Accuracy of continuous photoplethysmography-based 1 min mean heart rate assessment during atrial fibrillation.

AIMS: Although mobile health tools using photoplethysmography (PPG) technology have been validated for the detection of atrial fibrillation (AF), their utility for heart rate assessment during AF remains unclear. Therefore, we aimed to evaluate the accuracy of continuous PPG-based 1 min mean heart rate assessment during AF. METHODS AND RESULTS: Persistent AF patients were provided with Holter electrocardiography (ECG) (for ≥24 h) simultaneously with a PPG-equipped smartwatch. Both the PPG-based smartwatch and Holter ECG automatically and continuously monitored patients' heart rate/rhythm. ECG and PPG recordings were synchronized and divided into 1 min segments, from which a PPG-based and an ECG-based average heart rate estimation were extracted. In total, 47 661 simultaneous ECG and PPG 1 min heart rate segments were analysed in 50 patients (34% women, age 73 ± 8 years). The agreement between ECG-determined and PPG-determined 1 min mean heart rate was high [root mean squared error (RMSE): 4.7 bpm]. The 1 min mean heart rate estimated using PPG was accurate within ±10% in 93.7% of the corresponding ECG-derived 1 min mean heart rate segments. PPG-based 1 min mean heart rate estimation was more often accurate during night-time (97%) than day-time (91%, P < 0.001) and during low levels (96%) compared to high levels of motion (92%, P < 0.001). A neural network with a 10 min history of the recording did not further improve the PPG-based 1 min mean heart rate assessment [RMSE: 4.4 (95% confidence interval: 3.5-5.2 bpm)]. Only chronic heart failure was associated with a lower agreement between ECG-derived and PPG-derived 1 min mean heart rates (P = 0.040). CONCLUSION: During persistent AF, continuous PPG-based 1 min mean heart rate assessment is feasible in 60% of the analysed period and shows high accuracy compared with Holter ECG for heart rates <110 bpm.

Long-term intermittent versus short continuous heart rhythm monitoring for the detection of atrial fibrillation recurrences after catheter ablation.

BACKGROUND: The utility of long-term intermittent heart rhythm monitoring after atrial fibrillation (AF) ablation remains unclear. Therefore, we compared the efficacy and usability of long-term intermittent (AliveCor Kardia® (ACK)) versus short continuous (Holter) heart rhythm monitoring for the detection of AF recurrences after AF ablation and evaluated ACK accuracy to detect AF. METHODS: Patients were provided with Holter (for ≥24 h) simultaneously with an ACK (4 weeks) used three times a day and in case of symptoms. The primary endpoint was the difference in proportion of patients diagnosed with recurrent AF by ACK as compared to Holter monitoring. Secondary endpoints were the usability (System Usability Scale and a four-item questionnaire) of ACK and Holter monitoring; and the accuracy of the ACK algorithm for AF detection. RESULTS: Out of 126 post-ablation patients, 115 (91.3%; 35 females, median age 64.0 [58.0-68.0] years) transmitted overall 7838 ACK ECG recordings. ACK and Holter monitoring detected 29 (25.2%) and 17 (14.8%) patients with AF recurrences, respectively (p < 0.001). More than 2 weeks of ACK monitoring did not have additional diagnostic yield for detection of AF recurrences. Patients graded ACK higher than Holter monitoring and found ACK more convenient in daily usage than Holter (p < 0.001). Sensitivity and specificity of ACK for AF detection were 95.3% and 97.5%, respectively. CONCLUSIONS: Long-term intermittent monitoring by ACK more effectively detects AF recurrences after AF ablation and has a higher patients' usability than short continuous Holter monitoring. ACK showed a high accuracy to detect AF.