Heart Murmurs In General Chapter 12 Are G. Talking, MD, FACC Instructor Patricia L. Thomas, MBA, RCIS

Outline Position in the Cardiac Cycle Pitch and Loudness (Intensity) of Murmurs Grading Intensity of Murmurs Graphic Records Detection and Identification Murmurs to Memorize

Heart Murmurs are the result of turbulent blood flow, which produces a series of vibrations in cardiac structure –High rates of flow through normal or abnormal valves –Forward flow through an incompetent valve, septal defect, or PDA –Decreased viscosity, which causes increased turbulence and contributes to the production & intensity of murmurs –Factors influencing the intensity of murmurs as heard by the clinician are distance, angle, & tissue

Position in the Cardiac Cycle Systolic Murmurs –Between S 1 & S 2 –Classified as early, mid, late, holosystolic Diastolic Murmurs –Between S 2 & S 1 –Classified as early, mid, late Continuous Murmurs –S 1 through S 2 into part or all of diastole

Systole is shorter than diastole at normal heart rates. Three simple & helpful means by which one can separate systole from diastole: –Inspection & palpation of the carotid artery –Inspection & palpation of the LV apex –Visual inspection of the ECG on the oscilloscope

Pitch & Loudness (Intensity) of Murmurs The pressure differential across an orifice for blood flow that determines the velocity of that flow for a given orifice When the pressure differential is high, so is the velocity of flow. As the velocity increases, so does the turbulence, loudness, & pitch of the heart murmur Loudness is determined by the rate of blood flow & the turbulence produced through a given orifice

Pitch & Loudness (Intensity) of Murmurs Proximity to the chest wall is also a factor Respiration can change both the amount of blood flow & the proximity of the vessel to the chest wall Other changes in blood flow: hyperkinetic states, cardiac failure, pulmonary hypertension, hypothyroidism

Grading Intensity of Murmurs Grade I –Audible only with concentration & by adjustments of the stethoscope earpieces Grade II –Faint, but heard immediately after the stethoscope is placed on the chest Grade III –Not loud, but somewhat louder than grade II; of intermediate intensity

Grading Intensity of Murmurs Grade IV –Loud, but still of intermediate intensity; generally associated with a palpable vibration or thrill; detection of a palpable thrill indicates a murmur of grade IV or more

Graphic Records Loudness is indicated by the height of the block and duration by its width –High-pitched blowing murmurs: Closely placed vertical lines –Low-pitch rumbling murmurs Rounded humps –Rough murmurs: Spikes –Harsh murmurs: Higher Spikes

Graphic Records cont… Waxing and Waning –Crescendo Murmur Begins faintly and increases in loudness –Decrescendo Murmur Loud at first & then fades away –Crescendo-Decrescendo Murmur Which is diamond-shaped-first increasing in loudness & then fading away

Detection & Identification Listen with the patient in both supine & sitting position/expiration & inspiration –Position in the cardiac cycle –Graded intensity & duration –PMI –Direction of conduction –Site where best heard –Loudness, pitch, & quality –Effect of respiration & interventions –Whether or not S2 is normally split –Accompanying thrill –Accompanying change in heart sound

Murmurs to Memorize (see page 136) Mitral Stenosis Mitral Insufficiency Aortic Stenosis Tricuspid Stenosis Tricuspid Insufficiency Pulmonary Stenosis Pulmonary Insufficiency

The End of Chapter 12 Tilkian, Ara MD Understanding Heart Sounds and Murmurs, Fourth Edition, W.B. Sunders Company. 2002, pp