Predictive Role of f-QRST Angle in Subarachnoid Hemorrhage

The frontal QRS/T angle represents the angle between the ventricular depolarization (QRS) and repolarization (T) vectors on the ECG and serves as a parameter for assessing cardiac electrical heterogeneity. In this study, the frontal QRS/T angle was calculated using data obtained from standard 12-lead surface ECGs. The QRS and T axes in the frontal plane were derived from the automated ECG device reports.

The Hunt-Hess scale was used to assess SAH severity according to the clinical presentation and the visible neurological deficits. The Grades run from 1 to 5: - Grade 1: Asymptomatic or minimal headache, slight neck stiffness. - Grade 2: Moderate to severe headache, and neck stiffness, but no neurological deficit except cranial nerve palsy. - Grade 3: Drowsiness, confusion, or a mild focal deficit. - Grade 4: Stupor, moderate to severe hemiparesis, early decerebrate rigidity, and vegetative disturbance. - Grade 5: Deep coma, decerebrate rigidity, and a moribund appearance.

The modified Fisher scale was used to evaluate SAH severity by reference to the extent of hemorrhage as revealed by CT of the brain. Four grades are depending on the degree of bleeding observed: - Grade 0: No hemorrhage apparent in CT. - Grade 1: Minimal hemorrhage without intraventricular hemorrhage (IVH). - Grade 2: Thin or diffusely thin (\<1mm) hemorrhage with bilateral IVH. - Grade 3: Thick (\> 1 mm) hemorrhage without bilateral IVH. - Grade 4: Thick (\> 1 mm) hemorrhage with bilateral IVH.