Comparison of cardiac monophasic action potentials recorded by intracellular and suction electrodes

Abstract

The action potentials recorded from heart muscle with a suction electrode have been compared to those recorded with an intracellular microelectrode. It has been found that if the suction electrode is properly used the monophasic potentials recorded with it may be taken as a reliable index of the time of arrival of excitation at the electrode and as a reliable index of the shape of the action potential during the entire phase of repolarization. The suction electrode potentials differ from the microelectrode potentials in showing a lower rise velocity, a smaller amplitude, a quantitatively different reversal or overshoot and, in the beating heart, ‘afterpotentials’ caused by mechanical effects. When the shape of the action potential, as observed with the microelectrode, is changed by ions such as K+ or Ca++ a similar change is observed in the potential recorded with the suction electrodes.

The action‐potential duration and contractile response of the intact heart related to the preceding interval and the preceding beat in the dog and cat

“…Suction electrodes give imperfect action potential recordings when compared with intracellular micro-electrodes in vitro (Hoffman, Cranefield, Lepeschkin, Surawicz & Herrlich, 1959). However in the intact heart, intracellular electrodes would be affected by surrounding events (Lewartowski & Czarnecka, 1970) and therefore confer no practical advantage over suction electrodes.…”

Monophasic Action Potentials of the Right Atrium in Patients With Paroxysmal Atrial Fibrillation.

“…[16][17][18] Abnormally fractionated RA electrograms during sinus rhythm are characteristic in patients with PAF. 19 MAPs can be easily recorded from the endocardium using the contact catheter technique and Olsson et al have shown that such recordings accurately reproduce the repolarization time course of intracellular action potentials, 7,20 thus allowing basic cellular events to be studied in the human heart. We have confirmed that MAPs from the RA and RV provided extremely useful clinical and electrophysiological data in various diseases, 9,21,22 and Franz et al identified a very close correlation between action potential duration (MAPD) and ERP in the human myocardium.…”

Proceedings of the Physiological Society, 26–27 March 1971, University College London Meeting: Communications

“…To confirm this, three simultaneous records were obtained; the electrocardiogram, and monophasic action potentials from endocardial and from eipicardial surfaces, the latter recorded by suction electrodes as used by Hoffmann, Cranefield, Lepeshkin, Surawicz & Herrlich (1959). The single ventricles of Xenopus laevis were perfused with Ringer solution via the aorta with the venae cavae tied off.…”