Key Points
- This research aims to uncover the mechanics of left ventricular filling during early diastole and the associated pressure gradients.
- Recorded simultaneous LV apical and outflow tract pressures in patients with coronary artery disease.
- Used color M-mode Doppler echocardiography to analyze intraventricular flow velocities.
- Conducted experiments in anesthetized dogs measuring left atrial pressure and LV volume using sonomicrometry.
- Observed an apex-outflow tract pressure gradient of 3.5 mmHg (mean) correlated with peak flow velocity (r = 0.75, P < 0.05).
- Pressure gradient decreased from 3.1 mmHg to 1.7 mmHg (P < 0.05) during caval constriction, increased to 4.2 mmHg (P < 0.001) with volume loading.
- Gradient strongly correlated with peak early transmitral flow (r = 0.95) and stroke volume (r = 0.97).
Structured PICO
PPopulation8 coronary artery disease patients with normal LV ejection fraction and 5 anesthetized dogs
IInterventionSimultaneous recording of LV apical and outflow tract pressures and intraventricular flow velocities by color M-mode Doppler echocardiography (and sonomicrometry in dogs)
OOutcomeApex-outflow tract pressure gradient and its correlation with peak early apex-to-outflow tract flow velocitysurrogate
The arrival of the early LV filling wave at the apex is associated with a substantial pressure gradient between the apex and outflow tract, which is sensitive to preload changes.