ECG changes in malignant MCA infarction
Background and objective: Patients with massive hemispheric strokes are threatened by cardiac arrhythmias secondary to autonomic dysregulation. We evaluated ECG abnormalities in patients with massive MCA infarction to identify patients at risk for cardiac complications. Methods: From the placebo arm of the LUB-INT-9 study we identified a group of 144 patients with massive anterior circulation stroke. Patients with a history of myocardial infarction, atrial fibrillation or with febrile infection within 96h after admission where excluded. 52 patients remained and were assigned according to presence or absence of temporal lobe involvement, multiple territory involvement, brainswelling in CT scan and according to outcome (death due to neurological deterioration) and side of infarction. A groupwise comparison of ECG findings between patients with presence or absence of the previous findings was performed using Wilcoxon rank sum test and considered significant with a p-value < 0.05. Incidence of critical bradycardia (<50 / min.) was tested using Fisher exact test. Results: HR was significantly lower in case of temporal involvement (n=15) after 48h , in case multiple territory involvement (n=11) after 12h and 48h and swelling in the initial CT scan (n=33, 1h-72h). PR interval was prolonged in patients with right hemispheric infarcts (n=28), while HR did not differ according to side of infarction. ECG parameters did not differ between the outcome groups. Critical bradycardia (< 50 / min.) was found in case of brain swelling in significantly higher incidence after 1h (11%), and after 48h (31%). Conclusion: Bradycardia is a potential complication in patients presenting with large hemispheric infarcts and mass effect with high incidence also in patients with no history of cardiac disease. Highest incidence 48h after infarction underlines that ECG-monitoring should extend the first 24h. The observed PR-prolongation is consistent with clinical studies and indicates a higher incidence of autonomic impairment in case of right sided infarction.