Interventricular Mechanical Delay Research Articles

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 <0.0001) and interventricular e-DYS for 24 ± 5 ms (p <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<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

Comparison between left bundle branch area pacing and right ventricular pacing: ventricular electromechanical synchrony and risk of atrial high-rate episodes.

The electromechanical dyssynchrony associated with right ventricular pacing (RVP) has been found to have adverse impact on clinical outcomes. Several studies have shown that left bundle branch area pacing (LBBAP) has superior pacing parameters compared with RVP. We aimed to assess the difference in ventricular electromechanical synchrony and investigate the risk of atrial high-rate episodes (AHREs) in patients with LBBAP and RVP. We consecutively identified 40 patients with atrioventricular block and no prior atrial fibrillation. They were divided according to the ventricular pacing sites: the LBBAP group and the RVP group (including the right ventricular apical pacing (RVA) group and the right side ventricular septal pacing (RVS) group). Evaluation of ventricular electromechanical synchrony was implemented using electrocardiogram and two-dimensional speckle tracking echocardiography (2D-STE). AHRE was defined as event with an atrial frequency of ≥176 bpm lasting for ≥6 min recorded by pacemakers during follow-up. The paced QRS duration of the LBBAP group was significantly shorter than that of the other two groups: LBBAP 113.56 ± 9.66 ms vs. RVA 164.73 ± 14.49 ms, p < 0.001; LBBAP 113.56 ± 9.66 ms vs. RVS 148.23 ± 17.3 ms, p < 0.001. The LBBAP group showed shorter maximum difference (TDmax), and standard deviation (SD) of the time to peak systolic strain among the 18 left ventricular segments, and time of septal-to-posterior wall motion delay (SPWMD) compared with the RVA group (TDmax, 87.56 ± 56.01 ms vs. 189.85 ± 91.88 ms, p = 0.001; SD, 25.40 ± 14.61 ms vs. 67.13 ± 27.40 ms, p < 0.001; SPWMD, 28.75 ± 21.89 ms vs. 99.09 ± 46.56 ms, p < 0.001) and the RVS group (TDmax, 87.56 ± 56.01 ms vs. 156.46 ± 55.54 ms, p = 0.003; SD, 25.40 ± 14.61 ms vs. 49.02 ± 17.85 ms, p = 0.001; SPWMD, 28.75 ± 21.89 ms vs. 91.54 ± 26.67 ms, p < 0.001). The interventricular mechanical delay (IVMD) was shorter in the LBBAP group compared with the RVA group (-5.38 ± 9.31 ms vs. 44.82 ± 16.42 ms, p < 0.001) and the RVS group (-5.38 ± 9.31 ms vs. 25.31 ± 21.36 ms, p < 0.001). Comparing the RVA group and the RVS group, the paced QRS duration and IVMD were significantly shorter in the RVS group (QRS duration, 164.73 ± 14.49 ms vs. 148.23 ± 17.3 ms, p = 0.02; IVMD, 44.82 ± 16.42 ms vs. 25.31 ± 21.36 ms, p = 0.022). During follow-up, 2/16 (12.5%) LBBAP patients, 4/11 (36.4%) RVA patients, and 8/13 (61.5%) RVS patients had recorded novel AHREs. LBBAP was proven to be independently associated with decreased risk of AHREs than RVP (log-rank p = 0.043). LBBAP generates narrower paced QRS and better intro-left ventricular and biventricular contraction synchronization compared with traditional RVP. LBBAP was associated with a decreased risk of AHREs compared with RVP.

The relationship between mechanical dyssynchrony of the left ventricular myocardium and the number of affected coronary arteries in patients with coronary heart disease who underwent revascularization

Background. A promising method for early detection of myocardial dysfunction is the evaluation of mechanical dyssynchrony of the left ventricular myocardium, the prognostic value of which in the diagnosis of 3-vessel lesions was shown only in a single study and requires further confirmation. Purpose – to assess the relationship between the number of affected coronary arteries and the presence of mechanical dyssynchrony of the myocardium, and its significance in predicting 3-vessel lesions in patients with coronary heart disease. Materials and Methods. 134 patients who underwent coronary angiography with revascularization of coronary arteries were included in the study. Patients were divided into comparison groups depending on the number of affected coronary arteries (without lesions, one, two and three coronary arteries). Variables of mechanical myocardial dyssynchrony were determined for all patients by ultrasound examination of the heart using Doppler examination and synchronization with the ECG. Results. The largest relative number of patients with myocardial dyssynchrony was observed in the group with lesions of 3 coronary arteries – 23 (52%). The presence of myocardial dyssynchrony had a significant correlation with SYNTAX SCORE (r=0.18, p=0.035). The aortic pre-ejection interval in the group of patients with lesions of 3 coronary arteries was significantly longer compared to the group of patients without lesions of the coronary arteries, however, the pulmonary pre-ejection interval was the same in the comparison groups. As a result of this difference, interventricular mechanical delay was significantly greater in the group of patients with occlusion of 3 coronary arteries (54,8±36,6 ms; р=0,043). The time to peak systolic velocity in the group of patients with lesions of 3 coronary arteries was significantly longer (32,1±8,0 ms; р=0,021) compared to the group of patients without atherosclerotic lesions, which was confirmed by a positive correlation (r=0.190, p=0.003). The ROC analysis of the predictive capabilities of the combination of the factors of the presence of myocardial dyssynchrony, left ventricular ejection fraction, interventricular mechanical delay, root mean square deviation of the time to the peak of systolic velocity, and the E/A ratio in relation to lesions of 3 coronary arteries showed sufficient sensitivity (0.89) and specificity (0.87). Conclusions. Patients with lesions to 3 coronary arteries have a significantly higher relative frequency of mechanical myocardial dyssynchrony compared to patients without and lesions of 1 or 2 coronary arteries; correlation of myocardial dyssynchrony with 3-vessel lesions and SYNTAX SCORE was also found. The combination of variables of myocardial dyssynchrony in terms of predicting 3-vessel occlusion of coronary arteries has sufficient sensitivity and specificity.

