Abstract 3190: 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 recovery following exercise in a carefully phenotyped group of patients with heart failure with preserved left ventricular systolic function (HfpEF) and a control group of similar age and gender distribution.
Methods and Results: We studied 41 HfpEF patients and 44 healthy controls. None was taking heart rate-limiting medications. All study participants had clinical examination, 12-lead electrocardiogram, 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 (%HHR) and the peak exercise HR as a percentage of predicted maximal HR (%Max-PPHR). HfpEF Patients were generally females (70%), overweight, aged 69±8 years old. Controls were of similar gender (63%) and age (67±6 years old). Patients with HfpEF had significantly reduced VO2max compared to controls (20±4 ml/Kg/min vs. 31±6 ml/Kg/min, p<0.001) and greater minute ventilation– carbon dioxide production relationship (VE/VCO2 slope) (33±6 vs. 29±3, p<0.001). Chronotropic incompetence was significantly more common in patients with HfpEF compared to matched controls as measured by %HHR (63% vs. 2%, <0.001) and %Max-PPHR (34% vs. 2%, <0.001). In addition, abnormal HR recovery 1-minute post exercise (defined as the reduction in the HR from peak exercise one minute post-exercise) was also significantly more common in patients with HfpEF compared to controls (23% vs. 2%, <0.004).
Conclusions Patients with HfpEF have impaired chronotropic incompetence during maximal exercise and abnormal heart rate recovery post exercise.