Ventricular endomyocardial changes after mpairment of cardiac lymph flow in dogs

The mammalian heart has an extensive lymphatic system (Patek, 1939) which has been given little attention in the published reports on cardiovascular systems. Our interest in the cardiac lymphatics was stimulated by the possibility that obstruction to their flow might cause endocardial changes. Reasoning by analogy with elephantiasis and similar conditions due to interference with lymph flow, we postulated that endomyocardial fibrosis or endocardial fibro-elastosis or both might follow chronic impairment of cardiac lymph flow. This was tested in the dog. Our preliminary studies (Miller, Pick, and Katz, 1960) established that endomyocardial changes are produced by chronic interference with the cardiac lymph flow. The present communication is a final report of a more extended series of observations in which we tested our hypothesis more precisely. This expanded survey also permitted a clearer definition of the sequence of pathological events that follow chronic impairment of cardiac lymph flow in the dog. METHOD In general, our surgical technique of interrupting cardiac lymph drainage was the same as that pre-viously developed (Miller et al., 1960). In the first 22 operated dogs the lymphatics were ligated or the car-diac lymph node was resected. In subsequent experiments the entire lymphatic system was resected fro