Exercise Test for Patients with Long QT Syndrome

Area of Science:

• Cardiology
• Genetics
• Clinical Diagnostics

Background:

• Congenital long QT syndrome (LQTS) is a genetic disorder causing dangerous heart arrhythmias and sudden death.
• Exercise and postural change tests are recommended for diagnosing LQTS, especially in cases with subtle symptoms.
• Current evidence largely stems from single-center studies, lacking external validation and leading to diagnostic inconsistencies.

Purpose of the Study:

• To systematically review and summarize evidence on the diagnostic performance of QT interval measurements during exercise or postural changes for LQTS.
• To validate the efficacy and feasibility of these provocative tests in diagnosing LQTS across diverse studies.
• To identify and address challenges associated with exercise and postural tests in LQTS diagnosis.

Main Methods:

• Systematic review of cross-sectional and cohort studies.
• Evaluation of studies assessing exercise tests or postural changes for LQTS diagnosis.
• Analysis of diagnostic accuracy and feasibility data.

Main Results:

• QT interval changes during exercise/postural tests show promise for identifying LQTS phenotypes.
• Evidence synthesis highlights heterogeneity across studies, impacting diagnostic criteria.
• Potential limitations and practical issues of these tests are identified.

Conclusions:

• Exercise and postural change tests are valuable tools for diagnosing congenital long QT syndrome.
• A comprehensive, validated approach is needed to overcome inter-study heterogeneity and refine diagnostic criteria.
• Further research should focus on standardizing protocols and addressing identified challenges for improved clinical utility.