Acute deterioration in dyssynchrony and systolic function from Lot-CRT to LBBB pacing

Abstract Background Better electrical synchronization and left ventricular (LV) systolic function was recently reported in left bundle branch–optimized cardiac resynchronization therapy ( Lot-CRT ) when compared with conventional CRT. The implantation of left bundle branch pacing (LBBP) is less expensive, easier to operate and has shorter exposure time to X-ray than Lot-CRT. Purpose To observe whether there are negative changes in dyssynchrony and LV systolic function when switched from Lot-CRT to LBBP. determine whether LBBP pacing alone can replace CRT therapy. Methods 30 patients (21 males, 64.4±9.5 years, 43% with persistent atrial fibrillation) who fulfilled the criteria of CRT implantation received Lot-CRT. The right atrial electrode of the patients with atrial fibrillation or the right ventricular electrode of those with sinus rhythm was implanted into the left bundle branch area. After six months, 20 patients whose LV ejection fraction (LVEF) increased by more than 5% and New York Heart Association functional class increased by at least 1 grade were selected for further investigation. Right and left ventricular pacemaker electrodes were programmed to shut off, leaving only the left bundle branch area pacing for one month. The LV size, systolic function, interventricular mechanical delay (IVMD), and LV mechanical dyssynchrony (LVMD) were compared by using two-dimensional speckle tracking echocardiography. Results It was found that QRS duration slightly widened, the LA size increased, the LV size slightly increased and LVEF decreased, p&amp;lt;0.05. There was no statistical significance in the IVMD (p=0.064). The LV mechanical dyssynchrony increased significantly, p&amp;lt;0.001. Conclusions Deteriotation of LV dyssynchrony and systolic function was recorded when Lot-CRT to LBBP for a short period in recovering patients with systolic dysfunction. It indicates that LBBP may not yet maintain the benefits of Lot-CRT in this group of patients.The comparison between Lot-CRT and LBBP

Abnormal inter-ventricular diastolic mechanical delay in patients with ST-segment elevation myocardial infarction

BackgroundThis study aimed to investigate the ventricular mechanical relaxation pattern and its clinical influence in patients with ST-segment elevation myocardial infarction (STEMI).MethodsEchocardiography was performed to measure mitral and tricuspid diastolic opening times. Left ventricular diastolic mechanical delay (LVMDd) was defined as diastolic filling of the right ventricle earlier than that of the left ventricle, and right ventricular diastolic mechanical delay (RVMDd) was defined as the right ventricular diastolic filling later than left ventricular filling.ResultsAmong 152 patients with STEMI, 100 (65.8%) had LVMDd, and 47 (30.9%) had RVMDd. In-hospital complications were significantly increased in patients with RVMDd (61.6% vs. 41.0%, P = 0.017). Those with RVMDd exhibited significantly lower left ventricular global longitudinal strain (11.7 ± 4.1% vs. 13.2 ± 4.0%, P = 0.035), global work index (913.8 ± 365.9 vs. 1098.9 ± 358.8 mmHg%, P = 0.005) and global constructive work (1218.6 ± 392.8 vs. 1393.7 ± 432.7 mmHg%, P = 0.021). Mitral deceleration time significantly decreased (127.4 ± 33.5 vs. 145.6 ± 41.7 ms, P = 0.012), and the ratio of early mitral inflow to early mitral annular velocity (E/E’) significantly increased [13.0(11.0–20.0) vs. 11.9(9.3–14.3), P = 0.006] in the RVMDd group. Logistic regression analysis showed that age (odds ratio [OR]:0.920; P = 0.001), brain natriuretic peptide level (OR: 1.1002; P = 0.036) and mitral E/E’ (OR: 1.187; P = 0.003) were independently associated with RVMDd.ConclusionsDelayed right ventricular filling is related to more severe left ventricular systolic and diastolic dysfunction in STEMI patients. More attention should be paid to patients with RVMDd to prevent adverse events during hospitalization.

