An Assessment of the relationship between dicrotic notch timing and cardiac preload

Area of Science:

• Cardiovascular physiology
• Biomedical engineering
• Medical device development

Background:

• Accurate assessment of cardiac preload is crucial for managing cardiovascular disease (CVD).
• Left ventricular end-diastolic volume (LVEDV) is a key indicator of preload but is challenging to measure clinically.
• Existing methods for measuring cardiac volumes are often invasive or limited in accessibility.

Purpose of the Study:

• To develop and validate a novel 3-parameter model for estimating LVEDV from the aortic pressure waveform.
• To provide a non-invasive method for assessing cardiac preload in CVD patients.
• To correlate dicrotic notch location in the aortic waveform with LVEDV.

Main Methods:

• Utilized data from porcine experiments (N=5 pietrain pigs, 20-28kg).
• Developed a 3-parameter mathematical model linking dicrotic notch position to LVEDV.
• Validated the model by comparing modeled LVEDV with experimentally observed LVEDV.

Main Results:

• The model demonstrated a median difference of 5.4% between observed and modeled LVEDV (100% range: 3.0%-15.1%).
• A median correlation coefficient of ρ = 0.77 was achieved (range: 0.58-0.95).
• Model parameters showed variability influenced by individual pigs and contractile states.

Conclusions:

• The developed model offers a promising approach for estimating cardiac preload non-invasively.
• The aortic pressure waveform, specifically the dicrotic notch, can serve as a surrogate for LVEDV estimation.
• This method has potential clinical applications in improving CVD patient management and outcomes.