], 13.9–25.0) ms vs. FC: median, 2.7 [IQR, 1.5–3.5] ms; p < 0.001). ConclusionIncreased intraventricular DYS demonstrated an impact of maternal diabetes mellitus on fetal hearts independent of gestational age. The prototype M-mode method identified cardiac dysfunction with higher accuracy than the conventional analysis. High-quality echocardiographic image acquisition is imperative for clinical application of 2D-STE and related advanced technologies.

Horizontal QRS Axis Predicts Response to Cardiac Resynchronization Therapy in Heart Failure Patients with Left Bundle Branch Block

Electrocardiogram criteria for left bundle branch block (LBBB) inadequately predict left ventricular electrical dyssynchrony, complicating cardiac resynchronization therapy (CRT) candidate selection. To investigate the predictive value of the horizontal QRS axis for CRT response in heart failure (HF) patients with LBBB patterns. The direction and magnitude of the horizontal QRS axis were calculated using the net amplitudes in leads V2 and V6. CRT response was defined as a ≥10% increase in left ventricular ejection fraction (LVEF) and at least one New York Heart Association (NYHA) class reduction one-year post-CRT implantation. The composite endpoint included HF hospitalization or all-cause mortality. Among 244 consecutive CRT recipients, 156 (63.9%) responded favorably, while 88 (36.1%) were non-responders. The horizontal QRS axis demonstrated significant backward deviation [-75.5° (-79.7°, -69.0°) vs. -65.0° (-73.0°, -46.5°), P <0.001] and larger magnitude (35.5±10.9 mm vs. 25.5±10.5 mm, P <0.001) in CRT responders compared to non-responders. The direction and magnitude independently predicted CRT response with an area under the curve (AUC) of 0.778 (95% CI: 0.717, 0.839) and 0.749 (95% CI: 0.685, 0.814), respectively. Combining both parameters increased the AUC to 0.814 (95% CI: 0.760, 0.868). Moreover, the direction and magnitude of the horizontal QRS axis, or their combination, predicted the composite endpoint of HF hospitalization or all-cause mortality, with hazard ratios (HR) of 0.36 (95% CI: 0.22, 0.60), 0.41 (95% CI: 0.25, 0.67), and 0.25 (95% CI: 0.15, 0.41), respectively. Horizontal QRS axis accurately predicts CRT response and prognosis in HF patients with LBBB.

Usefulness of left ventricular mechanical dyssynchrony for predicting atrial fibrillation and adverse outcomes following first atrial fibrillation event

Abstract Background Left ventricular mechanical dyssynchrony (LVMD) has shown to predict many cardiovascular outcomes including ventricular arrhythmias. Our hypothesis is that LVMD can reveal early atrial dysfunction. Purpose The aim of this study was to investigate whether LVMD can be used to predict atrial fibrillation (AF) and adverse outcomes following first AF event in individuals from the general population. Methods A total of 3785 individuals (mean age 55±17 years, 57% women) from the general population free of AF, heart failure (HF) and prior stroke had an echocardiographic examination performed including two-dimensional speckle tracking echocardiography. LVMD was calculated as the standard deviation of the regional time-to-peak strain from the three apical views. The primary endpoint was AF, and the secondary endpoint was complicated AF as assessed by the occurrence of either stroke or HF after the diagnosis of AF. Results During a median follow-up of 5 years (interquartile range, 4.4-6.2 years), 142 (4%) individuals were diagnosed with AF, and of these 22 (15%) individuals developed HF or stroke. LVMD was a univariable predictor of AF (per 10ms increase: HR 1.03; 95% CI (1.02-1.05), p&amp;lt;0.001, Figure). The association remained significant even after multivariable adjustment for age, sex, body mass index, diabetes, hypertension, heart rate, previous ischaemic heart disease, systolic blood pressure, diastolic blood pressure, smoking, left ventricular ejection fraction, global longitudinal strain, left atrial volume index (LAVI), and E/e’ (per 10ms increase: HR 1.02; 95% CI (1.00-1.04), p=0.042). LVMD also predicted complicated AF, and the association remained significant even after multivariable adjustment (per 10ms increase: HR 1.05; 95% CI (1.01-1.09), p=0.026). Furthermore, LVMD provided incremental prognostic information over the LAVI with regard to predicting AF (Harrell’s C-statistics 0.66 vs. 0.70, p=0.012). Conclusion In a low-risk general population, LVMD provides prognostic information on the risk of AF. Additionally, LVMD can identify individuals with complicated AF defined as occurrence of either stroke or HF following the diagnosis of incident AF. Furthermore, LVMD provides incremental prognostic information over the LAVI in predicting AF.

