Explore the vast range of titles available.

PurposeWhether blood volume (BV) primarily determines the synchronous nature of the myocardium remains unknown. This study determined the impact of standard blood withdrawal on left ventricular mechanical dyssynchrony (LVMD) in women.MethodsTransthoracic speckle-tracking echocardiography and central hemodynamic measurements were performed at rest and during moderate- to high-intensity exercise in healthy women (n = 24, age = 53.6 ± 16.3 year). LVMD was determined via the time to peak standard deviation (TPSD) of longitudinal and transverse strain and strain rates (LSR, TSR). Measurements were repeated within a week period immediately after a 10% reduction of BV.ResultsWith intact BV, all individuals presented cardiac structure and function variables within normative values of the study population. Blood withdrawal decreased BV (5.3 ± 0.7 L) by 0.5 ± 0.1 L. Resting left ventricular (LV) end-diastolic volume (− 8%, P = 0.040) and passive filling (− 16%, P = 0.001) were reduced after blood withdrawal. No effect of blood withdrawal was observed for any measure of LVMD at rest (P ≥ 0.225). During exercise at a fixed submaximal workload (100 W), LVMD of myocardial longitudinal strain (LS TPSD) was increased after blood withdrawal (36%, P = 0.047). At peak effort, blood withdrawal led to increased LVMD of myocardial transverse strain rate (TSR TPSD) (31%, P = 0.002). The effect of blood withdrawal on TSR TPSD at peak effort was associated with LV concentric remodeling (r = 0.59, P = 0.003).ConclusionMarked impairments in the mechanical synchrony of the myocardium are elicited by moderate blood withdrawal in healthy women during moderate and high intensity exercise.

Electrical and mechanical dyssynchrony (MD) underlies left ventricular (LV) contractile dysfunction in patients with heart failure (HF) and left bundle branch block (LBBB). In some cases, cardiac resynchronization therapy (CRT) almost completely reverses LV contractile dysfunction. The LBBB electrocardiographic Strauss criteria and MD assessment were proposed to improve CRT response. However, using these techniques separately does not improve LV contraction in 20–40% of patients after CRT device implantation. We aimed to evaluate whether the combined use of electrocardiography (ECG), speckle-tracking echocardiography (STE) and cardiac scintigraphy could improve the prognosis of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. The study prospectively included patients with HF, classified as New York Heart Association (NYHA) functional class (FC) II–III in sinus rhythm with Strauss LBBB criteria and reduced left ventricular ejection fraction (LVEF). Before and 6 months after CRT device implantation, ECG, STE and cardiac scintigraphy were performed. The study’s primary endpoint was the NYHA class improvement ≥ 1 and left ventricle end systolic volume decrease > 30% or LVEF improvement > 15% after 6 months of CRT. Based on collected data, we developed a prognostic model regarding the CRT super-response. Out of 54 (100.0%) patients, 39 (72.2%) had a CRT super-response. Patients with CRT super-response were likelier to have a greater S wave amplitude in V2 lead (p = 0.004), higher rates of global longitudinal strain (GLS) (p = 0.001) and interventricular delay (IVD) (p = 0.005). Only three indicators (S wave amplitude in V2 lead, GLS and IVD) were independently associated with CRT super-response in univariable and multivariable logistic regression. We created a prognostic model based on the logistic equation and calculated a cut-off value (>0.73). The resulting ROC curve revealed a discriminative ability with an AUC of 0.957 (sensitivity 87.2%; specificity 100.0%). The electrical and mechanical dyssynchrony assessment using ECG, STE and cardiac scintigraphy is useful in the prediction of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. Our prognostic model can identify patients who are super-responders to CRT.