The relationship between mechanical dyssynchrony of the left ventricular myocardium and the degree of coronary artery occlusion in patients with coronary artery disease

Background. The prevalence of chronic heart failure in the world is increasing; however, it is stabilizing in developed countries. One of the reasons for this stabilization is an improvement of acute coronary syndrome treatment and revascularization. Revascularization in patients with chronic coronary syndromes without signs of the left ventricular dysfunction is less effective. One of the promising methods for assessing left ventricular dysfunction is the detection of electrical and mechanical dyssynchrony of the myocardium (DM). However, mechanical dyssynchrony of the myocardium has not been sufficiently studied in patients with coronary artery (CA) disease. The purpose was to assess the relationship between mechanical myocardial dyssynchrony and the degree of coronary artery occlusion in patients with coronary artery disease who underwent revascularization. Materials and methods. One hundred and thirty-four patients with coronary artery disease (35 with myocardial infarction and 99 with chronic coronary syndromes) who underwent coronary angiography and revascularization of coronary arteries were included in the study. According to the results of coronary angiography, patients were divided into 3 groups: 12 had unchanged CA (group 1), 17 had atherosclerotic lesions of CA without signs of occlusion (group 2), and 105 patients were with CA occlusion. Among those with CA occlusion, 10 people had an occlusion of less than 50 %, 26 patients had occlusion from 50 to 80 %, 36 had more than 80 %, and 33 patients had complete occlusion of at least one coronary artery. In all patients, parameters of mechanical DM were determined by ultrasound method. Results. In the first group, 3 patients (25 %) had mechanical DM, in the second — 4 patients (23.5 %), in the group with coronary artery occlusion, 42 patients (40 %) had mechanical DM. In the group with complete CA occlusion, mechanical DM was detected in 18 (53 %) cases. Septal to posterior wall motion delay (SPWMD) did not differ significantly in the comparison groups; however, it increased significantly to 64.8 ± 43.2 ms in patients with complete CA occlusion compared with 40.8 ± 13.1 ms in the group with unchanged CA (p &lt; 0.05). SPWMD had a significant correlation with the degree of CA occlusion (r = 0.254, p = 0.009). The interventricular mechanical delay increased significantly, to 61.3 ± 40.5 ms compared with 33.4 ± 3.4 ms in patients with unchanged CA (p &lt; 0.05). Left ventricular filling time was significantly shorter in the group with complete CA occlusion compared to the patients with incomplete CA occlusion and those with unchanged CA (47.3 ± 10.4 ms vs. 54.2 ± 5.7 ms, respectively; p &lt; 0.05). Left ventricular ejection time was not significantly different between comparison groups, but correlated significantly with the degree of CA occlusion (r = 0.241, p = 0.013). The early ventricular time deceleration, the time from the beginning of the QRS complex to the beginning of the peak systolic velocity did not differ significantly. The time to the peak systolic velocity was significantly longer in the group with complete CA occlusion (32.6 ± 8.5 ms), and had a significant correlation with the degree of CA occlusion (r = 0.26, p = 0.007). Conclusions. A third of patients with chronic coronary syndrome included in the study had DM. In the group with complete CA occlusion, the frequency of DM detection increased significantly and was diagnosed in half of cases. In patients with complete CA occlusion, DM manifested itself in a significant SPWMD, an increase in the period of pre-ejection into the aorta and, as a result, a significant increase in the interventricular mechanical delay. An increase in the time to peak systolic velocity was also found in the group of patients with complete CA occlusion. DM associated with left ventricular diastolic dysfunction was detected in a group of patients with complete CA occlusion and manifested itself in a reduced left ventricular filling time.

Two-dimensional speckle tracking imaging to assess the hazards of left ventricular function and ventricular wall motion disorders in children with pre-excitation syndrome and the efficacy of radiofrequency ablation treatment.

Our study aimed at analyzing the echocardiographic multi-indicator evaluation of the risk of Wolff-Parkinson-White syndrome (WPW) on the left ventricular function and ventricular wall motion disorders, as well as the effect of radiofrequency ablation treatment. The clinical data of 55 WPW patients treated with radiofrequency (RF) ablation at the Children's Hospital of Nanjing Medical University between January 2018 and December 2022 were retrospectively analyzed and included in the observation group, while other 50 healthy children were included in the control group during the same time. We analyzed the echocardiographic indices of the patients, assessed the effects of the disease on left ventricular myocardial function and ventricular wall motion disorders, and evaluated the effects of radiofrequency ablation treatment on the myocardium of the left ventricle. The echocardiographic parameters were analyzed to assess the effect of the disease on left ventricular myocardial function and ventricular wall dyskinesia. Of the 55 patients with pre-excited syndrome, 20 had type A bypass and 35 had type B bypass. Ten patients had pre-excited dilated cardiomyopathy with significant enlargement of the left ventricular cavity, reduced left ventricular systolic function, and a significant impairment of ventricular wall motion; the other 5 patients had basal segmental septal motion incoordination. Compared to the control group, patients with left ventricular end-diastolic diameter (LVEDD) (42.9±5.0 mm vs. 39.2±3.0 mm), peak strain dispersion (PSD) (38.8±15.3 ms vs. 21.7±2.2 ms), maximum peak time difference (MPTD) (200.2±92.8 ms vs. 89.5±9.8 ms) and interventricular mechanical delay (IVMD) (36.2±13.7 ms vs. 21.2±2.1 ms) before RF ablation were increased. Left ventricular ejection fraction (LVEF) (57.1±9.1% vs. 65.9±2.6%), E/A (1.1±0.2 vs. 1.8±0.2) and global longitudinal strain (GLS) (-18.7±2.2% vs. -22.4±0.5%) decreased, with statistically significant differences (p<0.05). All 55 patients had a successful procedure, and all postoperative echocardiographic parameters were found to be improved, compared to the preoperative period. The results of the postoperative review after 3 months showed differences in E/A, PSD, MPTD, and IVMD compared to the healthy group, suggesting that left ventricular diastolic function and synchrony had not fully returned to normal. Echocardiography can better evaluate myocardial motion and function in patients with Wolff-Parkinson-White syndrome and monitor the effect and progress of disease treatment, and has high clinical application value.

