Effect of the Valsalva maneuver on cardiac-coronary interaction assessed by wave intensity analysis.

The Valsalva maneuver (VM) provokes strong changes in the cardiovascular system and is therefore well suited to study the cardiac-coronary interaction in humans. In 12 patients undergoing catheterization we simultaneously recorded aortic pressure, left ventricular pressure, and intracoronary pressure (Pd) and flow velocity (U) while the patients were performing a VM. Coronary wave intensity was calculated (dI = dP*dU) at characteristic phases of the VM and related to hemodynamic parameters of left ventricular (LV) performance. During the strain, blood pressure increased transiently followed by a significant decrease (p < 0.001) at maximum strain. Changes in mean LV pressure followed the same pattern, while LV end-diastolic pressure increased to almost 40 mmHg (p < 0.001), with a 30% reduction in LV dP/dt (p < 0.005). Coronary flow velocity remained fairly constant throughout the VM. All hemodynamic values returned to the baseline at conclusion of the maneuver. Coronary wave intensity was strongly reduced during the strain and was related to the depression in LV performance. Wave intensity analysis clearly revealed the inherent features of cardiac-coronary interaction.