Frequent cyclic variation of heart rate is associated with left ventricular diastolic dysfunction in patients without ischemia

Abstract

Background: Cyclic variation of heart rate (CVHR) associated with sleep-disordered breathing reflects cardiac autonomic responses to apneic/hypoxic stress. However, the association of CVHR with cardiac function is unclear. Methods: We investigated a total of 181 patients who underwent both 24-hour Holter electrocardiography (ECG) and quantitative gated single-photon emission computed tomography (SPECT) myocardial functional imaging, excluding patients with atrial fibrillation, myocardial infarction, structural heart disease, and implantable devices, from January 2017 to July 2018. The number of CVHR per hour (CVHR index) in sleeping-time Holter ECG was compared with the parameters of left ventricular (LV) systolic and diastolic functions assessed by cardiac SPECT functional imaging, peak filling rate (PFR), first-third mean filling rate (1/3 MFR), and time to peak filling rate (TTPF). Results: In all patients, the CVHR index was not associated with any parameters of cardiac functions. However, in a propensity score–matched subgroup of patients without ischemia (N = 39), the CVHR index was negatively correlated with PFR (r = −0.35, P