Heart rate recovery immediately after treadmill exercise and left ventricular systolic dysfunction as predictors of mortality: the case of stress echocardiography.

BACKGROUND: An attenuated heart rate recovery after exercise has been shown to be predictive of mortality. In prior studies, recovery heart rates were measured while patients were exercising lightly, that is, during a cool-down period. It is not known whether heart rate recovery predicts mortality when measured in the absence of a cool-down period or after accounting for left ventricular systolic function.

METHODS AND RESULTS: We followed 5438 consecutive patients without a history of heart failure or valvular disease referred for exercise echocardiography for 3 years. Heart rate recovery was defined as the difference in heart rate between peak exercise and 1 minute later; a value
CONCLUSIONS: Even in the absence of a cool-down period and even after accounting for left ventricular systolic function, heart rate recovery is a powerful and independent predictor of death.