ECG as a screening tool for detection of significant functional mitral regurgitation in patients with left bundle branch block

Abstract Background Functional mitral regurgitation (FMR) may occur in the left bundle branch block (LBBB) due to mechanical left ventricular (LV) dyssynchrony, by the imbalance between the tethering and the closing forces exerted on the mitral apparatus1-3. Progressive FMR and LV remodeling result in a reciprocal worsening downward spiral and worse clinical outcomes1-3. Therefore, timely screening and follow-up of these patients to prevent the irreversible progression of FMR is required. To date, only LBBB morphology and QRS duration have been proven predictors of FMR4. Purpose This study aimed to assess the relationship between ECG parameters of LV dyssynchrony and the severity of FMR in patients with LBBB. Methods We retrospectively included 154 consecutive patients with LBBB, in sinus rhythm, who had an echocardiogram, with no more than mild organic valvular heart disease. We measured the following intraventricular dyssynchrony markers: LV activation times (LVAT), intrinsicoid deflection (ID) in lateral and aVF leads and a newly defined marker – the difference (Diff) between aVL and aVF ID’s (Diff_IDaVL_aVF). These two leads record the electrical activation of the two opposing myocardial segments adjacent to the posteromedial and anterolateral papillary muscles, respectively5 (Figure 1). Based on the severity of FMR, the patients were divided into two groups: no/mild FMR (grade II or less) (61%), and significant FMR (grade III and IV) (39%). Results In patients with significant FMR, the LVAT measured in lateral leads, the IDaVL and Diff_IDaVL_aVF were significantly longer, but IDaVF was significantly shorter compared to patients with no/mild FMR (p&amp;lt;0.001). Of all studied ECG parameters, the Diff_IDaVL_ aVF was the parameter that had the strongest correlation with significant FMR (r correlation coefficient 0.82, p &amp;lt; 0.001). In multivariable analysis the Diff_IDaVL_aVF (p = 0.010) was the only parameter independently correlated with significant FMR. On ROC analysis the best cut-off for significant FMR prediction was 55 ms (AUC of 0.99, sensitivity 90% and specificity 97%) (Figure 2). Conclusions In LBBB, a simple intraventricular dyssynchrony ECG parameter can provide insights into FMR severity. A 55 msec Diff_IDaVL_aVF identifies significant FMR that may benefit from early medical or CRT treatment to avoid progression and worse prognosis.

Myocardial single photon emission computed tomography imaging to identify non-responders to cardiac resynchronization therapy in patients with non-left bundle branch block

