Heart Rate Turbulence Predicts Risk After Heart Attack
Turbulence reflects hemodynamic disturbances
TUESDAY, Oct. 14 (HealthDay News) -- Heart rate turbulence, an electrocardiographic phenomenon reflecting minute hemodynamic disturbances, can be used to predict the risk of serious outcomes after a heart attack, according to a review in the Oct. 21 issue of the Journal of the American College of Cardiology.
Axel Bauer, M.D., from Medizinische Klinik der Technischen Universitat Munchen in Munich, Germany, and colleagues reviewed the topic of heart rate turbulence, focusing on technologies for measurement, physiologic background and interpretation, and clinical use.
Heart rate turbulence consists of a brief heart rate acceleration, followed by a more gradual deceleration, then a return to pre-ectopic levels, according to the authors. The available evidence shows that the initial acceleration is ultimately caused by hemodynamically inefficient ventricular contraction, leading to a missed baroreflex afferent input and transient vagal inhibition, which triggers the acceleration. The subsequent deceleration results from a sympathetically mediated overshoot of arterial pressure through vagal recruitment, they explain. Heart rate turbulence can be assessed by 24-hour Holter recordings. Noting that heart rate turbulence is an indirect measure of baroreflex, the authors write that it can be useful in assessing risk after acute myocardial infarction, risk prediction, and monitoring disease progression in heart failure.
"Several large-scale retrospective and prospective studies have established beyond any doubt that heart rate turbulence is one of the strongest independent risk predictors after myocardial infarction," Bauer and colleagues conclude. "It thus appears that the stage has now been reached when heart rate turbulence might be used in large prospective intervention studies."