Impaired myocardial contraction in the chronic stage.

The consequences of ischemia for the affected myocardium are highly variable. As a result, in chronic coronary heart disease there is little correlation between coronary arterial obstruction and myocardial dysfunction. Dysfunction can be permanent and related to replacement fibrosis or fixed disruption of the chain of events leading to effective contraction. Dysfunction can also be transient, as a direct consequence of acute myocardial ischemia. The mechanical lesions include generalized and localized myocardial dysfunction, mitral incompetence, and rarely, a left-to-right shunt through loss of integrity of the interventricular septum. Diagnosis per se is not difficult, but deciding on the true contribution of any given lesion to the overall symptoms and disability of the patient is. Therapy must be individually planned according to the total set of factors in each patient.