Abstract Background Non-response to cardiac resynchronization therapy (CRT) is an important issue in the treatment of heart failure with reduced ejection fraction (HFrEF) and non-left bundle branch block (LBBB). Although the QRS duration and morphology are crucial parameters for selecting CRT candidates, electrocardiogram (ECG) markers may inadequately represent the mechanical activation patterns within the heart. Owing to limitations associated with the ECG criteria, there is increasing interest in advanced multimodality imaging to improve patient selection. Recently, myocardial single-photon emission computed tomography imaging (G-MPI) is used for assessing left ventricular (LV) dyssynchrony. This technique is mostly automatic and has high intra- and inter-observer reproducibility and repeatability. Objectives This study aimed to examine whether preoperative G-MPI evaluation could predict non-responsiveness to CRT in patients with HFrEF with non-LBBB. Methods Between January 2021 and December 2022, 128 patients underwent CRT, of whom 73 with pre-operative evaluation using G-MPI were selected. Forty-three patients with non-LBBB (21 and 22 CRT responders and non-responders, respectively) were assessed. These patients were divided into CRT responder and non-responder groups. We evaluated the cut-off and clinical impact of pre-operative G-MPI parameters in predicting non-responsiveness to CRT. In addition, 30 patients with LBBB were analyzed. Results Among patients with non-LBBB, CRT responders and non-responders showed no significant differences in baseline characteristics, except for the LV dimension. A receiver operating characteristic curve analysis identified 108° and 27.7° as the optimal cut-offs for the bandwidth and phase standard deviation (SD), respectively, to predict non-responsiveness to CRT (area under the curve [AUC]=0.762; 95% confidence interval [CI]: 0.601–0.923 and AUC=0.742; 95% CI: 0.576–0.909, respectively). A multivariate analysis revealed that a cut-off bandwidth of ≥108° and phase SD of ≥27.7° are independent predictors of non-responsiveness to CRT in patients with non-LBBB (hazard ratios 5.65; 95% CI: 1.53–20.9; P=0.009). In contrast, there were no relationships between G-MPI parameters and non-responsiveness to CRT in patients with LBBB. Conclusions Pre-operative G-MPI findings were associated with non-responsiveness to CRT in patients with non-LBBB. The identification of potentially nonresponsive patients could influence patient management and alter outcomes.

Sex-specific prognostic implications of new-onset atrial fibrillation in patients treated with dual chamber pacemakers

Abstract Background Right ventricular pacing induces ventricular dyssynchrony, which over time may result in left ventricular dysfunction, increased left ventricular filling pressures, and ensuing left atrial dilatation, with increased risk of atrial arrhythmias. Atrial fibrillation (AF) prior to device implant is associated with worse prognosis, but the prognostic effects of new-onset AF during pacemaker treatment are less well described. Purpose To describe risk factors, incidence, and prognostic effects of new-onset AF after treatment is initiated with a dual chamber pacemaker. To evaluate mortality and risk of heart failure diagnosis or hospitalisation for heart failure in patients who develop AF, compared to those who do not develop AF. Methods All patients without pre-existing heart failure or atrial fibrillation, who received a dual chamber pacemaker at a large-volume tertiary care center during the period 2005–2020 were included. Data was crossmatched between the national pacemaker registry, the population registry and national disease registries. The primary outcome was 10-year mortality, and the secondary outcome was new-onset heart failure. Results 37127 patients were included in the study, of which 14760 (30%) were female. Median age was 76.4 years [interquartile range, IQR, 68.0–83.1] and the most common indication for pacemaker implant was AV block (57.7%), see Table 1. Overall, 10-year survival was higher for female patients, compared to male patients, p&amp;lt;0.0001 (see Kaplan-Meier curve in Figure 1A). Patients who developed new-onset AF had more comorbidities, were slightly older and a higher percentage were men. During follow-up 3661 (9.9%) developed atrial fibrillation within two years (9.1% of female and 10.3% of male patients, p&amp;lt;0.001), at a median of 291 [88–461] days after implant. In multivariable Cox regression analysis with new-onset AF as time dependent covariable and adjusted for clinically relevant covariables, AF was an independent predictor of higher all-cause mortality (HR 1.43 [1.37–1.49], p&amp;lt;0.0001). Risk factors for new-onset AF included increasing age, male sex, hypertension, malignancy, diabetes, chronic obstructive lung disease, chronic renal disease, and sick sinus syndrome indication (all p&amp;lt;0.01). In separate analyses for men and women, the risk factors and magnitude of odds ratios were the same. Conclusion In patients treated with dual chamber pacemakers due to bradycardia or AV block, development of new-onset AF within two years was associated with a higher 10-year mortality. The risk of developing AF was higher for men, but the negative prognostic effect was more pronounced for women.Figure 1A.-B. K-M survival curves

Changes and prognostic impact of noninvasive myocardial work indices in patients undergoing transcatheter aortic valve implantation.

