Continuous Heart Rate Monitoring for Automatic Detection of Atrial Fibrillation with Novel Bio-Sensing Technology

Background:
Asymptomatic atrial fibrillation (AF) is an important cause of fatal or disabling stroke. A continuous heart-rate monitoring device, comfortable enough to be worn continuously and reliable enough to detect AF, would allow for prompt initiation of anticoagulation therapy to prevent stroke.

Methods:
We studied a new custom-made portable photo-plethysmograph (PPG) wrist-watch sensor, designed for continuous heartrate monitoring and incorporating contact and motion noise-filters, and tested its ability to automatically detect AF. Sixteen patients undergoing elective cardioversion of AF during simultaneous electrocardiogram and PPG recording were studied.

Results:
A total of 18,608 RR-interval measurements were recorded with PPG and ECG, including 12,521 (67.3%) RR-intervals during AF and 6,087 (32.7%) during sinus rhythm. Scatter plots demonstrated that the PPG signals were highly correlated to the simultaneously recorded ECG (R=0.980, p<0.001), both during AF (Figure 1A) and during sinus rhythm (Figure 1B). The automatic algorithm distinguished AF from sinus rhythm with a sensitivity of 99.89% and specificity of 99.02%. All measurements were done with the patients at rest.

Conclusions:
This PPG-based wrist-watch sensor reliably detected AF.