Radionuclide assessment of right ventricular contractile reserve after acute myocardial infarction

• Published in: The American journal of cardiology Vol. 74; no. 10; pp. 982 - 986
• Main Authors: Coma-Canella, Isabel, del Val Gómez Martínez, María, Terol, Ignacio, Gallardo, Félix, Castro Beiras, JoséManuel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-11-1994; Elsevier Limited
• Subjects: Adult; Aged; Analysis of Variance; Cardiovascular disease; Coronary Angiography; Dobutamine; Drug therapy; Electrocardiography; Exercise; Female; Heart; Humans; Male; Medical research; Middle Aged; Myocardial Infarction - diagnostic imaging; Myocardial Infarction - physiopathology; Radionuclide Imaging; Stroke Volume - physiology; Ventricular Function, Right - drug effects; Ventricular Function, Right - physiology
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/0002-9149(94)90844-3

Conflicting data have been reported about the implications of a decreased right ventricular (RV) contractile reserve (i.e., a <5% stress-induced increase in ejection fraction [EF]). If a reduced reserve corresponds to ischemia, it will probably be associated with an electrocardiographic marker of RV ischemia, stress-induced ST-segment elevation (↑ST) in leads V
3R to V
6R. To test this hypothesis, 98 asymptomatic postinfarction patients (27 with RV infarction) were assigned to a dobutamine stress test (maximal dose 40 μg/kg/min) with equilibrium radionuclide angiography and electrocardiographic study, including leads V
3R to V
6R. All but 11 patients underwent coronary angiography. A dobutamine-induced ↑ST in VR leads was seen in 24 patients with and in 8 without RV infarction. This electrocardiographic sign was 75% sensitive and 84% specific for the diagnosis of proximal right coronary artery disease. It was 61% sensitive and 74% specific for the detection of reduced RV contractile reserve. Patients with RV infarction had reduced RVEF at rest (38 ± 9%), but the mean contractile reserve was normal (12 ± 12%). The contractile reserve was significantly smaller in patients with proximal versus distal or no right coronary artery disease. It was also smaller (p <0.01) in patients with ↑ST versus no ↑ST. In conclusion, high doses of dobutamine are useful in assessing RV contractile reserve after acute myocardial infarction. In these patients, a reduced RV contractile reserve is related to proximal right coronary artery disease and is associated with stress-induced ↑ST in VR leads.