Development of a multifrequency conductance catheter-based system to determine LV function in mice

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Transgenic Mouse Models

Background:

• Assessing cardiovascular phenotype in transgenic mice using pressure-volume analysis is challenging.
• Existing conductance measurement methods for left ventricular (LV) volume in mice are confounded by myocardial signals.

Purpose of the Study:

• To develop a multifrequency conductance system to differentiate and correct for myocardial signal interference in LV volume measurements.
• To enable accurate cardiovascular phenotyping in transgenic mice.

Main Methods:

• A novel mouse conductance system operating at multiple simultaneous frequencies was developed.
• The system leverages differential conductivity of blood and myocardium at varying frequencies.
• LV blood volume was empirically solved using data from two frequencies and myocardial resistivity.

Main Results:

• Higher excitation frequencies resulted in greater detected end-diastolic and end-systolic conductance.
• A smaller difference in conductance was observed at higher frequencies, indicating reduced myocardial influence.
• An accurate estimate of LV blood volume was extracted from the raw conductance signal.

Conclusions:

• A multifrequency catheter-based system can effectively determine LV function by correcting for myocardial signal.
• This technology provides a valuable tool for assessing cardiovascular phenotype in transgenic mice.
• Improved cardiovascular phenotyping in transgenic models will accelerate research into gene function and disease.