Cardiogenic Shock

Summary

Cardiogenic shock is a life-threatening condition characterized by the heart's inability to pump sufficient blood to meet the body's needs, leading to severe organ dysfunction. It is associated with high mortality rates, often exceeding 50%, despite advances in treatment. The etiology of cardiogenic shock commonly includes acute myocardial infarction, severe heart failure, and cardiomyopathy. Pathophysiologically, it involves a critical reduction in cardiac output and systemic blood pressure, resulting in inadequate tissue perfusion. Medical treatments focus on stabilizing the patient with inotropic agents, vasopressors, and anticoagulants. Mechanical treatments may include intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), and ventricular assist devices (VADs) to support cardiac function and improve outcomes.

Key Terms

IABP

Intra-aortic Balloon Pump. A mechanical device that is inserted into the femoral artery and placed in the descending aorta. It functions on the concept of counterpulsation.

Counterpulsation

ECMO

Extracorporeal Membrane Oxygenation. A mechanical device that provides cardiac and respiratory support to patients with severe heart and lung failure.

VAD

Ventricular Assist Device. A mechanical device that helps the heart pump blood to the rest of the body.

Cardiogenic Shock

A life-threatening condition characterized by the heart's inability to pump sufficient blood to meet the body's needs, leading to severe organ dysfunction.

Cardiac Output (CO)

CO=SV*HR The amount of blood the heart pumps through the circulatory system in a minute.

Systemic Blood Pressure

The pressure exerted by the blood on the walls of the arteries as it circulates through the body.

Revascularization

The restoration of blood flow to the heart muscle through procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Splanchnic Circulation

The blood flow to the gastrointestinal organs including the stomach, intestines, liver, spleen, and pancreas.

Epidemiology

• Mortality
  • 30%–50% risk of 30-day mortality ¹

Etiology

• MCC:acute decompensation of chronic HF up to >50% of the admissions (previously AMI)¹
• Heart Failure
• Acute Myocardial Infarction

Pathophysiology ¹

• Impairment in ventricular contractility: Leads to reduced mean arterial pressure (MAP) and cardiac output (CO).
• Systemic hypoperfusion: Decreased coronary perfusion pressure activates baroreceptors and chemoreceptors.
• Increased vascular resistance: Blood is redistributed away from splanchnic circulation, elevating pulmonary and central venous pressure (CVP).
• Multiorgan congestion: Exacerbates preexisting volume overload in heart failure patients.
• Worsening lactic acidemia: Results from compromised end-organ perfusion.
• Systemic inflammatory response syndrome (SIRS): Causes systemic vasodilation and inflammation, worsening myocardial dysfunction.
• Progressive maladaptive spiral: Culminates in multiorgan failure and death.

HPI

Presents like:This 65-year-old male with a history of hypertension, type 2 diabetes mellitus, and a previous myocardial infarction 2 years ago. He presented to the emergency department with severe chest pain, shortness of breath, and diaphoresis. On examination, he was found to be hypotensive with a blood pressure of 80/50 mmHg, tachycardic with a heart rate of 120 bpm, and had cool, clammy extremities. Jugular venous distension was noted, and lung auscultation revealed bilateral crackles. An electrocardiogram showed ST-segment elevation in the anterior leads, and cardiac biomarkers were significantly elevated. The patient was diagnosed with acute myocardial infarction complicated by cardiogenic shock and was immediately started on inotropic support and transferred to the cardiac cath lab for further management.

• V/S:Hypotension and tachycardia
• EKG:ST segment changes
• PMHX:likely prior hx of diabetes, htn, hpl

Physical Exam

Diagnostics

• EKG:

Treatment

• Mechanical Support
  • Intra-aortic Balloon Pump (IABP)
  • Extracorporeal Membrane Oxygenation (ECMO)
  • Ventricular Assist Devices (VADs)
• Pharmacologic Support
  • Inotropic Agents
  • Vasopressors
  • Anticoagulants

Referrals

Case Study

References

1. Mehta A, Vavilin I, Nguyen AH, et al. Contemporary approach to cardiogenic shock care: a state-of-the-art review. Front Cardiovasc Med. 2024;11:1354158. Published 2024 Mar 13. doi:10.3389/fcvm.2024.1354158
2. Thiele H, Akin I, Sandri M, et al. PCI Strategies in Patients with Acute Myocardial Infarction and Cardiogenic Shock. N Engl J Med. 2017;377(25):2419-2432. doi:10.1056/NEJMoa1710261