Effect of middle cerebral artery territory ischemic stroke on QT interval.

Background: Prolonged QT interval associates with increased risk for sudden cardiac death after acute ischemic stroke. However, pathophysiology of prolonged QT interval after stroke is poorly elucidated. In this study, we investigated whether QT interval dynamics is different in patients with right and left middle cerebral artery (MCA) territory stroke.

Method: Electrocardiogram (ECG) intervals were compared between baseline (retrieved retrospectively from medical records) and admission (acquired at the acute hospital admission) in 33 patients (65 ± 9.5 years) with right or left MCA territory ischemic stroke. Head computed tomography (CT), cardiac ultrasound, and cardiac CT scans were undertaken.

Results: Stroke was located in the right MCA territory in 21 (64%) and in the left MCA territory in 12 (36%) patients. Patients with right and left MCA stroke were similar with respect to time interval between baseline and admission ECG recordings, positive history of heart disease, and left ventricular dimensions. Increase in heart rate-corrected QT interval (QTc) from baseline to admission was demonstrated to occur more often in patients with right (16 of 21; 76%) than in patients with left (3 of 12; 25%; P < .01) MCA stroke. ΔQTc between baseline and admission was significantly longer in patients with right (23 ± 23 milliseconds) than in patients with left (-11 ± 19 milliseconds; P < .0001) MCA stroke. Percent ΔQTc between baseline and admission was longer in patients with right (5.5% ± 5.5%) than in patients with left (-2.6% ± 4.7%; P < .001) MCA stroke.

Conclusions: Right MCA ischemic stroke results in prolongation of QT interval. Findings indicate cerebral asymmetry in brain-heart interaction during acute ischemic stroke.