The prognostic significance of noninvasive myocardial work (MW) indices in patients undergoing transcatheter aortic valve implantation (TAVI) has not been adequately examined. We retrospectively selected 88 consecutive patients (mean age 79.9 ± 6.4 years, 40% males) with severe aortic stenosis scheduled for TAVI enrolled in the EffecTAVI registry. Exclusion criteria were prior valve surgery, atrial fibrillation, and left bundle branch block (LBBB) at baseline. Global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) were measured by echocardiography at baseline and at 30 days. Accuracy of the noninvasive measures was assessed by invasive evaluation of MW. In the overall population, a significant reduction in GWI (2406 ± 567 vs. 2063 ± 515 mmHg% before and after TAVI respectively, P < 0.001), GCW (2783 ± 616 vs. 2380 ± 495 mmHg%, P < 0.001) and GWW (238 ± 203 vs. 186 ± 135 mmHg%, P = 0.015) was observed at 30 days after TAVI. GWE improved only in patients who did not develop left ventricular dyssynchrony due to new-onset LBBB or pacemaker implantation following TAVI. In a multivariable Cox-regression analysis, GWE after TAVI (hazard ratio 0.892, 95% confidence interval 0.81-0.97; P = 0.011) was the strongest predictor of adverse events (a composite of all-cause death, worsening of dyspnea, or rehospitalization for cardiovascular events) at 1-year follow-up. TAVI results in significant changes in MW indices, including an early decrease in GWI, GCW and GWW, and an improvement in GWE in patients without left ventricle dyssynchrony. A GWE equal or less than 92% at 30 days is indicative of poor clinical outcomes at 1 year.

Association between an Early Revascularization Strategy and Major Cardiac Events Based on Left Ventricular Dyssynchrony in Patients at Intermediate Risk of Major Cardiac Events Using the J-ACCESS Risk Model.

Objective This retrospective study aimed to investigate the association between therapeutic strategies and the development of major cardiac events (MCEs) in intermediate-risk patients by using the the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (JACCESS) risk model in combination with the stress phase bandwidth (SPBW), an index of left ventricular dyssynchrony. Methods Patients were followed-up for three years to confirm their prognosis. Based on the estimated propensity scores, the patients who underwent revascularization within the first 60 days after SPECT and those who did not were matched 1:1 (n=367 per group). The composite endpoint was the occurrence of MCEs, consisting of cardiac death, non-fatal myocardial infarction, and severe heart failure. SPBW was calculated by a phase analysis using the Heart Risk View-F software program, and the MCE rate was compared between the two groups by applying the normal value of SPBW (38°). Patients The study included 2,053 patients with either known or suspected coronary artery disease who underwent electrocardiogram-gated single-photon emission computed tomography myocardial perfusion imaging and were at intermediate risk of MCE according to the J-ACCESS risk model. Results During follow-up, 54 of the 734 patients (7.4%) experienced MCEs. The overall incidence of MCE in intermediate-risk patients was not significantly different between the two groups. However, the incidence of MCE in patients with an abnormal SPBW was significantly lower in those who underwent early revascularization (4.8% vs. 11.9%, p=0.0407). Conclusion The combination of the J-ACCESS risk model and the SPBW is thus considered to be an optimal treatment strategy for patients at intermediate risk of MCE, and early revascularization may lead to an improved prognosis in intermediate-risk patients with an abnormal SPBW.

