Cardiogenic Shock – Symptoms and Treatment  
 
Definition: 

Cardiogenic shock is a life-threatening condition characterized by inadequate tissue perfusion due to cardiac pump failure, despite adequate intravascular volume. 

Common Causes: 

– Acute myocardial infarction (most common) 
– Mechanical complications of MI (papillary muscle rupture, VSD, free wall rupture) 
– Severe cardiomyopathy 
– Arrhythmias (VT/VF, severe bradycardia, heart block) 
– Acute valvular disease 
– Myocarditis 
– Stress (Takotsubo) cardiomyopathy 
 
Pathophysiology: 

Primary myocardial dysfunction leads to reduced stroke volume and cardiac output. This causes hypotension and compensatory vasoconstriction, increasing afterload and worsening cardiac performance, resulting in end-organ hypoperfusion and lactic acidosis. 
 
Clinical Presentation: 

Symptoms: 
– Chest pain 
– Dyspnoea, orthopnoea 
– Acute Confusion, altered mental status 
– Oliguria 
– Fatigue 
 
Signs: 
– Hypotension (usually sBP <90 mmHg) 
– Tachycardia or bradycardia 
– Cold, clammy extremities 
– Pulmonary crackles 
– Elevated JVP 
– S3 gallop 
– New murmur (acute MR or VSD) 
 
Diagnostic Evaluation: 

Laboratory Findings: 
– Elevated lactate 
– Metabolic acidosis 
– Elevated troponin 
– Acute kidney injury 
– Elevated liver enzymes 

ECG: 
– Ischaemic changes 
– Arrhythmias 
– Conduction abnormalities 
 
Imaging: 
– Echocardiography (essential): assesses ventricular function and mechanical complications 
– Chest X-ray: pulmonary oedema 

Haemodynamics: 
– Decreased cardiac index (<2.2 L/min/m²) 
– Elevated pulmonary capillary wedge pressure (>15–18 mmHg) 
– Increased systemic vascular resistance 

Management: 
Initial Stabilization: 
– Airway management and oxygen therapy 
– Non-invasive or invasive ventilation if needed 

Haemodynamic Support: 
– Noradrenaline is first-line vasopressor (to support blood pressure) 
– Dobutamine for inotropic support (to support contraction) 
– Careful fluid challenge if volume status unclear 

Definitive Treatment: 
– Urgent revascularization for MI (PCI preferred) 
– Surgical repair for mechanical complications 
– Management of arrhythmias (cardioversion, pacing) – to improve cardiac output 

Mechanical Circulatory Support: 
– Intra-aortic balloon pump 
– Impella 
– VA-ECMO 
 
Medications to Avoid Initially: 
– Beta-blockers 
– ACE inhibitors until stabilized 
– Excessive IV fluids 

Prognosis: 
Mortality remains high (30–50%), but early recognition and prompt intervention improve outcomes. 
 
Key Points: 

– Cold and wet shock suggests cardiogenic shock 
– Early Echocardiography is critical in supporting diagnosis (and guiding therapy)
– Early revascularization, in MI, and support is lifesaving