Direct left ventricle to great cardiac vein retroperfusion: a novel alternative to myocardial revascularization
Geng-Hua Yi1, Kun-Lun He, Nicholas C Dang
1Department of Medicine, Division of Circulatory Physiology, Columbia University,College of Physicians and Surgeons, New York, New York, USA.
Insights
A novel left ventricle-to-great cardiac vein (LV-GCV) conduit effectively restored heart muscle function after acute ischemia. Eliminating backward flow further enhanced this myocardial retroperfusion therapy for diffuse coronary disease.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Ischemic Heart Disease Research
Background:
- Growing prevalence of diffuse coronary artery disease necessitates innovative myocardial perfusion strategies.
- Traditional revascularization methods are often insufficient for widespread coronary blockages.
- Investigating alternative perfusion techniques is crucial for managing ischemic myocardium.
Purpose of the Study:
- To assess the feasibility of myocardial retroperfusion using a direct left ventricle-to-great cardiac vein (LV-GCV) conduit.
- To evaluate the efficacy of this conduit in supporting regional contractility in ischemic heart conditions.
- To determine the impact of eliminating diastolic backflow on the effectiveness of the LV-GCV circuit.
Main Methods:
- An extracorporeal circuit was established to create LV-GCV flow in a canine model.
- Measurements included left ventricle pressure, aortic pressure, and regional myocardial segment length.
- Regional function was quantified using pressure-segment length loop area divided by end-diastolic segment length (PSLA/EDSL).
- An in-line flow regulator was employed to prevent backward diastolic flow.
Main Results:
- Left anterior descending coronary artery (LAD) ligation significantly reduced regional function (PSLA/EDSL).
- LV-GCV retroperfusion restored regional function to approximately 39% of baseline levels.
- Eliminating backward diastolic flow further improved regional function to approximately 47% of baseline.
- Significant systolic flow and reduced diastolic backflow were observed with the LV-GCV circuit.
Conclusions:
- A LV-GCV circuit demonstrates significant potential in restoring regional function to acutely ischemic myocardium.
- An inline valve effectively improving regional function by eliminating backward diastolic flow enhances the therapy.
- This myocardial retroperfusion approach offers a promising therapeutic option for diffuse coronary disease unsuitable for conventional revascularization.
Background:
As the number of patients with diffuse coronary artery disease continues to grow, there is renewed interest in alternative methods of perfusing the ischemic myocardium. We tested the feasibility of myocardial retroperfusion via a direct left ventricle-to-great cardiac vein (LV-GCV) conduit to support regional contractility in this setting.
Methods:
LV-GCV flow was established using an extracorporeal circuit in 5 dogs. Left ventricle (LV) pressure, aortic pressure, regional myocardial segment length, and circuit blood flow were measured prior to left anterior descending coronary artery (LAD) ligation, following LAD ligation, and after LV-GCV circuit placement. To eliminate backward flow during diastole, an in-line flow regulator was placed. Regional myocardial function was quantified by pressure-segment length loop area divided by end-diastolic segment length (PSLA/EDSL).
Results:
LAD ligation reduced PSLA/EDSL from 10.0 +/- 1.2 mm Hg mm to 1.6 +/- 0.3 mm Hg mm (P < .05). With LV-GCV retroperfusion, mean peak systolic flow was +152 +/- 14 mL/min, mean peak diastolic flow was -39 +/- 11 mL/min, and net mean flow was +36 +/- 13 mL/min. Regional function recovered to approximately 39% of baseline (3.9 +/- 0.4 mm Hg mm, P < .05). Upon elimination of backflow, mean flow increased to +41 +/- 12 mL/min and regional function recovered even further to approximately 47% of baseline (4.6 +/- 0.7 mm Hg mm, P < .05).
Conclusions:
A LV-GCV circuit can significantly restore regional function to the acutely ischemic myocardium. An inline valve that eliminates backward diastolic flow improves regional function even further. This approach may provide an effective therapy for diffuse coronary disease not amenable to traditional revascularization strategies.
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