Screening for Atrial Fibrillation in Patients ≥65 Years Using an Automatic Blood Pressure Monitor in a Skilled Nursing Facility.

Early detection of asymptomatic atrial fibrillation (AF) provides an opportunity to treat patients to reduce their risk of stroke. Long-term residents of skilled nursing facilities frequently have multiple risk factors for strokes due to AF and may benefit from screening for AF. Patients in a skilled nursing facility 65 years and older, without a history of AF and without a pacemaker or defibrillator, were evaluated using a Microlife WatchBP Home A automatic blood pressure monitor that can detect AF when set to a triple reading mode. Those with readings positive for AF were evaluated with a standard 12-lead electrocardiogram (ECG) or a 30-second single-channel ECG to confirm the presence of AF. A total of 101 patients were screened with an average age of 78 years, and 48 (48%) were female. Nine automatic blood pressure monitor readings were positive for possible AF. Of those, 7 (6.9%, 95% confidence intervals 3.0% to 14.2%) had AF confirmed with ECG. Only 2 (2%, 95% confidence interval 0.3% to 7.7%) were false-positive readings. One-time screening for AF using an automatic blood pressure monitor in a skilled nursing facility resulted in a high number of patients with newly diagnosed AF.

Comparison of the Microlife blood pressure monitor with the Omron blood pressure monitor for detecting atrial fibrillation.

Screening for atrial fibrillation (AF) by assessing the pulse is recommended in high-risk patients. Some clinical trials demonstrated that the Microlife blood pressure monitor (BPM) with AF detection is more accurate than pulse palpation. This led to a change in practice guidelines in the United Kingdom where AF screening with the Microlife device is recommended instead of pulse palpation. Many BPMs have irregular heart beat detection, but they have not been shown to detect AF reliably. Recently, one study, in a highly select population, suggested that the Omron BPM with irregular heart beat detection has a higher sensitivity for AF than the Microlife BPM. We compared the Microlife and Omron BPMs to electrocardiographic readings for AF detection in general cardiology patients. Inclusion criteria were age≥50 years without a pacemaker or defibrillator. A total of 199 subjects were enrolled, 30 with AF. Each subject had a 12-lead electrocardiography, 1 Omron BPM reading, and 3 Microlife BPM readings as per device instructions. The Omron device had a sensitivity of 30% (95% confidence interval [CI] 15.4% to 49.1%) with the sensitivity for the first Microlife reading of 97% (95% CI 81.4% to 100%) and the Microlife readings using the majority rule (AF positive if at least 2 of 3 individual readings were positive for AF) of 100% (95% CI 85.9% to 100%). Specificity for the Omron device was 97% (95% CI 92.5% to 99.2%) and for the first Microlife reading of 90% (95% CI 83.8% to 94.2%) and for the majority rule Microlife device of 92% (95% CI 86.2% to 95.7%; p<0.0001). The specificity of both devices is acceptable, but only the Microlife BPM has a sensitivity value that is high enough to be used for AF screening in clinical practice.

Screening for asymptomatic atrial fibrillation while monitoring the blood pressure at home: trial of regular versus irregular pulse for prevention of stroke (TRIPPS 2.0).

Asymptomatic atrial fibrillation (AF) is a common cause of strokes. Physician screening for AF has been recommended. Home screening for AF may increase the likelihood of detecting asymptomatic AF in patients at risk for stroke because of AF. The aim of this study was to assess the feasibility and accuracy of screening for AF when taking home blood pressure (BP) measurements using an automatic AF-detecting BP monitor. Subjects aged >64 years or those with hypertension, diabetes, congestive heart failure, or previous stroke were enrolled by their primary physicians and given the AF-BP monitor and an electrocardiographic event monitor to use at home for 30 days. The AF-BP monitor reading was compared with the electrocardiographic reading to calculate the sensitivity and specificity of the device for detecting AF. A total of 160 subjects were enrolled, with 10 withdrawing, 1 excluded, and 10 with no AF-BP monitor logs or electrocardiographic recordings. Of the 139 subjects included, 14 had known AF. There was a total of 3,316 days with AF-BP monitor readings and electrocardiographic readings. On the basis of the initial daily AF-BP monitor readings, the AF-BP monitor demonstrated sensitivity of 99.2% and specificity of 92.9% for detecting AF. Two subjects with no histories of AF had AF-BP monitor readings of AF that were confirmed by the electrocardiographic monitor. One of these subjects was started on warfarin. In conclusion, home screening for asymptomatic AF while taking BP measurements can be performed accurately. This can be used to detect new AF, allowing treatment with anticoagulation to reduce the future risk for stroke.

