Dyssynchrony In Patients Research Articles

Balloon pulmonary angioplasty improves interventricular dyssynchrony in patients with inoperable chronic thromboembolic pulmonary hypertension: a cardiac MR imaging study.

To use cardiac magnetic resonance imaging (MRI) to investigate the effect of balloon pulmonary angioplasty (BPA) on interventricular dyssynchrony and its associations with ventricular interaction, which impairs LV function in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). This prospective observational study was approved by our institutional review board. Cardiac MRI and right heart catheterization were conducted before BPA sessions and at the follow up after BPA in 20 patients with CTEPH. We measured right ventricular (RV) and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) using MRI. For the LV and RV free walls, the time to peak (Tpeak) of circumferential strain was calculated as a parameter for interventricular dyssynchrony. Following BPA, the RV-EDV and -ESV were significantly decreased, and the RVEF was significantly increased. Conversely, BPA led to significantly increased LV EDV and SV without changing LVESV. The left-to-right free wall delay (L-R delay) in Tpeak strain decreased from 105 ± 44ms to 47 ± 67ms (p < 0.001). Increased LV EDV (r = 0.65, p < 0.01), SV (r = 0.74, p < 0.001) and 6-minute walk distance (6MWD) (r = 0.54, p < 0.05) were correlated to the reduction in L-R delay. In patients with inoperable CPEPH, BPA improved interventricular dyssynchrony, which was strongly associated with increased SV and 6MWD. The assessment of interventricular dyssynchrony using cardiac MRI has an important role in evaluating ventricular interaction, which reduces LVSV and exercise tolerance.

Mechanical dyssynchrony in patients with heart failure and reduced ejection fraction

This article summarizes the most recent imaging techniques to assess left ventricular mechanical dyssynchrony and discusses their value to predict response to cardiac resynchronization therapy (CRT) together with assessment of myocardial scar and cardiac venous anatomy. Left ventricular mechanical dyssynchrony has been associated with prognosis of heart failure patients and has been shown to influence the efficacy of CRT. Although current guidelines do not recommend the assessment of left ventricular mechanical dyssynchrony to select heart failure patients for CRT, technological advances in echocardiography, cardiac magnetic resonance, nuclear imaging and computed tomography have provided powerful tools to characterize left ventricular mechanical dyssynchrony and predict response to CRT. Most important, these imaging techniques permit integration of additional information that is relevant for the efficacy of CRT, such as the extent and location of myocardial scar and the anatomy of the coronary sinus and tributaries where the left ventricular pacing lead may be positioned. Left ventricular mechanical dyssynchrony is an important parameter to select heart failure patients who are candidates for CRT. The integration of this parameter together with extent and location of myocardial scar and cardiac venous anatomy is a key to optimize the efficacy of CRT.

Determinants of left ventricular mechanical dyssynchrony in patients submitted to myocardial perfusion imaging: A cardiac CZT study

BackgroundAn interaction between coronary anatomy, myocardial perfusion, and left ventricular (LV) functional parameters in the development of mechanical LV dyssynchrony (LVD) has been suggested. This study examined the correlates of LVD in a large sample size of patients with known or suspected coronary artery disease (CAD) using cadmium-zinc-telluride camera. MethodsSix-hundred and fifty-seven consecutive patients who underwent myocardial perfusion imaging (MPI) and coronary angiography were included. Coronary stenosis >70% was considered significant. LV perfusion and functional parameters were computed from MPI images. The presence of significant LVD was evaluated by phase standard deviation and histogram bandwidth. Results415/657 (63%) patients had significant CAD. LVD was present in 247 (38%) patients and was associated with the presence of a higher CAD burden (P < .001), more impaired measures of LV perfusion (P < .001), contractile function (P < .001), and larger LV volumes (P < .001). By multivariate analysis, the LV end-systolic volume index (P < .001) and ischemic burden (P < .001) were the strongest predictors of LVD independent of CAD extent and LV systolic dysfunction. ConclusionsLVD is frequent in patients undergoing MPI for suspected or known CAD. Its presence is independent of CAD burden and LV systolic dysfunction, but is dependent on the presence of myocardial perfusion abnormalities and LV end-systolic volume.

