Innocent Systolic Murmur Chapter 13

1. Innocent Systolic MurmurChapter 13 Are G. Talking, MD, FACC Instructor Patricia L. Thomas, MBA, RCIS

2. Outline • Characteristics of an Innocent Murmur • Characteristics of a Pathological Murmur • Where Systolic Murmurs May be Produced • Classification • Still’s Vibratory Systolic Murmur • Physiological Pulmonary Ejection Murmur • Supraclavicular Arterial Bruit, Venous Hum • Peripheral Pulmonary Stenosis of the Newborn • Innocent Aortic Systolic Murmur • Mammary Arterial Souffle • Straight-Back Syndrome & Pectus Excavatum

3. Characteristic of An Innocent Murmur • Short (early to mid-systolic, except for the venous hum • Low to medium pitch • Possibly a musical component • Normal physiological splitting of S2 • Commonly found in children & early teen year • Isolated systolic murmurs in the elderly are common & are frequently innocent

4. Characteristics of A Pathological Murmur • Six Cardinal Clinical Signs • Holosystolic Murmur • Harsh Murmur • Abnormal heart sound • Early or mid-systolic click • Grade III murmur or greater • Heard over the upper left sternal border

5. Where Systolic Murmurs May Be Produced • Connection of the jugular, subclavian, & innominate veins to SVC (venonus hum; supraclavicular spaces) • Connection of RV to MPA (Pulmonary flow murmur; left sternal border, 2nd 3rd intercostal spaces) • Connection of the MPA to the RT & LT PA branches (peripheral PS of the newborn; upper sternal border) • Connection of the LV to the AO (Still’s murmur; apex) • Connection of the Aortic Arch to the brachiocephalic vessels (supra-clavicular arterial bruit; supracalvicular fossa)

6. Classification • Five types of innocent murmurs heard in childhood: • Still’s murmur or vibratory systolic murmur • Physiological or functional pulmonary ejection murmur • Supraclavicular arterial bruit • Venous hum • Peripheral Pulmonary stenosis of the newborn

8. Still’s Vibratory Systolic Murmur • Peak incidence in children 3 to 7 years, disappears at puberty • Musical, vibratory, low-frequency, early systolic ejection murmur • George F. Stills in 1909 • “A twanging sound” • Turbulence produced by the physiological narrowing of the LV outflow tract • Listen with the bell of the stethoscope over the lower mid-precordium or left lower sternal border & across to the apex

10. Physiological Pulmonary Ejection Murmur • Early systolic, crescendo-decrescendo, mid-frequency, grade II • Decreases during inspiration when a child sits • Turbulent flow at the origin of the RT & LT pulmonary arteries • Listen with the diaphragm of the stethoscope along the left sternal border in the 2nd to 3rd intercostal space in supine position • Heard best during inspiration

12. Supraclavicular Arterial Bruit • Low to medium pitched, short, systolic, crescendo-decrescendo murmur • Unaffected by respiration; Grade II or Grade III • Heard at any age mid-childhood & in 30% to 40% of young adults • Common in high-output conditions; anemia & anxiety; prominent in trained athletes with slow heart rates & high stroke volume • Turbulence in the brachiocephalic or carotid arteries at their branching from the aorta • Listen with the bell of the stethoscope over the supraclavicular fossa and over the sternomastoid muscle with patient sitting

13. Venous Hum • Blowing & Continuous extracardiac murmur that is loudest during diastole • Whining, roaring, or whirring; intensity varies form faint to grade VI • Louder under the inner edge of the right clavicle but extends form the supraclavicular area over the right internal jugular vein to the base of the heart • Thrill is often present in children with venous hum • Causes result form turbulent blood flow caused by two streams of blood entering the SVC • Listen with the bell of the stethoscope in the right supraclavicular space

15. Peripheral Pulmonary Stenosis of the Newborn • Short mid-systolic ejection murmur of medium pitch & intensity is best heard in the second intercostal space at the left sternal border • Result of the turbulence caused when the MPA is bigger or dilated than its branches • Heard in newborns and premature infants • Listen with the bell of the stethoscope during systole at the upper left sternal border & axillary areas

18. Innocent Aortic Systolic Murmur • Short, crescendo-decrescendo, low to medium pitch • Children, systolic flow murmurs may be secondary to any condition with increased systemic cardiac output • Listen with the bell of the stethoscope over the aortic area

19. Mammary Arterial Souffle • Described by Van Den Bergh in 1908 • A medium to high-pitched murmur, arising in systole & possibly continuing into diastole • Listen with the diaphragm of the stethoscope on the anterior chest wall over the breast

21. Straight-Back Syndrome & Pectus Excavatum • Decrease of the anteroposterior diameter of the chest because of the loss of the normal degree of kyphosis of the upper thoracic spine, straight-back syndrome or because of the inward cavitation of the sternum at the anterior chest wall • Pulmonary systolic ejection murmur • Exaggerated inspiratory splitting of S2 • X-ray revealing displacement of the heart to the left, apparent cardiomegaly, pancake heart

23. THE END OF CHAPTER 13 Tilkian, Ara MD Understanding Heart Sounds and Murmurs, Fourth Edition, W.B. Sunders Company. 2002, pp. 138-153