Method to orient cardiac tissue specimens for uniaxial mechanical testing with long axis parallel to sarcomeres

Muscle tissue is strongly anisotropic, and uniaxial tests of muscle are typically performed by stretching parallel to the myofiber direction. Dissection of a properly aligned cardiac muscle specimen for such uniaxial biomechanical tests is often a difficult task. When tissue samples are derived from a frozen block of myocardium excised from the ventricular wall, there are often few superficial clues to the underlying orientation of the sarcomere chains. Moreover, the direction of the sarcomeres changes as one travels through the thickness of the heart wall, and this further complicates the task. A technique for dissecting a small specimen with proper myofiber orientation is demonstrated below, in particular, for uniaxial stress/strain analysis of non-contracting myocardial tissue.