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.

Systematic review: comparing routine and selective invasive strategies for the acute coronary syndrome.

BACKGROUND: Patients with non-ST-segment elevation acute coronary syndrome (ACS) are managed with either a routine invasive strategy, in which all patients receive coronary angiography, or a selective invasive strategy, in which only patients with refractory or inducible ischemia receive coronary angiography. PURPOSE: To evaluate whether a routine invasive strategy improves cardiovascular outcomes more than a selective invasive strategy in patients with non-ST-segment elevation ACS. DATA SOURCES: English-language publications in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from 1966 to 18 September 2007. STUDY SELECTION: Two investigators independently reviewed searches and selected trials that compared death or myocardial infarction outcomes among adults with non-ST-segment elevation ACS by randomly assigning patients to either a routine invasive strategy or a selective invasive strategy. DATA EXTRACTION: Three investigators independently abstracted data from trial reports by using standardized forms. DATA SYNTHESIS: 10 trials with a total of 10,648 patients (mean age, 62 years; 71% male; median follow-up, 16.5 months) were found. Trial participants had typical symptoms of unstable angina and frequently had a positive electrocardiogram or marker evidence of myocardial ischemia. Of the 5330 participants assigned to the routine invasive strategy group, 847 had the composite outcome of death or nonfatal myocardial infarction, compared with 928 of 5318 participants assigned to the selective invasive strategy group (relative risk, 0.90 [95% CI, 0.74 to 1.08]). Four hundred thirty-eight patients in the routine invasive strategy group and 463 in the selective invasive strategy group died (relative risk, 0.95 [CI, 0.80 to 1.14]). Four hundred ninety and 569 nonfatal myocardial infarctions, respectively, occurred in the 2 groups (relative risk, 0.86 [CI, 0.68 to 1.08]). LIMITATIONS: Methodology, protocols, and outcome definitions differed substantially among the trials. The lower bound of the CI for the pooled results did not rule out the superiority of the routine invasive strategy. CONCLUSION: Available trial evidence is heterogeneous and insufficient for comparing routine and selective invasive strategies. Therefore, in patients with non-ST-segment elevation ACS a routine invasive strategy cannot be proven to reduce deaths or nonfatal myocardial infarction.

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.

Fluoroscopic balloon-guided transesophageal echocardiography in a patient with Zenker's diverticulum.

During the past 20 years, transesophageal echocardiography (TEE) became an important diagnostic technique. Indications for TEE include: defining the cause and severity of native valve disease, particularly mitral regurgitation; detecting vegetations and other sequelae of endocarditis; assessing prosthetic valve function; and identifying a potential cardiac source for emboli.(1) TEE is usually well tolerated and is associated with few adverse events. However, structural abnormalities of the esophagus such as diverticula, stenoses, tumors, and advanced varices are relative contraindications to TEE because of the technical difficulties associated with probe advancement and the risk of esophageal perforation.(2) This report describes the successful performance of TEE in a patient with a Zenker's diverticulum. The patient was severely symptomatic of atrial fibrillation and was a poor candidate for long-term anticoagulation. Therefore, it was necessary to rule out a thrombus before cardioversion. Because the Zenker's diverticulum was large, a novel approach was taken using a balloon to occlude the orifice allowing safe passage of the TEE probe.

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.