Dobutamine-Mediated Dynamic Left Ventricular Outflow Tract Obstruction Associated with Hypovolemic Shock: Value of Echocardiography and Importance of Early Recognition and Appropriate Volume Substitution

ABSTRACT

A 67-years old woman with no cardiac past history was presented postoperatively after elective surgery for pertrochanteric femur fracture with dyspnea, hypotension, pulmonary congestion, oliguria and tachycardia. Cardiogenic shock was suspected and she was transferred to the Coronary Care Unit (CCU) and treated as such with diuretic and an inotropic agent. No improvement occurred and her condition deteriorated with a new systolic parasternal cardiac murmur. Dynamic left ventricular outflow tract obstruction (DLVOTO) was considered and proven by echocardiographic studies. The inotropic therapy was discontinued and fluid expansion was given. Rapid uneventful recovery occurred. Myocardial infarction was biochemically excluded. Follow-up echocardiography demonstrated mild left ventricular hypertrophy (LVH) without evidence of hypertrophic cardiomyopathy.

Echocardiographic evaluation of critically ill patients deteriorating after the initiation of inotropic treatment for hypotension, especially when a new cardiac murmur is heard, is of pivotal importance since dobutamine-induced DLVOTO, associated with hypovolemia, is conversely treated with discontinuation of inotropic drugs and appropriate volume expansion.

Keywords:

Hypovolemic shock, inotropic agents, dynamic left ventricular outflow tract obstruction, echocardiography.