Regional left ventricular epicardial deformation in the passive dog heart.

摘要: Epicardial wall motion was measured on the left ventricular free in six isolated potassium-arrested dog hearts using a biplane video technique. Significant regional variations epicardial deformations were recorded during static filling. stretches varied linearly with cavity volume, sometimes exceeding 20% at physiological end-diastolic pressures. The maximum component of stretch and derived thinning increased substantially from base to apex both anterior posterior walls ventricle. In five hearts, direction greatest moderate high filling pressures coincided closely local fiber direction, suggesting that left-handed helices preferentially passive maximize lengths. rotation always counterclockwise, consistent reduction pitch helix These results suggest that, surface, myocardium is anisotropic respect direction. We resulting torsional shear acts minimize transmural gradients stretch.