FIGURE 1.

Illustrative cases of acute severe mitral regurgitation induced by abrupt changes in left ventricular loading conditions and increased adrenergic tone during a T-piece trial. Patients developed severe weaning-induced pulmonary edema and were promptly reconnected to the ventilator to be assessed using transesophageal echocardiography. In the first patient (upper panels) with acute hypertension (192/101 mmHg), a massive functional mitral regurgitation (central jet on color Doppler mapping, upper left panel, arrow) with markedly elevated mitral Doppler velocities (upper left middle panel; E wave maximal velocity: 1 m/s) was evidenced. Nitrates were administered intravenously as sequential boli to rapidly normalize blood pressure (129/72 mmHg). This allowed to dramatically reduce the volume of mitral regurgitation as reflected by a marked decrease of color Doppler jet area (upper right middle panel, arrow) as well as mitral Doppler velocities (upper right panel; maximal E wave velocity: 0.5 m/s). In the second patient (lower panels), echocardiography depicted a dynamic obstruction of left ventricular outflow tract by an anterior motion of the mitral valve (lower left panel, arrow). This resulted in high end-systolic pressure gradient and associated massive eccentric mitral regurgitation (lower middle left panel, arrow). Beta-blockers were successfully used: both the dynamic left ventricular outflow tract obstruction and mitral regurgitation fully resolved as depicted by two-dimensional imaging (lower middle right panel; end-systole) and color Doppler mapping which only disclosed a residual trivial central mitral regurgitation (lower right panel, arrow). Abbreviations: LA, left atrium; LV, left ventricle; RV, right ventricle; MR: mitral regurgitation.