Compression of the Heart

In making a presentation to this Society I feel that I need not attempt to discuss the radiological aspects of my subject. I know you have given considerable attention to the x-ray study of what you call con-strictive pericarditis. I know that the roentgenologist has been responsible for the diagnosis of many instances of this lesion. I should like to present something of a supplementary nature—views gathered by a surgeon working in an experimental laboratory. I like to divide diseases of the heart into two groups, One group consists of the intrinsic lesions of the heart. It ineludes the vast majority of cardiac lesions. The other, smaller group consists of the extrinsic lesions, and includes those patients whose hearts are crippled by some factor just outside the heart. The extrinsic lesions of the heart deserve special consider ation for if this outside factor can be removed by operation the patient can be cured. In extrinsic lesions of the heart we deal with a good heart together with a crippling factor. The heart is secondarily involved by an extracardiac process. This simple classification of heart disease sheds new light upon the problems of heart surgery. It helps the surgeon in the selection of patients for operation; it helps him with the operation and tells him what steps are beneficial and what steps are not beneficial. This classification gives something in the way of scientific order to this group of deformities and dislocations of the heart. Extrinsic lesions lend themselves to classification and study. Indeed, they lend themselves to experimental study because they can be produced in animals. These lesions consist of (1) angulation, (2) rotation, and (3) compression. On first thought you would probably like to add traction as a fourth factor producing an extrinsic lesion, but as shown by experiment, traction in the long axis of the heart is not a factor in this group. Angulation (Fig. I-D) or rotation (Fig. 1-B) when applied to a heart experimentally produces tachycardia, a fall in arterial pressure, and a rise in venous pressure. After a few minutes these dislocations lead to ventricular fibrillation in the dog. They are equally deleterious with the human heart. If the human heart must be dislocated during an operation, we have found it advisable to carry out the dislocation for short periods of time and then give the heart a rest period. Rotation is more deleterious than angulation. These are acute dislocations of the heart. Chronic dislocations also occur. They are seen in patients with pulmonary and medi-astinal tuberculosis. Angulation of the heart and mediastinum can be produced by artificial pneumothorax. Other extrinsic infections in the pericardium, mediastinum, and pleura can produce adhesions which can angulate or rotate the heart. Other mediastinal structures can be dislocated with the heart. The vagus and sympathetic nerves may be displaced with the great vessels and these displacements may produce tachycardia, dyspnea, pain, and fainting attacks. In one of my patients fainting attacks were brought on by hyperextension of the chest. Relief was obtained by bending forward. This patient's symptoms were relieved by thora-coplasty.