The diagnostic and prognostic value of right ventricular myocardial velocities in inferior myocardial infarction treated with primary percutaneous intervention.

BACKGROUND: Right ventricular (RV) involvement increases mortality and morbidity in inferior myocardial infarction (MI). There are sparse data on the usefulness of pulsed tissue Doppler imaging (TDI) in the diagnosis of RV dysfunction in ST segment elevation MI (STEMI) treated by primary percutaneous coronary intervention (pPCI).

AIM: To evaluate the diagnostic and prognostic significance of RV myocardial velocities compared to classical electrocardiographic RVMI diagnostic criteria in this group of patients.

METHODS: Consecutive patients with first, acute, inferior STEMI treated with pPCI were prospectively assessed. The RVMI was defined as an ST-segment elevation ≥ 0.1 mV in lead V4R. Echocardiography with TDI was performed after pPCI within 24 h of the onset of symptoms. Follow up including in-hospital events was performed.

RESULTS: Out of 101 patients (58 males, mean age 63.7 ± 11.1 years), RVMI was found in 37 (37%). In multivariate analysis, peak systolic RV velocity (SmRV) (OR 5.12), peak early diastolic RV velocity (EmRV) (OR 5.03) and RV wall motion abnormalities (OR 4.94) were independent parameters for RVMI diagnosis. Receiver operating characteristics revealed high diagnostic significance of SmRV (C statistics = 0.90) and EmRV (C statistics = 0.89). The SmRV < 12 cm/s as a cut-off for a diagnosis of RVMI had a 89% sensitivity and a 83% specificity, whereas EmRV < 10 cm/s - 81% and 80%, respectively. Multivariate analysis showed that two variables - SmRV and ST-segment elevation ≥ 0.1 mV in lead V4R, were independent predictors of in-hospital prognosis.

CONCLUSIONS: Right ventricular myocardial velocities derived from TDI predict ECG diagnosis of RVMI with relatively high sensitivity and specificity. Their high negative predictive value may be of practical importance when ECG tracings are equivocal. More importantly, decreased RV systolic myocardial Doppler velocity predicts unfavourable clinical outcomes in patients with inferior STEMI independently of ECG changes.