Effects of permanent cardiac pacing on ventricular repolarization when compared to cardioneuroablation
Tolga Aksu1, Mohit Turagam2, Sandeep Gautam3
1University of Health Sciences, Kocaeli Derince Training and Research Hospital, Department of Cardiology, Kocaeli, Turkey.
Introduction:
The impact of cardioneuroablation (CNA) on ventricular repolarization by using corrected QT interval (QTc) measurements has been recently demonstrated. The effects of cardiac pacing (CP) on ventricular repolarization have not been studied in patients with vasovagal syncope (VVS). We sought to compare ventricular repolarization effects of CNA (group 1) with CP (group 2) in patients with VVS.
Methods:
We enrolled 69 patients with age 38 ± 13 years (53.6% male), n = 47 in group 1 and n = 22 in group 2. Clinical diagnosis of cardioinhibitory type was supported by cardiac monitoring or tilt testing. QTc was calculated at baseline (time-1), at 24 h after ablation (time-2), and at 9-12 months (time-3) in the follow-up.
Results:
In the group 1, from time-1 to time-2, a significant shortening in QTcFredericia (from 403 ± 27 to 382 ± 27 ms, p < 0.0001), QTcFramingham (from 402 ± 27 to 384 ± 27 ms, p < 0.0001), and QTcHodges (from 405 ± 26 to 388 ± 24 ms, p < 0.0001) was observed which remained lower than baseline in time-3 (373 ± 29, 376 ± 27, and 378 ± 27 ms, respectively). Although the difference between measurements in time-1 and time-2 was not statistically significant for QTcBazett, a significant shortening was detected between time-1 and time-3 (from 408 ± 30 to 394 ± 33, p = 0.005). In the group 2, there was no time-based changes on QTc measurements. In the linear mixed model analysis, the longitudinal reduction tendency in the QTcFredericia and QTcFramingham was more pronounced in group 1.
Conclusions:
Our results demonstrate that CNA reduces QTc levels through neuromodulation effect whereas CP has no effect on ventricular repolarization in patients with VVS.
Related Concept Videos
01:30Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
01:19Electrophysiology of Normal Cardiac Rhythm
01:18Dysrhythmias IV: Characteristics of Bradyarrhythmias
01:28Mechanism of Cardiac Arrhythmias
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:19Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...