Subarachnoid hemorrhage: frequency and severity of cardiac arrhythmias. A survey of 70 cases studied in the acute phase.

The frequency and severity of cardiac arrhythmias were studied in 70 patients with spontaneous subarachnoid hemorrhage investigated prospectively with 24-hour Holter monitoring. Patients were less than 70 years old and without clinical and/or ECG signs of previous heart disease; Holter monitoring was initiated within 48 hours of subarachnoid hemorrhage. Arrhythmias were detected in 64 of the 70 patients (91%). Twenty-nine of the 70 patients (41%) showed serious cardiac arrhythmias; malignant ventricular arrhythmias, i.e., torsade de pointe and ventricular flutter or fibrillation, occurred in 3 cases. Serious ventricular arrhythmias were associated with QTc prolongation and hypokalemia. No correlation was found between the frequency and severity of cardiac arrhythmias and the neurologic condition, the site and extent of intracranial blood on computed tomography scan, or the location of ruptured malformation. The extremely high incidence of cardiac arrhythmias, sometimes serious, in the acute period after subarachnoid hemorrhage and the absence of clinical and radiologic predictors make systematic continuous ECG monitoring compulsory to improve the overall results of subarachnoid hemorrhage, irrespective of early or delayed surgical treatment.