Doppler echocardiography in critically ill cardiac patients.

E-D is a powerful technique that can provide invaluable information in the acutely ill cardiac patient. It can help in the early diagnosis of conditions causing acute chest pain such as AMI and aortic dissection. E-D can help diagnose the causes of underlying hemodynamic instability such as hypotension and pulmonary edema, and it can help determine the initial management strategy. In this regard, E-D can replace Swan-Ganz catheterization in most patients. In patients with AMI who may appear to be hemodynamically stable, it can provide information regarding the following: size of risk area; status of the regions of the myocardium remote from the infarcted zone; effect of reperfusion therapy on regional myocardial function; presence or absence of nonsurgical complications such as ischemic mitral regurgitation, LV thrombus, or aneurysm; and patients at risk for immediate or late cardiac events. It is likely that as the newer generation of cardiologists becomes adequately trained in E-D, this technique will find routine use in every critical care unit.