Mechanical dyssynchrony in patients with chronic heart failure and left bundle branch block

Background. The main problem in patient selection for cardiac resynchronization therapy (CRT) is the lack of unified approaches to the definition of mechanical dyssynchrony (MD) and selection criteria, particularly, in patients with left bundle branch block (LBBB).Aim: To study mechanical dyssynchrony indices and three-dimensional Echo (3DE) criteria of global and local contractility function in patients with chronic heart failure (CHF) and LBBB during different types of isolated left ventricle (LV) pacing.Methodology and Research Methods. The experimental intraoperative study involved 88 points obtained from 12 patients with CRT class IA indications and LBBB. During isolated LV pacing as part of CRT implantation procedure endocardial and epicardial pacing were obtained. Transesophageal Echo (TEE) cineloops recording and paced QRS complex morphology registrations by means of LabSystem Pro Electrophysiological Recording System (Bard Electrophysiology, USA) were performed during each stimulation episode. Philips Qlab 10 software was used for TEE data analysis.Results. The global (3D EF, 23.8 [22; 28.4], GLS, –5.33% [10.90%; –15.4%]) and local contractility (ExсAvg 3.5 [2.1; 5.6]) criteria and dyssyncrony indices (SDI-16, 14.9 [8.9; 23.1]) showed severe systolic dysfunction and intraventricular dyssynchrony – typical signs in this patient group, and differed significantly (3D EF, p = 0.003; GLS, p = 0.004; ExcAvg, p &lt; 0.001; Tmsv-6 SD, р = 0.03) depending on the stimulation method and site. A moderate direct correlation between SDI-16 and the QRS duration (common electical dyssynchrony criterium) and inverse correlation with ExcAvg and 3D LVEF also describes LV response.

Right ventricular dyssynchrony predicts outcome in pulmonary arterial hypertension when assessed in multiple CMR views

BackgroundRight ventricular (RV) dyssynchrony or post systolic contraction (PSC) cause inefficient pumping and have not been investigated as prognostic markers in pulmonary arterial hypertension (PAH). ObjectivesTo investigate if RV dyssynchrony and PSC are prognostic markers of transplantation-free survival in PAH and if multiple RV views improve the prognostication. MethodsPatients with PAH undergoing cardiac magnetic resonance (CMR) between 2003-2021 were included. For strain analysis, endocardial end-diastolic RV contours were delineated in RV 3-chamber (RV3ch), 4-chamber (4ch) and midventricular short axis slice (SAX). RV dyssynchrony was defined as standard deviation of time to peak strain in the walls from one (4ch), two (4ch and SAX) or three views (4ch, SAX and RV3ch). PSC was defined as peak strain occurring after pulmonary valve closure. Outcome was defined as death or lung transplantation. ResultsOne hundred-one patients (58±19 years, 66% women) were included. Median follow-up was 37 [51] months. There were 60 events (55 deaths and 5 lung transplantations). Outcome was associated with RV dyssynchrony from three views and with RV strain in 4ch. An increase of RV dyssynchrony - from 3 views - by 1% was associated with a 10% increased risk of lung transplantation or death. There was no association between outcome and RV dyssynchrony in one or two views nor with PSC. ConclusionRight ventricular dyssynchrony from three views were associated with outcome in PAH, whereas assessing dyssynchrony from one or two views and PSC were not. This implies that assessment of multiple instead of single RV views potentially could be used for prognostication in PAH.

Вплив реваскуляризації коронарних артерій на механічну дисинхронію міокарду лівого шлуночка у хворих з коронарною хворобою серця

Introduction. Defining a treatment strategy for patients with stable coronary heart disease will require the development of personalized criteria, among which the assessment of myocardial dyssynchrony is considered promising. The aim of the study was to evaluate the effect of revascularization of coronary arteries on indicators of mechanical myocardial dyssynchrony in patients with stable coronary heart disease. Materials and methods. The study included 121 patients with coronary heart disease, who were assessed for mechanical myocardial dyssynchrony before and 2 weeks after revascularization. The main group included 48 patients with myocardial dyssynchrony, and the comparison group included 73 patients without myocardial dyssynchrony. Complete occlusion and lesions of 3 coronary arteries were found more often in the group with myocardial dyssynchrony, and the main group also had a higher SYNTAX SCORE. The results. Mechanical dyssynchrony of the myocardium was found in 39% of patients with coronary heart disease. Before revascularization, a signifiant increase in SPWMD, APEI, IVMD, and a decrease in LVFT and LVET were found in the group of patients with myocardial dyssynchrony. After revascularization in the main group, in 9 patients out of 48 (18.7%), indicators of myocardial dyssynchrony returned to normal values. LVFT in the group of patients with myocardial dyssynchrony significantly increased, as well as left ventricular ejection time (LVET) (from 318.5±9.6 ms to 344.9±23.2 ms, p&lt;0.01). Conclusions. After revascularization, the number of patients with myocardial dyssynchrony significantly decreased due to the improvement of interventricular and intraventricular dyssynchrony indicators. Key words: myocardial dyssynchrony, coronary heart disease, revascularization, coronary angiography, SYNTAX SCORE.

