Key Points
- To quantify the isolated systolic mechanical effects of transient left ventricular (LV) pressure reductions on right ventricular (RV) function without altering diastolic parameters.
- Studied eight open-chest, open-pericardium anesthetized pigs (45 kg; N=8).
- Rapidly withdrew blood from the LV apex immediately after diastole during a single cardiac cycle to reduce LV midsystolic pressure by up to 75 mm Hg without changing diastolic volume or pressure.
- Calculated instantaneous left-to-right systolic pressure gain [G(t)] and mean systolic pressure gain as ratios of RV-to-LV pressure changes.
- A mean systolic LV pressure reduction of 62.6 ± 12.3% led to significant RV functional declines, including a 13.6 ± 6.4% decrease in mean RV systolic pressure, a 17.9 ± 10.4% reduction in RV stroke volume, and a 27.0 ± 11.3% reduction in RV stroke work.
- Instantaneous systolic pressure gain G(t) varied dynamically during systole, reaching a minimum of 0.042 ± 0.014 mm Hg/mm Hg at 0.70 normalized systolic duration and a maximum of 0.079 ± 0.029 mm Hg/mm Hg at the end of RV ejection.
Structured PICO
PPopulation8 open-chest, open-pericardium anesthetized pigs (45 kg)
IInterventionRapid withdrawal of blood from the LV immediately after diastole via an apex cannula during a single cardiac cycle
OOutcomeChanges in RV flow and pressure development (instantaneous left-to-right systolic pressure gain and mean LV-to-RV systolic pressure gain)surrogate
Transient reductions in left ventricular pressure during systole directly reduce right ventricular systolic pressure, stroke volume, and stroke work, demonstrating pure systolic ventricular interaction.