Interarterial Coronary Anastomoses and Coronary Arterial Pattern

Anatomical study of length and branching pattern of main trunk of the left coronary artery

The left coronary artery is responsible for the irrigation of important heart structures. The objective of this study was to analyze the morphological characteristics of the main trunk of left coronary artery in the Brazilian population and its clinical implications. The study was carried out by using 63 adult human hearts of the human anatomy laboratory of the Federal university of Ceará, Brazil. The hearts were dissected for exposure and analysis of the left coronary artery and its branches. The data collected were statistically analyzed. The main trunk arose from the left aortic sinus under the left atrial auricle in all the 63 hearts. The mean length of the main trunk was 8.53±4.03mm. According to the criteria for the classification of the main trunk length, about 78% were medium-sized. The majority of the hearts (52.38%) showed trifurcation of the main trunk. Anova test followed by the Tukey's post hoc test showed that the main trunk length of hearts with trifurcation was significantly longer when compared with hearts with bifurcation (9.77±4.31mm vs. 6.44±3.01mm; P=0.0029). Similar findings were observed in the main trunk length of the hearts with tetrafurcation in comparison with hearts with bifurcation (10.78±1.4mm vs. 6.44±3.01mm; P=0.0387). This study showed that there is a correlation between the branching pattern and the length of the main trunk. Additionally, we showed that the most common branching pattern of the main trunk is the trifurcation, differing from other Brazilian studies and providing additional information to professionals of cardiology, cardiovascular surgery, and radiology.

Familial clustering of cardiac conditions in patients with anomalous aortic origin of a coronary artery and myocardial bridges

BACKGROUND

Anomalous aortic origin of a coronary artery is the second leading cause of sudden cardiac arrest/death in young athletes in the United States of America. Limited data are available regarding family history in this patient population.

METHODS

Patients were evaluated prospectively from 12/2012 to 02/2017 in the Coronary Anomalies Program at Texas Children's Hospital. Relevant family history included the presence of CHD, sudden cardiac arrest/death, arrhythmia/pacemaker use, cardiomyopathy, and atherosclerotic coronary artery disease before the age of 50 years. The presence of one or more of these in 1st- or 2nd-degree relatives was considered significant.

RESULTS

Of 168 unrelated probands (171 patients total) included, 36 (21%) had significant family history involving 19 (53%) 1st-degree and 17 (47%) 2nd-degree relatives. Positive family history led to cardiology referral in nine (5%) patients and the presence of abnormal tests/symptoms in the remaining patients. Coronary anomalies in probands with positive family history were anomalous right (27), anomalous left (five), single right coronary artery (two), myocardial bridge (one), and anomalous circumflex coronary artery (one). Conditions present in their family members included sudden cardiac arrest/death (15, 42%), atherosclerotic coronary artery disease (14, 39%), cardiomyopathy (12, 33%), CHD (11, 31%), coronary anomalies (3, 8%), myocardial bridge (1, 3%), long-QT syndrome (2, 6%), and Wolff-Parkinson-White (1, 3%).

CONCLUSION

In patients with anomalous aortic origin of a coronary artery and/or myocardial bridges, there appears to be familial clustering of cardiac diseases in approximately 20% of patients, half of these with early occurrence of sudden cardiac arrest/death in the family.

Determinants of human coronary collaterals

The human coronary collateral circulation is prognostically relevant. The understanding of collateral formation and its determinants may guide future therapeutic strategies aiming at promoting collateral growth and functionality, and hence reducing the global burden of coronary artery disease (CAD).

Inheritance of a cardiac arterial asymmetry in mice

A pair of coronary arteries supplies the interventricular septum of the heart of Mus musculus. The members of this pair tend to be of unequal size, which permits distiniction between specimens displaying left asymmetry and those showing righit asymmetry. Three inbred strains (C57BL/1O, DBA/1, and Bulb/c) differ with regard to this asymmetry. However, variation exists within strains, which suggests that nongenetic factors also influence the development of the asymmetry. Right arterial asymmetry is dominant over left asymmetry.

Effects of Exercise and Anemia on Coronary Arteries of Small Animals as Revealed by the Corrosion-Cast Technique

Vinyl acetate corrosion casts were prepared of the coronary arterial trees of chronically exercised rats and of suitable control animals. In four experiments, there was a statistically significant increase in the mean coronary-cast weight of the exercised animals over that of controls. In two experiments, the coronary- cast/heart-weight ratios were significantly increased.

In three-week-old ducklings rendered anemic by an iron-deficient diet, corrosion casts of the coronary vessels showed marked increases in cast weight, increase in size of homologous vessels, and generally more luxuriant arborization of the tree. No differences were found when coronary casts of thyroxin-injected or of pentaerythritol tetranitrate-injected rats were compared with those of control animals. Right-to-left-side coronary anastomoses were demonstrated in 75 per cent of guinea-pig hearts studied by the corrosion-cast technique. In five experiments, retrograde filling of a ligated anterior descending branch of the left coronary artery was demonstrated when the vinyl acetate solution was injected into the aorta.