Continuous Stroke Unit Electrocardiographic Monitoring Versus 24-Hour Holter Electrocardiography for Detection of Paroxysmal Atrial Fibrillation After Stroke

Occult atrial fibrillation in cryptogenic stroke: detection by 7-day electrocardiogram versus implantable cardiac monitors

BACKGROUND AND PURPOSE

A significant number of patients with cryptogenic stroke suffer from intermittent atrial fibrillation (iAF) which was not detected during the standard diagnostic procedures. We investigated whether implantation of an insertable cardiac monitor (ICM) is feasible in patients with cryptogenic stroke, and compared the iAF detection rate of the ICM with 7-day Holter monitoring.

METHODS

Sixty patients (median age 63; interquartile range, 48.5-72 years) with acute cryptogenic stroke were included. ICM was implanted 13 days (interquartile range; 10-65 days) after the qualifying event. Seven-day Holter was performed after the ICM was implanted.

RESULTS

The iAF was detected by the ICM in 10 patients (17%; 95% CI, 7% to 26%). Only 1 patient (1.7%; 95% CI, 0% to 5%) had iAF during 7-day Holter monitoring as well (P=0.0077). Episodes of iAF lasting 2 minutes or more were detected 64 (range, 1-556) days after implantation. There were no recurrent strokes during the observation period. The implantation procedure was well tolerated with no adverse events; the daily data transmission protocol was easy to handle by the patients.

CONCLUSIONS

ICM implantation for the detection of iAF during outpatient follow-up is feasible in patients with cryptogenic stroke. ICMs offer a much higher diagnostic yield than 7-day Holter monitoring.

Stepwise screening of atrial fibrillation in a 75-year-old population: implications for stroke prevention

BACKGROUND

Atrial fibrillation (AF) is a frequent source of cardiac emboli in patients with ischemic stroke. AF may be asymptomatic and therefore undiagnosed. Screening for silent AF seems suitable in risk populations, however little is known on the yield and cost-effectiveness of such screening.

METHODS AND RESULTS

All inhabitants in the municipality of Halmstad, Sweden aged 75 to 76 years were invited to a stepwise screening program for AF. As a first step, participants recorded a 12-lead ECG and reported their relevant medical history. Those with sinus rhythm on 12-lead ECG, no history of AF, and ≥2 risk factors according to CHADS(2) were invited to a 2-week recording period using a hand-held ECG and asked to record 20 or 30 seconds twice daily and if palpitations occurred. One thousand, three hundred thirty inhabitants were invited, of whom 848 (64%) participated. Previously undiagnosed silent AF was found in 10 (1%) among 848 individuals who recorded 12-lead ECG. Among 81 patients with known AF, 35 (43%) were not on oral anticoagulation treatment. Among 403 persons with ≥2 risk factors for stroke, who completed the hand-held ECG event recording, 30 (7.4%) were diagnosed with paroxysmal AF. Thus 75/848 (9%) of the screened population were candidates for new oral anticoagulation treatment, of those 57 actually started oral anticoagulation treatment.

CONCLUSIONS

Stepwise risk factor-stratified AF screening in a 75-year-old population yields a large share of candidates for oral anticoagulation treatment on AF indication.