QT dispersion after subarachnoid hemorrhage

Abstract

Subarachnoid hemorrhage (SAH) causes a stress response with increased concentrations of plasma catecholamines and serious cardiac arrhythmias. Increased QT dispersion has been shown to predispose to cardiac arrhythmias. In SAH patients, QT dispersion has not been studied previously. QT dispersion was analyzed in 26 patients with SAH and in 16 patients (control group) scheduled for ligation of a nonruptured cerebral aneurysm. In 15 patients with SAH, the plasma concentrations of catecholamines were analyzed, and an 18-hour continuous electrocardiogram (ECG) recording was obtained. In the other 11 patients, electrocardiography was repeated daily for up to 9 days for analysis of QT dispersion. The median (25th and 75th percentiles) QT dispersion in all SAH patients was 78 milliseconds (50 and 109 milliseconds, respectively), and in control patients, it was 25 milliseconds (15 and 33 milliseconds, respectively) (P < .001). There was a positive correlation with QT dispersion and the plasma concentration of DHPG, a metabolite of norepinephrine (P < .05). All patients had episodes of cardiac arrhythmia during the 18-hour recording period. In conclusion, increased QT dispersion is a common finding after SAH and may be a result of high plasma concentrations of catecholamines in these patients.