Response to Cardiac Resynchronization Therapy in Cardiomyopathy Patients with Right Bundle Branch Block.

The use of cardiac resynchronization therapy (CRT) in heart failure patients with right bundle branch block (RBBB) is under debate. We present early and late echocardiographic characteristics of a series of heart failure patients with RBBB who underwent CRT. In this retrospective descriptive study, 18 patients with RBBB in the surface electrocardiogram underwent CRT between 2005 and 2015. All the patients had the New York Heart Association functional class III/IV, a left ventricular ejection fraction (LVEF) ≤35%, and a QRS duration ≥120 milliseconds. The median follow-up duration was 19 months. The echocardiographic response was based on a ≥5% increase in LVEF. Within 48 hours after CRT implantation, LVEF increased from 24.58%±7.08% before to 28.46±8.91% after CRT (P=0.005) and to 30.00±9.44% at follow-up (P=0.008). Among the 18 patients, 12 (66.7%) were responders within 48 hours after CRT. The following baseline echocardiographic parameters were higher in the responders than in those without an increased LVEF, although the difference did not reach statistical significance: septal-to-lateral wall delay (48.33±33.53 vs 43.33±38.82 ms), anteroseptal-to-posterior wall delay (41.7±1.75 vs 38.33±18.35 ms), and interventricular mechanical delay (48.50±21.13 vs 31.17±19.93 ms). The mean QRS duration was higher in the responders than in the non-responders (183.58±40.69 vs 169.00±27.36 ms). Death was reported in 3 out of the 18 patients (16.7%) at follow-up. The 3 deceased patients had a higher baseline interventricular mechanical delay than those who survived. Our results indicated that patients with RBBB might benefit from CRT. Further, patients with higher intra and interventricular dyssynchrony and a wider QRS may show better responses.

Traditional Criteria of Mechanical and Electrical Dyssynchrony as a Predictor of Super-Response in Patients with Cardiac Resynchronization Therapy

Aim: To evaluate clinical and morpho-functional predictors of super-response to cardiac resynchronization therapy (CRT) in patients with heart failure and reduced ejection fraction (HFrEF) in the short-term period after implantation.Material and Methods. The study enrolled 86 patients (88.4% men, 54.0 ± 8.9 years mean age, New York Heart Association (NYHA) class II–IV). Patients were examined at baseline and in dynamics (mean follow-up was 10.6 ± 3.6 months). According to the change in left ventricular (LV) end-systolic volume (ESV) patients were divided into two groups: Group I (n = 19) with a decrease in LV ESV ≥ 30% (super-responders (SR) and Group II (n = 67) – decrease in LV ESV &lt; 30% (non-super-responders (non-SR). Parameters of mechanical dyssynchrony (MD) were assessed in the two groups including LV pre-ejection period, interventricular mechanical delay (IVMD), intraventricular delay (IVD).Results. At baseline, traditional parameters of MD were higher in SR: LV pre-ejection period (156.8 ± 35.4 ms vs 135.0 ± 35.6 ms; p = 0.021) and IVMD (73.0 [43.0; 108.0] ms vs 47.0 [19.5; 70.0] ms; p = 0.017). Logistic regression results showed that female gender (HR 7.048; 95% CI 1.496–33.206; p = 0.014) and QRS width (HR 1.017; 95% CI 1.000–1.034; p = 0.048) had an independent association with super-response.Conclusion. In patients with HFrEF, more severe mechanical and electrical dyssynchrony is associated with super-response to CRT in a short-term follow-up period.

Comparison of ventricular synchrony in children with left bundle branch area pacing and right ventricular septal pacing.

This study aimed to determine the ideal pacing site in children by comparing the postoperative ventricular synchrony in children with left bundle branch area pacing and those with right ventricular septal pacing. This retrospective study included children with complete atrioventricular block who underwent permanent pacemaker implantation from March 2019 to August 2021. Patients were grouped according to their ventricular pacing site, the left bundle branch area pacing group and the right ventricular septal pacing group. Two-dimensional speckle tracking echocardiography was used to evaluate the ventricular synchrony. Forty-eight children (median age, 2.7 years; interquartile range, 1.7-4.6 years) were included. The paced QRS duration in the left bundle branch area pacing group was significantly narrower than that in the right ventricular septal pacing group (100.2 ± 9.3 versus 115.4 ± 15.1 ms, p = 0.001). The median follow-up duration was 1.5 years (interquartile range, 1-2 years). At the last follow-up, the average capture threshold of the ventricular electrode in the left bundle branch area pacing group was lower than that in the right ventricular septal pacing group (0.79 ± 0.18 versus 1.20 ± 0.56 V, p = 0.008). The left ventricular intraventricular synchrony parameters in the left bundle branch area pacing group were better than those in the right ventricular septal pacing group (e.g. standard deviation of the time to peak longitudinal strain, 37.4 ± 4.3 versus 46.6 ± 8.2 ms, p = 0.000). The average interventricular mechanical delay time in the left bundle branch area pacing group was significantly shorter than that in the right ventricular septal pacing group (36.4 ± 14.2 versus 52.5 ± 22.7 ms, p = 0.016). Compared with right ventricular septal pacing, left bundle branch area pacing in children produces a narrower QRS duration and better pacing and ventricular synchrony parameters postoperatively.