Cardiovascular magnetic resonance features of mechanical dyssynchrony in patients with left bundle branch block.

Patients with left bundle branch block (LBBB) can exhibit mechanical dyssynchrony which may contribute to heart failure; such patients may benefit from cardiac resynchronization treatment (CRT). While cardiac magnetic resonance imaging (CMR) has become a common part of heart failure work-up, CMR features of mechanical dyssynchrony in patients with LBBB have not been well characterized. This study aims to investigate the potential of CMR to characterize mechanical features of LBBB. CMR examinations from 43 patients with LBBB on their electrocardiogram, but without significant focal structural abnormalities, and from 43 age- and gender-matched normal controls were retrospectively reviewed. The following mechanical features of LBBB were evaluated: septal flash (SF), apical rocking (AR), delayed aortic valve opening measured relative to both end-diastole (AVOED) and pulmonic valve opening (AVOPVO), delayed left-ventricular (LV) free-wall contraction, and curvatures of the septum and LV free-wall. Septal displacement curves were also generated, using feature-tracking techniques. The echocardiographic findings of LBBB were also reviewed in those subjects for whom they were available. LBBB was significantly associated with the presence of SF and AR; within the LBBB group, 79 % had SF and 65 % had AR. Delayed AVOED, AVOPVO, and delayed LV free-wall contraction were significantly associated with LBBB. AVOED and AVOPVO positively correlated with QRS duration and negatively correlated with ejection fraction. Hearts with electrocardiographic evidence of LBBB showed lower septal-to-LV free-wall curvature ratios at end-diastole compared to normal controls. CMR can be used to identify and evaluate mechanical dyssynchrony in patients with LBBB. None of the normal controls showed the mechanical features associated with LBBB. Moreover, not all patients with LBBB showed the same degree of mechanical dyssynchrony, which could have implications for CRT.

Echocardiographic evaluation of mechanical dyssynchrony in heart failure patients with reduced ejection fraction.

The aim of this study is to observe the differences between mechanical and electrical dyssynchrony in patients with impaired systolic ventricular function and symptomatic heart failure and to highlight the importance of mechanical dyssynchrony besides electrical dyssynchrony in clinical guidelines and clinical practice. Fifty-eight patients with heart failure, who are with the New York Heart Association (NYHA) functional class II-IV and left ventricular ejection fraction (LVEF) under 35%, were enrolled. Patients were divided into two groups, according to the duration of QRS complex (> 120 ms and ≤ 120 ms respectively). Echocardiographic parameters of interventricular (interventricular mechanical delay - IMD) and intraventricular (septal-to-posterior wall motion delay - SPWMD) dyssynchrony were measured in both groups. Results indicate that the duration of the QRS complex (i.e. electrical dyssynchrony) is not a fully reliable indicator of ventricular dyssynchrony; therefore ecocardiographic evaluation of mechanical dyssynchrony should also be recommended for better selection of candidates for cardiac resynchronization therapy (CRT).

Left Ventricular Dyssynchrony in Acute ST Elevated Myocardial Infarction in Patients with Normal QRS duration

Background: The aim of this study was to assess left ventricular dyssynchrony after acute ST elevated myocardial infarction (STEMI) in patients with normal QRS duration. Real time 3D echocardiography (RT3DE) with triplane tissue synchronization imaging (TSI) used to identify segmental left ventricular systolic velocity in ejection phase to evaluate LV dyssynchrony in patients with STEMI and the findings were compared with control.Materials and methods: RT3DE with triplane TSI was performed within 4 days of AMI after thrombolysis or primary PCI in 31 patients and compared with 31 agematched controls. Regional myocardial velocities were assessed in 12 segments in ejection phase, and the corresponding time to peak systolic velocity (Ts) was measured. To assess LV dyssynchrony Ts-4, Ts-6, Ts- SD-6, Ts-12 and Ts-SD-12 were computed by offline dedicated software semi-automatically.Results: The dyssynchrony parameters were significantly prolonged in patients with AMI. Among the dyssynchrony parameters TS-SD-12 was better indicator of LV dyssynchrony. The Ts-SD-12 was significantly prolonged in the STEMI group when compared with controls. In patients with acute STEMI mean Ts-SD-12 was 43.2±19.1 milliseconds whereas in control group it was 23.0 ±6.5 milliseconds (p&lt;0.05). The Ts-SD-12 was prolonged in patients with Anterior than Inferior STEMI as follows respectively 45.9± 17.6 and 40.0± 21 milliseconds.Conclusions: Triplane TSI by RT3DE is useful in evaluating LV dyssynchrony in patients with acute STEMI and even in those with normal QRS duration there is significant left ventricular dyssynchrony early after STEMI.Bangladesh Heart Journal 2015; 30(1) : 13-21

