Abstract
Arteriovenous aneurysm offers an opportunity for the study of factors concerned in the production of cardiac hypertrophy. In the presence of an arteriovenous fistula between the carotid artery and jugular vein, we have confirmed the observation of an immediate enlargement of the cardiac shadow as the fistula is opened. This we feel can be nothing other than dilatation of the heart as a result of the blood shunt. Thus, one of the primary factors in this condition seems to be cardiac dilatation.
It is interesting to note that in a series, 10 dogs in each of which an arteriovenous aneurysm was produced, but thrombosed within a day or two, we found heart weight-body weight ratios ranging from .00690 to .00900, with an average of .00850, which, in our opinion, are not increased enough to be considered significant of actual hypertrophy. The ratios of left ventricular weight were likewise within our normal limits. (See Table I.)
In one dog, No. 366, 2 unsuccessful femoral fistulae and one unsuccessful carotid jugular anastomoses were attempted. During these operations the dog had a patent orifice for about a total of 4 days, and at autopsy a H.W./B.W. ratio of .00750 and a L/R ratio of 1.130 were found. In dog No. 355, in which a small slitlike fistula, 3.5 × 1.5 mm., persisted for 80 days, a H.W./B.W. ratio of .01000 and a L/R ratio of 1.420 were found. The left ventricular capacity was 17 cc., while the right ventricle held 14 cc. Dog No. 352, with a 2nd fistula measuring 4 × 2 mm. which had persisted for 40 days (a first, and unsuccessful, fistula had been made 80 days before the 2nd), presented a H.W./B.W. ratio of .01180 which was definitely greatly increased, while the L/R ratio was 1.050. The hypertrophy was thus definitely of the right ventricular type. Dog No. 351, with a carotid jugular fistula 3 × 2 mm. for 143 days, presented the greatest degree of general hypertrophy with a H.W./B.W. of .01250, while the right ventricular predominance was conspicuously indicated by the L/R ratio of 1.000.
Get full access to this article
View all access options for this article.