Comportamento hemodinâmico do ventrículo direito no infarto agudo de parede inferior: comparaçäo entre pacientes que evoleum com e sem choque / Behavior of the Right Ventricle in Acute Inferior Wall Myocardial Infarction. Comparison Between Patients With and With out Cardiogenic Shock

ABSTRACT

PURPOSE--To evaluate the hemodynamic profile of patients (pts) with acute inferior wall myocardial infarction (AMI) and dysfunction of right ventricle (RV). METHODS--Ninety nine consecutive pts (aged 56.6 +/- 3.4 years), 47 men, with inferior AMI and RV dysfunction were studied. RV infarction was diagnosed based on ST segment elevation (> lmm) in precordial V4R lead and RV abnormalities found in echocardiography. All pts were undergone to bedside hemodynamic studies, by measuring mean right atrial (RAP), pulmonary artery (PAP), wedge pulmonary (PWP), and radial artery (AP) pressures and cardiac output (CO). Cardiac index (CI), pulmonary (PAR) and systemic arterial resistance (SAR) were calculated in dynes x sec x cm-5. Left ventricle (LV) ejection fraction (EF) and RV-EF were obtained by contrast ventriculography. Cardiogenic shock was diagnosed based on AP < or = 70 mmHg, RAP > or = 7 mmHg, PWP < or = 20mm Hg, CI < or = 1.8l/min/m2 and oliguria. Pts were then subdivided in 2 groups with cardiogenic shock (group A, n = 41) with a mean age of 55.4 +/- 2.1 and without shock (group B, n = 58) with a mean age of 57.2 +/- 1.7. RESULTS--No significant differences between groups regarding RAP, PWP, AP and LVEF were observed, but compared to group B, group A had lower CI (1.3 +/- 0.3 vs 2.6 +/- 0.5 l/min/m2, p < 0.05), higher SVR (2314 +/- 252 vs 1324 +/- 324 dynes.sec.cm-5, p < 0.01), and lower RVEF (0.27 +/- 0.08 vs 0.41 +/- 0.11//, p < 0.05). CONCLUSION--Pts with inferior AMI and RV dysfunction, cardiogenic shock depends on of RV failure and is independent of a preserved LV function