Patterns of left atrial activation and evaluation of atrial dyssynchrony in patients with atrial fibrillation and normal controls: Factors beyond the left atrial dimensions

Left atrial (LA) remodeling causing slower and asynchronous conduction is crucial for the maintenance of atrial fibrillation (AF). We propose a simple and quick method to evaluate the LA asynchrony. One hundred thirty patients with AF (AF group) and 70 patients without a history of AF (controls) were examined prospectively using pulsed-wave tissue Doppler imaging. The time intervals from the onset of the P wave to the onset of the A' wave (P-A' intervals) were measured at 4 sites at the mitral annulus: septal, lateral, anterior, and posterior. To assess the LA asynchrony, the differences between the longest and the shortest P-A' interval as well as the standard deviation of all 4 P-A' intervals were calculated. Both groups were matched for the baseline characteristics. The AF group had longer differences between the longest and the shortest P-A' than did controls (37 ± 16 ms vs 28 ± 13 ms; P = .0001). The standard deviation of all 4 P-A' intervals was also higher in the AF group (17 ± 7 ms vs 13 ± 5 ms; P = .0001). Furthermore, distinct patterns of LA activation were observed with most patients with AF showing upward LA activation (86.5%) whereas normal controls were showing downward LA activation (65.5%). Receiver operating characteristic analysis revealed that P-A' anterior successfully discriminated patients with AF from controls (area under the curve 0.85; P < .0001). Furthermore, P-A' anterior > 55 ms discriminated between patients with AF and controls with a sensitivity of 85% a specificity of 81%, a positive predictive value of 0.898, and a negative predictive value of 0.707. Patients with AF showed greater LA asynchrony in pulsed-wave tissue Doppler imaging, upward LA activation, and a prolonged activation time at the anterior mitral annulus. Prolongation of P-A' anterior discriminated between patients with AF and controls with high sensitivity and specificity.

Echocardiographic evaluation of cardiac dyssynchrony in patients with congestive heart failure.

The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure (CHF). A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization (CRT) and presented with low ejection fraction (EF) and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio (FT/RR), left ventricular pre-ejection delay (PED), interventricular mechanical delay (IVMD), longitudinal opposing wall delay (LOWD) and radial septal to posterior wall delay (RSPWD). Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group (P<0.01). In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter (LVESd), LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) (P<0.01), but positively with the LVEF (P<0.01). Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV (P<0.01), but negatively with the LVEF (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group (78% sensitivity, 83% specificity), those in QRS-2 group (83% sensitivity, 77% specificity) and in QRS-3 group (89% sensitivity, 79% specificity). In conclusion, echocardiography is a convenient and sensitive method for evaluating cardiac dyssynchrony in patients with CHF.

176-24: Patterns of left atrial activation and evaluation of atrial dyssynchrony in patients with atrial fibrillation and normal controls: steps beyond the left atrial dimensions

176-24: Patterns of left atrial activation and evaluation of atrial dyssynchrony in patients with atrial fibrillation and normal controls: steps beyond the left atrial dimensions

A novel method for sensitive determination of subclinical right ventricular systolic dysfunction in patients with obstructive sleep apnea.

