Fluctuating Electrocardiographic Changes Predict Poor Outcomes After Acute Subarachnoid Hemorrhage

Electrocardiogram (ECG) abnormalities following aneurysmal subarachnoid hemorrhage (SAH) have been well documented. Evidence suggests that ECG changes and cardiac dysfunction worsen outcome. Determining which patients are at most risk is unclear but important to ascertain.

We prospectively studied clinical markers, cardiac abnormalities, and clinical outcomes in 20 patients admitted within 48 hours of aneurysmal SAH. All patients had ECGs prior to surgical clipping, during the clipping surgery, and during the postoperative period.

The aneurysm was located in the anterior circulation in 17 patients (85%) and in the posterior circulation in 3 patients (15%). Abnormal ECG changes in patients with acute SAH were observed, with a total incidence rate of 65%. The incidence of T wave abnormalities was 53.8% among the patients with ECG changes, 46.2% had ST segment change, and 30.8% had QT interval prolongation. Of the 13 patients with ECG changes, 4 (30.8%) had fluctuating ECG abnormalities (an abnormality that presented and disappeared during the study period or changed in character). All 4 patients with fluctuating ECG changes had a poor outcome (100%) compared to 3 of the 9 patients (33.3%) patients with fixed abnormalities (P<0.05).

The unique finding in this study that has not been reported previously in the literature is the contribution of dynamic ECG changes to the prognosis for good recovery from aneurysmal SAH. In our group, all the patients who had ECG changes that fluctuated from one abnormal change to another had a poor outcome. The etiology of this finding is not clear but may open the door to further study into the pathogenesis of cardiac changes in aneurysmal SAH. The clinical utility of the variability of ECG abnormalities needs to be validated in a larger cohort of patients with longer follow-up than was possible in this study.