QT dispersion after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) causes a stress response with increased conce ntrations of plasma catecholamines and serious cardiac arrhythmias. Increas ed QT dispersion has been shown to predispose to cardiac arrhythmias. In SA H patients, QT dispersion has not been studied previously. QT dispersion wa s analyzed in 26 patients with SAH and in 16 patients (control group) sched uled for ligation of a nonruptured cerebral aneurysm. In 15 patients with S AH, the plasma concentrations of catecholamines were analyzed, and an 18-ho ur continuous electrocardiogram (ECG) recording was obtained. In the other 11 patients, electrocardiography was repeated daily for up to 9 days for an alysis of QT dispersion. The median (25th and 75th percentiles) QT dispersi on in all SAH patients was 78 milliseconds (50 and 109 milliseconds, respec tively), and in control patients, it was 25 milliseconds (15 and 33 millise conds, respectively) (P < .001). There was a positive correlation with QT d ispersion and the plasma concentration of DHPG, a metabolite of norepinephr ine (P < .05). All patients had episodes of cardiac arrhythmia during the 1 8-hour recording period. In conclusion, increased QT dispersion is a common finding after SAH and may be a result of high plasma concentrations of cat echolamines in these patients.