Introduction:Children with a single ventricle post-Fontan palliation are at increased risk of poor outcomes with peak oxygen consumption acting as a surrogate outcome marker. The purpose of this study is to evaluate the relationship between peak oxygen consumption and echocardiographic measures of ventricular function and deformation, including ventricular global longitudinal strain and dyssynchrony, in children and adolescents following Fontan palliation.Methods:Patients (age 8–21 years) with single ventricle post-Fontan palliation were prospectively recruited and participated in an echocardiogram, including views optimised for two-dimensional speckle tracking, and a cardiopulmonary exercise test on a cycle ergometer to maximal volitional fatigue.Results:Thirty-eight patients (mean age 13.7 ± 2.3 years) post-Fontan palliation had either a single left ventricular (n = 20), single right ventricular (n = 14), or biventricular (n = 4) morphology. Peak oxygen consumption (24.9 ± 5.6 ml/kg/minute) was correlated with global longitudinal strain (r = −0.435, p = 0.007), a strain discoordination time to peak index (r = −0.48, p = 0.003), and the presence of an electro-mechanical dyssynchrony strain pattern (p = 0.008). On multivariate regression modelling, these three variables were associated with peak oxygen consumption independently of age and sex. The single right ventricular group had evidence of possible diastolic dysfunction by E/e’ compared to the single left ventricular and biventricular groups (p = 0.001).Conclusions:Strain analysis measures are correlated with peak oxygen consumption in this cohort of children, adolescents, and young adults following Fontan palliation, suggesting that ventricular mechanics may influence the efficiency of the Fontan circulation.

We investigated the effects of cell therapy on local mechanical dyssynchrony (LMD) in patients with nonischemic dilated cardiomyopathy (NICM). We analyzed electromechanical data of 30 NICM patients undergoing CD34+ cell transplantation. All patients underwent bone marrow stimulation; CD34+ cells were collected by apheresis and injected transendocardially. At baseline and at 6 months after therapy, we performed electromechanical mapping and measured unipolar voltage (UV) and LMD at cell injection sites. LMD was defined as a temporal difference between global and segmental peak systolic displacement normalized to the average duration of the RR interval. Favorable clinical response was defined as increase in the left ventricular ejection fraction (LVEF) ≥5% between baseline and 6 months. Using paired electromechanical point-by-point analysis, we were able to identify 233 sites of CD34+ cell injections in 30 patients. We found no overall differences in local UV between baseline and 6 months (10.7 ± 4.1 mV vs 10.0 ± 3.6 mV, P = 0.42). In contrast, LMD decreased significantly (17 ± 17% at baseline vs 13 ± 12% at 6 months, P = 0.00007). Favorable clinical response at 6 months was found in 19 (63%) patients (group A), and 11 (37%) patients did not respond to cell therapy (group B). At baseline, the two groups did not differ in age, gender, LVEF, or N terminal-pro brain natriuretic peptide (NT-proBNP) levels. Similarly, we found no differences in baseline UV (9.5 ± 2.9 mV in group A vs 8.6 ± 2.4 mV in group B, P = 0.41) or LMD at cell injection sites (17 ± 19% vs 16 ± 14%, P = 0.64). In contrast, at 6 months, we found higher UV in group A (10.0 ± 3.1 mV vs 7.4 ± 1.9 mV in group B, P = 0.04). Furthermore, when compared with group B, patients in group A displayed a significantly lower LMD (11 ± 12% vs 16 ± 10%, P = 0.002). Thus, it appears that favorable clinical effects of cell therapy in NICM patients may be associated with a decrease of LMD at cell injection sites.

IntroductionElectrical transmission disorders have a deleterious effect on cardiac depolarization, resulting in a disorganized ventricular contraction that reduces global mechanical efficiency; this mechanical dyssynchrony can be corrected by cardiac resynchronization therapy. However, despite adjustments in the electrical criteria selection of QRS for the recognition of mechanical dyssynchrony, a significant proportion of patients do not currently respond to this therapy.PurposeTo find if a new predictor of dyssynchrony, the electrocardiogram spatial variance, is a better marker of mechanical dyssynchrony than QRS duration.MethodsForty-seven electrocardiograms and 47 strain (2D speckle tracking) echocardiograms were prospectively collected simultaneously in consecutive, non-selected patients; the left ventricular mechanical dispersion was measured in all the cases. The electrocardiographic analysis of variance was made with a digital superposition of the electrocardiographic leads and generates different indexes of variance of both QRS complex and repolarization phase.ResultsROC analysis probed that the best area under the curve (AUC) value correlated with left ventricular mechanical dispersion and was obtained combining several spatial variance markers (considering depolarization and repolarization spatial variance together; AUC = 0.97); the same analysis using the QRS duration versus mechanical dispersion showed a significantly lower AUC value (AUC = 0.64).ConclusionSpatial variance combining depolarization and repolarization markers is a superior predictor of left ventricular mechanical dispersion than QRS duration.

