Dimensional ratios of normal mitral valve structures: a tool for determining the degree of geometric distortion in individual patients.

Background And Aim Of The Study: One objective of mitral valve repair is to restore the distorted mitral apparatus geometry to its normal dimensions specific for each patient. Because all dimensions of the normal aortic and mitral valves should be related, it was hypothesized that, in the presence of a normal aortic annulus, it would be possible to determine the dimensions of the structures needed for mitral valve repair.

Methods: In seven sheep, sonometric ultrasound crystals were implanted at the left and right trigones (T1, T2), lateral annulus (P1, P2), and the tips of the anterior and posterior papillary muscles (Ml, M2).

Coronary flow obstruction in percutaneous aortic valve replacement. An in vitro study.

Objective: Coronary flow obstruction is a serious complication reported in percutaneous aortic valve replacement. In an in vitro study of porcine hearts, the effects of valved stent implantation on coronary artery flow were studied with the native valve's leaflets intact and excised.

Methods: The right and left main coronary arteries of porcine hearts were dissected 20mm distal to the aortic root and directed into lengths of latex tubing leading to collection flasks.

The papillary muscles as shock absorbers of the mitral valve complex. An experimental study.

Objective: Although it is known that the papillary muscles ensure the continuity between the left ventricle (LV) and the mitral apparatus, their precise mechanism needs further study. We hypothesize that the papillary muscles function as shock absorbers to maintain a constant distance between their tips and the mitral annulus during the entire cardiac cycle.

Materials And Methods: Sonomicrometry crystals were implanted in five sheep in the mitral annulus at the trigones (T1 and T2), mid anterior annulus (AA) mid posterior annulus (PA), base of the posterior lateral scallops (P1 and P2), tips of papillary muscles (M1 and M2), and LV apex.

Sutureless stented aortic valve implantation under direct vision: lessons from a negative experience in sheep.

Background And Aim Of The Study: Percutaneous aortic valve replacement has been proposed as a valid alternative to surgery in selected cases; however, it still has many problems. As a less radical preliminary step, we implanted a balloon-expandable stented aortic valve under direct vision in sheep.

Methods: Under cardiopulmonary bypass (CPB) and through a transverse aortotomy, an aortic valve mounted in a long tubular balloon-expandable stent was implanted in six acute sheep.

An experimental method for the percutaneous induction of a posterolateral infarct and functional ischemic mitral regurgitation.

Background And Aim Of The Study: Appropriate experimental models are needed to study the mechanisms underlying left ventricular (LV) remodeling and functional ischemic mitral regurgitation (IMR). Herein is described an original percutaneous method for inducing a well-defined posterolateral infarct and significant IMR.

Methods: Under videofluoroscopic guidance, the second (OM2) and third (OM3) obtuse marginal branches of the circumflex artery of six sheep were selectively and sequentially injected with 100% ethyl alcohol.