Does the clover technique fit the annular physiology?
نویسندگان
چکیده
Wehave read the studyof Lapennaet al.with great interest [1]. We think that these techniques are not compatible with the co-aptation physiology. Our concerns are as follows. If we apply the clover technique to a normal (without regurgitation) tricuspid valve, would this create an insufficiency? Yes, it would. This is because the free edges of the leaflets could not adapt to changes in filling and stroke volumes and ejection fractions after the clover technique. In the changing volume system, do not the leaflet edges change their locations at the annular plane? What kind of strategies did the authors use to prevent this? The tricuspid annulus shrinks from diastole to systole, thus decreasing its area and contributing to co-aptation. Flexible rings change the annular shape and decrease the annular area. (Can the flexible rings you used decrease their circumference?) These changes occur through bulging internally or externally and inferiorly or superiorly. Would not these changes disrupt the co-aptation mechanism? In the de-Vega annuloplasty technique, we could not be sure of co-aptation. This is because we leave the initiative to annular movement and regurgitating volume regarding what part of the annulus would shrink. In rupture of chordae, why did the authors not think to treat this situation without formation of a new chordae?
منابع مشابه
Dynamic response determination of viscoelastic annular plates using FSDT – perturbation approach
In this paper, the transient response of a viscoelastic annular plate which has time-dependent properties is determined mathematically under dynamic transverse load. The axisymmetric conditions are considered in the problem. The viscoelastic properties obey the standard linear solid model in shear and the bulk behavior in elastic. The equations of motion are extracted using Hamilton’s principle...
متن کاملBending Solution for Simply Supported Annular Plates Using the Indirect Trefftz Boundary Method
This paper presents the bending analysis of annular plates by the indirect Trefftz boundary approach. The formulation for thin and thick plates is based on the Kirchhoff plate theory and the Reissner plate theory. The governing equations are therefore a fourth-order boundary value problem and a sixth-order boundary value problem, respectively. The Trefftz method employs the complete set of solu...
متن کاملEvaluation of salinity tolerance of different clover species at germination and seedling stages
In order to study the effects of salinity stress on growth indices of three clover species including, Trifolium resupinatum, T. alexandrinum, and T. incarnatum, an experiment was conducted as factorial based on a completely randomized design arrangement with three replications. Factors included seven levels of salinity stress (0, 41, 82, 123, 164, 205, and 246 mM) and three clover species. Diff...
متن کاملThermo-Mechanical Vibration Analysis of FG Circular and Annular Nanoplate Based on the Visco-Pasternak Foundation
In this study, the vibration behavior of functional graded (FG) circular and annular nanoplate embedded in a Visco-Pasternak foundation and coupled with temperature change is studied. The effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of FG circular and annular nanoplate. To obtain the vibration frequencies of the FG circular and annular nanopla...
متن کاملPhytoremediation ability and oxidative enzymes activity of Persian clover (Trifolium resupinatum L.) in the presence of nickel. Mojtaba Yousefi Rad*, Homayun Ghasemi
Phytoremediation is a relatively new method in agricultural science for removing soil contaminants to some extent through cultivating some plants with the least cost. This research was conducted to examine the role of nickel as a heavy metal in catalase and peroxidase activities and also to study uptake and transfer ability of nickel in the organs of Persian clover. Experiment was done as rando...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery
دوره 39 2 شماره
صفحات -
تاریخ انتشار 2011