Background The left ventricular ejection fraction (LVEF) and QRS duration (QRSd) are prognostic factors in patients with systolic heart failure (HF). However, no study has evaluated the prognosis was evaluated by adding three-dimensional left ventricular mechanical dyssynchrony (LVMD) and cardiac sympathetic dysfunction. Results In 1011 consecutive patients with HF having LVEF < 50%, LVMD was evaluated as the phase SD of the regional onset-of-mechanical contraction phase angles on a phase histogram created by Fourier phase analysis applied to regional time-activity curves obtained by gated myocardial perfusion. 123 I- meta -iodobenzylguanidine scintigraphy was also performed in all cases. Patients were followed up with a primary endpoint of lethal cardiac events (CEs). During the follow-up period (44 months), CEs were documented in 315 of the patients with HF. The CE group had a greater phase SD and lower standardized late heart-to-mediastinal ratio (slHMR) than the non-CE group. Phase SD and slHMR were identified by overall multivariate analysis to be significant prognostic determinants. ROC curve analyses revealed cutoff values of 36° for phase SD and 1.89 for slHMR for identifying patients with high-risk HF. Patients with HF and both phase SD > 36° and slHMR < 1.89 showed a significantly higher CE rate than other patients in the overall population, and patients’ CE rates were divided into four groups according to the cutoff values of LVEF (35%) and QRSd (130 ms). Conclusions The addition of three-dimensional LVMD and cardiac sympathetic function to the evaluation of LVEF and QRSd in patients with systolic HF may stratify the risk of their prognosis.

Background Heart failure (HF) significantly impacts quality of life and healthcare systems worldwide. Assessing left ventricular mechanical dyssynchrony (LVMD) is crucial for understanding cardiac function and optimizing treatments like cardiac resynchronization therapy (CRT). Phase analysis using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has shown promise in predicting outcomes, yet recent comprehensive reviews are lacking. Objective To systematically assess the prognostic value of phase analysis by gated SPECT MPI in the HF population through a systematic review. Methods We conducted a systematic review by collecting studies from databases including PubMed, CINAHL, and Web of Science. Two reviewers independently performed study selection, data extraction, and risk of bias assessment. Systematic reviews were conducted using Review Manager Software 5.4 and STATA 16.0. Results A total of 2004 patients from seven studies were included in our review and analysis. The systematic review indicated that patients with predetermined clinical events had higher PSD [MD = 6.45, 95% CI (5.83, 7.07), p  < 0.00001] and PBW [MD = 7.91, 95% CI (5.64, 10.19), p  < 0.00001]. The diagnosis of LVMD determined by PSD [HR = 1.05, 95% CI (1.01, 1.08), p  = 0.007] was a strong predictor of endpoint events compared to PBW [HR = 1.95, 95% CI (0.48, 7.89), p  = 0.35]. Conclusions The analysis demonstrated that phase information obtained from gated SPECT MPI is of significant prognostic value in patients with heart dysfunction. It effectively enhances clinical risk models, providing reliable guidance for patient treatment.

