Tissue Doppler tricuspid annular motion in acute inferior wall myocardial infarction and infarction related artery

Patients with inferior wall myocardial infarction (IWMI) associated with right ventricular (RV) infarction have much higher rates of adverse events. Tissue Doppler (TDI) systolic annular velocity (S′) and myocardial performance index may be useful predictors of proximal right coronary artery (RCA) stenosis as a culprit lesion in inferior wall myocardial infarction. In a prospective study, patients with first episode of acute IWMI underwent early conventional and tissue Doppler echocardiographic assessment (within 24 h) of symptom onset and RV indices; Tricuspid annular systolic plane excursion(TAPSE), myocardial performance index (MPI) and tissue Doppler velocities from RV free wall were measured. Patients underwent coronary angiogram within one month and were divided into two groups (A, B) according to angiographic findings based on the presence or absence of significant proximal RCA stenosis. There were 35 patients with first episode of IWMI, group A includes (n 14 patients) and group B includes (n 21patients), There was significant difference between groups in TAPSE (1.28 cm vs 1.98 p < 0.001), MPI–TDI (0.69 ± 0.12 vs 0.38 ± 0.05 p < 0.001), and in S′ velocity from RV free wall (0.09 m/s ± 0.02 vs 0.12 m/s ± 0.02 p < 0.001). It was found that S′ < 10 cm/s is a predictor of proximal RCA lesion with a sensitivity of 92.86% and a specificity of 85.71% ppv 81.25, npv 94.74, MPI–TDI > 0.55 with a sensitivity of 92.86% and a specificity of 100%, 100% ppv and 95.45% npv, and TAPSE < 16 mm (sensitivity 93%, specificity 100%). RV indices (S′ velocity, MPI–TDI and TAPSE) are useful in predicting proximal RCA as infarct related artery in IWMI.