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Device based left ventricular shape change: validation of conductance technology in shape changed hearts
Masami Takagaki1, Patrick M McCarthy, Raymond Dessoffy
1Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, OH 44195, USA.
ASAIO Journal (American Society for Artificial Internal Organs : 1992)
|June 13, 2002
Summary
Conductance technology accurately measures left ventricular (LV) volumes in shape-altered hearts. This validation supports its use for evaluating pressure-volume loops in hearts modified by devices like the Myosplint.
Area of Science:
- Cardiovascular Physiology
- Medical Device Technology
- Echocardiography
Background:
- Device-based left ventricular (LV) shape alteration, using Myosplint, has shown promise in improving LV systolic function.
- Accurate assessment of cardiac mechanics, particularly the pressure-volume relationship, is crucial for understanding the effects of such interventions.
- Validating measurement techniques in modified cardiac geometries is essential for reliable physiological evaluation.
Purpose of the Study:
- To validate the use of conductance technology for assessing left ventricular (LV) volumes in hearts with altered shapes.
- To determine if conductance catheter measurements correlate with established volume assessment methods before and after cardiac shape modification.
- To establish the reliability of conductance technology for evaluating pressure-volume loops in shape-changed hearts.
Main Methods:
- Ex vivo study using excised ovine hearts (n=11) and an in vivo study using a canine heart failure model (n=11).
- Implantation of three Myosplints to induce left ventricular (LV) shape changes.
- Comparison of LV volumes measured by conductance catheter against saline volumes (ex vivo) and three-dimensional echocardiography (3-D echo) (in vivo) before and after shape alteration.
Main Results:
- Conductance volumes showed a strong linear correlation with saline volumes in the ex vivo study (r2 = 0.961+/-0.046; p < 0.0001).
- Conductance volumes were also linearly correlated with 3-D echo volumes in the in vivo study (r2 = 0.757+/-0.220; p < 0.0001).
- These correlations were maintained even after left ventricular (LV) shape modification, confirming the technology's applicability.
Conclusions:
- Conductance technology provides reliable measurements of left ventricular (LV) volumes in shape-altered hearts.
- This validation supports the use of conductance technology for evaluating pressure-volume loops in hearts modified by interventions like the Myosplint.
- Accurate calibration of conductance volume measurements is key to its effective application in these complex scenarios.