Nueva clasificación del infarto de miocardio con ondas q: correlación entre el electrocardiograma y la resonancia magnética nuclear.

Abstract

The electrocardiogram (ECG) is the main diagnostic technique for chronic myocardial infarction (MI) detection through the analysis of Q wave and its equivalents. However, the ECG classification presently used in clinical practice for MI location is based on old pathology studies and has not been validated with modern image methods._x000D_ Presently¸ cardiac magnetic resonance (CMR) is the Gold Standard technique for chronic MI location and its quantification. It sensibility is so good that detects small areas of necrosis and its high resolution allows MI location as accurate as necropsy studies, with the advantage of showing the precise anatomical position of the heart within the thorax. _x000D_ In this doctoral thesis all the investigation performed in order to obtain a new ECG classification of myocardial infarction is reviewed. For that purpose we compared the infarcted myocardial segments of the left ventricle assessed by CMR with gadolinium hyperenhancement with the location of Q waves in the ECG. _x000D_ Our main objective was to obtain 7 clinically useful ECG patterns from the analysis of left ventricular infarcted segments identified by cardiac magnetic resonance. We obtained from this first study 4 ECG patterns of the anteroseptal zone and 3 ECG patterns of the inferior zone that had good correlation with CMR for MI location. This was the first study that methodically correlated ECG and CMR for MI location, since previous CMR studies focused on MI detection and its transmural extent with respect to Q waves on ECG._x000D_ In the second study, once ECG patterns were obtained, we prospectively validated them. These ECG patterns were very accurate and showed high level of concordance with respect to CMR._x000D_ Finally, in a third study we obtained- thanks to CMR correlation- the most sensitive and specific criteria for lateral MI, focusing on R wave height and R/S ratio in V1 lead._x000D_ Classically it was considered that a tall R wave in V1 lead reflected inferior MI, but we demonstrated that in fact this sign corresponds to a lateral infarction and that the so called “posterior wall” does not exist._x000D_ At the end of the thesis the relevance of these findings, the impact on different scientific society’s statements and its pitfalls are mentioned.

Date of Award	17 Jul 2012
Original language	Spanish
Supervisor	Antoni Bayes de Luna (Director)