Progression of first degree atrioventricular block to second degree Mobitz type I block during spinal anesthesia...

A case is presented in which an elderly patient with preexisting first degree atrioventricular (AV) block progressed to second degree Mobitz Type I AV block during spinal anesthesia and associated with hypertension induced by a pure alpha 1 agonist. Second degree AV block caused by increased vagal tone was transient, which resolved as the blood pressure normalized. Hypotension due to spinal anesthesia treated with pure alpha 1 agonist can increase AV block in patient with pre-existing first degree heart block.