The aim of this study was to evaluate right ventricular (RV) regional systolic function and dyssynchrony in patients with newly diagnosed obstructive sleep apnea using real-time three-dimensional (3D) echocardiography. Eighty-two subjects without hypertension, diabetes mellitus or any cardiac or pulmonary disease referred for evaluation of obstructive sleep apnea (OSA) had overnight polysomnography and complete echocardiographic assessment. According to the apnea hypopnea index (AHI), subjects were divided into four groups: group 1: control subjects (AHI < 5, n = 19), group 2: patients with mild OSA (AHI: 5-14, n = 21), group 3: moderate OSA (AHI: 15-30, n = 18), group 4: severe OSA (AHI > 30, n = 24). Real-time three-dimensional echocardiographic images were acquired to obtain RV regional (inflow, body and outflow) ejection fraction (EF) and time to minimum systolic volume in all subjects. Body weight and body mass index were greater in the severe and moderate OSA group than those of mild and controls group (P < 0.05). There was a significant decrease in mean SaO2 and the lowest SaO2 in severe OSA when compared to other groups (P < 0.001). Inflow EF and global EF were significantly lower in moderate and severe OSA patients than in controls (P < 0.05). Inflow EF and global EF were negatively correlated with AHI (r = -0.534 and r = -0.479, respectively, P < 0.001). In patients with OSA, RV inflow and global systolic function were impaired and were in inverse relationship with AHI. Evaluation of RV regional systolic function using real-time three-dimensional echocardiography may play a potential role in the noninvasive assessment of the severity of OSA.

The role of electrocardiography in the elaboration of a new paradigm in cardiac resynchronization therapy for patients with nonspecific intraventricular conduction disturbance.

Cardiac resynchronization therapy (CRT) is associated with a favorable outcome only in patients with left bundle branch block (LBBB) pattern and in patients with a QRS duration > 150 ms, in patients with non-LBBB pattern with a QRS duration of 120–150 ms usually is not beneficial. After adjusting for QRS duration, QRS morphology was no longer a determinant of the clinical response to CRT. In contrast to the mainstream view, we hypothesized that the unfavorable CRT outcome in patients with non-LBBB and a QRS duration of 120–150 ms is not due to the QRS morphology itself, but to less dyssynchrony and unfavorable patient characteristics in this subgroup, such as more ischemic etiology and greater prevalence of male patients compared with patients with LBBB pattern. Further, the current CRT technique is devised to eliminate the dyssynchrony present in patients with LBBB pattern and inappropriate to eliminate the dyssynchrony in patients with non-LBBB pattern. We also hypothesized that electrocardiography may also provide information about the presence of interventricular and left intraventricular dyssynchrony and the approximate location of the latest activated left ventricular (LV) region. To this end, we devised new ECG criteria to estimate interventricular and LV intraventricular dyssynchrony and the approximate location of the latest activated LV region. Our preliminary data demonstrated that the latest activated LV region in patients with nonspecific intraventricular conduction disturbance (NICD) pattern might be at a remote site from that present in patients with LBBB pattern, which might necessitate the invention of a novel CRT technique for patients with NICD pattern. The application of the new interventricular and LV intraventricular dyssynchrony ECG criteria and a potential novel CRT technique might decrease the currently high nonresponder rate in patients with NICD pattern.

Assessment of cardiac dyssynchrony in Nigerian patients with dilated cardiomyopathy

Background: Interventricular, intraventricular, and atrioventricular dyssynchrony (AVD) have been reported in patients with dilated cardiomyopathy (DCM). However, the causes of DCM vary with the regional distribution in various etiologies, with expected differences in the pattern and frequency of cardiac dyssynchrony. Objective: The aim of this study was to evaluate cardiac dyssynchrony in patients with DCM by conventional echocardiographic assessment. Materials and Methods: Fifteen patients with DCM were studied. All patients underwent conventional Doppler echocardiographic evaluation including septal-to-posterior wall motion delay (SPWMD), interventricular motion delay (IVMD), and diastolic filling period. Results: Cardiac dyssynchrony was present in 13 of the 15 patients (86.7%). The overall frequencies of intra-left ventricular dyssynchrony (intra-LVD), interventricular dyssynchrony (inter-VD), and AVD are 38.5%, 30.8%, and 53.9%, respectively. Conclusion: The prevalence of dyssynchrony in our patients with DCM was significant. This raises the need for the development of local expertise in interventional cardiology including cardiac resynchronization therapy (CRT).

