Heart rate turbulence

Area of Science:

• Cardiology
• Physiology
• Medical Technology

Background:

• Survivors of acute myocardial infarction (AMI) face a heightened risk of sudden cardiac death.
• Autonomic cardioverter defibrillators have shown efficacy in reducing mortality in high-risk post-AMI patients.
• Accurate risk stratification is crucial for effective post-myocardial infarction management.

Purpose of the Study:

• To introduce and evaluate heart rate turbulence (HRT) as a novel risk stratification tool.
• To assess the predictive value of HRT for mortality in post-myocardial infarction patients.
• To explore the potential application of HRT in other cardiac conditions.

Main Methods:

• Quantification of short-term sinus rhythm cycle length fluctuations following ventricular premature complexes.
• Measurement of turbulence onset and turbulence slope.
• Statistical adjustment for established mortality predictors like ejection fraction and heart rate variability.

Main Results:

• Heart rate turbulence is a consistent finding in low-risk ischemic heart disease patients.
• The absence of heart rate turbulence is a significant predictor of increased subsequent mortality.
• HRT measures (turbulence onset, turbulence slope) are strong independent predictors of mortality.

Conclusions:

• Heart rate turbulence offers a valuable new method for risk stratification in post-myocardial infarction patients.
• The absence of HRT indicates a significantly elevated risk for sudden cardiac death.
• HRT shows promise for risk prediction in conditions beyond myocardial infarction, including dilated cardiomyopathy and Chagas disease.