DOI: 10.1111/j.1540-8175.2010.01318.x C  2011, Wiley Periodicals, Inc. Tissue Doppler Imaging of the Tricuspid Annulus and Myocardial Performance Index in the Evaluation of Right Ventricular Involvement in the Acute and Late Phase of a First Inferior Myocardial Infarction Nicholaos Kakouros, M.D., ∗ Stavros Kakouros, M.D.,† John Lekakis, M.D.,‡ Ioannis Rizos, M.D.,‡ and Dennis Cokkinos, M.D.§ ∗ Johns Hopkins University, Maryland; †“Amalia Fleming” Hospital, Athens, Greece; ‡Attikon University Hospital, Athens, Greece; and §Biomedical Research Foundation, Academy of Athens, Greece Background: Ischemic involvement of the right ventricle (RV) can complicate the early course of inferior ST elevation myocardial infarction (IMI) and has significant management implications but its diagnosis is difficult. This study assessed RV involvement in the acute and late phase of IMI by pulse-wave tissue Doppler (PW-TDI) and RV myocardial performance index (RVMPI). Methods: We prospectively evaluated 38 patients with first IMI, of whom 14 had RV involvement and 24 no RV involvement, as defined by ST segment elevation ≥0.1 mV in lead V4R. Thirty age-matched healthy subjects served as controls. Echocardiographic assessment included PW-TDI measurements from the lateral tricuspid annulus with MPI evaluation and was repeated at 6-month follow-up. Results: Peak systolic velocity of the tricuspid annulus, S’, was significantly lower and RVMPI higher in patients with RVMI compared to patients without RVMI and controls. Patients with proximal RCA lesion had lower S’ and higher RVMPI than patients with distal RCA or left coronary lesion. In the acute setting, the index S’/MPI < 17 was perfectly discriminatory for RV involvement and had moderate sensitivity and specificity (85%, 87%) for identifying proximal RCA disease. S’/MPI < 23 at 6 months had moderate-to-good sensitivity and specificity in identifying patients with previous RVMI. Conclusions: Echocardiographic assessment of the RV by PW-TDI of the lateral tricuspid annulus, with derivation of MPI is a sensitive and specific marker of RV involvement in first IMI and remains so 6 months after the ischemic event. The novel index of S’/MPI appears to have potentially improved diagnostic accuracy in identifying RV involvement and proximal RCA lesion. (Echocardiography 2011;28:311-319) Key words: echocardiography, follow-up, myocardial performance index, right ventricular myocardial infarction, tissue Doppler imaging, ventricular function assessment Right ventricular (RV) ischemic dysfunction may occur in up to 50% of acute inferior left ventricular infarctions. 1,2 Patients with acute in- ferior infarctions complicated by RV involvement have significantly increased in-hospital mortality, cardiogenic shock, and arrhythmias 3,4 compared with patients with isolated inferior infarcts. Elec- trocardiographic (ECG) diagnosis of RV involve- ment is most reliably based on the finding of ST elevation in the right precordial leads, such as V4R, although this finding is subtle and often tran- sient. 5–7 Standard two-dimensional echocardio- graphic assessment of the RV is rendered difficult by the chamber’s complex geometry. Trabecula- tions make endocardial border detection difficult and visual assessment tends to underestimate hy- pokinesia. M-mode measurements of the systolic Address for correspondence and reprint requests: Nikolaos Kakouros, M.D., Division of Cardiology, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Carnegie 568, Baltimore, MD 21287. Fax: +30 210 6745117; E-mail: nikos@jhmi.edu displacement of the lateral tricuspid annular plane have been used to assess RV function, including in the setting of acute infarction. 8–11 More recently, pulsed-wave tissue Doppler imaging (TDI) of the tricuspid annulus has also been used to assess RV function and found systolic and early diastolic ve- locities of the lateral tricuspid annulus to be re- duced in patients with RV infarction complicating inferior MI, compared with patients without RV involvement and with healthy controls. 12 The aim of this study was to further assess the utility of TDI and TDI-derived RV myocardial per- formance index (RVMPI) in detecting RV involve- ment in the setting of an acute first ST elevation inferior myocardial infarction and, unlike previous studies, reevaluate the utility of these markers at a later-stage following the ischemic event. Methods: Population: Fifty patients, who were hospitalized with an acute ST elevation inferior myocardial infarction 311