Subarachnoid bleed: ECG effects

Evidence from a number of studies indicates that patients with SAH are at high risk for malignant ventricular arrhythmias, including ventricular tachycardia, torsades de pointes, and ventricular fibrillation, particularly if the corrected QT (QTc) interval is prolonged. A decrease in cardiac output due to alterations in cardiac rate associated with SAH, such as sinus bradycardia, sinus tachycardia, or rapid atrial fibrillation, also can adversely affect patients’ clinical status.

ECG changes associated with SAH primarily reflect repolarization abnormalities involving the ST segment, T wave, U wave, and QTc interval. Because of the combination of ST-segment elevation or depression and abnormal T-wave morphology, myocardial ischemia or infarction is often suspected in patients with SAH.