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Endocardial excision versus encircling endocardial ventriculotomy. A comparison of effects on ventricular structure
Insights
Endocardial excision and encircling endocardial ventriculotomy procedures showed minimal long-term impact on canine left ventricular structure and function, with scarring localized to the intervention site.
Area of Science:
- Cardiovascular Surgery
- Cardiac Physiology
- Myocardial Histopathology
Background:
- Endocardial excision and encircling endocardial ventriculotomy are utilized in patients with severe coronary artery disease and impaired ventricular function.
- Long-term effects of these interventions on left ventricular structure and function remain largely undetermined.
Purpose of the Study:
- To evaluate the long-term structural and functional consequences of endocardial excision and encircling endocardial ventriculotomy on the left ventricle.
Main Methods:
- The study involved three groups of healthy dogs: control (ventriculotomy alone), endocardial excision, and encircling endocardial ventriculotomy (n=5 per group).
- Hemodynamic parameters including cardiac output, left ventricular volume indices, myocardial performance, systolic elastance, and diastolic pressure-volume relationships were assessed six weeks post-procedure.
- Histopathological examination of myocardial tissue was conducted.
Main Results:
- Left atrial pressures were elevated at similar end-diastolic volumes in the endocardial excision group (p<0.05).
- Myocardial performance and systolic elastance were comparable across all three groups.
- Histological analysis revealed scarring confined to the intervention area in both endocardial excision and encircling endocardial ventriculotomy groups, with no significant changes elsewhere in the myocardium.
Conclusions:
- Both endocardial excision and encircling endocardial ventriculotomy demonstrate minimal long-term effects on overall left ventricular structure and function in healthy canine hearts.
- Scarring is localized to the operative site, suggesting potential for future therapeutic applications with careful consideration of patient selection.
Abstract:
Although endocardial excision and encircling endocardial ventriculotomy are being performed in patients with extensive triple-vessel disease and compromised ventricular function, long-term effects of the operative intervention on structure and function of the left ventricle have not been determined. These procedures were performed in healthy dogs in three groups: control (ventriculotomy alone), endocardial excision, and encircling endocardial ventriculotomy (five dogs per group). Six weeks later, through a left thoracotomy, an arterial line, left atrial line, and Swan-Ganz catheter were inserted. Cardiac output measurements permitted calculation of left ventricular stroke work index, and gated nuclear ventriculograms permitted calculation of left ventricular volume indices. Myocardial performance (stroke work index/end-diastolic volume index relation), systolic elastance (systolic blood pressure/end-systolic volume index relation) and diastolic pressure-volume relationship (left atrial pressure/end-diastolic volume index relation) were determined from volume loading studies. In the endocardial excision group, the left atrial pressures were increased at similar end-diastolic volumes (p less than 0.05 by performance and systolic elastance were similar in the three groups. On completion of hemodynamic studies, the hearts were excised. Gross and light microscopic examination showed that the inner layer of myocardium was scarred in the area of intervention after both endocardial excision and encircling endocardial ventriculotomy. In neither group was there significant morphologic change elsewhere in the myocardium. Both endocardial excision and encircling endocardial ventriculotomy have little effect on long-term structure and function when performed in healthy canine hearts.