# Nutritional Factors and Arrhythmic Risk in Long QT Syndrome: A Narrative Review of Mechanistic and Clinical Evidence

## TL;DR

This review explores how diet can affect arrhythmic risk in people with Long QT syndrome, a genetic heart condition, and provides guidance for dietary management.

## Contribution

The paper integrates mechanistic and clinical evidence to offer genotype-specific dietary recommendations for managing Long QT syndrome.

## Key findings

- Certain nutrients and food constituents can influence repolarization and arrhythmic risk in LQTS patients.
- Gene–nutrient interactions impact ion channel function and drug metabolism in LQTS.
- Potassium supplementation and dietary adjustments are recommended for specific LQTS subtypes like Andersen-Tawil and Timothy syndromes.

## Abstract

Long QT syndrome (LQTS) is an umbrella term for a group of genetic cardiac channelopathies characterized by prolonged ventricular repolarization and increased risk of life-threatening arrhythmias. Although β-blockers and lifestyle modifications remain central to management, specific dietary components may influence repolarization and arrhythmic risk, particularly in genetically predisposed individuals. This review summarizes mechanistic and clinical evidence on the electrophysiological effects of selected nutrients, food constituents, and supplements—including grapefruit juice, licorice, over-the-counter products, and energy drinks. Gene–nutrient interactions and their impact on ion channel function, drug metabolism, and electrolyte balance are discussed. The second part of the review outlines genotype-specific considerations, such as potassium supplementation and dietary guidance for rare forms of LQTS, including Andersen-Tawil and Timothy syndromes. Clinical data are presented in tabular format to facilitate interpretation. By integrating mechanistic and clinical data, the review aims to support dietary counseling and inform clinical decision making in the management of LQTS.