Right ventricular myocardial infarction initial care

In addition to the reperfusion therapy for STEMI, the acute treatment of right ventricular myocardial infarction is supportive. Volume expansion with normal saline is the primary supportive treatment for the hemodynamic abnormalities of a right ventricular myocardial infarction. Inotropic agents, such as intravenous dopamine, are appropriate in patients whose hypotension is not corrected after 1 L of saline infusion. B-blocker therapy with metoprolol is contraindicated due to bradycardia. Additionally, nitroglycerin is contraindicated in these patients due to risk of hypotension.

• Initial therapy in symptomatic patients is aimed at reversing the decreased filling and right-sided stroke volume while also improving right ventricular function.

• Intravenous fluid, usually isotonic saline, should be given to raise the central filling pressure. This is an attempt to maximize forward flow out of the right ventricle, which prevents inappropriate low left-sided filling pressures. ^{[1] [2]}
• In most cases, several liters of saline are infused rapidly until there is an increase in the pulmonary capillary wedge pressure to approximately 15 mmHg.
• If central hemodynamic monitoring in not available, 1 – 2 liters of saline can be infused while closely following the blood pressure and urine output and examining the patient for signs of pulmonary congestion.

• Systemic cardiac output is dependent upon filling of the left ventricle. In the setting of right ventricular dysfunction and decreased contractility, a reduced preload results sequentially in diminished right sided stroke volume, reduced flow to the left heart, and a fall in cardiac output. As a result, any medication (such as diuretics or nitrates) or any maneuvers that decrease preload should be avoided.

• When fluid resuscitation is insufficient, inotropic and chronotropic stimulation with dobutamine may increase forward flow and augment cardiac output.
• Dobutamine may also act by reducing pulmonary vascular resistance and therefore right ventricular afterload.
• The initial dose of dobutamine is 5 µg/kg/min and it can be titrated up to 20 µg/kg/min as needed.

Template:WH Template:WS