716 Abstracts

crease to 43.6 ml./minute/mm. Hg when CVP was in- creased 13 mm. Hg. Using the method of Forster and co-workers, the pulmonary capillary blood volume (V,) and the true diffusing capacity of the pulmonary membrane (D,) were calculated from the values of Dn determined at different alveolar 0s tensions in two of the seated subjects. In these two subjects, mean control Dr. was 36.3 ml/minute/mm. Hg and increased to 52 ml/minute/mm. Hg with inflation of the suit. Mean D,, at rest was 68.2 ml/minute/mm. Hg with an increase to 79.5 ml/minute/mm. Hg during inflation of the suit. Mean V, at rest was 112 ml. and mean V, during suit inflation was 221 ml. These studies indicate that the pulmonary capillary bed can be passively enlarged by dilatation of patent capillaries and/or by opening of previously closed capillaries.

THE “ECToRCARDIoCRAM IN DIRECT POSTERIOR WALL MYOCARDIAL INFARCTION. Edwin L. Rothfeld, M.D., Fred W. Wachtel, M.D., William S. Karlen, M.D. and Arthur Bernstein, M.D., F.A.C.C. Newark Beth Israel Hospital, Newark, N. J.

In posterior wall myocardial infarction, there is a loss of electrical forces directed to the left and posteriorly so that forces oriented to the right and anteriorly are en- hanced. This results in prominent R waves in right precordial leads. Employing the cube reference system, vectorcardiograms were obtained in six cases of myo- cardial infarction in which tall R waves were displayed in right precordial leads. In all cases, the initial portion of the QRS SE-loop was displaced markedly to the right and anterior and showed a bizarre contour and delay in inscription.

The vectorcardiogram is of ma.jor diagnostic import in confirming the diagnosis of direct posterior myo- cardial infarction and in differentiating it from other causes of prominent R waves in right precordial leads, such as right ventricular hypertrophy and right bundle branch block which can be most confusing in cases in which there is no history of myocardial infarction.

EMOTIONAL. STRESS AND CORONARY HEART DISEASE IN

PHYSICIANS. Henry I. Russ&, M.D., F.A.C.C. U. S. Public Health Service Hospital, Staten Island, N. Y.

In previous investigations, it was found that emotional stress of occupational origin was far more significant in the etiologic picture of coronary heart disease than a prodigiously high fat diet, heredity, obesity, physical exercise or the use of tobacco. In order to further test this finding, a survey was made by means of a question- naire to determine the incidence of recognized clinical coronary heart disease among physicians in two medical specialties which are manifestly dissimilar with respect to daily occupational stresses. One thousand letters were sent to doctors certified by the American Board of Anesthesiology, and one thousand letters to doctors certified by the American Board of Dermatology. Since it is acknowledged that the duties of the dermatologist, in general, are considerably less stressful than those of the anesthesiologist, sign&ant differences in the inci- dence of coronary heart disease were to be anticipated if emotional stress is a major etiologic factor in this dis- order. The finding of a higher frequency of coronary artery disease in general practitioners as compared with medical specialists by Morris in England, would also lead to similar expectation.

The results, based on an analysis of more than one thousand replies to the questionnaire survey, revealed that coronary disease was significantly more prevalent in anesthesiologists than in dermatologists in all age groups from forty to sixty-nine years. Among anesthe- siologists, the disease was two and a half times more prevalent in the forty to forty-nine year age group, three times more prevalent in the fifty to fifty-nine year age group and four times more prevalent in the sixty to sixty-nine year age group. Moreover, angina pectoris and myocardial infarction occurred an average of eight years earlier in anesthesiologists than in derma- tologists. The results strongly confirm previous findings which have indicated that emotional stress of occupa- tional origin is a potent factor in the pathogenesis of coronary heart disease in the American male.

EFFECT OF INTRAVENOUS FAT EMULSIONS ON HUMAN BI.OOD

VISCOSITY. Martin A. Shearn, M.D. and A&ides Gousios, M.D. Kaiser Foundation Hospital, Oakland, Calif.

The effect of intravenously administered fat emulsion on the viscosity of human blood was investigated be- cause (1) hyperlipidemia in animals has been shown to result in increased blood viscosity (Swank) and (2) increased blood viscosity has been implicated in the pathogenesis of thrombosis.

Other investigators have employed viscometers with tube lumens smaller than that requisite for laminar flow. Since, in man, major thrombotic episodes occur in vessels of medium caliber (coronary or cerebral arteries, femoral vein, etc.), we determined blood vis- cosity by a simple, reproducible technic that utilized laminar flow, thus more accurately reflecting the situation in medium-sized vessels. The coefficient of variation as determined by a two-way analysis of variance on the first 103 determinations was 2.2 percent.

In thirteen hospitalized subjects in the basal state, blood viscosity was determined in triplicate before and after injection of 600 ml. of an emulsion containing 90 gm. of lipids. All serums became extremely turbid. In some instances the total blood lipid content increased threefold after injection of the emulsion. Despite the magnitude of this rise, blood viscosity showed no significant change.

CARDIOVASCULAR FINDINGS IN CHILDREN WITH SICKLE

CELL ANEMIA. Herbert Shubin, M.D., Morse J. Shapiro, M.D., Ruebin Kaufman, M.D. and David C. Leuimm, M.D., F.A.C.C. Cedars of Lebanon Hospital, Los Angeles, Calif.

Seven children from six to sixteen years of age with heinatocrits between 18 and 27 per cent and hemoglobin S in excess of 90 per cent showed the following cardio- vascular features: (1) exertional dyspnea and fatigue; (2) fixed splitting of the second heart sound on deep inspiration; (3) third “lilling” heart sound in five of the seven children; (4) systolic murmur of grade 2 intensity or louder, most prominent over the upper left sternal border; (5) roentgenographic evidence of diffuse cardio- megaly and increased pulmonary vascularity; (6) abnormal electrocardiograms in four; and (7) increased blood and plasma volumes.

Right heart catheterizations in these seven patients revealed the following: (1) normal vena caval, right atrial, right ventricular, pulmonary artery and wedged pulmonary artery pressures; (2) normal pulmonary

THE AMERICAN JOURNAL OF CARDIOLOGY