[Hemodynamic surveillance: transesophageal echocardiography or Swan-Ganz catheter?]

Pulmonary artery catheter (PAC) and transoesophageal echocardiography (TOE) are two different windows on haemodynamics. PAC observes mainly right heart and pulmonary circulation; it measures pressures and outputs. Its contribution is essential to the management of situations accompanied by hypervolemia, pulmonary stasis, and severe pulmonary pathology, whereas it has little impact on diagnosis of hypovolemia and ventricular function. TOE offers a dynamic vision of the four heart chambers and their valves; it measures flows, surfaces and volumes. It allows quantification of systolic and diastolic functions for each ventricle. It is particularly adapted to the evaluation of hypovolemia and to the differential diagnosis of intractable hypotension. Its applications in cardiac surgery are numerous. The cost/benefice ratio of each technique is dependent of their indications and of their impact on therapy. Both require specific knowledge and learning time in order to have an major clinical impact.