Pressure-Volume Relationships in Right Ventricle

Abstract

Contour changes of the pressure curve of the isovolumic right ventricle were analyzed as its volume increased and during spontaneous tachycardia and l-epinephrine exhibition. Evidence of an early diastolic dip going below ambient pressure was observed when spontaneous tachycardia developed. Evidence was clear that the impedance to filling during the phase of active relaxation lessened in the right ventricle when spontaneous tachycardia occurred and l-epinephrine was exhibited, and to a lesser extent when the ventricle became more dynamic. However, there was no evidence of any shift in the right ventricular pressure/volume relationship at the end of diastole during spontaneous tachycardia or l-epinephrine action. On the other hand, the pressure/volume relationship at the end of systole was altered under these two conditions, in that the pressure for any volume was increased. The curves of the pressure/volume relationship of the right ventricle at the end of systole and at the end of diastole were found to be similar in contour to those of the left ventricle except for the magnitude of change.