Left bundle branch area pacing in patients with baseline narrow, left, or right bundle branch block QRS patterns: insights into electrocardiographic and echocardiographic features.

Left bundle branch area pacing (LBBAP) is a recent technique aiming at preservation of physiological ventricular electrical activation. Our goal was to assess mechanical synchrony parameters in relation to electrocardiographic features during LBBAP performed in routine practice. From June 2020 to August 2021, all patients of our institution with permanent pacemaker implantation indication were eligible for LBBAP. A 'qR' pattern in V1 and a delay from pacing spike to the peak of the R-wave in V6 < 80 ms defined a successful LBBAP. Electrocardiogram and echocardiography were performed during spontaneous rhythm and LBBAP: left ventricular mechanical synchrony (LVMS) parameters using 2D Speckle tracking and interventricular mechanical delay (IVMD) were collected. LBBAP was attempted with success in 134/163 patients (82.2%). During LBBAP, the mean QRS width was 104 ± 12 ms. In patients with left bundle branch block (n = 47), LBBAP provided a significant decrease of QRS width from 139 ± 16 to 105 ± 12 ms (P < 0.001) with reduction of LVMS (53 ± 21 vs. 90 ± 46 ms, P = 0.009), and IVMD (14 ± 13 vs. 49 ± 18 ms, P < 0.001). In patients with right bundle branch block (n = 38), LBBAP led to a significant decrease of QRS width from 134 ± 14 to 106 ± 13 ms (P < 0.001) with no effect on LVMS and a reduction of IVMD (17 ± 14 vs. 50 ± 16 ms, P < 0.001). LBBAP in routine practice preserved intra-ventricular mechanical synchrony in patients with narrow and RBBB QRS and improved asynchrony parameters in patients with LBBB.

Оцінка механічної диссинхронії міокарду у хворих з різними формами коронарної хвороби серця, яким проводилась реваскуляризація

The purpose of the study was to determine the presence of mechanical dyssynchrony of the myocardium in patients with various clinical variants of coronary heart disease undergoing revascularization. Materials and methods. 137 patients (106 men and 31 women, aged from 31 to 81 years) took part in the study, including 121 patients with coronary heart disease who underwent a revascularization procedure. Results and discussion. The frequency of detection of mechanical dyssynchrony of the myocardium is significantly higher in patients with coronary heart disease compared to patients without coronary heart disease who underwent revascularization (41.3% vs. 6.2%, respectively). Aortic transit time was significantly and significantly greater in the group of patients with coronary heart disease compared to patients without coronary heart disease, while pulmonary transit time was the same in the comparison groups. Accordingly, this caused a significant difference in interventricular mechanical delay. Left ventricular filling time was significantly shorter in the group of patients with coronary heart disease and, conversely, left ventricular ejection time was shorter in the group of patients without coronary heart disease. The study showed a significant increase in the frequency of myocardial dyssynchrony in patients with coronary heart disease who underwent revascularization, which creates conditions for studying the prognostic value in relation to the clinical results of revascularization. The time of advancement to the aorta was significantly and reliably longer in the group of patients with coronary heart disease compared to patients without coronary heart disease, while the time of advancement to the pulmonary artery was the same in the comparison groups, which caused a significant difference in the interventricular mechanical delay and confirms dependence of the development of myocardial dyssynchrony on the localization of the coronary artery lesion. Conclusion. Indicators of diastolic dysfunction of the left ventricular myocardium, although there was a tendency for a difference between the group of patients with coronary heart disease and the comparison group, this tendency was unreliable, which demonstrated their later change in relation to the indicators of myocardial dyssynchrony. The data obtained by us confirm the greater informativeness of mechanical dyssynchrony of the left ventricle indicators in comparison with indicators that characterize diastolic function and their earlier changes in patients with coronary heart disease. In turn, early detection and treatment of mechanical dyssynchrony of the left ventricle can delay the onset of left ventricular dysfunction in patients with coronary heart disease

Why does CRT work better in women?

