Cardiogenic shock is a medical emergency that needs to be treated before irreversible damage is caused to the vital organs such as the brain, lungs and kidneys. Diagnosing cardiogenic shock involves checking the patient for signs and symptoms of shock as well as performing tests to find out what is causing the shock.
An outline of how cardiogenic shock is diagnosed is given below:
- The patient’s symptoms and medical history are checked including the details of any myocardial infarction or heart attack. Other causes of shock that are checked for include blood loss, hypovolemia (low blood volume), sepsis (blood infection), pulmonary embolism, tamponade, aortic dissection, and pre-existing valvular disease.
- On clinical examination, the patient is often an ashen or bluish colour, a condition called cyanosis caused by low oxygenation of tissues near the skin surface. The pulse may also be rapid, irregular or faint and the breathing fast and shallow. The jugular veins in the neck may be distended and chest examination by stethoscope may reveal a systolic murmur or ventricular septal defect.
- Electrocardiography is performed to detect heart function and rhythm problems.
- A chest X-ray may be performed to check for cardiomegaly (enlarged heart size), pulmonary venous congestion (increased blood vessel visibility within the lungs), or both.
- Arterial blood gas is measured to assess the blood levels of oxygen.
- Blood levels of electrolytes sodium, potassium and calcium are measured.
- Routine blood counts may be checked.
- Cardiac enzymes are measured as indicators of heart attack. B-type natriuretic protein (BNP) can help diagnose early heart disease as well as congenital heart disease and heart failure in children.
- Echocardiography is one of the best diagnostic methods for confirming the diagnosis of cardiogenic shock and ruling out causes of the condition. Echocardiography provides information about the general function of the heart and can help detect disorders such as papillary muscle rupture, acute mitral regurgitation, acute free-wall rupture, ventricular septal defect, and cardiac tamponade.
- A pulmonary artery catheter called the Swan-ganz catheter can be used to provide useful information on hemodynamics to assist in diagnosis.
Reviewed by Sally Robertson, BSc