Automated method for calculation of a load-independent index of isovolumic pressure decay from left ventricular
Leonid Shmuylovich1, Sándor J Kovacs
1Cardiovascular Biophysics Laboratory, Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, Washington University Department of Physics, College of Arts and Sciences. 660 Euclid Avenue Box 8086, Saint Louis, MO 63110, USA.
Insights
Diastolic heart failure diagnosis can be improved using a new load-independent index of isovolumic pressure decay (LIIIVPD). This method analyzes left-ventricular pressure contours during catheterization for better diastolic function assessment.
Area of Science:
- Cardiology
- Biomedical Engineering
- Physiology
Background:
- Diastolic heart failure (DHF) affects over 50% of hospitalized patients.
- Diastolic dysfunction is a key pathophysiologic factor in heart failure.
- Current left-ventricular pressure (LVP) catheterization methods for diastolic function (DF) evaluation do not fully utilize pressure contour data.
Purpose of the Study:
- To detail methods and provide guidelines for real-time computation of a novel load-independent index of isovolumic pressure decay (LIIIVPD).
- To enhance the evaluation of diastolic function using pressure contour analysis during cardiac catheterization.
Main Methods:
- Utilized a previously established kinematic model of isovolumic pressure decay (IVPD).
- Incorporated stiffness and resistance parameters from the IVPD kinematic model.
- Derived the LIIIVPD from the IVPD kinematic model parameters.
- Applied methods to pressure contours recorded during cardiac catheterization.
Main Results:
- A novel load-independent index of isovolumic pressure decay (LIIIVPD) was derived.
- The LIIIVPD computation is feasible in real-time from cardiac catheterization pressure contours.
- The kinematic model accurately fits the recorded pressure decay contour, accounting for restoring force and resistance.
Conclusions:
- The LIIIVPD offers a new, load-independent metric for assessing diastolic function.
- Real-time computation of LIIIVPD from pressure data can improve DHF diagnosis and management.
- This approach provides mechanistic insight into isovolumic pressure decay physiology.
Abstract:
Diastolic heart failure (DHF) is present in over 50% of hospitalized heart failure patients, and diastolic dysfunction is known to play a critical pathophysiologic role. Measurement of left-ventricular pressure (LVP) via catheterization is the gold standard for diastolic function (DF) evaluation, but current methods fail to fully capitalize on the complete information content of the pressure contour. We have previously demonstrated that a kinematic model of isovolumic pressure decay (IVPD), which accounts for restoring force (stiffness) and resistance (viscoelasticity/relaxation), provides mechanistic insight into IVPD physiology and provides an accurate fit to the recorded contour. Recently we derived a novel load-independent index of isovolumic pressure decay (LIIIVPD) involving IVPD kinematic model stiffness and resistance parameters. In this work we detail methods and provide guidelines by which LIIIVPD computation may be achieved in real-time from the pressure contour recorded during cardiac catheterization.