SPECT myocardial perfusion imaging for the evaluation of left ventricular mechanical dyssynchrony in obese patients.

Left ventricular dyssynchrony (LVD), the loss of coordinated contraction in the left ventricle, is an early sign of heart failure. LVD can be assessed using phase analysis techniques with gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). This study aimed to investigate the impact of obesity on LVD through phase analysis. We retrospectively enrolled 152 obese patients and 80 age- and sex-matched nonobese patients who showed normal myocardial perfusion and normal left ventricular ejection fraction (LVEF) on MPI. Phase standard deviation (PSD) and phase histogram bandwidth (PBW), as phase analysis parameters, were compared between patients with and without obesity. Although PSD values were within the normal range (cut-off value >23) for both groups, the PSD values of obese patients were higher than those of the nonobese (20.49 ± 8.66 vs. 14.81 ± 4.93; p < 0.05). PBW values of obese patients were statistically significantly higher than those of the nonobese (57.03 ± 23.17 vs. 41.40 ± 9.96; p < 0.05). The PBW values of obese patients exceeded the normal limits (cut-off value >49). A weak positive correlation was observed between body mass index (BMI) and PBW values in obese patients (r = 0.181, p < 0.05). In patients of normal weight, no correlations were found between BMI and phase analysis parameters. LVD may develop in obese patients, even when myocardial perfusion and ejection fraction are preserved. The use of phase analysis with gated SPECT could be an additional finding improving the early detection of left ventricular dyssynchrony in obese patients.

Outcomes with physiologic His bundle pacing in patients with narrow QRS complex

BackgroundIn patients with narrow QRS complex, both ventricular and biventricular pacing is associated with increased cardiac morbidity and mortality. This risk is not decreased by ventricular pacing avoidance algorithms, which cause nonphysiologic atrioventricular (AV) delays. ObjectiveThis study aimed to report outcomes in patients with narrow QRS complex when the paced complex is in normal range and physiologic AV delays are programmed. MethodsIn 196 patients with QRS duration of 92 ± 10 ms, permanent pacing was done at the site of the His bundle electrogram. The pacemakers were then programmed to maintain physiologic AV delays and to increase heart rates in response to exercise. Patients received usual care and were observed for 3 years. ResultsThe paced complex exhibited a delta wave, and the ventricular activation time, QRS axis, and lead I voltage remained in normal range. Physiologic programming resulted in His bundle pacing burden of 92%. In patients with decreased ejection fraction, there was significant improvement in left ventricular function, left ventricular dilation, and mitral regurgitation (P < .003). In patients with normal ejection fraction, left ventricular function remained normal without new valvular abnormalities. The 3-year all-cause mortality was 10%, and there was no increase in heart failure admissions. ConclusionIn patients with narrow QRS complex, when paced QRS morphology is maintained in normal range and AV dyssynchrony is avoided, His bundle pacing is associated with low all-cause mortality and improvement in abnormal echocardiographic parameters. The paced QRS morphology and physiologic AV delays may be important factors to evaluate in future trials of conduction system pacing.

Mitral regurgitation increases systolic strains in remote zone and worsens left ventricular dyssynchrony in a swine model of ischemic cardiomyopathy.

