Paced QT interval is a better predictor of mortality than the intrinsic QT interval: Long-term follow-up study

Liang

Cardiovasc electrophysiol

et al. 2019

Introduction: Left bundle branch area pacing (LBBAP) has recently been reported to be a new physiological pacing strategy with clinical feasibility and safety. The present study aims to investigate depolarization-repolarization measures including QT interval, QT dispersion (QTD), and T peak-end interval (T p T e ) in this novel LBBAP strategy. Methods and Results:A total of 131 pacing-indicated patients were prospectively enrolled and randomized to the LBBAP group (n = 66) and right ventricular septum pacing (RVSP) group (n = 65). LBBAP was successfully achieved in 61 subjects with stable lead performance and comparable complications (ie, pocket hematoma, lead perforation, and dislodgement) compared with RVSP. Of the 61 patients with successful LBBAP, the mean LV peak activation time was 67.89 ± 6.80 ms, with the LBB potential mapped in 46 cases (75.4%). Electrocardiogram (ECG) indices were compared between these two groups before and after implantation. As a result, LBBAP yielded a narrower paced QRS duration (121.49 ± 9.87 ms vs 145.62 ± 8.89 ms; P < .001), shorter QT interval (434.16 ± 32.70 ms vs 462.66 ± 32.04 ms; P < .001), and QT c interval (472.44 ± 33.30 ms vs 499.65 ± 31.35 ms; P < .001), lower QTD (40.10 ± 8.68 ms vs 46.11 ± 10.85 ms; P = .001), and QT c D (43.57 ± 8.78 ms vs 49.86 ± 11.98 ms; P = .001), and shorter T p T e (96.59 ± 10.76 ms vs 103.77 ± 10.16 ms; P < .001) than RVSP. However, T p T e /QT ratio did not differ between these two groups (0.223 ± 0.026 vs 0.225 ± 0.022; P = .733). Furthermore, LBBAP displayed less increased QRS duration, QT c interval, QTD, QT c D, and a more shortened QT interval compared with RVSP (all P < .05).Conclusion: LBBAP proves to be a feasible and safe pacing procedure with better depolarization-repolarization reserve, which may predict lower risk of ventricular arrhythmia and sudden cardiac death. K E Y W O R D S depolarization-repolarization reserve, left bundle branch area pacing, pacemaker, physiological pacing, right ventricular septum pacing Jingfeng Wang and Yixiu Liang are co-first authors.

Section: Discussionmentioning

confidence: 99%

Left bundle branch area pacing is superior to right ventricular septum pacing concerning depolarization‐repolarization reserve

Liang

Cardiovasc electrophysiol

et al. 2019

Pacing Clinical Electrophis

“…This case also highlights the involved mechanism, based on repolarization instability after acute changes in heart rates associated with modification of ventricular activation. While QRS widening in paced beats is known to prolong QT interval, and although different correction formulas had been proposed, several studies have shown that long‐paced QT interval was associated to an increase of cardiac mortality . International guidelines agree in recommending an initial pacing rate programmed about 90 beats/min after AV junction ablation to be gradually tapered over several months, according to the relatively low evidence reporting in the literature .…”

Section: Discussionmentioning

confidence: 99%

“…While QRS widening in paced beats is known to prolong QT interval, and although different correction formulas had been proposed, several studies have shown that long-paced QT interval was associated to an increase of cardiac mortality. 9 International guidelines agree in recommending an initial pacing rate programmed about 90 beats/min after AV junction ablation to be gradually tapered over several months, according to the In addition to programming a relatively rapid ventricular rate, a special attention should be given to QT interval monitoring, through regular 12D-ECG during the day after the procedure, giving the opportunity to optimize ventricular pacing rate.…”

Section: Discussionmentioning

confidence: 99%

Holter‐monitored sudden cardiac arrest after atrioventricular junction ablation

Waldmann

Marijon

Combes

2017

We present a case of sudden cardiac arrest 7 hours after radiofrequency ablation of the atrioventricular junction for symptomatic permanent atrial fibrillation unresponsive to medical therapy. The Holter monitoring revealed a progressive increasing of QT interval after the procedure, highlighting the repolarization instability after acute changes in heart rates associated with modification of ventricular activation, leading to occurrence of short coupling interval ventricular extra beats and finally to a "torsade de pointes." This illustration underlines the need to program a relatively rapid ventricular rate first weeks after junction ablation, especially in case of rapid ventricular rate prior to the procedure, as well as the role of continuous ECG and QT interval monitoring during hospital stay.

“…It seems that a B-type natriuretic peptide augmentation in patients with heart failure is associated with an increased risk of sudden cardiac death only in patients with QTc interval prolongation (14). The paced QTc interval appears to be a more useful marker for predicting increased total mortality and cardiac mortality than the intrinsic QTc interval in patients with indications for a permanent pacemaker (15). A 50-ms increase in the QTc interval is associated with doubling in the probability for all-cause mortality in patients with rheumatoid arthritis (16).…”

Section: Introductionmentioning

confidence: 99%

QT interval variations and mortality risk: Is there any relationship?

Rezuş¹,

Moga²,

Ouatu³

et al. 2015

Anatol J Cardiol

Abnormal prolongation and shortening of the electrocardiographic QT interval duration, which occur in the hereditary forms of long and short QT syndromes, are associated with an increased risk of ventricular arrhythmias and sudden cardiac death. Even within the normal range, these altered durations are associated with an increased mortality risk in the general population. While extreme prolongation or reduction of the QT interval predisposes patients to malignant ventricular arrhythmias and sudden cardiac death, the precise dose-response relationship between the QT interval and cardiovascular disease mortality is still unknown. This paper describes the need for more standardized methods for measuring and reporting the QT interval and the need for more precise assessments of the risk associated with QT interval variation.