Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective study

Abstract

PurposeIschemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality. There are several causes of stroke, affecting prognosis, outcomes, and management, but in many cases, the etiology remains undetermined. We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by standard methods. The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months. The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation.Methods and resultsWe prospectively enrolled 24 patients under 75 years of age, 15 men and 9 women of mean age 49 years, who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism. All causes of stroke were excluded by normal 12-lead ECG, 24-h Holter monitoring, echocardiography, cervical Doppler, hematological, and inflammatory tests. All patients underwent electrophysiological study. Of the patients, 37.5% had latent atrial vulnerability, and 33.3% had inducible sustained arrhythmia. Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months. No sustained arrhythmia was found. Only one patient had non-significant episodes of atrial fibrillation.ConclusionIn this study, symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder in patients under 75 years with unexplained cerebral ischemia. The use of this device should not be generalized in the systematic evaluation of these patients. In addition, this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients.

Evaluation of Cryptogenic Stroke With Advanced Diagnostic Techniques

“…31 Recent technological advances have made it possible to perform long-term cardiac rhythm monitoring up to months or even years after a stroke. 32 When compared with 24-hour Holter monitoring, higher yield of AF detection with in-hospital [33][34][35][36][37] and outpatient telemonitoring, [38][39][40][41] and more recently implantable loop recorder, [42][43][44][45][46] has been reported. However, the yield varied greatly depending on the study population (age and stroke subtypes), interval of monitoring from stroke onset, duration of monitoring, and the definition of AF, as well as the choice of monitoring devices (Figure 2).…”

Improved Detection of Silent Atrial Fibrillation Using 72-Hour Holter ECG in Patients With Ischemic Stroke

“…Because of chance variations in smaller series and different technologies for detection of undiagnosed AF, the diagnostic yield in these studies varies from 0% to 20%, [9][10][11] (Table 1) and the cost-effectiveness of prolonged ECG monitoring has been questioned. 12 Limited patient size (maximum number of patients, 425), but more importantly, custom-made ECG detection algorithms or specific ECG analyses, and singlecenter protocols render the published findings difficult to implement into routine care.…”

Prolonged Rhythm Monitoring for the Detection of Occult Paroxysmal Atrial Fibrillation in Ischemic Stroke of Unknown Cause

“…For inclusion, studies were required to fulfill the following criteria: (1) consecutive recruitment of stroke or TIA subjects, (2) cardiac monitoring to detect AF for a minimum duration of 12 hours; and (3) detection of new AF with the use of either a noninvasive or invasive cardiac monitoring device. We identified 19 studies (6 prospective and 13 retrospective) that assessed the ability of cardiac monitoring devices to identify AF in consecutive patients after ischemic stroke, [41][42][43][44][45] TIA, 46 or both [47][48][49][50][51][52][53][54][55][56][57][58][59] (Tables 2 and 3). The methods of cardiac monitoring in these studies were ambulatory ECG, 41 57,58 and implantable loop recorder.…”