Ischemic mitral regurgitation (IMR) imposes volume overload on the left ventricle (LV), accelerating adverse LV remodeling. In this study, we sought to investigate the impact of volume overload due to IMR on regional myocardial contractile mechanics. Ten Yorkshire swine were induced with myocardial infarction (MI) by occluding the left circumflex coronary artery (LCx). Cardiac MRI was performed at baseline (BL) and 2.5 months (2.5M) post-MI. IMR was quantified with epicardial echocardiography 3 months post-MI. The animals were then assigned to 2 groups: no/mild MR (nmMR, n = 4) and moderate/severe MR (msMR, n = 6). MRI images were analyzed to assess infarction size, end-diastolic and end-systolic volume (EDV and ESV, respectively), ejection fraction (EF), longitudinal strain (LS), circumferential strain (CS), and systolic dyssynchrony index (SDI). The myocardial region was divided into infarction, border, and remote zones based on the LCx-supplied region. There was no difference in the infarction size. Group-wise comparison of LS and CS between BL and 2.5M demonstrated that LS and CS in the infarction zone and the border zone decreased at 2.5M in both groups. However, LS and CS in the remote zone were elevated only in the msMR group (LS: -9.81 ± 3.96 vs. -12.58 ± 5.07, p < 0.01; CS; -12.78 ± 3.81 vs. -16.09 ± 3.33, p < 0.01) at 2.5M compared to BL. The SDI of CS was significantly elevated in the msMR group (0.1255 vs. 0.0974, p = 0.015) at 2.5M compared to BL. Elevated LS and CS in the remote zone were observed in moderate/severe MR and ventricular dyssynchrony. These elevated cardiac strains, coupled with ventricular dyssynchrony, may contribute to the progression of MR, thereby accelerating heart failure.

A Comparative Analysis of Apical Rocking and Septal Flash: Two Views of the Same Systole?

Heart failure (HF) is a complex medical condition characterized by both electrical and mechanical dyssynchrony. Both dyssynchrony mechanisms are intricately linked together, but the current guidelines for cardiac resynchronization therapy (CRT) rely only on the electrical dyssynchrony criteria, such as the QRS complex duration. This possible inconsistency may result in undertreating eligible individuals who could benefit from CRT due to their mechanical dyssynchrony, even if they fail to fulfill the electrical criteria. The main objective of this literature review is to provide a comprehensive analysis of the practical value of echocardiography for the assessment of left ventricular (LV) dyssynchrony using parameters such as septal flash and apical rocking, which have proven their relevance in patient selection for CRT. The secondary objectives aim to offer an overview of the relationship between septal flash and apical rocking, to emphasize the primary drawbacks and benefits of using echocardiography for evaluation of septal flash and apical rocking, and to offer insights into potential clinical applications and future research directions in this area. Conclusion: there is an opportunity to render resynchronization therapy more effective for every individual; septal flash and apical rocking could be a very useful and straightforward echocardiography resource.

Conduction system pacing preserves both electrical and mechanical interventricular synchrony, a UHF ECG validation study

