Right ventricular (RV) dysfunction in the setting of acute MI accounts for only 5% of cases of cardiogenic shock but carries nearly the same mortality as LV shock. Shock due to RV dysfunction is usually treated by aggressive volume loading with IVF. However...
In some cases of RV dysfunction, RV end-diastolic pressure can be very high, resulting in shiftng of the invterventricular septum into the LV cavity, which in turn decreases LV filling and cardiac output. Aggressive fluid resuscitation in these patients may actually further worsen RV pressures, leading to further reductions in cardiac output. These patients should instead be treated early with vasopressors.
How do you tell if your patient needs aggressive fluid resuscitation or early vasopressors? Bedside ultrasound can be the answer...if you find marked distension of the RV, go with early vasopressors. If the RV appears normal in size (smaller than LV), go with the IVF.
And of course early revascularization is critical as well.
(adapted from: Reynolds HR, Hochman JS. Cardiogenic shock: current concepts and improving outcomes. Circulation 2008;117:686-697.)
