Right ventricular asynergy during dobutamine-atropine echocardiography

We sought to analyze right ventricular contractility during dobutamine infusion in patients with right coronary artery disease and to elucidate whether the development of right ventricular asynergy aids in characterizing a right coronary artery stenosis.

Clinical investigations are emphasizing the importance of right ventricular function in patients with coronary artery disease. Thus, prognosis of patients with inferior myocardial infarction is influenced by right ventricular function. This study describes the echocardiographic and electrocardiographic findings during dobutamine-atropine echocardiography in patients with right coronary artery disease.

We studied 31 patients with isolated right coronary artery disease and no previous myocardial infarction. Six patients with poor acoustic window were excluded (feasibility 80%). The remaining 25 patients underwent dobutamine-atropine echocardiography. A right coronary artery stenosis located before the origin of the right ventricular branches was considered proximal; otherwise, it was considered distal.

Right ventricular asynergy during dobutamine-atropine testing developed in 17 patients (sensitivity 68%); 14 had proximal and 3 had distal right coronary artery disease. The following segments were involved: inferior (n = 17), lateral (n = 5) and outflow tract (n = 1). No patient showed anterior asynergy. All 17 patients had left ventricular asynergy as well. Ischemia-free time was 10.7 +/- 6.2 (mean +/- SD) min for the right ventricle and 8.9 +/- 5.2 min for the left ventricle (p < 0.05). Ischemic ST changes were recorded in 15 patients (in standard leads in 14 and in right precordial leads in 8). All patients with right precordial changes showed ST elevation and had right ventricular asynergy (sensitivity and specificity for right ventricular asynergy 47% and 100%, respectively). A control group of 25 patients with no right coronary artery disease (5 with no disease, 15 with left anterior descending and 5 with left circumflex coronary artery disease) underwent dobutamine echocardiography. Right ventricular asynergy developed in two patients with left anterior descending artery stenosis (specificity 92%); in both, the anterior wall was affected.

Echocardiography during dobutamine infusion is a reliable technique for assessing right ventricular dysfunction in patients with right coronary artery disease. Right ventricular contractility can be assessed during dobutamine echocardiography in selected patients.