Regional venous drainage of the human heart.

Blood samples obtained from the coronary sinus in man contain venous blood draining from left ventricular myocardium. It is believed by many investigators that coronary sinus blood in man is composed almost entirely of left ventricular efflux. That this is true in the canine heart is firmly established (Rayford et al., 1959). This principle has been widely accepted in the many studies which have been carried out using highly diffusible indicators to measure coronary blood flow, in which it is presumed that left ventricular flow per unit muscle mass is being measured (Gorlin, 1960). The present study was designed to test the hypothesis that coronary sinus blood is composed primarily of left ventricular efflux. The methods employed are those of detailed analysis of the fine ramifications of the coronary venous system to determine in semiquantitative fashion the number of small vessels contributing to venous drainage from each segment of the myocardium. METHODS Nineteen human hearts were obtained at necropsy for these studies. Patients ranged in age from 19 to 75, with a mean of 46 years. There were 11 men and 8 women in the series. Death was due to neoplasm in 12, carbon monoxide poisoning in 3, trauma in 2, and to pneumonia and cerebral vascular accident in one case each. All hearts were normal on gross inspection except for one which showed uraemic pericarditis. This case was included because the anatomical findings were identical to those of other specimens. Chambers and vessels of each heart were flushed with physiological saline, then injected with neoprene latext. This injection medium was chosen because it enables vessel dimensions to be well preserved without shrinkage vessel casts thus formed were flexible, and very small vessels could be displaced from their original location, care was taken in handling and inspecting the specimens. The right heart chambers and coronary veins were injected through a plastic cannula sutured into the superior vena cava, following ligation of the pulmonary artery and inferior vena cava. Left heart chambers and coronary arteries were injected through a plastic cannula inserted into a pulmonary vein, following ligation of the aorta and non-perfused veins. Different colours of latex were employed for each side of the heart. In one case only, there was some mixing of colours due to leakage through a patent foramen ovale. Injection pressures were uniformly set at 30 mm. Hg, except in two instances in which the left …