The cyclic changes and structure of the base of the aortic valve
| Autor: | Mano J. Thubrikar, L.Paul Bosher, Stanton P. Nolan, J. David Deck |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Aortic valve
medicine.medical_specialty Time Factors Systole Diastole Perimeter Dogs Internal medicine medicine Animals Left ventricular geometry cardiovascular diseases Base (exponentiation) Isovolumetric contraction Aorta business.industry Heart Trigonal crystal system Anatomy Elastic Tissue Myocardial Contraction medicine.anatomical_structure Aortic Valve Heart Valve Prosthesis cardiovascular system Cardiology Collagen Cardiology and Cardiovascular Medicine business |
| Zdroj: | American heart journal. 99(2) |
| ISSN: | 0002-8703 |
| Popis: | The structure and behavior of the base of the aortic valve in the dogs were investigated. The structure was studied under light microscopy to determine the distribution of collagenous, elastic, and myocardial elements. The dimensional changes were studied in vivo, by attaching radio-paque markers to the base and observing their movement by x-ray studies. The base is partly composed of ventricular myocardium. Two of the three trigonal regions consist of myocardium, and the right and left coronary leaflets and sinuses are encompassed by ventricular myocardium. The collagenous tissue that lies internal to the myocardium is neither dense nor thick and does not form a complete ring. The cyclic dimensional changes in the base are similar to the cyclic changes in left ventricular geometry and volume. The base perimeter is maximal in early systole coincident with the “rounding” of the ventricular cavity during isovolumetric contraction. The base perimeter decreases during systole when the ventricular volume decreases during systolic ejection. The base perimeter increases during diastole as the ventricular volume increases due to diastolic filling. The amount of cyclic change in the base perimeter at normal systemic pressure was different for different dogs. In four dogs the amount of change varied from 5% to 28% over a wide range of systemic pressures. The importance of the behavior of the base in normal valvular function is discussed. It is speculated that the mismatch between the nonexpansile sewing ring of an aortic bioprosthesis and the normally expansile base of the valve could cause occasional periprosthetic leaks. |
| Databáze: | OpenAIRE |
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