What are the key aspects of right ventricular (RV) myocardial infarction (MI)?

From the Guidelines

The 10 most important things to know about right ventricular myocardial infarction (RVMI) are crucial for prompt diagnosis and effective management, with the most critical aspect being the recognition of RVMI as a complication of inferior wall myocardial infarction, occurring in about 30-50% of inferior MIs, as noted in the 2018 study by the American Heart Association 1.

Key Points to Consider

• RVMI typically occurs in conjunction with inferior wall myocardial infarction, with about 30-50% of inferior MIs involving the right ventricle.
• Recognizing the classic triad of hypotension, clear lung fields, and elevated jugular venous pressure is crucial for diagnosis.
• ST-segment elevation in right-sided ECG leads, particularly V4R, is the most sensitive diagnostic finding and should be obtained in all suspected cases, as recommended by the European Society of Cardiology in 2008 1.
• RVMI patients are preload-dependent, so maintaining adequate volume status with IV fluid boluses (typically 1-2 liters of normal saline) is a cornerstone of treatment.
• Vasodilators like nitroglycerin, morphine, and diuretics should be avoided as they can precipitate profound hypotension by reducing preload.
• Early reperfusion therapy, preferably primary percutaneous coronary intervention (PCI), is essential to restore blood flow to the right coronary artery, as emphasized by the American College of Cardiology/American Heart Association in 2004 1.
• Inotropic support with dobutamine (starting at 2-5 mcg/kg/min) may be necessary if hypotension persists despite adequate fluid resuscitation.
• Temporary pacing may be required as RVMI frequently causes bradyarrhythmias and heart blocks.
• Mechanical complications like tricuspid regurgitation and right ventricular free wall rupture, though rare, should be monitored for.
• RVMI has a higher in-hospital mortality rate than isolated left ventricular infarction, but patients who survive typically have good long-term prognosis due to the right ventricle's remarkable ability to recover.

Treatment and Management

• Dual antiplatelet therapy with aspirin (325mg loading dose, then 81mg daily) and a P2Y12 inhibitor like clopidogrel (600mg loading, then 75mg daily) is standard, along with other post-MI medications including statins, beta-blockers, and ACE inhibitors as tolerated.
• The management of RVMI should prioritize maintaining RV preload, achieving AV synchrony, and optimizing RV afterload, as outlined in the ACC/AHA guidelines 1.

Prognosis and Outcomes

• The one-year mortality after RVMI is reported to be 18% in patients with isolated right coronary artery lesions compared to 27% in the presence of combined right and left coronary artery disease, as noted in the 2018 study by the American Heart Association 1.
• Long-term follow-up shows that mortality beyond the first year remains at an additional 2%/y to 3%/y through year 10, highlighting the importance of ongoing management and care.

From the Research

Key Points About Right Ventricular Myocardial Infarction

• Right ventricular myocardial infarction (RVMI) is a complication of an acute occlusion of a dominant right coronary artery (RCA) or left anterior descending (LAD) artery 2.
• RVMI is associated with high rates of in-hospital morbidity and mortality driven by hemodynamic compromise, cardiogenic shock, and electrical complications 2, 3.
• The diagnosis of RVMI is based on physical examination, electrocardiography, echocardiography, and coronary angiography, with right-sided precordial leads being essential for assessing RV involvement 3, 4.
• Treatment of RVMI includes adequate fluid administration, positive inotropic agents, and early coronary reperfusion, while diuretics and nitrates should be avoided 4.
• The use of oral antiplatelets, such as aspirin and clopidogrel, is important in the management of acute coronary syndrome, including RVMI 5, 6.
• The addition of clopidogrel to aspirin has been shown to reduce mortality and major vascular events in patients with acute myocardial infarction 6.
• Right ventricular involvement is an independent prognostic factor that increases in-hospital mortality, due in part to a higher risk of hemodynamically compromising arrhythmias 4.
• Early identification and aggressive treatment of RVMI may improve patients' prognosis 4.
• RVMI can accompany inferior wall ischemia in up to one-half of cases, and the clinical sequelae can vary from no hemodynamic compromise to severe hypotension and cardiogenic shock 3, 4.
• Intra-aortic balloon counterpulsation and right ventricle assist devices may be used in RVMI associated with medically refractory heart failure 4.