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Effect of balloon aortic valvuloplasty on the dynamics of left ventricular ejection
J J Ferguson1, H S Bush, E P Riuli
1Cardiology Section, Texas Heart Institute, St. Luke's Episcopal Hospital, Houston 77225.
Insights
Balloon aortic valvuloplasty improves left ventricular ejection dynamics by increasing ejection rate and reducing ejection time, particularly in late systole. This procedure enhances blood flow by improving aortic leaflet mobility.
Area of Science:
- Cardiovascular Physiology
- Interventional Cardiology
Background:
- Aortic stenosis obstructs blood flow, increasing left ventricular pressure and affecting ejection dynamics.
- Balloon aortic valvuloplasty is a less invasive treatment option for aortic stenosis.
Purpose of the Study:
- To assess the impact of balloon aortic valvuloplasty on left ventricular ejection dynamics.
- To analyze changes in accelerative and decelerative phases of ejection post-procedure.
Main Methods:
- Simultaneous left ventricular and aortic pressure measurements using micromanometer catheters in nine patients.
- Analysis of ejection times, stroke volumes, ejection rates, and pressure gradients before and after valvuloplasty.
- Division of ejection into accelerative and decelerative components for detailed analysis.
Main Results:
- Significant decrease in overall ejection time and mean/peak pressure gradients post-valvuloplasty.
- Significant increase in overall ejection rate, with improvements in both accelerative and decelerative components.
- Reduced time for ejection of the final 25% of stroke volume and gradient, indicating improved late systolic emptying.
Conclusions:
- Balloon aortic valvuloplasty positively alters left ventricular ejection dynamics, primarily affecting late systole.
- The procedure enhances forward blood flow by reducing resistance during the decelerative phase of ejection.
- Improved leaflet mobility following valvuloplasty contributes to more efficient ventricular emptying.
Abstract:
To evaluate the effect of balloon aortic valvuloplasty on left ventricular ejection dynamics, simultaneous left ventricular and aortic pressures were obtained by use of a micromanometer catheter in nine patients before and after the procedure. Ejection times, stroke volumes (thermodilution), ejection rates, and pressure gradients were measured. For each parameter, ejection was then divided into two components: accelerative (onset systole to peak gradient) and decelerative (peak gradient to end systole). After valvuloplasty, there was 1) a decrease in overall ejection time and in mean and peak pressure gradients; 2) an increase in overall ejection rate; 3) no change in stroke volume or heart rate; 4) an increase in both accelerative and decelerative ejection rates and a decrease in the decelerative ejection time (expressed as a percentage of the R-R interval); and 5) a decrease in the time for the ejection of the final 25% of stroke volume (P less than 0.01) and time occupied by the final 25% of the gradient. Immediately following balloon aortic valvuloplasty, there is a decrease in ejection time and in increase in ejection rate. Balloon aortic valvuloplasty has a significant effect on the dynamics of left ventricle ejection, with changes primarily expressed in late systole. By improving the mobility of calcified leaflets, balloon aortic valvuloplasty may reduce the forces opposing forward blood movement during the decelerative phase of ejection.