Sinus Bradycardia Is Highly Prevalent in ADPKD

Background: Systematic investigation of heart rate in ADPKD has been limited despite clinical observations of bradycardia. We estimated the prevalence of resting bradycardia in ADPKD, compared to the general U.S. population, and analyzed its relation to PKD severity, heart structure, and clinical factors. Methods: Adults with ADPKD and eGFR>15 ml/min/1.73m2 were enrolled in a single-center cohort study. Those treated with beta-blockers or without sinus rhythm were excluded. Resting heart rate of ADPKD patients (by 12-lead EKG) was compared to a representative sample of the U.S. population (NHANES). Multiple linear regression was used to estimate the association of heart rate with ADPKD status and severity, clinical/demographic factors, and left heart function/size by 2D echocardiography. Results: Among 250 ADPKD patients, 50% had bradycardia (<60/min) and mean (SE) for heart rate (61 (0.7)) was markedly lower compared to the U.S. general population (72 (0.4), p=0.001 after adjustment for age and gender). Male sex (β^=-0.20, p=0.002), higher K+ (β^=-0.13, p=0.04), lower diastolic blood pressure (β^=0.19, p=0.02), absence of cardiovascular disease (β^=0.18, p=0.003), and greater self-reported physical activity (p=0.02) were associated with lower heart rate. Neither eGFR nor height-adjusted total kidney volume were independently associated with heart rate. Greater left atrial size and left ventricular mass/volumes were associated with lower heart rate among 162 ADPKD patients with echocardiograms. Conclusion: In a contemporary cohort of ADPKD patients not treated with beta-blockade, one-half had resting bradycardia, with a markedly lower heart rate than the general population. Bradycardia was associated with heart structure but not PKD severity. Funding: NIDDK SupportMean heart rate (with 95% CI) of ADPKD patients vs. general U.S. population (NHANES) by sex and agePercentage with bradycardia (with 95% CI) of ADPKD patients vs. general U.S. population (NHANES) by sex and age