Excessive Supraventricular Ectopic Activity is Indicative of Paroxysmal Atrial Fibrillation in Patients with Cerebral Ischemia

Background: Detecting paroxysmal atrial fibrillation (PAF) in patients with cerebral ischemia is challenging. Frequent premature atrial complexes (PAC/h) and the longest supraventricular run on 24-h-Holter (SV-run(24 h)), summarised as excessive supraventricular ectopic activity (ESVEA), may help selecting patients for extended ECG-monitoring, especially in combination with echocardiographic marker LAVI/a' (left atrial volume index/late diastolic tissue Doppler velocity).

Methods: Retrospective analysis from the prospective monocentric observational trial Find-AF (ISRCTN-46104198). Patients with acute stroke or TIA were enrolled at the University Hospital Göttingen, Germany. Those with sinus rhythm at presentation received 7-day Holter-monitoring. ESVEA was quantified in one 24-hour interval free from PAF. Echocardiographic parameters were assessed prospectively.

Results: PAF was detected in 23/208 patients (11.1%). The median was 4 [IQR 1; 22] for PAC/h and 5 [IQR 0; 9] for SV-run(24 h). PAF was more prevalent in patients with ESVEA: 19.6% vs. 2.8% for PAC/h >4 vs. ≤ 4 (p<0.001); 17.0% vs. 4.9% for SV-run(24 h >5) vs. ≤ 5 beats (p = 0.003). Patients with PAF showed more supraventricular ectopic activity: 29 PAC/h [IQR 9; 143] vs. 4 PAC/h [1]; [14] and longest SV-run(24 h = 10) [5]; [21] vs. 0 [0; 8] beats (both p<0.001). Both markers discriminated between the PAF- and the Non-PAF-group (area under receiver-operator-characteristics-curve 0.763 [95% CI 0.667; 0.858] and 0.716 [0.600; 0.832]). In multivariate analyses log(PAC/h) and log(SV-run(24 h)) were independently indicative of PAF. In Patients with PAC/h ≤ 4 and normal LAVI/a' PAF was excluded, whereas those with PAC/h >4 and abnormal LAVI/a' showed high PAF-rates.

Conclusions: ESVEA discriminated PAF from non-PAF beyond clinical factors including LAVI/a' in patients with cerebral ischemia. Normal LAVI/a'+PAC/h ≤ 4 ruled out PAF, while prevalence was high in those with abnormal LAVI/a'+PAC/h >4.