Which type of shock is defined by low cardiac output due to reduced preload, high afterload, or poor myocardial contractility?

• A. Pulmonary edema
• B. Neurogenic shock
• C. Cardiogenic shock
• D. Obstructive shock

Answer: (C)

Cardiogenic shock happens when the heart can’t pump effectively, so cardiac output drops even if there’s enough blood returning to the heart. The defining problem is poor myocardial contractility, meaning the heart’s pumping strength is reduced (as from a severe heart attack, decompensated heart failure, myocarditis, or dangerous arrhythmias). Because of this pump failure, tissues don’t get enough blood, leading to signs of poor perfusion and often pulmonary congestion.

In contrast, hypovolemic shock results from too little circulating blood (reduced preload), obstructive shock from a blockage that raises afterload or prevents blood flow, and neurogenic (distributive) shock from loss of vessel tone causing low systemic resistance. Pulmonary edema can accompany cardiogenic shock but is not itself a type of shock.