Comunicaçäo interventricular após infarto do miocárdio: análise ecocardiográfica de pacientes submetidos a pressäo expiratória final positiva / Ventricular septal defect following myocardial infarction ­ echocardiographic analysis of patients submitted to positive final expiratory pressure

RESUMO

Comunicaçäo interventricular (CIV) como complicaçäo do infarto agudo do miocárdio (IAM) ocorre em 0,5 a 1,0% dos pacientes e freqüentemente resulta em falência biventricular. Avaliamos os efeitos ecocardiográficos da pressäo expiratória final positiva (PEEP) sobre as dimensöes dos ventrículos direito (VD) e esquerdo (VE) em três pacientes que desenvolveram CIV pós-infarto, complicado com insuficiência respiratória aguda. Em todos os casos houve súbito aumento nas dimensöes do VD e, provavelmente através da interdependência ventricular, uma proporcional diminuiçäo nas dimensöes do VE. Concluímos que a terapia com PEEP neste grupo de pacientes näo teve efeito benéfico comprovado e provavelmente acentuou a dilataçäo ventricular direita

ABSTRACT

Interventricular septal rupture is a life-threatening complication occuring in 0,5 to 1,0% of patients following acute myocardial infarction and often results in right and left ventricular failure. This study aimed at evaluating the echocardiographic effects of PEEP on right (RV) and left (LV) ventricular dimension in three patients who developed a postinfarction septal defect and in whom acute respiratory failure was a preterminal event. The effects of PEPP on the heart remain controversial. We observed in all three patients a sudden large increase in RV dimensions and hence, probably through ventricular interdependence, a proportional decrease in LV dimensions. The progressive leftward septal displacement with increasing levels of PEEP probably contributed to reduce LV compliance. We concluded that PEEP therapy in this group of patients had no proven beneficial effects and probably contributed to further RV dilatation and failure