CLINICAL-SIGNIFICANCE OF RIGHT-VENTRICULAR DILATATION IN PATIENTS WITH RIGHT-VENTRICULAR INFARCTION

Background: Right ventricular infarction can be accurately diagnosed b y ST-segment elevation in the right precordial leads. However, the cli nical outcome of right ventricular infarction encompasses a wide spect rum, ranging from no hemodynamic compromise to cardiogenic shock. The present study examined the clinical significance of echocardiographic right ventricular dilatation in patients with right ventricular infarc tion. Methods: We studied 60 consecutive patients with ECG evidence of right ventricular infarction (at least 1 mm ST-segment elevation and QS or QR in V(4)R) after their first acute Q-wave inferior infarction. They had been admitted to the coronary care unit within 24 h of the o nset of chest pain. The presence of right ventricular dilatation was d iagnosed when the end-diastolic ratio between right and left ventricle was more than 0.5 on two-dimensional echocardiogram. Results: Of the 60 patients with ECG evidence of right ventricular infarction, 29 had right ventricular dilatation (group 1) and 31 did not (group 2). We us ed four clinical Variables in multivariate analysis to determine the s ignificant factors related to right ventricular infarction. Mean right atrial pressure and number of left ventricular segments with advanced asynergy were found to be the important factors. Furthermore, a signi ficantly higher incidence of major complications (cardiogenic shock an d need for temporary pacing) was observed in group 1 than in group 2. Right ventricular dilatation was found to be the significant factor re lated to major complications. Conclusion: Echocardiographic right vent ricular dilatation is an important non-invasive sign obtained on admis sion in patients with right ventricular infarction, because it is asso ciated with larger left ventricular infarct size and increased risk of major complications.