Right ventricular involvement in myocardial infarction and cardiogenic shock.

CONTEXT

Right ventricular involvement in acute myocardial infarction and cardiogenic shock has received little attention by clinicians and researchers, although its pathophysiology, clinical presentation, and natural history are distinctly different from those of left ventricular infarction and associated cardiogenic shock. Right ventricular shock has important therapeutic implications for the management of patients, which need to be recognised.

STARTING POINT

Investigators at the SHOCK Registry (Alice Jacobs and colleagues, J Am Coll Cardiol 2003; 341: 1273-79) evaluated 49 patients with cardiogenic shock predominantly due to right ventricular infarction and compared them with 884 patients with cardiogenic shock and predominantly left ventricular failure. Perhaps surprisingly, these investigators found that the in-hospital mortality of patients with right ventricular shock was not significantly lower than that of patients with left ventricular shock (53% vs 61%, p=0.296), despite the fact that patients with right ventricular shock were younger, with a lower prevalence of previous infarctions, fewer anterior infarct locations, and less multivessel disease. There was a shorter median time between index infarction and diagnosis of shock in patients with right ventricular shock. In multivariate analysis, right ventricular shock was not an independent predictor of lower in-hospital mortality. WHERE NEXT? The unexpectedly high mortality of patients with cardiogenic shock due to predominantly right ventricular infarction challenges the general notion that right ventricular involvement in myocardial infarction has only little relevance for patient's outcome. Therefore, more attention should be given to the detection of right ventricular involvement in acute myocardial infarction and particularly in cardiogenic shock. If right ventricular shock is diagnosed, urgent reperfusion of the infarct related artery and appropriate circulatory support are required.