In cardiogenic shock, which hemodynamic pattern is typical?

In cardiogenic shock, which hemodynamic pattern is typical?

• A. Low cardiac output, high systemic vascular resistance, elevated pulmonary capillary wedge pressure
• B. High cardiac output, low systemic vascular resistance, normal pulmonary capillary wedge pressure
• C. Low cardiac output, low systemic vascular resistance, low pulmonary capillary wedge pressure
• D. High cardiac output, high systemic vascular resistance, low pulmonary capillary wedge pressure

Answer: (A)

In cardiogenic shock the heart cannot pump effectively, so forward flow drops. That leads to a low cardiac output. The body responds by activating sympathetic nervous system and the renin-angiotensin system, which constrict blood vessels to preserve blood pressure, raising systemic vascular resistance. At the same time, the failing left ventricle backs up pressure into the left atrium and pulmonary veins, increasing left-sided filling pressures. This is reflected as an elevated pulmonary capillary wedge pressure. So the typical pattern is low cardiac output with high systemic vascular resistance and elevated wedge pressure. If the cardiac output were high, or if the wedge pressure were low, that would point away from cardiogenic shock and toward other shock types (distributive with high CO and low SVR, or hypovolemic with low filling pressures).

In cardiogenic shock the heart cannot pump effectively, so forward flow drops. That leads to a low cardiac output. The body responds by activating sympathetic nervous system and the renin-angiotensin system, which constrict blood vessels to preserve blood pressure, raising systemic vascular resistance. At the same time, the failing left ventricle backs up pressure into the left atrium and pulmonary veins, increasing left-sided filling pressures. This is reflected as an elevated pulmonary capillary wedge pressure. So the typical pattern is low cardiac output with high systemic vascular resistance and elevated wedge pressure.

If the cardiac output were high, or if the wedge pressure were low, that would point away from cardiogenic shock and toward other shock types (distributive with high CO and low SVR, or hypovolemic with low filling pressures).