Patients with heart failure frequently develop mechanical dyssynchrony, which impairs ventricular function, coronary perfusion and their interactions. The underlying mechanisms, however, remain poorly understood due to numerous confounding factors. The objective of this study was to determine the acute effects of mechanical dyssynchrony on global and regional left ventricular (LV) function, coronary perfusion and their interactions based on experimental and computational approaches. Mechanical dyssynchrony was created with right ventricular apical pacing in Yorkshire domestic swine (n = 9). The heart was paced at 100 and 140 bpm and the results were compared to right atrial pacing. An inverse finite element computational framework based on an animal-specific geometry of the LV and measurements was developed to investigate the effects of mechanical dyssynchrony on LV function and its correlation with regional coronary perfusion. Cardiac dyssynchrony induced significant decrease in LV pressure, volume, dP/dt , stroke volume, ejection fraction, and regional longitudinal and circumferential strain. With mechanical dyssynchrony, passive flow decreased by 70% in the left anterior descending artery (LAD) and 67% in the left circumflex (LCX). An animal-specific inverse finite element computational model predicted that in mechanical dyssynchrony, global and regional LV contractility in the septum and LV free wall (LVFW), and myocardial work done in the septum and LVFW decreased. The computational model predicted reduction in global and regional contractility, and regional myocardial work done in the septum and LVFW with mechanical dyssynchrony are positively correlated with the corresponding decrease in experimentally measured regulated coronary flow in the LAD and LCX. These findings demonstrate that this interrelated mechanism between LV function and coronary flow in mechanical dyssynchrony may affect cardiac resynchronization therapy responder rate.

Left ventricular (LV) mechanical dyssynchrony (LVMD) is fundamental to the progression of heart failure and ventricular remodeling. The status of LVMD in different patterns of bundle branch blocks (BBB) is unclear. In this study, we analyzed the relationship between LVMD and left ventricular systolic dysfunction using real-time three-dimensional echocardiography (RT-3DE). RT-3DE and conventional two-dimensional echocardiography were performed on 68 patients with left bundle branch block (LBBB group), 106 patients with right bundle branch block (RBBB group), and 103 patients without BBB (Normal group). The RT-3DE data sets provided time-volume analysis for global and segmental LV volumes. The LV systolic dyssynchrony index (LVSDI) was calculated using the standard deviation (SD) and maximal difference (Dif) of time to minimum segmental volume (tmsv) for LV segments adjusted by the R-R interval. LVMD was considered if the LVSDI (Tmsv-16-SD) was greater than or equal to 5%. LVSDI is negatively and significantly correlated with left ventricular ejection fraction (LVEF), but not with BBB or QRS duration. The proportion of LVMD in the LBBB, RBBB, and Normal group was 30.88%, 28.30%, and 25.24%, respectively, and there was no significant difference. In dilated cardiomyopathy, LVMD is more closely related to LVEF reduction than QRS morphology and duration.

Cardiac resynchronisation therapy (CRT) is an established treatment for patients with symptomatic heart failure with reduced left ventricular ejection fraction (LVEF ≤ 35%; HFrEF) and conduction disturbances (QRS duration ≥ 130 ms). The presence of mechanical dyssynchrony (MD) on echocardiography has been hypothesised to be of predictive value in determining indication for CRT. This study investigated the impact of MD (apical rocking [AR] and septal flash [SF]) on long-term survival in CRT recipients. HFrEF patients (n = 425; mean age 63.0 ± 10.6 years, 72.3% male, 60.7% non-ischaemic aetiology) with a guideline-derived indication for CRT underwent device implantation. MD markers were determined at baseline and after a mean follow-up of 11.5 ± 8.0 months; long-term survival was also determined. AR and/or SF were present in 307 (72.2%) participants at baseline. During post-CRT follow-up, AR and/or SF disappeared in 256 (83.4%) patients. Overall mean survival was 95.9 ± 52.9 months, longer in women than in men (109.1 ± 52.4 vs. 90.9 ± 52.4 months; p < 0.001) and in younger (< 60 years) versus older patients (110.6 ± 53.7 vs. 88.6 ± 51.1 months; p < 0.001). Patients with versus without MD markers at baseline generally survived for longer (106.2 ± 52.0 vs. 68.9 ± 45.4 months; p < 0.001), and survival was best in patients with resolved versus persisting MD (111.6 ± 51.2 vs. 79.7 ± 47.6 months p < 0.001). Age and MD at baseline were strong predictors of long-term survival in HFrEF patients undergoing CRT on multivariate analysis. Novel echocardiography MD parameters in HFrEF CRT recipients predicted long-term mediated better outcome, and survival improved further when AR and/or SF disappear after CRT implantation.