Abstract

Background: Cardiac dyssynchrony is common in advanced heart failure (HF), but the changes in cardiac synchrony after myocardial infarction (MI) have not been adequately described. Aim: To study the relationship between cardiac synchrony and left ventricular remodeling after acute myocardial infarction. Material and methods: Forty nine patients aged 59±10 years (77% men) with a first episode of a ST segment elevation MI, were studied. Scintigraphic left ventricular function and synchrony analyses were performed at baseline and after a six months follow-up. Determinations were compared with 33 healthy subjects. Results: At baseline, patients with MI had a decreased left ventricular ejection fraction (LVEF) and significant dyssynchrony, when compared with controls. LVEF was 36.4%±10%, left ventricular end-diastolic volume (LVEDV) 127±38 mL, interventricular delay (IEV) 29±35 miliseconds (ms), and intraventricular delay (IAV), 234±89 ms. After 6 months, LVEF significantly improved (38%±10%, p =0.042) without significant changes in LVEDV (129±32 mL, p =0.97), IEV (24±17, p =0.96) or IAV (231±97, p =0.34). At baseline there were significant correlations between IAV and LVEF, and between IAV and LVEDV (r =-0.48, p =0.001 and r =-0.41, p =0.004, respectively). These correlations remained significant after 6 months. There was a positive correlation between IAV and LVEDV changes at six months (r =0.403, p =0.04). Conclusions: The development of cardiac dyssynchrony correlates with adverse left ventricular remodeling after MI.