Shock Syndrome Produced by Failure of the Heart

Two clearcut types of circulatory failure have emerged from the experimental and clinical studies of the cardiovascular system. The first, congestive heart failure, is the result of the inability of the heart to pump blood because of mechanical defects or disease of the heart muscle. It is characterized clinically by dyspnea, edema, prolonged circulation time, increased venous pressure and an increase in blood volume. Congestion may be present in the pulmonary circuit and absent in the systemic circulation. The second type, circulatory collapse, or shock, is the result of a diminished venous return to the heart. It is characterized clinically by the signs of a marked decrease in cardiac output and tissue anoxia, namely, pallor, cold extremities, sweating, weak pulse, low arterial blood pressure, narrowing of the field of consciousness and a normal or decreased venous pressure. The clinical pictures of congestive failure and of shock are so different that