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Some notes on the transmission of heart murmurs
This factor determines the size of the infarct that follows the obstruction of any given vessel and whether or not a recurrence of the episode is to be expected. The varying condition of the coronary arteries is probably the cause of the great variation in the expectation of life after myocardial infarction-a variation from a few moments to some fifteen years. A knowledge of the behavior of diseased eorona.ry vessels is essential in disc.ussing the surgical procedures advocated for improving the myocardial blood supply in coronary artery disease. These procedures aim at establishing new anastomotic channels between extracardiac and cardiac arteries by placing intercostal musr’les or omentum in contact with the pericardium. It is assumed in these procedures that the arterial pressure gradient will force blood from the extracardiac to the oardiac~ vessels. There is, however, no guarantee that such a gradient will exist. In those cases generally suitable for operative interference the one deficient in blood suppl! will frequently be deep in the ventricular wall. It is then very doubtful if a satisfactory pressure gradient will exist to transfer any quantity of blood to the heart, and it is possible that the flow will be in the opposite direction. This unpredictable fartor probably causes the very variable results that follow these surgical procedures. hl:THORS.
Stokes, W. : Nicotinic 6: 157, 1944.
Acid
in the
Treatment
of
Angina
Pectoris.
Brit.
Heart
J.
Changes in the electrocardiogram of cardiac ischemia in man, following the administration of nicotinic acid, suggest that the drug can improve coronary bloocl flow; but this only results from a dosage large enough to produce peripheral flush ing, which in itself is an uncertain and unpleasant effect. In a controlled clinical trial no improvement resulted from the oral administration of nicotinic acid in moderate dosage, either in the prevention or relief of angina, and nicotinamide in larger doses failed to give better results. Once again glyceryl trinitrate has shown that it has no equal in the treatment of angina pectoris, and nicotinic acid has no claim to routine use in this complaint.
Levine, S. A., and Likoff, W. B.: Some MUIYDU~S. Ann. Int. Med. 21: 298, 1944.
Notes
on the
Transmission
of
Heart
Numerous simple questions concerning the production and propagation of murmurs remain unanswered. We believe that the velocity of blood flow through the cardiar chambers and great vessels is one important factor in the production of murmurs and in determining their intensity. Other factors, such as the amount of residual blood in cardiac. chambers, the proximity of the heart and great vessels to the chest wall, and the respiratory (ayele may influence the presence or absence of murmurs. The gradation of systolic murmurs from 1 to 6 is important in attempting to est,imate their significance, for those of grade :: intensity, or louder, are never observed in normal individuals, whereas those of grade 1, and occasionally grade 2, are found where there is no evidence of cardiac or other disease. The detection of murmurs over the olecranon process even with the blood pressure are t,ransnrittr(l cuff’ inflated above the systolic pressure level, prove, c( that murnmr~ through bone. The transmission of an aortic diastolic murmur to the skull, and of t,he systolic murmur of ventricular septal defect. to the carotid area proves tha! murmurs are not propagated with the blood stream, for the blood flow in these circumstances is in the opposite direction.
135
SELECTED ABSTRACTS
Systolic murmurs after effort occur in normal individuals. The production or accentuation of such murmurs after exercise, therefore, cannot be used as a diagnostic test. There are several mechanisms involved when murmurs are influenced by respiration. All faint murmurs, organic or functional, may disappear with a deep inspiration. In some instances extracardiac systolic murmurs may be louder, and in others fainter, with a deep expiration. The current teaching about propagation of murmurs needs revision. These considerations are important in the examination of selectees for military service. AUTHORS.
de 10s Reyes, R. P., de la Terre, H., Labourdette, J., and Junco, J. A.: Cardiopathies in Cuban Children. Arch. de med. inf. 13: 3, 1944.
Rheumatic
The authors refer to the incidence and importance of rheumatic cardiopathy among Cuban children, which, though relatively less numerous than in the cold countries, constitutes the greatest calamity children’s hearts suffer with acquired cardiopathies. The study is based on 100 children, 50 boys and 50 girls, chosen from among 200 clinical records of rheumatic children which have been followed up for a long time with a series of electrocardiographic and orthodiagraphic studies, sedimentation rates, and other complementary investigations, pointing out the lesional diagnosis, course of the disease, and treatment used, plus an anatomopathologic study of post-mortem examinations. The authors have found 30 per cent more incidence in the girls than in the boys; the ages ranged from 5 to 11 years, inclusive. The white race was attacked most often, then the Negro, and third, the mulatto. The poorer and most needy classes offer the greatest number of cases. Mortality has been found to reach 18 per cent. AUTHORS.
Peete, D. C.: Rheumatic 21: 44, 1944.
Fever:
Diet as a Predisposing
Factor.
Ann. Int. Med.