Abstract Introduction It has been recently postulated that cardiac resynchronization therapy (CRT) might have a higher efficacy in women, with a greater reverse cardiac remodeling in this population. The reasons for these differences are not yet completely understood. We aimed to detect sex differences in the degree of ventricular asynchrony (VA) and mitral regurgitation (MR) in patients undergoing CRT implantation. Methods We analyzed baseline characteristics of a prospective international clinical trial that compared CRT response rate in a HF population with a comparable distribution of men and women (BIOWOMEN). A total of 408 patients were analyzed. The degree of mitral regurgitation and intra and inter-ventricular asynchrony was assessed by independent echocardiographers in a core lab. Inter-ventricular asynchrony was defined as an interventricular mechanical delay greater than 40ms and intra-ventricular asynchrony as differences greater than 50ms among regional pre-ejection periods. Multivariable logistic regression was performed using commercial data analysis software. Results As expected, ventricular asynchrony was dependent on QRS duration and the presence of LBBB (p&amp;lt;0.01). Baseline QRS duration was significantly shorter in women than men (155.85±19.0 in women vs 160.4±21.6, p=0.02). However, for a similar QRS duration, there were no differences in asynchrony parameters between the two groups (p=0.43; Figure 1). Female sex was associated with a significantly higher proportion of mitral regurgitation for a given QRS duration, which was independent of the etiology (p=0.05). Conclusions In our analysis, for a given QRS duration there was not a higher degree of asynchrony in women with HF. However, female sex was associated with a significantly higher proportion of mitral regurgitation for a given QRS duration irrespective of baseline HF etiology. Further investigations are needed to establish a possible link between these findings and better CRT outcomes in women. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): BIOTRONIK SE &amp; Co. KG

Early assessment of ventricular synchronization and function after left bundle-branch-area pacing with right bundle-branch block

AimTo evaluate ventricular synchronization and function in patients with right bundle-branch block after left bundle-branch-area pacing (LBBAP) by echocardiography.MethodsForty patients who successfully received LBBAP were selected and divided into the right bundle-branch block group (RBBB group) and the non-RBBB group by pre-operation ECG. Echocardiography and follow-up were performed 1 month after operation. Interventricular synchronization was evaluated by tissue Doppler (TDI), tissue mitral annular displacement (TMAD), and interventricular mechanical delay. The tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RVFAC), tricuspid annulus sidewall systolic velocity (TV-s’), left ventricular global ventricular longitudinal strain (GLS), right ventricular free wall longitudinal strain (LS-RV), standard deviation of left ventricular 18 segments peak time difference (SDt-L) and standard deviation of right ventricular free wall 3 segments peak time difference (SDt-R) were applied to evaluate intraventricular synchronization and ventricular function.ResultsThe difference of displacement peak time of the tricuspid and mitral valves, namely ΔPTTV-MV measured by TMAD, the difference of systolic time to peak of the tricuspid and mitral valves, namely ΔTsTV-MV measured by TDI, were statistically different between the two groups (P < 0.05). Compared with the non-RBBB group, there were no statistically significant differences in the GLS, RVFAC, LS-RV, TAPSE, TV-s’, SDt-L, SDt-R (P > 0.05).ConclusionEchocardiography technology including two-dimensional speckle tracking imaging (2D-STI), TDI, and TMAD can effectively analyze interventricular synchronization, intraventricular synchronization, and ventricular function. Although the movement of the right ventricular myocardium in the RBBB group was slightly later than that of the left ventricular myocardium after LBBAP, LBBAP could still be applied in RBBB patients with pacing indication.

To go left or right? Driving towards the best direction in paediatric pacing.

Permanent pacing in children with isolated congenital complete atrioventricular block may cause left ventricular dysfunction. To prevent it, alternative pacing sites have been proposed: left ventricular epicardial or selective right ventricular endocardial pacing. To compare the functional outcome (left ventricular systolic function and synchrony) in paediatric patients with congenital complete atrioventricular block and left ventricular apical epicardial or right ventricular transvenous mid-septal pacing. Retrospective study. Epicardial leads were implanted by standard surgical technique, transvenous leads by 3D electroanatomic mapping systems. 3D mapping acquired 3D right ventricular local pacing map and defined the narrowest paced QRS site. 3D mapping guided screw-in bipolar leads on that ventricular site. Electrocardiogram (ECG) (QRS duration) and echocardiographic data (synchrony: interventricular mechanical delay, septal to posterior wall motion delay, systolic dyssynchrony index; contractility: global longitudinal strain, ejection fraction) were recorded. Data are reported as median [interquartile ranges]. p < 0.05 was significant. There were 19 transvenous systems (age 8.8 [6-14] years; right ventricular mid-septum) and 17 epicardial systems (0.04 [0.001-0.6] years; left ventricular apex). Post-implantation QRS significantly widened either in endocardial or in epicardial patients. Most patients reached 4-year follow-up. One-year and 4-year ejection fraction and global longitudinal strain were mostly within normal limits and did not show significant differences between the two groups and between the same endocardial/epicardial group. Synchrony parameters were within normal limits in the two groups. Left ventricular apical epicardial pacing and 3D mapping-guided right ventricular mid-septal pacing preserved left ventricular contractility and synchrony in children and adolescents with congenital complete atrioventricular block at short-/mid-term follow-up, without relevant significant differences between the two groups.

