[Acute right ventricular infarction: assessment with radionuclide ventriculography]

Area of Science:

• Cardiology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Right ventricular (RV) infarction's clinical significance is historically underestimated compared to left ventricular infarction.
• Recent research highlights the crucial role of RV function in managing myocardial infarction (MI).

Purpose of the Study:

• To assess the incidence and prognosis of RV infarction in patients with acute myocardial infarction.
• To evaluate the recovery of RV function using radionuclide studies.

Main Methods:

• Prospective radionuclide ventriculography performed within 48 hours, 1-2 weeks, and 1 month post-MI.
• Diagnosis of RV infarction based on RV regional wall motion abnormalities and ECG, scintigraphy, or right heart catheterization findings.
• Coronary arteriography to identify coronary artery lesions.

Main Results:

• RV infarction occurred in 15/25 inferior MI cases, but none in anterior MI cases.
• Right ventricular ejection fraction (RVEF) improved significantly in inferior MI with RV infarction (34% to 39%) over one month.
• RV regional wall motion abnormalities resolved in 11/15 RV infarction cases, correlating with RVEF improvement.
• Right coronary artery lesions proximal to the RV branch were found in all RV infarction cases undergoing arteriography.

Conclusions:

• Right ventricular infarction, particularly in inferior MI, shows significant RVEF recovery within four weeks, contrasting with left ventricular infarction.
• The unique coronary circulation of the RV may explain the improved RVEF.
• RV infarction is primarily linked to lesions in the right coronary artery's RV branch.