Abstract 13940: Risk Stratification of Future Left Ventricular Dysfunction in Patients With Indications for Right Ventricular Pacing Owing to Bradycardia

Background: Although right ventricular (RV) pacing is the only effective treatment for patients with symptomatic atrioventricular block, it creates left ventricular (LV) mechanical dyssynchrony, which can induce LV dysfunction and heart failure. Current criterion for consideration of cardiac resynchronization therapy (CRT) is LV ejection fraction (LVEF) ≤35%, but indication for CRT in patients required for RV pacing with LVEF &gt;35% remains uncertain. Methods: We studied 35 consecutive patients with LVEF of 51±9% (all≥35%) who had undergone implantable cardioverter-defibrillator implantation (RV pacing &lt;5%). Echocardiography was performed at baseline and during RV pacing. LV dyssynchrony was determined by the anteroseptal-to-posterior wall delay from mid-LV short-axis view using two-dimensional speckle-tracking radial strain (≥130ms as significant). Patients were divided into two groups based on baseline LVEF: preserved LVEF≥50% (n=19) and mildly reduced LVEF of 35-50% (n=16). Results: LV dyssynchrony in patients with mildly reduced LVEF was significantly worsened during RV pacing compared to that in patients with preserved LVEF (from 86.0±103.9ms to 214.6±132.1ms vs. from 21.7±29.0ms to 65.6±90.9ms, p=0.01). Furthermore, the prevalence of significant LV dyssynchrony during RV pacing in patients with mildly reduced LVEF was significantly higher than that in patients with preserved LVEF (68% vs. 16%, p&lt;0.01). LVEF in patients with mildly reduced LVEF was also significantly worsened during RV pacing compared to that in patients with preserved LVEF (from 42.8±4.6% to 37.6±6.8% vs. from 58.3±5.7% to 57.9±6.9%, p&lt;0.01). Conclusions: The amount of RV pacing-induced LV dysfunction may be associated with baseline LV function. Thus, these adverse effects in patients with mildly reduced LVEF of 35-50% and indications for RV pacing owing to bradycardia can be prevented by CRT.

Right Ventricular Strain and Dyssynchrony Assessment in Arrhythmogenic Right Ventricular Cardiomyopathy: Cardiac Magnetic Resonance Feature-Tracking Study.

Analysis of right ventricular (RV) regional dysfunction by cardiac magnetic resonance (CMR) imaging in arrhythmogenic RV cardiomyopathy (ARVC) may be inadequate because of the complex contraction pattern of the RV. Aim of this study was to determine the use of RV strain and dyssynchrony assessment in ARVC using feature-tracking CMR analysis. Thirty-two consecutive patients with ARVC referred to CMR imaging were included. Thirty-two patients with idiopathic RV outflow tract arrhythmias and 32 control subjects, matched for age and sex to the ARVC group, were included for comparison purpose. CMR imaging was performed to assess biventricular function; feature-tracking analysis was applied to the cine CMR images to assess regional and global longitudinal, circumferential, and radial RV strains and RV dyssynchrony (defined as the SD of the time-to-peak strain of the RV segments). RV global longitudinal strain (-17±5% versus -26±6% versus -29±6%; P<0.001), global circumferential strain (-9±4% versus -12±4% versus -13±5%; P=0.001), and global radial strain (18 [12-26]% versus 22 [15-32]% versus 27 [20-39]%; P=0.015) were significantly lower and SD of the time-to-peak RV strain in all 3 directions were significantly higher among patients with ARVC compared with patients with RV outflow tract arrhythmias and controls. RV global longitudinal strain >-23.2%, SD of the time-to-peak RV longitudinal strain >113.1 ms, and SD of the time-to-peak RV circumferential strain >177.1 ms allowed correct identification of 88%, 75%, and 63% of ARVC patients with no or only minor CMR criteria for ARVC diagnosis. Strain analysis by feature-tracking CMR helps to objectively quantify global and regional RV dysfunction and RV dyssynchrony in patients with ARVC and provides incremental value over conventional cine CMR imaging.

