[PP.14.24] DIAGNOSTIC ACCURACY OF NEW ALGORITHM TO DETECT ATRIAL FIBRILLATION

Objective: Several reports about the detection of paroxysmal atrial fibrillation (AF) by home blood pressure (BP) monitors have been published. The sensitivity values were near or equal to 100%, but the specificity values were 80–90%, and the agreement between pulse rate and heart rate were not examined simultaneously. We confirmed the correlation between the interval of pulse wave and QRS wave, and we evaluated a new algorithm for the detection of AF by a home BP monitor. Design and method: We enrolled 16 AF patients and 20 patients with sinus rhythm. Three serial BP values (UA-1020, A&D, Japan) were measured in all patients. Pulse waves were evaluated for 30 sec after each BP measurement. We defined ’monitor AF in irregular pulse peak (IPP) 25%’ as follows: 1) IPP: |interval of pulse peak - average of interval of pulse peak| > or = average of interval of pulse × 25%, 2) irregular heart beat (IHB): beats of IPP > or = total pulse × 20%, 3) the ’monitor AF (IPP25)’:> or = 2 IHB of the three BP measurements. We also confirmed the diagnostic accuracy when the cut-off IPP values were set at 20% (IPP20) and 15% (IPP15). We confirmed the concordance between the interval of pulse wave and QRS wave in electrocardiography in five AF patients (total 100 beats). Results: The correlation between the interval of pulse wave and QRS wave was very high (R = 0.98, p < 0.001). The diagnostic accuracy of IHB was as follows: the specificity was 1.0 in IPP25 and IPP20, and the sensitivity was 0.69–0.88 in IPP25 and 0.88–0.94 in IPP20; the specificity was 0.95–1.00 and the sensitivity was 1.0 in IPP15. One sinus rhythm case was judged as IHB by the IPP15 setting. The diagnostic accuracy of the monitor AF was as follows: specificity was 1.0 in IPP25, IPP20 and IPP15, and the sensitivity was 0.88 in IPP25, 0.94 in IPP20, and 1.0 in IPP15. Conclusions: The new algorithm for a home BP monitor had high diagnostic accuracy to detect AF, and had a low false-positive rate in IPP 20.