Shock is something we see a lot of in the ICU. Frequently, aggressive intervention can reverse, or at least, mediate the symptoms and hospital course. There are times though that the response is too advanced to be reversed, and the result, fatal.

  Shock is not a single entity. It is a clinical syndrome that is complex and multi faceted, and manifests itself in various hemodynamic scenarios. The etiologies are multiple but the end result in all situations is compromise of end tissue perfusion. The reduced perfusion can be due to low cardiac output, maldistribution of blood flow, or both. Shock usually presents as hypotension, sometimes profound, decreased renal and cerebral blood flow, and frequently respiratory distress.

  Shock can be grouped into three categories...cardiogenic, hypovolemic, and septic.

  Cardiogenic shock can be secondary to brady or tachy arrhythmias, related to mechanical factors such as aortic or mitral regurgitation, interventricular septal rupture,  a sizable left ventricular aneurysm, left ventricular outflow obstructions like congenital valve stenosis and hypertrophic obstructive myopathy, and left ventricular inflow obstructions such as mitral stenosis. There are also myopathic considerations such as those that impair left ventricular contractility such as acute MI, impairment of right ventricular contractility such as RV infarct, and an impairment of left ventricular relaxation or compliance such as hypertrophic myopathy.