Comparison of left ventricular systolic function and mechanical dyssynchrony using equilibrium radionuclide angiography in patients with right ventricular outflow tract versus right ventricular apical pacing: A prospective single-center study

BackgroundChronic ventricular pacing is known to adversely affect left ventricular (LV) function. Studies comparing right ventricular outflow tract (RVOT) pacing with RV apical (RVA) pacing have shown heterogeneous outcomes. Our aim was to objectively assess LV function and mechanical dyssynchrony in patients with RVOT and RVA pacing using equilibrium radionuclide angiography (ERNA). MethodsFifty-one patients who underwent permanent pacemaker implantation and had normal LV function were prospectively included. Twenty-nine patients had pacemaker lead implanted in the RVOT and 22 at the RVA site. All patients underwent ERNA within 5 days post-pacemaker implantation and follow-up studies at 6 and 12 months. Standard deviation of LV mean phase angle (SD LV mPA) expressed in degrees, which was derived by Fourier first harmonic analysis of phase images, was used to quantify left intraventricular dyssynchrony. ResultsNo significant difference was observed between the two groups with respect to indication (P = .894), Type/mode (P = .985), and percentage of ventricular pacing (P = .352). Paced QRS duration was significantly longer in RVA group than RVOT group (P = .05). There was no statistically significant difference between the RVA and RVOT groups at baseline with respect to LVEF (P = .596) and SD LV mPA (P = .327). Within the RVA group, a significant decline in LVEF was observed over 12-month follow-up (from 57.3% ± 5.32% to 55.6% ± 6.25%; P = .012). In the RVOT group, the change in LVEF was not statistically significant (from 56.7% ± 4.08% to 54.3% ± 6.63%; P = .159). No significant change in SD LV mPA was observed over 12-month follow-up within the RVA group (from 10.5 ± 2.58° to 10.4 ± 3.54°; P = 1.000) as well as in the RVOT group (from 9.7 ± 3.28° to 9.4 ± 2.85°; P = .769). However, between the RVA and RVOT groups, no significant difference was observed at 12-month follow-up in terms of LVEF and dyssynchrony (LVEF P = .488; SD LV mPA P = .296). ConclusionNo significant difference was observed between RVOT and RVA groups with regard to LV function and synchrony over a 12-month follow-up. RVOT pacing offers may lead to better preservation of LV function on longer follow-up.

Effect of activating intrinsic conduction search on left ventricular dyssynchrony in patients with conventional pacemaker

Rightventricular(RV)apicalpacingcreatesanabnormalventricularactivation pattern inducing cardiac dyssynchrony, ventricular dysfunc-tion,andanincreasedmortalityrisk[1–3].Atrial-basedpacingtomain-tainatrioventricular(AV)synchronycandecreasetheincidenceofatrialfibrillation (AF), heart failure and overall mortality rates [1]. However,evenwhenAV-nodefunctionispreserved,dual-chamber(DDD)pacingoften results in frequent ventricular pacing [3]. Previous analyses linkthefrequencyofRVpacedbeatstoincreasedrisksofAFandheartfailurein patients with sinus-node disease [4].To overcome the limitations of pacing-induced asynchronouselectricalactivation,devicealgorithmshavebeendevelopedtopromotenormal AV synchrony by preserving the physiologic ventricular activa-tion sequence [2].Specifically, intrinsic conduction search (ICS) hasbeen shown to lead to a decrease in unnecessary RV pacing and itsadverse consequences on left ventricular function [5,6].Moreover,pulsegeneratorlongevityisanimportant issueinthecareof pacemaker patients [7]. One of the determinants of pacemaker lon-gevityisthe energy consumption ofthepulsegenerator,whichdependson programmable variables, including output parameters of the system(voltage and pulse width), and the frequency and percentage of pacing.A previous study using an algorithm to preserve normal AV synchrony

Prognostic significance of NT-proBNP, 3D LA volume and LV dyssynchrony in patients with acute STEMI undergoing primary percutaneous intervention

