Electrocardiogram and cardiac stimulation

Czech version

Authors: M. Sepši; D. Pospíšil; M. Kozák
Authors‘ workplace: Interní kardiologická klinika LF MU a FN Brno
Published in: Kardiol Rev Int Med 2017, 19(2): 132-137

Overview

Determining the electrical axis of the heart is the key to assessing the origin of the depolarisation wave. A normal heart axis is a vector ranging from – 30 degrees to +90 degrees. Pacing from the right ventricle apex pushes the electrical axis to the left (from – 30 degrees to more negative values). Pacing from the left ventricle moves the electrical axis to the right (from +90 degrees to positive values). Biventricular pacing leads to extreme axis deviation (from – 90 degrees to – 180 degrees). Placing a magnet over the pacemaker will cause an asynchronous pacing and thereby allows us to verify basic pacemaker functions. Placing a magnet over the implantable cardioverter-defibrillator will inhibit tachyarrhythmia therapy and can be used for temporary deactivation. Algorithms reducing right ventricular pacing allow temporary higher-grade atrioventricular blockades and thereby imitate pacing malfunction.

Keywords:
electrocardiography – pacemaker – implantable cardioverter defibrillator

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