Nonsustained atrial tachycardia in 24-hour Holter monitoring: a potential cardiac source of embolism in acute ischemic stroke

BACKGROUND: Whether nonsustained atrial tachycardia (NSAT) has a causative role similar to paroxysmal atrial fibrillation (AF) in ischemic stroke is unclear. We investigated the clinical and imaging features of ischemic stroke patients with NSAT to demonstrate that these patients would have a higher proportion of embolic strokes. METHODS: We retrospectively reviewed ischemic stroke patients who underwent Holter monitoring and selected patients with NSAT. The clinical and imaging characteristics were compared between patients with and without NSAT, and the risk factors for embolic stroke were evaluated. Moreover, the images of the selected patients were analyzed according to the Trials of Org 10172 in Acute Stroke Treatment classification. RESULTS: From a total of 1,051 patients who had 24-hour Holter monitoring, 681 patients were selected for the study. Among the selected patients, NSAT was detected in 243 patients. The patients with NSAT had a significantly higher proportion of imaging findings suggestive of cerebral embolism compared with patients without NSAT (27% vs. 14%, P<0.001). Moreover, the presence of NSAT was a statistically significant factor associated with imaging findings suggestive of cerebral embolism in the univariate (OR, 2.22; 95% CI, 1.51–3.27; P<0.001) and multivariate (OR, 2.26; 95% CI, 1.53–3.34; P<0.001) analyses. The patients with NSAT had a significantly older age at diagnosis, higher proportion of female sex, higher proportion of hypertension, lower proportion of smokers, higher CHA(2)DS(2)-VASc score, and higher left atrium index value compared with patients without NSAT. CONCLUSIONS: The embolic pattern of acute ischemic stroke in patients with NSAT was frequently observed and shared clinical characteristics of AF rather than those of atherosclerosis. As NSAT may be a potential source of cardiac embolism, we suggest a more intensive search for modifiable risk factors such as AF in ischemic stroke in patients with NSAT.