SHORT TERM EVALUATION OF LEFT VENTRICULAR FUNCTION FOLLOWING DUAL CHAMBER PACEMAKER A SPECKLE TRACKING STUDY

Objective: Background:In 2012 the consensus issued by both the American College of Cardiology &amp; Foundation Heart Rhythm Society Recommend the use of Dual Chamber Pace maker instead of Single chamber pace maker for patients with Sinus Node dysfunction. Restoration of atrioventricular synchrony in patient with sinus node dysfunction or Atrioventricular block representing a new era in electrical therapy. the focus on normal physiology led to the nearly universal application of dual-chamber pacing to restore atrioventricular (AV) synchrony in patients with sinus rhythm. Design and method: Speckle tracking was used to evaluate the percent of ventricular deformation before and 3months follow upafter dual chamber implantation, this study included 28 patients with Sinus node dysfunction or Heart Failure-LBBB. This prospective observational study was carried out on patients of medical city, Baghdad Teaching Hospital, cardiology &amp; Echocardiography Higher Education (Diploma) center from November 2016 to July 2017. Results: No statistical difference was noted between both gender groups in regard to main risk factors.Four methods were used to evaluate ventricular function synchrony (Ejection Fraction %, Global longitudinal stain, intraventricular synchrony using septal to posterior wall motion delay, interventricular Mechanical delay by Pulse wave), Global EF evaluated by Simpson biplane method remained the same in all patients after 3-month follow-up (P = NS). Global longitudinal strain (GLS) significantly decreased in all patients. Inter-ventricular dyssynchrony evaluation revealed no significant change after 3 months. Conclusions: Global longitudinal strain and Left Ventricular dessynchrony assessment enables us to detect early signs of LV dysfunction in Subjects with dual chamber pacemaker.

Evaluation of electrophysiological characteristics and ventricular synchrony: An intrapatient-controlled study during His-Purkinje conduction system pacingversus right ventricular pacing.

Objectives to BackgroundTo compare electromechanical ventricular synchrony when pacing from different sites, including right ventricular apex pacing (RVAP), right ventricular septum pacing (RVSP), His bundle pacing (HBP), left bundle branch pacing (LBBP), and RVSP during unipolar pacing from the ring electrode of LBBP lead (RVSPring) in each patient and evaluate the correlations between electrophysiological characteristics and ventricular synchrony.MethodsTwenty patients with complete atrioventricular block indicated for dual‐chamber pacemaker implantation were included in the study. Unipolar pacing at different sites, including RVAP, RVSP, HBP, LBBP, and RVSPring, was successively performed in each patient. The pacing characteristics and echocardiogram parameters were collected and compared among intrinsic rhythm and pacing at different sites.ResultsSimilar to HBP (114.84 ± 18.67 ms), narrower paced QRSd was found in LBBP (116.15 ± 11.60 ms) as compared to RVSPring (135.11 ± 13.68 ms), RVSP (141.65 ± 14.26 ms), and RVAP (160.15 ± 19.35 ms) (p < .001). LBBP showed comparable pacing parameters to RVAP or RVSP and was significantly better than HBP, with maintained cardiac function. TS‐12‐SD was significantly improved in LBBP (41.80 ± 20.97 ms) than RVAP (69.70 ± 32.42 ms, p = .003) and RVSP (63.30.56 ± 32.53 ms, p = .018) but similar to HBP (51.50 ± 25.67 ms, p = .283) or RVSPring (57.80 ± 25.65 ms, p = .198). Among these pacing strategies, negative values of interventricular mechanical delay (IVMD) were only identified in LBBP (−19.25 ± 18.43 ms), significantly different from RVAP (35.00 ± 30.72 ms), RVSP (22.85 ± 22.05 ms), HBP (5.20 ± 18.64 ms), and RVSPring (16.00 ± 26.76 ms (all p < .05). Using Pearson's analysis, Sti‐LVAT was positively correlated with QRS duration, IVMD, TS‐12‐SD, LVEDV, and LVESV, while a negative relationship could be observed for left ventricular ejection fraction.ConclusionsHis‐Purkinje conduction system pacing (HPCSP) achieved better electrical and mechanical synchrony than conventional RV pacing. For interventricular synchrony, only LBBP initiated earlier LV activation than RV, in accordance with the right bundle branch block (RBBB) pattern of paced QRS during LBBP. Sti‐LVAT might be a good parameter correlating with LV systolic function and mechanical synchrony.

Clinical Outcomes of Left Bundle Branch Area Pacing in Comparison with Right Ventricular Septal Pacing in Patients with High Ventricular Pacing Ratio ≥40.

BackgroundThe aim of the present study is to compare the clinical outcomes between left bundle branch area pacing (LBBaP) and right ventricular septal pacing (RVSP) in patients with percent ventricular pacing (VP%) ≥40%.MethodsFifty-four patients with VP% ≥40% were retrospectively studied, including 33 patients with LBBaP and 21 patients with RVSP. QRS duration (QRSd), interventricular mechanical delay (IVMD) and septal-posterior wall motion delay (SPWMD) were measured to evaluate ventricular synchrony. Heart failure hospitalization (HFH), pacing parameters, and complications were evaluated postoperatively and at follow-ups.ResultsThe mean follow-up duration of the study participants was 13.80 ± 4.47 months. In the LBBaP group, no significant differences were noted in paced QRSd, IVMD and SPWMD of the LBBaP capture and intrinsic-conduction modes, but the paced QRSd was narrower (QRSd, 110.88 ± 7.37 vs 132.90 ± 14.78 ms, P< 0.0001) and the IVMD and SPWMD were lower when compared with the RVSP group (IVMD, 28.16 ± 4.76 vs 40.28 ± 6.97 ms, P <0.0001; SPWMD, 43.68 ± 26.41 vs 97.94 ± 12.77 ms, P <0.0001). LBBaP was associated with better left ventricular function in comparison with RVSP during follow-ups (LVEDD, 47.09 ± 4.47 vs 51.28 ± 7.58, P = 0.017; LVEF, 64.81± 5.49 vs 60.44 ± 9.28, P = 0.041). Patients with LBBaP had lower occurrences of HFH than patients with RVSP (3.13% vs 27.78%, P = 0.034). Pacing parameters showed no differences between the two groups and remained stable throughout the study period.ConclusionThe results of this study suggest that LBBaP may be more suitable for patients requiring long-term high ventricular pacing ratio.

