ELECTROCARDIOGRAPHIC ABNORMALITIES AFTER NONTRAUMATIC SUBARACHNOID HEMORRHAGE

Electrocardiographic (ECG) abnormalities and rhythm disorders are freq uently observed in the acute phase after spontaneous subarachnoid hemo rrhage (SAH). These abnormalities are benign and transient in most cas es; however, in some patients they can take the form of life-threateni ng arrhythmias such as ventricular flutter/fibrillation and torsade de pointe. Among the ECG abnormalities observed, prolongation of the Q-T interval, especially if associated with hypokalemia, deserves particu lar attention because it is frequently present in those patients who w ill develop fife-threatening ventricular arrhythmias. In some cases, t he ECG abnormalities mimic those observed in the setting of acute myoc ardial infarction. Elevated creatine phosphokinase-myocardial fraction isoenzyme, suggesting underlying cardiac damage, has also been report ed. The pathophysiology of these abnormalities is related to an imbala nce of autonomic cardiovascular control. Because some electrical and m orphological heart abnormalities are experimentally induced by catecho lamine injection, the role of circulating catecholamines has been inve stigated in depth. Pathologically, the hearts of patients who die afte r SAH can show a peculiar morphological lesion defined as ''myocytolys is.'' Intramyocardial hemorrhages have also been described. These obse rvations confirm the utility of continuous cardiac monitoring in patie nts with SAH.