Detection of atrial fibrillation using a modified microlife blood pressure monitor.

BACKGROUND: Hypertension is a major risk factor for the development of atrial fibrillation (AF) and for stroke due to AF. Asymptomatic AF can result in a stroke, in patients with risk factors, if it is not detected and treated appropriately. This study evaluated the sensitivity and specificity of an automatic oscillometric sphygmomanometer designed to detect AF. METHODS: The sphygmomanometer incorporates an algorithm for detecting AF while reducing false positive readings due to premature beats. A total of 405 unselected outpatients seen in two cardiology offices were evaluated by taking three sequential device readings and one electrocardiogram (EKG) on each patient. RESULTS: For detecting AF, the sensitivity was 95% and the specificity 86% with a positive predictive value of 68% and a negative predictive value of 98% for single device readings. For the three sequential device readings grouped together, the sensitivity was 97% and the specificity was 89%. The device correctly categorized most of the non-AF, abnormal rhythms. The specificity for those in sinus rhythm was 97%. CONCLUSIONS: This device is able to detect AF with high sensitivity and specificity. Use of this device by patients who monitor their blood pressure at home may help detect asymptomatic AF and allow for treatment prior to the development of a stroke.

Home monitoring with a modified automatic sphygmomanometer to detect recurrent atrial fibrillation.

OBJECTIVES: Detecting asymptomatic atrial fibrillation would help identify patients who would benefit from anticoagulation. This study examined the application of a modified blood pressure monitor to screen for episodes of atrial fibrillation. METHODS: A modified sphygmomanometer was designed to detect atrial fibrillation. The device has a sensitivity near 100% and a specificity of up to 91%. Therefore, this device can be expected to detect all episodes of atrial fibrillation. However, the lower specificity may result in false-positive readings that could prompt unnecessary clinic visits for electrocardiogram confirmation of the rhythm. Outpatients in sinus rhythm with a history of atrial fibrillation were given the device to monitor their pulse regularity once daily to detect atrial fibrillation. Patients with irregular readings were evaluated with an electrocardiogram. RESULTS: Nineteen patients were monitored at home for a period ranging from 5 days to 5 months. Seven patients had recurrent atrial fibrillation identified by the monitor. Nine patients had no irregular readings for a mean of 82 +/- 40 days. Of 19 patients, 3 had false-positive irregular readings that were a result of sinus arrhythmia or ectopy. CONCLUSIONS: The device had an acceptably low false-positive rate allowing 16 of 19 patients to use it at home for long-term atrial fibrillation monitoring. This device may help prevent strokes by identifying patients with prolonged episodes of asymptomatic atrial fibrillation who are candidates for anticoagulation.

The use of a modified sphygmomanometer to detect atrial fibrillation in outpatients.

This study was designed to assess the accuracy of a modified sphygmomanometer, that measures pulse irregularity, to detect atrial fibrillation (AF). An irregularity index, defined as the standard deviation of the time intervals between beats divided by the mean of the time intervals, was used to analyze standard 12-lead ECGs from hospitalized patients. A threshold irregularity index was selected such that all ECGs with AF exceeded this irregularity index value. A modified automatic blood pressure monitor was designed to detect AF by calculating the irregularity index of the pulse. The device was used to calculate the irregularity index in an unselected group of outpatients during scheduled office visits in which a standard 12-lead ECG was performed. A total of 125 ECGs, 53 with AF, were analyzed. Using a threshold irregularity index of 0.066, the sensitivity for detecting AF was 100%, the specificity was 92% and diagnostic accuracy 95%. A modified sphygmomanometer was used to analyze the pulse of 450 outpatients, 54 of whom were documented by ECG to be in AF. When paired readings were analyzed, the rhythm was considered to be irregular if both readings were greater than the threshold index. Using a threshold index of 0.06, all the AF patients were correctly identified while 37 non-AF patients also exceeded the threshold irregularity index. In this analysis, the sensitivity was 100%, the specificity 91%, and the diagnostic accuracy 92% for detecting AF. The irregularity index determined using a modified sphygmomanometer can accurately identify AF.