Electrophysiologic effects of papillary muscle traction in the intact heart
| Autor: | M C Pritzker, Adrian K. Almquist, David G. Benditt, H G Tobler, I. C. Tuna, Charles C. Gornick |
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| Rok vydání: | 1986 |
| Předmět: |
Male
medicine.medical_specialty Refractory Period Electrophysiological genetic structures Refractory period Radioactive microsphere technique medicine.medical_treatment Diastole Beat (acoustics) Stimulation Electrocardiography Dogs Physiology (medical) Internal medicine medicine Animals Papillary muscle business.industry Cardiac Pacing Artificial Arrhythmias Cardiac Blood flow Papillary Muscles Traction (orthopedics) Myocardial Contraction Electric Stimulation Biomechanical Phenomena Electrodes Implanted Electrophysiology medicine.anatomical_structure Cardiology Female Stress Mechanical sense organs Cardiology and Cardiovascular Medicine business Pericardium Endocardium |
| Zdroj: | Circulation. 73:1013-1021 |
| ISSN: | 1524-4539 0009-7322 |
| DOI: | 10.1161/01.cir.73.5.1013 |
| Popis: | In this study we used transmural multipolar electrodes, sonomicrometers implanted within the left ventricular wall, and cardiac electrical stimulation techniques to examine the effect of transient mechanical posterior papillary muscle traction on local myocardial electrophysiologic characteristics. Nine open-chest dogs were atrially paced (cycle length 400 msec) followed by insertion of timed premature extrastimuli at left ventricular epicardial pacing sites either in the vicinity of (traction zone) or remote from (nontraction zone) the site of papillary muscle traction. Electrophysiologic recordings were made before and during periods of intermittent papillary muscle traction of predetermined timing, application rate (25 cm/sec), and duration (170 msec). Papillary muscle traction was applied in late diastole just before the last beat of each atrial drive train. In seven of nine dogs application of transient papillary muscle traction resulted in significantly earlier local ventricular activation (mean activation advancement 30 +/- 13 msec), altered QRS morphology of the last conducted atrial drive-train beat, and relative prolongation of ventricular functional refractory period in the traction zone. Conversely, in nontraction zones in these seven dogs, early activation did not occur and refractoriness remained unchanged as tested by a locally placed extrastimulus. In two of nine dogs traction failed to induce early activation and changes in refractoriness did not occur. Alterations in regional myocardial blood flow (assessed by radioactive microsphere technique) did not appear responsible for the observed changes, since there was no demonstrable traction-induced difference in regional blood flow between the traction and nontraction zones.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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