Ultrastructural investigations of the myocardium were carried out on 42 mature rabbits after formation of the fixed rotational thoracic vertebra subluxation by surgery. The dynamics of ultrastructural changes in the myocardium was determined 15, 30, 45, 60, 90 and 180 days after the surgery procedure. Simultaneously changes in the spinal motional segment of animals were identified with accompanying mechanical influence on the nervous and vascular structures inside the intervertebral canal. Neural mechanisms of the cardiac function regulation may be disturbed. Changes in the myocardium are caused by: compression of neural structures inside the intervertebral canal; activation of receptors deformed in the stretched soft tissues of the spinal motional segment when vertebra subluxation is present.