The relation between the length of the main left coronary artery and the presence of atherosclerosis in its branches or the presence of complete left bundle-branch block was studied by selective coronary arteriography in 43 persons.The length of the main left coronary artery wasfound to be significantly shorter in patients with coronary atherosclerosis than in subjects without angiographic evidence of coronary artery disease. In patients with electrocardiographic evidence of complete left bundle-branch block, the length of the left main coronary artery was significantly shorter than that in both previous groups.In view of these findings, it is suggested that a short main left coronary artery should be considered as a congenitalfactor predisposing to the development of coronary artery disease. The possible mechanisms leading to atherosclerosis of the left coronary arterial branches in the presence of a short main trunk are discussed.In recent studies coronary arteriographic findings of coronary artery disease. Some further data are were related to intraventricular conduction distur-also presented concerning its length in patients bances (Haft, Herman, and Gorling, 1969; Beach with complete left bundle-branch block. et Lewis et al., 1970;Hamby, Tabrah, and Gupta, 1973). A remarkable observation was made by Lewis et al. (1970), who noted that a Subjects and Methods short main left coronary artery was present in a great proportion of patients with complete left The study was based on the coronary arteriographic bundle-branch block. It was suggested that in the findings in 43 subjects. The only criterion for inclusion presence of a short main left coronary artery was the satisfactory visualization of the main left corotrunk, the initial part of the left anterior descending nary artery and its branches. artery is exposed to unusual stress from systolicThe patients studied were divided into three groups. kinking, with resulting impairment of the blood The first group included 19 patients without arteriosupply tothebundleofHis. Segmentsofar graphic evidence of coronary atherosclerosis. Twelve of supplyted toth bundleo His. Segmeknt to a e these had a form of heart disease, usually aortic and subjectea to systolc inkilg are Known to be mitral valve lesions, leading to left ventricular hyperparticularly liable to intimal changes and athero-trophy. The others presented with atypical findings sclerosis (Fulton, 1965;Glagov, 1972).suggestive of coronary artery disease. From these observations, it might be supposed The second group included 20 patients with atherothat the length of the main left coronary artery is sclerotic lesions in the left anterior descending or both one of the factors that may contribute to the de-branches of the left coronary artery. Two also had left velopment of atherosclerosis in its branches. The ventricular hypertrophy caused by valvular disease. purpose of ths investigation was to find out if Stenotic lesions in the left anterior descending artery tartery in varied from 50 per cent to complete o...

A 17-year-old girl developed an acute myocardial infarction immediately after being bitten by a viper and four days later she had a cerebrovascular accident. The close clinical and laboratory follow-up of this case suggested that myocardial damage could be attributed to a direct cardiotoxic effect of the venom, while the brain injury that subsequently appeared was probably the result of a disseminated intravascular coagulopathy, possibly in conjunction with vasculitis.

The relation between the length of the main left coronary artery and the degree of atherosclerosis in its branches was studied by postmortem examination in 204 subjects aged 20 to 90 years.The findings suggest that in cases with a short main left coronary artery the atherosclerotic lesions in the anterior descending and circumflex branches appear earlier, progress faster at higher levels of severity, and lead more frequently to myocardial infarction, than in cases with a long left coronary artery trunk. In cases over the age of 50 years, where disease is expected to have developed, it was shown that the degree of atherosclerosis in the left anterior descending and circumflex branches was inversely related to the length of the main left coronary artery. The correlation coefficients were -0-527 and -(*428, respectively, and in either case a test for zero correlation was significant (P <0.001).The possible changes in the haemodynamic and mechanical conditions associated with the variations of the anatomical pattern of the coronary arteries and their influence in the development of atherosclerosis are discussed. It is suggested that the length of the main left coronary artery is a congenital anatomical and possibly hereditary factor influencing the rate of devzelopment of atherosclerosis in the branches of the main left coronary artery.The involvement of local mechanical and haemodynamic factors in the development of atherosclerosis of the coronary arteries is a generally accepted fact and the significance of such factors has been emphasized in recent publications (Glagov, 1972;Fry, 1972;Texon, 1974;Stehbens, 1975).In a coronary arteriographic study from our department, we found that patients with a short main left coronary artery showed a high degree of atherosclerosis in its branches (Gazetopoulos et al., 1976). This finding was attributed to the haemodynamic conditions associated with this anatomical pattern. However, the study was based on limited material derived mainly from patients suffering either from advanced coronary artery disease or valvular heart disease, who were candidates for heart surgery. Furthermore, these observations were indirect being based on coronary arteriographic appearance. For this reason a further study

The basic elements for quantitation of the three-dimensional electromotive forces generated during the electric cardiac cycle are the spherical coordinates of each instantaneous vector, i.e. its spatial magnitude and its elevation and azimuth angles. Since presently used display systems provide only projections of the spatia vectors, their spherical coordinates have to be computed from these data By using combinations of the projection data provided by the vectorcardiogram (VCG) and/or the orthogonal electrocardiogram (OECG), the determination of a vector’s spherical coordinates was attempted by geometric construction, by algebra and trigonometry and by electronic processing. Geometric constructions on the scalar recording of the ‘corrected’and properly amplified orthogonal leads proved more convenient than the other methods, and eliminated the need for expensive electronic equipment. Since the OECG is also suitable for morphologic interpretation, it could replace both the 12-lead ECG and the VCG in either research or routine practice.

30 healthy individuals and 20 patients suffering from coronary artery disease had orthogonal electrocardiograms taken at rest, after moderate exercise and during smoking. The heart rate increased during smoking to approximately the same level as after exercise. The unadjusted Q-T interval did not change significantly during smoking, but it significantly decreased after exercise when its value was compared with that at rest. The linearly corrected Q-T (Q-T/R-R) increased significantly after exercise and even more during smoking. The parabolically corrected Q-T (QTc) increased significantly only during smoking, suggesting that this was not a heart rate dependent phenomenon. The factors responsible for the prolongation of the corrected Q-Ts during smoking could include increased sympathetic tone, slight myocardial ischemia, slight heart decompensation, substances interfering with metabolic processes in the myocardial cell and myocardial strain due to increased cardiac work.