The author relates evidence which indicates that diet, and sunshine are the most important predisposing factors in the causation of acute rheumatic fever. He discusses various climatic conditions which are related. He believes that the dietary deficiency which closely follows the incidence of clinical rickets alters the individual’s immunity to the organism which produces the clinical picture of acute rheumatic fever. MCCULLOCH. Rodbard, S., and Katz, L. N.: The Effect of Pregnancy on Blood Pressure in Normotensive and Hypertensive Dogs. Am. J. Obst. & Gynec. 47: 753, 1944. The blood pressure in normotensive and especially in hypertensive dogs tends to fall late in pregnancy. The degree of reduction of blood pressure is apparently affected by the size of the litter. It is possible that the blood pressure decline is related to the low resistance placental circuit which develops during pregnancy. It is also possible that some humoral factor (not involving the fetal kidneys) caused by the maternal endocrine alterations which accompany pregnancy contributes to the blood pressure change and helps to account for the variability in the time at which this blood pressure drop occurs. Surgical or other traumatic intervention during the latter part of pregnancy appears to predispose to abortion in the dog. AUTHORS.
Stokes, W. : Nicotinic 6: 157, 1944.
Acid
in the
Treatment
of
Angina
Pectoris.
Brit.
Heart
J.
Changes in the electrocardiogram of cardiac ischemia in man, following the administration of nicotinic acid, suggest that the drug can improve coronary bloocl flow; but this only results from a dosage large enough to produce peripheral flush ing, which in itself is an uncertain and unpleasant effect. In a controlled clinical trial no improvement resulted from the oral administration of nicotinic acid in moderate dosage, either in the prevention or relief of angina, and nicotinamide in larger doses failed to give better results. Once again glyceryl trinitrate has shown that it has no equal in the treatment of angina pectoris, and nicotinic acid has no claim to routine use in this complaint.
Levine, S. A., and Likoff, W. B.: Some MUIYDU~S. Ann. Int. Med. 21: 298, 1944.
Notes
on the
Transmission
of
Heart
Numerous simple questions concerning the production and propagation of murmurs remain unanswered. We believe that the velocity of blood flow through the cardiar chambers and great vessels is one important factor in the production of murmurs and in determining their intensity. Other factors, such as the amount of residual blood in cardiac. chambers, the proximity of the heart and great vessels to the chest wall, and the respiratory (ayele may influence the presence or absence of murmurs. The gradation of systolic murmurs from 1 to 6 is important in attempting to est,imate their significance, for those of grade :: intensity, or louder, are never observed in normal individuals, whereas those of grade 1, and occasionally grade 2, are found where there is no evidence of cardiac or other disease. The detection of murmurs over the olecranon process even with the blood pressure are t,ransnrittr(l cuff’ inflated above the systolic pressure level, prove, c( that murnmr~ through bone. The transmission of an aortic diastolic murmur to the skull, and of t,he systolic murmur of ventricular septal defect. to the carotid area proves tha! murmurs are not propagated with the blood stream, for the blood flow in these circumstances is in the opposite direction.
135
SELECTED ABSTRACTS
Systolic murmurs after effort occur in normal individuals. The production or accentuation of such murmurs after exercise, therefore, cannot be used as a diagnostic test. There are several mechanisms involved when murmurs are influenced by respiration. All faint murmurs, organic or functional, may disappear with a deep inspiration. In some instances extracardiac systolic murmurs may be louder, and in others fainter, with a deep expiration. The current teaching about propagation of murmurs needs revision. These considerations are important in the examination of selectees for military service. AUTHORS.
de 10s Reyes, R. P., de la Terre, H., Labourdette, J., and Junco, J. A.: Cardiopathies in Cuban Children. Arch. de med. inf. 13: 3, 1944.
Rheumatic
The authors refer to the incidence and importance of rheumatic cardiopathy among Cuban children, which, though relatively less numerous than in the cold countries, constitutes the greatest calamity children’s hearts suffer with acquired cardiopathies. The study is based on 100 children, 50 boys and 50 girls, chosen from among 200 clinical records of rheumatic children which have been followed up for a long time with a series of electrocardiographic and orthodiagraphic studies, sedimentation rates, and other complementary investigations, pointing out the lesional diagnosis, course of the disease, and treatment used, plus an anatomopathologic study of post-mortem examinations. The authors have found 30 per cent more incidence in the girls than in the boys; the ages ranged from 5 to 11 years, inclusive. The white race was attacked most often, then the Negro, and third, the mulatto. The poorer and most needy classes offer the greatest number of cases. Mortality has been found to reach 18 per cent. AUTHORS.
Peete, D. C.: Rheumatic 21: 44, 1944.
Fever:
Diet as a Predisposing
Factor.
Ann. Int. Med.
The author relates evidence which indicates that diet, and sunshine are the most important predisposing factors in the causation of acute rheumatic fever. He discusses various climatic conditions which are related. He believes that the dietary deficiency which closely follows the incidence of clinical rickets alters the individual’s immunity to the organism which produces the clinical picture of acute rheumatic fever. MCCULLOCH. Rodbard, S., and Katz, L. N.: The Effect of Pregnancy on Blood Pressure in Normotensive and Hypertensive Dogs. Am. J. Obst. & Gynec. 47: 753, 1944. The blood pressure in normotensive and especially in hypertensive dogs tends to fall late in pregnancy. The degree of reduction of blood pressure is apparently affected by the size of the litter. It is possible that the blood pressure decline is related to the low resistance placental circuit which develops during pregnancy. It is also possible that some humoral factor (not involving the fetal kidneys) caused by the maternal endocrine alterations which accompany pregnancy contributes to the blood pressure change and helps to account for the variability in the time at which this blood pressure drop occurs. Surgical or other traumatic intervention during the latter part of pregnancy appears to predispose to abortion in the dog. AUTHORS.