Background Subarachnoid hemorrhage (SAH) has been associated with ECG changes, arrhythmias, and release of cardiac enzymes. Several studies indicated that an excessive release of norepinephrine (NE) may be the cause of these manifestations. Recently, stress-induced cardiomyopathies, presenting typical ECG changes and left ventricular wall motion abnormalities (LVWMA), have been reported and considered as a result of high NE. We hypothesized that ST-T wave changes in patients with SAH may be manifestations of stress-induced cardiomyopathy and associated with LVWMA . Methods From August 2003 to May 2004, we instituted consecutive echocardiographic screening of all patients with acute (24 hours after onset) aneurysmal SAH admitted to the Neurological ICU via ER. A standard 12-lead ECG was obtained and blood samples for CK-MB and troponin-T. To evaluate sympathetic nervous activity, we obtained arterial blood samples and 24 hours urine samples for NE. Results Of 42 patients (53.2짹11.7 years, 17 men) with acute aneurysmal SAH, 26 (61.9%) had abnormal ECG including rhythm abnormalities, repolarization abnormalities, and conduction abnormalities; sinus tachycardia, atrial fibrillation, ST-T wave abnormalities, bundle branch block. In 12 patients (28.6%) with ST-T wave changes, 10 patients had severe neurologic grade (> 3 Hunt-Hess grade) but only one patient had LVWMA on echocardiography. Another one patient with LV dysfunction showed normal ST-T wave. In patients with ST-T wave change, Tn-T (0% vs. 3.3%), CK-MB (8.3% vs. 10.0%), plasma and urine NE level (16.7% and 33.3% vs. 16.7% and 50.0%), and mortality (8.3% vs. 13.3%) were not significantly higher. All 5 deaths resulted from noncardiac causes. High plasma and urine NE level were not related to neurologic severity or mortality. Conclusions Although ECG abnormalities are frequently seen in SAH patients, the incidence of LVWMA is very low. Electrocardiographic manifestations in patients with SAH and stress-induced cardiomyopathy are similar, but ECG abnormalities in patients with SAH are mostly not related to LV dysfunction.