BDX4  Heart Murmurs - General and Mid-Systolic

Michael S. Feldman, M.D., F.A.C.C.
Disclosures		The author has no relationships with commercial interests related to the content of the presentation.

Bernard Segal, M.D., F.A.C.C.
Disclosures		The author has no relationships with commercial interests related to the content of the presentation.

Michael S. Feldman, MD, is Clinical Professor of Medicine at the University of Pennsylvania School of Medicine and chairman of the Graduate Education Foundation. Bernard Segal, MD, is professor of medicine at Thomas Jefferson University Hospital, and director of the Jefferson Heart Institute. In this fourth of a seven-part series, they explain how murmurs, which are produced by structural and hemodynamic abnormalities, are characterized by varying frequency, intensity, quality, and duration. Here, they focus on general and mid-systolic heart murmurs. Auscultatory examples of the most common and significant murmurs are provided.

Accompanied by more than 60 illustrations, this lecture is designed to provide an understanding of the importance of interpreting sounds and murmurs in diagnosing and treating heart disease.

The authors define and trace the causes of ejection mid-systolic murmurs and where they are best heard. Among the most common is a functional (innocent) pulmonic flow murmur, the murmur of aortic sclerosis and aortic stenosis, which, on palpation of the precordium, reveals a hypertrophied left ventricle, a presystolic lift, and a dynamic thrust or lift at the apical area. The authors describe the causes and the best way to detect the ejection mid-systolic murmur of left ventricular outflow tract obstruction, and note that ejection mid-systolic murmur can occur in patients with aortic dilatation, aortic valve stenosis, or essential hypertension.

The lecture continues with a detailed discussion of the ejection mid-systolic murmurs associated with idiopathic pulmonary artery dilatation, pulmonary branch stenosis, and right ventricular outflow tract obstruction, and notes that the latter two may be included in the tetralogy of Fallot. In contrast to these the intensity of the ejection mid-systolic murmur in tetralogy of Fallot bears an inverse relationship to the degree of pulmonary obstruction. An ejection mid-systolic murmur is also observed in atrial septal defect at the pulmonary valve area.

The authors describe the characteristics of ejection mid-systolic murmurs that can be heard and recorded in patients with hyperkinetic circulation as in hyperthyroidism, severe anemia, pregnancy, beri-beri, cor pulmonale, marked febrile reaction, and after exercise. The lecture concludes with a discussion of how ejection vibrations can be recorded in many normal subjects, especially in most children and in thin adults.