Evaluation of clinical safety and efficacy of left bundle branch area pacing in comparison with right ventricular septal pacing.

Left bundle branch area pacing (LBBaP) has recently emerged as a new physiological pacing strategy. The purpose of this study is to compare LBBaP with right ventricular sepal pacing (RVSP) in terms of their clinical safety and efficacy.From February 2019 to May 2020, consecutive pacing-indicated patients were prospectively enrolled and divided into 2 groups. Ventricular synchrony indexes such as QRS duration (QRSd), interventricular mechanical delay and septal-posterior wall motion delay, left ventricular function such as left ventricular end-diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF), pacing parameters, and complications were evaluated in the perioperative period and during follow-up.LBBaP was successful in 45 patients (88.2%), and finally 46 patients underwent RVSP. With LBBaP, ventricular electricalmechanical synchrony were similar to those of native-conduction system (P = .78). However, the ventricular electrical synchrony (QRSd, 108.47±7.64 vs 130.63±13.63ms, P < .001) and mechanical synchrony (interventricular mechanical delay, 27.68±4.33 vs 39.88±5.83, P < .001; septal-posterior wall motion delay, 40.39±23.21 vs 96.36±11.55, P < .001) in the LBBaP group were significantly better than those in the RVSP group. No significant differences in LVEDD (46 [44-48.5] vs 47 [44-52] mm, P = .49) and LVEF% (66 [62.5-70] vs 64 [61-68], P = .76) was observed between 2 groups at last follow-up. But, in the subgroup analysis, LVEDD was shorter (46 [44-49] vs 50 [47-58] mm, P = .03) and the LVEF% was higher (65 [62-68] vs 63 [58-65], P = .02) in the LBBaP-H (high ventricular pacing ratio >40%) group compared with RVSP-H group at last follow-up. There were lower capture thresholds (0.59±0.18V vs 0.71 ± 0.26 V, P = 0.01) at implantation in the LBBaP group than those in the RVSP group, with R-wave amplitudes and pacing impedances showing no significant difference between 2 groups. No serious complications were found in both 2 groups at implantation and follow-ups.This study confirms the clinical safety and efficacy of LBBaP, and it produces better ventricular electrical-mechanical synchrony than RVSP. The event of pacing-induced left ventricular dysfunction is lower in the LBBaP-H group than RVSP-H group.

Abstract 11164: Better Electromechanical Synchrony During Left Bundle Branch Pacing and His Bundle Pacing as Compared to Right Ventricular Pacing in Atrioventricular Block

Objectives: To compare electromechanical ventricular synchrony when pacing from different sites including right ventricular apex pacing (RVAP), right ventricular septum pacing (RVSP), His Bundle pacing (HBP), left bundle branch pacing (LBBP) and RVSP during unipolar pacing from the ring electrode of LBBP lead (RVSP ring ) in each patient during implantation. Methods: Twenty patients with complete atrioventricular block (AVB) indicated for dual-chamber pacemaker implantation were included. Unipolar pacing at different sites including RVAP,RVSP,HBP,LBBP and RVSP ring were successively performed in each patient while pacing characteristics and echocardiogram parameters were collected and compared. Results: Similar to HBP, narrower paced QRSd was found in LBBP as compared to RVSP ring , RVSP and RVAP(p&lt;0.001). LBBP showed comparable pacing parameters to RVAP or RVSP and were significantly better than HBP, with maintained cardiac function. For ventricular mechanical synchrony, TS-12-SD was significantly improved in LBBP(27.00±21.53ms) than RVAP(54.05±34.21ms, p=0.004) and RVSP(47.56±33.26ms, p=0.029) but similar to HBP or RVSP ring . Among these pacing strategies, negative values of interventricular mechanical delay(IVMD) were only identified in LBBP(-20.16±18.47ms), significantly different from RVAP(33.68±30.98ms), RVSP (21.68±22.02ms), HBP (4.74±19.04ms) and RVSP ring (14.56±26.76ms(all p&lt;0.001). Using Pearson’s analysis, Sti-LVAT was found to be positively corelated with QRS, IVMD, TS-12-SD, LVEDV and LVESV while a negative relationship could be observed for LVEF. Conclusions: Similar to HBP, LBBP achieved better electrical and mechanical left ventricular synchrony than conventional RV pacing. For interventricular synchrony, only LBBP initiated earlier LV activation than RV among these pacing strategies, in consistent with the RBBB pattern of paced QRS during LBBP.