Abstract Background Interventricular mechanical delay (IVMD) is an established echocardiographic risk factor for pacing-induced cardiomyopathy development. Ultra-high-frequency ECG (UHF-ECG) is a non-invasive tool visualizing the ventricular activation sequence. Purpose To compare UHF-ECG interventricular dyssynchrony with echocardiography and to establish interventricular dyssynchrony related to conductive system pacing (CSP) and right ventricular myocardial pacing (RVP). Methods 53 patients with advanced AV conduction disease, without organic heart disease, and preserved LV systolic function were prospectively included. Thirty-two had RVP, and twenty-one had CSP. CSP included both His bundle pacing (n=5) and left bundle branch area pacing (n=16). UHF-ECG and echocardiography were obtained at the baseline (during spontaneous rhythm) and after 1 year (during pacing). IVMD was manually calculated as a difference between the time from a distinct point of the QRS until the onset of the flow through LV and RV outflow tract using pulsed wave doppler imaging. Analysis was performed by two experienced and blinded cardiologists. Interventricular e-DYS was calculated automatically by a software as a time difference between activation in V8 (LV free wall) and V1 electrode (RV free wall). Results The average age of all included patients was 76 ± 6 years old and patients in both RVP and CSP group had similar clinical characteristics. The values of IVMD and interventricular e-DYS were similar in the whole study population both before the pacemaker implantation (-2 ± 21 ms for IVMD vs. 0 ± 20 ms for interventricular e-DYS; p=0.31) and after one year (14 ± 23 ms for IVMD vs. 14 ± 24 ms for UHF; p = 0.7). There were no significant differences in the baseline IVMD and interventricular e-DYS between those receiving CSP vs. RVP (IVMD -6 ± 22 ms for CSP vs 2 ± 20 ms for RVP, p=0.22) and interventricular e-DYS (e-DYS -5 ± 20 ms for CSP vs. 3 ± 20 ms for RVP, p=0.34). After one year of pacing, the patients with CSP preserved similar levels of both IVMD (mean change -2 ± 5 ms, p=0.74) and interventricular e-DYS V8-V1 (mean change 0 ± 4 ms, p = 0.95) – Figure 1. There was no difference between IVMD and interventricular e-DYS in CSP patients after one year (p=0.92). On the contrary, in the RVP group IVMD increased for 27 ± 5 ms (p &amp;lt;0.0001) and interventricular e-DYS for 24 ± 5 ms (p &amp;lt;0.0001) compared to the baseline - Figure 1. There was no difference between IVMD and interventricular e-DYS in RVP patients after one year (p=0.75). There was a moderate overall correlation between IVMD and e-DYS V8-V1 in all studied ventricular rhythms (R=0.73, p&amp;lt;0.0001) – Figure 2. Conclusions UHF-ECG expresses the interventricular dyssynchrony noninvasively by measuring the activation difference between V8-V1 chest leads. RV myocardial pacing increases interventricular dyssynchrony, while CSP preserves synchronous ventricular activation.CSP vs RVPcorrelation of dyssynchrony

Intra-operative ultra high-frequency ECG in relation to left ventricular reverse remodelling after cardiac resynchronization therapy

Abstract Aims Ultra-high-frequency electrocardiography (UHF-ECG) has evolved as a potential tool for the assessment of ventricular dyssynchrony. We sought to determine whether changes in ventricular dyssynchrony at the time of cardiac resynchronization therapy (CRT) device implantation, measured using UHF-ECG, relate to post-implantation left ventricular reverse remodelling (LVRR). Methods and Results Patients undergoing CRT (n = 46; aged 70.3 ± 11.2 years; 37/46 male) underwent intra-operative UHF-ECG assessment of ventricular dyssynchrony before and after CRT. Multiple frequency bands (n=16) within the 150 to 1000Hz range were used to create ventricular depolarization maps (Figure). Ventricular dyssynchrony (e-DYS) was assessed using the maximum time difference in ms between the QRS complex centres of mass of leads V1 to V6. Left ventricular reverse remodelling was defined in terms of a reduction in left ventricular end-systolic volume (LVESV) at 3 months post-implantation. During implantation, CRT led to a 103% reduction in e-DYS from 36.6 ms during AAI pacing to 1.4 ms during CRT (P&amp;lt;0.001). CRT also led to a reduction in QRS duration (from 156.3 ms during AAI pacing to 119.9 ms during CRT [P&amp;lt;0.001]) and QRS area (from 100.5 ms*mV (or µVs) during AAI pacing to 65.6 ms during CRT [P&amp;lt;0.001]). In regression analyses, intra-operative Δ e-DYS (ms) was associated with ΔLVESV at 3 months (Figure). In contrast, no associations were observed between intra-operative ΔQRS duration or ΔQRS area and ΔLVESV. Conclusion Intra-operative Δ e-DYS derived from UHF-ECG, relates to LVRR after CRT. In contrast, no such relationship emerged for ΔQRS or ΔQRS area.