Catheter Induced Complete Heart Block in Tetralogy of Fallot

Abstract

7 month old female with tetralogy of Fallot underwent pre-surgical cardiac catheterization and developed complete heart block. Persistence of heart block led to placement of a pacemaker. Induction of cardiac arrhythmias is a recognized complication of cardiac catheterization in children with congenital heart disease. Heart defects that alter the course of the conduction system, as in corrected transposition of the great arteries, have an increased risk of this procedural complication [1]. Complete atrioventricular block coincident with cardiac catheterization is rarely reported in children with tetralogy of Fallot. [2][3][4] we present a patient with tetralogy of Fallot who developed complete atrioventricular block during diagnostic catheterization prior to definitive surgical repair and her subsequent clinical course.

Effects of Vasodilation and Arterial Resistance on Cardiac Output

“…Control of Heart Rate: With the activity of both sympathetic and parasympathetic nerve fibers, Sino Atrial node of the heart gets enervated [84]. The parasympathetic fibers release acetylcholine, under rest conditions which slows the pacemaker potential of the Sino Atrial node, thus reducing the heart rate [85]. The sympathetic nerve fibers release norepinephrine, under physical or emotional conditions which speeds up the pacemaker potential of the Sino Atrial node, increasing the heart rate [86].…”