# Differential effects of non-selective and cardio-selective beta-blocker therapy on ECG parameters in long QT syndrome type 1

## TL;DR

Non-selective beta-blockers reduce ECG repolarization time in LQT1 patients, suggesting better heart rhythm control compared to cardio-selective ones.

## Contribution

The study identifies Tpeak/end as a novel ECG marker for assessing beta-blocker efficacy in LQT1.

## Key findings

- Non-selective beta-blockers significantly shorten Tpeak/end in LQT1 patients.
- Cardio-selective beta-blockers do not consistently affect Tpeak/end.
- Tpeak/end shortening correlates with reduced arrhythmic risk in LQT1.

## Abstract

•Non-selective β-blockers markedly reduce Tpeak/end in LQT1 patients.•Cardio-selective β-blockers show no consistent effect on Tpeak/end.•The nsBB effect persists after exercise, independent of heart rate.•Tpeak/end shortening indicates decreased global repolarization heterogeneity and reduced arrhythmic risk.•Tpeak/end may serve as a novel ECG marker for β-blocker efficacy in LQT1.

Non-selective β-blockers markedly reduce Tpeak/end in LQT1 patients.

Cardio-selective β-blockers show no consistent effect on Tpeak/end.

The nsBB effect persists after exercise, independent of heart rate.

Tpeak/end shortening indicates decreased global repolarization heterogeneity and reduced arrhythmic risk.

Tpeak/end may serve as a novel ECG marker for β-blocker efficacy in LQT1.