Sensitivity and specificity of handheld one lead ECG detecting atrial fibrillation in an outpatient clinic setting.

AIMS: To validate the sensitivity and specificity of the Zenicor One handheld ECG device for detection of atrial fibrillation in an outpatient clinical setting. METHODS AND RESULTS: Patients attending outpatient clinics at Danderyd Hospital (n = 220) were examined with one lead handheld ECG immediately after standard care 12­lead ECG recording. Twelve recordings were excluded (atrial flutter or pacing) or missing. The recordings were dichotomously categorized as "atrial fibrillation" or "not atrial fibrillation" by two senior cardiologists. In cases of diverging interpretations, a third senior cardiologist had the deciding vote. Sensitivity and specificity in diagnosing atrial fibrillation was calculated with 12­lead ECG as gold standard. Sensitivity and specificity for diagnosis of atrial fibrillation with one lead handheld ECG and 12­lead ECG as gold standard was 98% and 99% respectively. CONCLUSION: In a health-care outpatient setting, Zenicor One handheld ECG had high sensitivity and specificity for detection of atrial fibrillation when compared with 12­lead ECG.

Echocardiographic measures of atrial function may predict atrial fibrillation in stroke patients.

OBJECTIVE: In patients with a prior stroke or transient ischemic attack (TIA) and atrial fibrillation anticoagulant treatment is indicated. This study's purpose was to investigate if echocardiography can predict unknown AF in patients after stroke. DESIGN: Prospectively, 174 stroke/TIA patients without diagnosed AF underwent echocardiographic evaluation including tissue Doppler imaging (TDI) focusing on functional parameters of the left atrium and left ventricular diastolic function. AF screening was performed during 30 d. RESULTS: Fifteen patients (8.6%) were diagnosed with AF. Echocardiography in the AF group compared to those without AF, showed larger left atrial volume index (LAVI), (37.2 ± 6.7 vs. 31.6 ± 8.6 ml/m(2), p = 0.018), lower A' velocities in ventricular (5.9 ± 2.2 vs. 7.2 ± 1.6, p = 0.010) and atrial (4.8 ± 1.4 vs. 5.9 ± 1.4, p = 0.013) septa, higher LAVI/A' in ventricular septum (6.7 (5.0-8.7) vs. 4.2 (3.2-5.5), p = 0.001) and atrial septum (8.5 (5.9-11.0) vs. 5.1 (4.1-6.8), p = 0.003). Receiver operating characteristic analyses to detect AF was performed, area under the curve for LAVI was 0.71 (0.61-0.83), p = 0.008, and for LAVI/A' in ventricular septum 0.76 (0.59-0.93), p = 0.006 and atrial septum 0.78 (0.63-0.93), p = 0.002, respectively. CONCLUSIONS: LAVI and measures of atrial contraction as measured by TDI predict unknown AF in patients after an stroke/TIA and may be used to detect silent AF.

Thrombin generation in acute cardioembolic and non-cardioembolic ischemic stroke.

OBJECTIVE: Increased thrombin generation, as measured by the Calibrated Automated Thrombogram (CAT), has recently been reported to predict ischemic stroke, especially stroke with a cardioembolic source. However, there are few studies on thrombin generation using CAT in patients with manifest ischemic stroke, particularly in patients with cardioembolic stroke not yet on anticoagulation. MATERIALS AND METHODS: Therefore, a prospective cohort study of 205 stroke patients > 45 years of age was performed. They were recruited during their hospital stay or shortly thereafter. Inclusion criteria were ischemic stroke or TIA within two weeks and no atrial fibrillation (AF) in the history or at inclusion. Patients received a thumb ECG device in order to detect silent AF. Blood samples were collected at inclusion and after 1 month. Thrombin generation in plasma after addition of tissue factor was assessed in patients and in healthy controls. RESULTS: Mean age of patients was 72 ± 7 years and 43% were females. Peak thrombin concentrations were variable among stroke patients but overall significantly higher at both time points (p < 0.0001) compared to controls, and tended to be highest in patients in whom paroxysmal atrial fibrillation was subsequently documented. CONCLUSION: Thrombin generation in patients with acute cardioembolic and non-cardioembolic schemic stroke/TIA is variable but overall higher compared to healthy subjects. The long-term prognostic value of thrombin generation in patients with a recent ischemic stroke deserves further investigation.

Paroxysmal atrial fibrillation with silent episodes: intermittent versus continuous monitoring.

OBJECTIVES: Asymptomatic atrial fibrillation (AF) presents the same risk for cardioembolic events as symptomatic AF. Intermittent ECG recordings may be helpful in detecting asymptomatic paroxysmal arrhythmias. The objective of this study was to compare short intermittent heart rhythm recordings with or without symptoms with continuous ECG recordings. DESIGN: Twenty-two patients with diagnosed symptomatic paroxysmal AF participated. Patients used a handheld transtelephonic ECG device for a 30-day period performing two registrations of 10 seconds per day. Additionally patients were asked to make registrations if arrhythmia symptoms occurred. Patients also performed a 24-hour ambulatory continuous ECG recording during a single twenty-four hours period of the 30 day period. AF was defined as an irregular ventricular rhythm without visible p-waves for at least 10 seconds. RESULTS: 1425 intermittent ECG recordings were performed. AF episodes were diagnosed in 18 (82%) patients compared with 7 (32%) patients using continuous ECG, (p = 0.001). All patients with AF detected by continuous monitoring were also detected by intermittent recordings. Of the episodes, 16% were judged as symptomatic. CONCLUSION: Short-term ECG registrations over extended time periods seem to be a more sensitive tool, compared with short continuous ECG recordings, for detection of AF episodes.