ObjectivesThe aim of the present study was to assess the short term prognostic significance of N-terminal pro BNP (NT-proBNP), 3D left atrial volume (LAV) and left ventricular (LV) dyssynchrony in patients of acute ST-elevation myocardial infarction (STEMI) who underwent primary Percutaneous intervention (PCI). BackgroundNT-proBNP, LV dyssynchrony and LAV in patients with acute coronary syndrome have been associated with PCI outcomes and predict the short and long-term prognosis. MethodsThis study consisted of 142 patients with a first STEMI who underwent primary PCI. Baseline echocardiographic data was collected at admission and at 6 months follow up. Left ventricular dyssynchrony was measured by tissue Doppler imaging and LAV by real time 3D-echocardiography, plasma NT-proBNP levels were estimated between 72 and 96 h of admission. ResultsDuring study period 3 patients expired and 4 developed congestive heart failure (CHF). Baseline NT-proBNP and LV dyssynchrony correlated with LV size and LV ejection fraction (LVEF) at baseline and during follow up. Patients with higher NT-proBNP levels and higher LV dyssynchrony showed significant increase in LV size with decrease in LVEF during follow-up. Baseline Left atrial volume index (LAVI) showed significant correlation with LV size but no association with LVEF at baseline and during follow-up. ConclusionsHigher levels of NT-proBNP and higher LV dyssynchrony can predict patients with increase in LV size, worsening of LV systolic and diastolic function during follow-up. Patients with higher NT-proBNP levels at baseline developed CHF during follow-up.

Left Ventricular Septolateral Mechanical Delay Is Associated with Reduced Long-Term Survival in Systolic Heart Failure with Narrow QRS Duration: Nine-Year Outcome in 109 Patients.

The long-term prognostic importance of left ventricular (LV) dyssynchrony in patients with systolic heart failure is not known. We investigated this question in 109 consecutive patients with systolic heart failure with an LV ejection fraction (EF) ≤35% and QRS duration <130 ms. The cohort is a prospective series of 109 patients with EF ≤35% and QRS duration <130 ms who did not receive a defibrillator. Onset to onset septolateral and anteroposterior mechanical delays were computed from tissue Doppler velocity signals of the four quadrants of the mitral annulus and related to mortality. Patient characteristics included age 53 ± 12 years, 73% male, 23% with coronary artery disease, LVEF 24 ± 7%, LV end-diastolic dimension 64 ± 9 mm, LV end-systolic dimension 55 ± 9 mm, QRS duration 107 ± 30 ms, and 92 with QRS duration <120 ms. Over a follow-up of 9 years, there were 51 deaths. Univariate predictors of mortality included LV septolateral delay (HR 1.01 per ms, P < 0.0001), anteroposterior delay (P = 0.003), and age (P = 0.005), but not EF, LV size, or QRS duration. Using Cox regression analysis, LV septolateral delay was an independent predictor of higher mortality (P = 0.0005) after adjusting for age, gender, EF, LV size, QRS duration, coronary artery disease, diabetes mellitus, and use of beta blockers or angiotensin-converting enzyme inhibitors. In patients with heart failure, LVEF ≤35% and QRSd < 130 ms, LV mechanical dyssynchrony is a strong and independent predictor of long-term mortality.

Left ventricular diastolic dyssynchrony in patients with treatment-naive hypertension and the effects of antihypertensive therapy.

