The authors evaluated a new algorithm for detecting atrial fibrillation (AF) using a home blood pressure monitor. Three serial blood pressure values were measured by the monitor in 16 patients with AF and 20 patients with sinus rhythm. The authors defined "monitor AF in irregular pulse peak (IPP) 25" as follows: (1) IPP: |interval of pulse peak − the average of the interval of the pulse peak| ≥ the average of the interval of the pulse peak ×25%; (2) irregular heart beat: beats of IPP ≥ total pulse ×20%; and (3) monitor AF: two or more irregular heart beats of the three blood pressure measurements. Cutoff IPP values were set at 20% (IPP20) and 15% (IPP15). The monitor's AF specificity was 1.0 in IPP25, IPP20, and IPP15, and its sensitivity was 0.88 in IPP25, 0.94 in IPP20, and 1.0 in IPP15. The new algorithm had high diagnostic accuracy for detecting AF and a low false-positive rate.
| INTRODUCTIONAtrial fibrillation (AF) is not only a major risk factor for stroke, it also causes heart failure and cardiovascular death.1-4 AF is a common disease and the prevalence of AF increases with age. 2,[5][6][7] Patients with paroxysmal AF have a stroke risk that is similar to that of patients with persistent AF. 8 However, paroxysmal AF is often not detected by standard 12-lead electrocardiography (ECG), as was shown both in patients who have undergone pacemaker implantation 9 and those with cryptogenic stroke who have received an implantable loop recorder.
10Pulse self-examination is useful to detect AF, 11 but paroxysmal AF is often asymptomatic.
12Hypertension is an important risk factor for the onset of AF.
13The causes of the onset of AF are an increase in the stress of the left atrium and autonomic nervous abnormality. 14,15 An increase in the afterload caused by hypertension causes left atrial hypertrophy and fibrosis, which are related to AF. It has been shown that a reduction in blood pressure (BP) results in a decrease in the incidence of AF.
16Two studies revealed that home BP had a higher predictive value for cardiovascular events than office BP. the specificity values were 80% to 90%, 21-24 and the agreement between pulse rate and heart rate was not examined simultaneously. In the present study, we confirmed the correlation between the interval of the pulse wave and QRS wave, and we evaluated a new algorithm for the detection of AF by a home BP monitor.
| METHODS
| PatientsWe enrolled 16 patients with AF and 20 outpatients with sinus rhythm. Findings from the ECG showed AF during all three BP measurements in the patients with AF and showed sinus rhythm during all three measurements in the 20 patients with sinus rhythm.
| Pulse wave analysis and ECGFor each patient, three BP measurements were taken after the patient had rested for ≥5 minutes in the lying position and with at least 30 seconds between measurements, using a validated home BP monitor (UA-1020, A&D). 25 The three BPs were measured by cuff inflation to