Summation and Cancellation Effects on QRS and ST-Segment Changes Induced by Simultaneous Regional Myocardial Ischemia
Vives-Borrás, Miquel (Institut d'Investigació Biomèdica Sant Pau)
Jorge, Esther (Institut d'Investigació Biomèdica Sant Pau)
Amorós-Figueras, Gerard (Institut d'Investigació Biomèdica Sant Pau)
Millán, Xavier (Institut d'Investigació Biomèdica Sant Pau)
Arzamendi, Dabit (Institut d'Investigació Biomèdica Sant Pau)
Cinca, Juan (Institut d'Investigació Biomèdica Sant Pau)
Universitat Autònoma de Barcelona

Date:	2018
Abstract:	Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries (n = 4); Group 2: left anterior descending artery (LAD) and LCX (n = 4) and; Group 3: LAD and RCA (n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p < 0. 05). In contrast, LAD+LCX or LAD+RCA did not induce significant QRS widening and markedly attenuated the ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p < 0. 05). ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.
Grants:	Instituto de Salud Carlos III RD12-0042-0002
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Myocardial ischemia ; QRS complex ; ST-segment ; Coronary artery occlusion ; In situ heart ; Pigs
Published in:	Frontiers in physiology, Vol. 9 (april 2018) , ISSN 1664-042X

DOI: 10.3389/fphys.2018.00275
PMID: 29666583

11 p, 5.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Recerca Sant Pau
Articles > Research articles
Articles > Published articles