Influence of left bundle branch block on the electrocardiographic changes induced by acute coronary artery occlusion of distinct location and duration
Jorge, Esther (Institut d'Investigació Biomèdica Sant Pau)
Solé-Gonzalez, Eduard (Institut d'Investigació Biomèdica Sant Pau)
Amorós-Figueras, Gerard (Institut d'Investigació Biomèdica Sant Pau)
Arzamendi, Dabit (Institut d'Investigació Biomèdica Sant Pau)
Guerra Ramos, José María. (Institut d'Investigació Biomèdica Sant Pau)
Millán, Xavier (Institut d'Investigació Biomèdica Sant Pau)
Vives-Borrás, Miquel (Institut d'Investigació Biomèdica Sant Pau)
Cinca, Juan (Institut d'Investigació Biomèdica Sant Pau)
Universitat Autònoma de Barcelona

Date:	2019
Abstract:	Background: Electrocardiographic (ECG) diagnosis of acute myocardial ischemia is hampered in the presence of left bundle branch block (LBBB). Objectives: We analyzed the influence of location and duration of myocardial ischemia on the ECG changes in pigs with LBBB. Methods: LBBB was acutely induced in 14 closed chest anesthetized pigs by local electrical ablation. Thereafter, episodes of 5 min catheter balloon occlusion followed by 10 min reperfusion of the left anterior descending (LAD), left circumflex (LCX), and right (RCA) coronary arteries were done sequentially in 5 pigs. Additionally, a 3-h occlusion of these arteries was performed separately in the other 9 pigs. A 15-lead ECG including leads V7 to V9 was continuously recorded. Results: Ablation induced LBBB showed QRS widening, loss of r wave in V1, and predominant R waves in V2 to V9. After 5 min of ischemia the occluded artery could be identified in all cases: the LAD by R waves and ST elevation in V1-V3; the LCX by both ST segment elevation in II, III, aVF, V7 to V9 and ST segment depression in V1 to V4; and the RCA by ST depression and new S-waves in all precordial leads. Three hours after coronary occlusion, ST segment changes declined progressively and only the LAD occlusion could be reliably recognized. Conclusion: LBBB did not mask the ECG recognition of the occluded coronary artery during the first 60 min of ischemia, but 3 h later only the LAD occlusion could be reliably identified. ST elevation in leads V7 to V9 is specific of LCX occlusion and it could be useful in the diagnosis of acute myocardial ischemia in the presence of LBBB.
Note:	Altres ajuts: This work was supported by Spanish Ministerio de Economia y Competitividad, Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red Enfermedades Cardiovaculares, CIBERCV (CB16/11/00276), and Fondo Europeo de Desarrollo Regional (FEDER).
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 ; Coronary occlusion ; Left bundle block ; ECG ; Swine
Published in:	Frontiers in physiology, Vol. 10 Núm. FEB (2019) , p. 82, ISSN 1664-042X

DOI: 10.3389/fphys.2019.00082
PMID: 30809155

10 p, 3.1 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