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Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
Published on: April 5, 2011
Relationship between QT interval duration and exercise-induced ventricular arrhythmias.
S Cuomo1, L de Caprio, D Acanfora
1Servizio di Cardiologia, Ospedale C.T.O., Napoli, Italy.
European Heart Journal
|July 1, 1989
Summary
Longer resting QTc intervals may indicate a higher risk of exercise-induced ventricular arrhythmias (EIVA) in patients with coronary artery disease (CAD). However, a prolonged QTc is only a weak predictor of EIVA occurrence.
Area of Science:
- Cardiology
- Electrophysiology
- Exercise Physiology
Background:
- Exercise-induced ventricular arrhythmias (EIVA) are a concern in patients with coronary artery disease (CAD).
- The relationship between QT interval prolongation and EIVA requires further investigation.
Purpose of the Study:
- To determine if QT prolongation before and during early exercise correlates with the occurrence of EIVA in patients with CAD.
Main Methods:
- Prospective study comparing patients with and without CAD undergoing exercise testing.
- Electrocardiographic (ECG) monitoring, including QT interval measurements, during early exercise.
- Analysis of EIVA occurrence in relation to resting and exercise QT intervals.
Main Results:
- Resting QTc was significantly longer in CAD patients who experienced EIVA (443 ± 40 ms) compared to those without EIVA (424 ± 37 ms) and healthy controls (421 ± 32 ms).
- QT intervals during early exercise remained significantly longer in patients with EIVA.
- A resting QTc > 440 ms predicted subsequent EIVA in CAD patients with 43% sensitivity and 72% specificity.
Conclusions:
- A trend towards longer resting QTc values exists in CAD patients who develop EIVA.
- While a prolonged resting QTc (> 440 ms) shows a trend, it is a weak predictor of subsequent EIVA in CAD patients.
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