Association between paced QRS duration and atrial fibrillation after permanent pacemaker implantation: A retrospective observational cohort study

Cardiac variables associated with atrial fibrillation occurrence and mortality in octogenarians implanted with dual chamber permanent pacemakers

BACKGROUND

There is a dearth of data on the predictors of atrial fibrillation (AF) and the association between AF and long-term mortality in octogenarians with dual-chamber permanent pacemakers (PPM). We investigate the occurrence of AF and whether it is associated with overall mortality among octogenarians with dual-chamber PPM implants.

METHODS

Three hundred and fifty-four patients with PPM implants were divided into two groups based on their long-term survival status. Baseline characteristics, laboratory variables, and echocardiographic variables were then compared between the groups, and independent predictors of the long-term incidence of AF and mortality were determined.

RESULTS

Multivariable Cox regression analysis performed after adjusting for the parameters in univariable analysis revealed that diabetes, urea levels, albumin levels, paced QRS duration, and the frequency of atrial high-rate episodes (AHREs) were independently associated with a long-term risk of AF in octogenarians after having dual chamber PPMs implanted. The left ventricular (LV) ejection fraction, left atrial (LA) anteroposterior diameter, and AHRE + AF (HR 1.498, 95%CI 1.003-2.237, p = 0.048) were independent risk factors for the long-term mortality in octogenarians receiving dual-chamber PPMs implants.

CONCLUSION

The occurrence of AF following dual-chamber PPM implantation is a significant prognostic factor in octogenarian patients.

Pacemaker detected prolonged atrial high rate episodes - Incidence, predictors and implications; a retrospective observational study

Introduction

Atrial tachyarrhythmias especially atrial fibrillation are the most commonly encountered arrhythmias in clinical practice. Most atrial tachyarrhythmia episodes are subclinical. Cardiac implantable electronic devices with atrial sensing function enable detection of atrial tachyarrhythmias through means of atrial high rate event algorithms. Prolonged atrial high rate episodes(AHRE) above a defined rate and duration threshold represent episodes of atrial fibrillation, atrial flutter, and longer atrial tachycardias that correlate strongly with risk for thromboembolic events.

Objective

1. To examine the occurrence of prolonged AHRE in dual-chamber pacemaker recipients over the study period. 2. To examine the factors which influence the occurrence of prolonged AHRE in these patients.

Methods

In this study, we analyzed data of 398 patients without valvular heart disease or history of atrial fibrillation who underwent dual chamber permanent pacemaker implantation at our center from January 2013 to June 2018. Patient demographics, cardiovascular comorbidities, medications, echocardiographic parameters such as ejection fraction and left atrial(LA) dimension were obtained. Also, we collected pacing characteristics such as paced QRS duration(QRSd), ventricular pacing site and cumulative percentage ventricular paced beats.

Results

Prolonged AHRE occurred in 59 patients(14.8%). Baseline LA dimension was greater in patients with prolonged AHRE(median 35 mm, IQR 33-37 vs median 35 mm, IQR 34-38, P = 0.004) compared to those without. Paced QRSd was significantly longer in patients with prolonged AHRE (median of 147 ms, IQR 139-160 ms vs 140 ms, IQR 132-150 ms; P < 0.001). On multivariable logistic regression, paced QRSd(OR 1.04, 95%CI 1.02-1.06; P = 0.001) and baseline LA dimension(OR 1.14, 95%CI 1.03-1.27; P = 0.01) significantly co-predicted AHRE. On Kaplan Meier analysis, patients with paced QRSd≥142 ms had more likelihood of developing prolonged AHRE during follow up (HR 2.46, CI 1.40-4.3, P = 0.001). After adjusting for baseline values, patients with paced QRSd≥142 ms had significant decline in left ventricular ejection fraction (adjusted mean difference -1.27%; P = 0.02) and significant LA dilation (adjusted mean difference 0.62 mm; P = 0.05).

Conclusion

In our study, paced QRSd and LA dimension were the strongest predictors for prolonged AHRE. The incidence of AHRE may be reduced by achieving the narrowest possible paced QRSd during device implantation.