Effects of intraaortic balloon counterpulsation on translesional coronary hemodynamics.

The intraaortic balloon pump (IABP) provides counterpulsation by displacing a 40-50 cc blood volume during diastole augmenting diastolic pressure. The rapid deflation of the balloon timed to the initiation of systole reduces the afterload of ventricular ejection and thus peak systolic pressure. As a direct result, IABP increases mean arterial pressure (MAP) and peak diastolic pressure while reducing systolic pressure and myocardial work. IABP increases coronary flow velocity in non-obstructed vessels, but does not increase flow across a severe obstruction as shown by intracoronary Doppler flow studies (Kern et al., Circulation, 1993;87:500-511 and Kern et al., Circulation 1991;84:II-485). There are few studies using pressure sensor guidewires to confirm these responses. We present a case illustrating the translesional hemodynamics using an angioplasty sensor pressure wire across a severe stenosis and the unique influence of the IABP.