# QT Prolongation Following Premature Ventricular Contractions Leading to Ventricular Storms: A Case Report

## TL;DR

A case report shows that QT interval prolongation after premature ventricular contractions may indicate arrhythmic risk, even when standard tests are inconclusive.

## Contribution

Highlights post-PVC QT prolongation as a potential diagnostic marker for arrhythmic risk in long QT syndrome.

## Key findings

- QTc prolongation following PVCs was observed in a patient with LQTS despite standard interventions.
- Genetic testing revealed variants of uncertain significance not previously studied or reported.
- Post-PVC QT prolongation may serve as a valuable marker for malignant arrhythmias when standard assessments fail.

## Abstract

QT interval behavior following premature ventricular contractions (PVCs) has not been widely studied, but it may serve as a valuable diagnostic and prognostic marker for malignant arrhythmias, particularly when standard QT assessment fails to provide clear answers. This report follows up on a previous case involving a 53-year-old woman with recurrent syncope and QTc prolongation following PVCs. She was initially diagnosed with long QT syndrome (LQTS) in 2007. Despite interventions, including implantation of an implantable cardioverter-defibrillator (ICD), high-dose beta-blockers, and cardiac sympathetic denervation, she continued to experience torsades de pointes, ventricular tachycardia storms, and multiple hospitalizations. Genetic testing revealed variants of uncertain significance (VUS), none of which, to our knowledge, have been functionally studied in vitro or reported in the existing literature. This case highlights the potential importance of post-PVC QT prolongation as a marker of arrhythmic risk and underscores the challenges in diagnosing and managing LQTS. Greater awareness of this phenomenon could enhance risk assessment in patients with unexplained syncope and borderline QT intervals. Further research is needed to determine its prognostic value and clinical relevance.