Electrocardiographic alterations in subarachnoid haemorrhage. Correlation between spasm of the arteries of the left side on the brain and T inversion and QT prolongation.

In a retrospective study of 89 patients with subarachnoid haemorrhage (SAH), the frequency and specificity of changes in the electrocardiogram (ECG) were determined, as well as electrocardiographically established arrhythmias. The ECG changes were correlated with neurological as well as angiographic findings (localization of the aneurysm and vascular spasm). Abnormal ECGs were found in about 80% of the patients. The following abnormalities were found with decreasing frequency: depression and elevation of the ST segment, prolongation of the QT interval, flattening and inversion of the T wave, U waves and TU fusion waves, and arrhythmias (sinus tachycardia and bradycardia, extrasystole). A verified correlation (chi-square test) was shown between angiographically demonstrated spasm of the brain arteries of the left side and negative T waves as well as a prolongation of the QT interval. These results are related to the causal role of the left stellate ganglion in the generation of ECG changes and arrhythmias (animal experiments, and the success by blockade or surgical removal of the stellate ganglion in hereditary QT prolongation.