Der monophasische Aktionsstrom von Spitze und Basis des Warmblüterherzens und die Theorie der T-Welle des Ekg

Schaefer, H.; Peña, Arsacio; Schölmerich, P.

doi:10.1007/bf01753348

Cited by 34 publications

(5 citation statements)

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“…Longer durations at the base have been hypothesized from studies on human [Wilson et al (1931), ventricular gradient], frog [Schaefer et al (1943), suction electrode], and dog hearts [van Dam Circulation Research/Vo/. 57, No.…”

Section: Comparisons Between Regionsmentioning

confidence: 99%

Ventricular action potentials, ventricular extracellular potentials, and the ECG of guinea pig.

Watanabe¹,

Rautaharju²,

McDonald³

1985

Circulation Research

103

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Action potentials were recorded from different regions of the guinea pig ventricle to characterize regional differences in waveform configuration, and to acquire insight into the generation of the T-wave of the electrocardiogram. Isolated tissue preparations were driven at 1 Hz, and microelectrodes were used to map accessible surface regions of the epicardium, endocardium, and septum. There were minimal differences in regional resting potentials (mean -87 mV) and amplitudes (mean 122 mV), but Vmax in the epicardium (mean 110 V/sec) was much smaller than elsewhere (mean 247 V/sec). The action potential duration at the -80 mV repolarization level was longest in the papillary muscles (mean 154 msec), shortest in the septum (mean 126 msec), and generally 10-15 msec longer at the base than at the apex. The characteristics of intramural action potentials were inferred from measurements on enzymatically isolated myocytes, the rationale being that most dissociated myocytes originated from intramural cell layers. The action potentials in about 40% of the myocytes had durations similar to those recorded from the tissue surface (110-170 msec), and the remainder ranged from 170-290 msec long. The existence of longer-than-surface action potentials in the ventricle was also inferred from the body surface electrocardiogram and from bipolar electrograms of isolated left ventricles. In both cases, the Q-T intervals could be accounted for only by action potentials longer than those recorded from the ventricular surface.

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Section: Comparisons Between Regionsmentioning

confidence: 99%

Ventricular action potentials, ventricular extracellular potentials, and the ECG of guinea pig.

Watanabe¹,

Rautaharju²,

McDonald³

1985

Circulation Research

103

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“…potentials recorded epicardially than endocardially has been found in isolated cardiac muscle preparations from the dog (Moore, Preston andMoe 1965, Edmands, Greenspan andFisch 1966) and the frog (Lab 1971). Recording from the endocardial side of the right ventricle in man, Olsson ( 197 1 ), found shorter monophasic action potentials in the basal than in the apical region, which is the reverse of the findings by Schaefer et al (1943) who recorded from the epicardial side of the dog heart. Relatively few in situ investigations have been made in which the depolarization and repolarization phases have been recorded simultaneously and where the spatial distribution in the ventricular muscle and the temporal distribution in relation to the Q-T interval, of these phases, have been studied (Irisawa, Ninomiya and Seyama 1966, Omura 1970, Olsson 1971.…”

mentioning

confidence: 87%

Studies on Myocardial Excitation of the Right Ventricle of the Dog Heart in Situ

Samuelsson

Sjöstrand

1971

Acta Physiologica Scandinavica

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SAMUELSSON, R. and U. SJOSTRAND. Studies on myocardial excitation of the right ventricle of the dog heart in situ. Acta physiol. scand. 1972. 85. 477-487. Monophasic action potentials (MAP) were recorded by a suction electrode catheter which was pushed against the endocardial side of the free wall of the right ventricle in the dog heart in situ. The spatial and temporal distributions of the depolarization and repolarization processes were studied. The durations of the MAP recorded from different subendocardial areas of the ventricular wall showed no systematic differences. The excitation process spiead radially from the prepapillary region. During stimulation of the vagal nerves no change of the impulse propagation velocity or of the shape and duration of the MAP was observed. On endocardial, unipolar pacing in the prepapillary region of the right ventricle the excitation process in the free ventricular wall corresponded closely to that noted on spontaneous excitation; this electrode position also gave the shortest Q-T interval.

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“…The main controversy is whether the electrode in contact with the injured (depolarized) myocardium, or the electrode in contact with uninjured myocardium, is the recording electrode [1,18]. On the one hand, Schaefer argued that MAPs can only be obtained when there is an injury present, and therefore, the electrode in contact with the injured myocardium is the recording electrode [22,23]. On the other hand, others contended that injured cells are electrically inactive and, therefore, the signals recorded must originate from the uninjured cells [24][25][26].…”

Section: Controversies and Bringing It All Togethermentioning

confidence: 99%

Monophasic action potential recordings: which is the recording electrode?

Tse

Wong

Tse

et al. 2016

Journal of Basic and Clinical Physiology and Pharmacology

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The aim of this article is to provide an overview of current debate on the monophasic action potential (MAP) recording technique, specifically whether the depolarizing or the reference electrode is responsible for recording the MAP waveform. A literature search was made using key words including monophasic action potential, MAP, electrophysiological basis, recording electrode, depolarizing electrode, contact electrode, indifferent electrode, and reference electrode. References from articles were screened for additional relevant papers. Articles published by the different experimental groups claim that depolarizing electrode, but not reference electrode, records MAPs from the myocardium. This can be more accurately described when considering biophysical theory, which states that MAP is a bipolar signal with contributions from not only the depolarizing electrode but also remote activation at the reference electrode. It is not meaningful to claim that one is the recording electrode because potential differences must be measured between two points in space. Nevertheless, the MAP technique is useful for assessing the local electrical activity of the myocardium in contact with the depolarizing electrode. It is important to have the recording electrode in close proximity with the reference electrode to minimize contamination from far-field signals.

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Der monophasische Aktionsstrom von Spitze und Basis des Warmblüterherzens und die Theorie der T-Welle des Ekg

Cited by 34 publications

References 0 publications

Ventricular action potentials, ventricular extracellular potentials, and the ECG of guinea pig.

Ventricular action potentials, ventricular extracellular potentials, and the ECG of guinea pig.

Studies on Myocardial Excitation of the Right Ventricle of the Dog Heart in Situ

Monophasic action potential recordings: which is the recording electrode?

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