VALIDITY OF THE POLAR H10 DURING THE DEEP BREATHING AUTONOMIC FUNCTION TEST

PURPOSE: Clinical assessment of cardiac-autonomic function often involves the deep breathing test, administered using an electrocardiogram (ECG). The Polar H10 Bluetooth heart rate monitor would make this test more accessible, but its ability to accurately capture inter-beat interval data during large fluctuations in heart rate has received little investigation. Therefore, we aimed to evaluate the level of agreement between the Polar H10 and ECG during the deep breathing test. METHODS: Data from twenty apparently healthy adults (60% female, 22.6 years, 25.2 kg/m2) met inclusion criteria for analysis (0 ectopic beats) from this ongoing investigation. Participants rested in a supine position for 5 min to stabilize. Subsequently, inter-beat intervals were simultaneously recorded by an ECG (lead II, 1000 Hz) and a Polar H10 during the 1-min deep breathing test. Participants followed breathing prompts from a tablet screen during the test which displayed 5-s inspirations and 5-s expirations (0.1 Hz). Inter-beat interval files were analyzed in Kubios Scientific HRV software to calculate the expiratory-to-inspiratory ratio (E/I) and respiratory sinus arrhythmia (RSA). Comparison statistics included paired t-tests and Bland-Altman analyses. Relative and absolute agreement were assessed with Lin’s concordance correlation coefficient (CCC) and the coefficient of variation (CV), respectively. RESULTS: The E/I and RSA for ECG (1.33 ± 0.15 and 17.6 ± 7.2 beats·min-1, respectively) and Polar H10 (1.33 ± 0.15 and 17.7 ± 7.2 beats·min-1, respectively) demonstrated minimal mean biases (0.0 ± 0.0 and 0.1 ± 0.4 beats·min-1, respectively, Ps ≥ 0.48), tight 95% limits of agreement (-0.01-0.01 and -0.7-0.8 beats·min-1, respectively), along with near perfect relative (CCC ≥ 0.99) and absolute agreement (CV ≤ 1.3%). CONCLUSIONS: The Polar H10 provided nearly identical E/I and RSA values to ECG in the current sample of healthy young adults during the deep breathing test.