The presence of left ventricular diastolic dyssynchrony is well known to be a frequent and important manifestation in heart failure. We investigated diastolic dyssynchrony in patients with treatment-naive hypertension, compared with normal controls; the determinants of the presence of diastolic dyssynchrony by performing comprehensive studies including laboratory, arterial stiffness, central blood pressure (BP), ambulatory BP monitoring (ABPM), and transthoracic echocardiography (TTE) evaluations; the effects of 6-month antihypertensive therapy on diastolic dyssynchrony; and the predictors associated with the change of diastolic dyssynchrony after medical therapy. A total of 325 treatment-naive hypertensive patients and 172 normal controls were prospectively enrolled. Hypertensive patients were followed up at 6 months after medical therapy, and were assessed by serial TTE (at baseline and 6-month follow-up visit) and clinical evaluations. The time-to-peak myocardial early diastolic velocity (Te) of the 12 left ventricular segments was measured with reference to the QRS complex. The standard deviation (SD) of Te of all 12 left ventricular segments (Te-SD12) and the maximal difference in Te between any two of the 12 left ventricular segments (Te-Max) were calculated. A Te-SD12 at least 34 or Te-Max at least 113 ms was regarded as indicating the presence of diastolic dyssynchrony. Diastolic dyssynchrony was more prevalent in treatment-naive hypertensive patients, compared with normal controls (15.4 versus 7.0%, P = 0.007). Male sex [odds ratio (OR), 9.36 (1.93-45.41)], magnesium [OR per 1 SD, 2.54 (1.32-4.90)], night-time heart rate [HR; OR per 1 SD, 2.44 (1.18-5.05)], and mitral E/A [OR per 1 SD, 0.13 (0.04-0.45)] were independent determinants for the diastolic dyssynchrony in hypertensive patients. A 6-month follow-up, echocardiography was performed in 74 of 275 patients without diastolic dyssynchrony (group 1) and 26 of 50 patients with diastolic dyssynchrony (group 2). Diastolic dyssynchrony (Te-SD12, Δ = -8.3 ms; Te-Max, Δ = -27.6 ms; prevalence, Δ = -42.3%; all P < 0.05) improved in group 2, whereas it did not in group 1. Baseline daytime HR (P = 0.008) and magnesium levels (P = 0.029) and changes of the midwall fractional shortening (P = 0.026), mitral E/A (P = 0.003), mean annulus Ea (P = 0.003), mean annulus Ea/Aa (P = 0.020), and mitral peak E (P = 0.042) were independent predictors for changes of Te-SD12. Diastolic dyssynchrony is not rare in treatment-naive hypertensive patients. Male sex, magnesium levels, night-time HR, and mitral E/A are independent determinants for the impaired diastolic dyssynchrony. Antihypertensive therapy reduces both the severity and prevalence of diastolic dyssynchrony in patients with impaired diastolic dyssynchrony. Daytime HR, magnesium levels, and indications of systolic or diastolic dysfunction are independent predictors for improvements in diastolic dyssynchrony. Thus, magnesium levels, HR, and diastolic dysfunction seem to have important implications for diastolic dyssynchrony in hypertensive patients, whereas left ventricular hypertrophy, office BPs, arterial stiffness, central BPs, and ABPM parameters do not.

Prevalence of Left Ventricular Dyssynchrony in Patients with Congenital Atrioventricular Block and Long-Term Pacing: A Three-Dimensional Echocardiographic Study.

Left ventricular (LV) dysfunction is the major reason for poor outcomes in patients with congenital complete atrioventricular block (CCAVB) and pacemaker. Long-term pacing has been associated with LV mechanical dyssynchrony. However, the relationship of dyssynchrony and LV dysfunction is not clear. We sought to evaluate the prevalence of LV dyssynchrony by real time three-dimensional echocardiography (RT3DE) in patients with CCAVB and its association with LV dysfunction. In addition, we evaluated the agreement between RT3DE and tissue Doppler imaging (TDI) for detecting LV dyssynchrony. We studied 50 patients [median age 20 years old (5 months to 62 years), 68% women] with CCAVB and pacemaker who underwent complete two-dimensional echocardiography and RT3DE. LV dyssynchrony was considered if the systolic dyssynchrony index (SDI) was ≥ 5%. Intraventricular mechanical delay was defined by TDI when differences in electromechanical activation between LV walls were > 65 msec. LV systolic dysfunction was present in 16 patients (32%) by two-dimensional and in 20 patients (40%) by RT3DE. There was a good correlation between LV ejection fraction by two-dimensional and RT3DE (r = 0.75; P < 0.001). Fourteen (28%) patients had intraventricular dyssynchrony by TDI, while 12 (24%) had intraventricular dyssynchrony by RT3DE. There was a good agreement between LV dyssynchrony by TDI and RT3DE (Kappa = 0.735; P < 0.001). There was a negative correlation between LV ejection fraction and SDI obtained by RT3DE (r = -0.58; P < 0.001) CONCLUSIONS: In patients with CCAVB and long-term pacing, LV dyssynchrony occurred in one-third of patients and was related to LV dysfunction. There was a good correlation between dyssynchrony obtained by RT3DE and TDI.