Cardiogenic shock

Cardiogenic shock is a medical emergency in which the heart’s inability to pump effectively leads to insufficient blood flow to the body’s organs. This condition is most often triggered by a heart attack, complicating an estimated 5–10% of all heart attacks. The underlying causes are categorized as cardiomyopathic, arrhythmic, or mechanical. In the setting of a heart attack, shock may develop at the time of the event or later; registry data indicate that about three-quarters of people develop shock within 24 hours, with nearly half doing so within six hours.

The left anterior descending artery and the left main coronary artery are the most frequently blocked vessels in such cases. Signs of inadequate perfusion include low urine output (less than 30 mL per hour), cool extremities, and a decreased level of consciousness. People may also present with severely low blood pressure, shortness of breath from fluid in the lungs, a rapid and weak pulse, mottled skin, confusion, and distended jugular veins due to increased heart filling pressures. Diagnosis typically involves an electrocardiogram to assess heart muscle damage or rhythm abnormalities, and an echocardiogram to detect structural complications such as ventricular wall rupture or valve problems.

Medication therapy

Invasive hemodynamic monitoring with a pulmonary artery catheter can help gauge disease severity and treatment response. Treatment goals focus on improving blood flow; when a heart attack is the cause, opening the blocked coronary artery is key. Medications like dobutamine or milrinone can enhance the heart’s pumping function. If these measures fail, mechanical support devices—such as an intra-aortic balloon pump, left ventricular assist device, or veno-arterial extracorporeal membrane oxygenation—may serve as a bridge to more definitive therapy like heart transplantation or surgical correction.

Despite early diagnosis, the condition is difficult to fully reverse, and care must address affected organs (e.g., dialysis for kidney failure, mechanical ventilation for lung dysfunction). Mortality remains high: the 30-day rate after a heart attack is about 40%, and the one-year rate is about 50%. However, rates have been declining in the United States, likely due to faster recognition and treatment advances. Multi-organ failure further increases mortality risk.