Impaired heart rate recovery and chronotropic incompetence in patients with heart failure with preserved ejection fraction

Background-This study assessed the chronotropic response to exercise and heart rate (HR) recovery after exercise in a carefully phenotyped group of patients with heart failure with preserved left ventricular ejection fraction (HfpEF) and a control group of similar age and gender distribution.

Methods and Results-We studied 41 patients with HfpEF, 41 healthy controls, and 16 hypertensive controls. None were taking HR-limiting medications. All study participants had clinical examination, 12-lead ECG, pulmonary function test, echocardiogram, and metabolic exercise test with HR monitoring throughout exercise. Chronotropic response was measured by the percentage of the HR reserve used during maximal exercise and the peak exercise HR as a percentage of predicted maximal HR. Patients with HfpEF were generally women (70%), overweight, aged 69+/-8 years. Controls were of similar gender (63%) and age (67+/-6 years). Patients with HfpEF had significantly reduced peak VO2 compared with controls (20+/-4 mL . kg(-1) . min(-1) versus 31+/-6 mL . kg(-1) . min(-1), P<0.001) and greater minute ventilation-carbon dioxide production relationship (VE/VCO2 slope) (33+/-6 versus 29+/-4, P<0.001). Chronotropic incompetence was significantly more common in patients with HfpEF compared with matched healthy controls as measured by the percentage of the HR reserve used during maximal exercise (63% versus 2%, <0.001) and percentage of predicted maximal HR (34% versus 2%, <0.001). In addition, abnormal HR recovery 1-minute after exercise (defined as the reduction in the HR from peak exercise 1-minute after exercise) was also significantly more common in patients with HfpEF compared with controls (23% versus 2%, P=0.01). Hypertensive controls showed similar chronotropic response to peak exercise and HR recovery after exercise as healthy controls.

Conclusions-Patients with HfpEF have impaired chronotropic incompetence during maximal exercise and abnormal HR recovery after exercise.