ABNORMAL LEFT CORONARY ARTERY OF OX HEART 



COMMUNICATING DIRECTLY WITH THE CAVITY OF 



THE LEFT VENTRICLE NEAR THE APEX 



By CHARLES REID, M.A., B.Sc, M.B., Ch.B. 



From the Physiological Laboratory, University of Aberdeen 



A HITHERTO undescribed abnormality was observed in an ox heart received 

 by the above department about the end of October, 1921. Externally, the 

 heart showed at the apex of the left ventricle a circular cyst-like structure. 

 The heart was then held, with the cut end of the aorta pointing upwards, 

 under a tap of running water. The water was allowed to run gently into the 

 aorta, and the cyst-like structure was observed to bulge with fluid. On closer 

 examination, a tubular vessel of arterial type about the calibre of one's middle 

 finger was observed in the interventricular groove between the aorta and this 

 structure at the apex of the left ventricle. This vessel appeared to follow the 

 usual course of the descending branch of the left coronary artery towards the 

 apex of the heart. It should be noted that, anteriorly, over the cyst-like 

 dilatation, the ventricular muscle was quite deficient, and seemed to have been 

 displaced by this abnormal structure. 



Heart : weight with attachments of great vessels and fat, 95 ounces. 

 [Weight of another normal ox heart, 89 ounces.] 



Length of heart, 24 cm.) , . 



Width of heart, 19 cm.] ^"""^ "^^^- 



The auricles looked normal. The thickness of the walls of the left ventricle 

 during rigor was about 5 cm. and did not differ materially from that of the 

 normal ox heart. 



With regard to the previous history and health of the animal, the following 

 facts were obtained: 



Age, rising 3 years old. Never off feed; very good feeder; always active; 

 walked to sale from the farm (f mile). Proportion of beef to live weight, fair 

 average. 



The calibre and thickness of the walls of the following vessels are given for 



the purpose of comparison : 



Thickness 

 Vessel Calibre of wall 



Aorta (about 8 cm. beyond the valves) ... 3*0 cm. 8 mm. 



Innominate artery (at its origin) 1-75 „ 5 „ 



Abnormal artery (at its origin above the cusp) 1-5 „ 1-5 „ 



It will be observed that, while the calibres of the innominate artery and 

 abnormal artery are approximately equal, the wall of the latter is much 

 thinner than that of the former. 



