Cardiac Auscultation in the Older Adult

Mark E. Williams, MD

Disclosures

January 18, 2012

In This Article

Characteristics of Cardiac Murmurs

Murmurs are characterized by their grade, pitch, timing in the cardiac cycle, change in intensity, quality, location heard best, and radiation.

Grade

The grade of a murmur is a basic measure of the loudness (see Table 2 ).

Pitch

A low-pressure gradient, a large opening, or both cause low-pitched murmurs. A high-pressure gradient, a small opening, or both cause high-pitched murmurs.

Timing

Systolic murmurs. Almost all systolic murmurs begin in early systole. If the murmur lasts throughout systole (holosystolic), think of mitral insufficiency or tricuspid insufficiency.

Diastolic murmurs. Almost all diastolic murmurs begin in early diastole. Consider aortic insufficiency and pulmonic insufficiency if the murmur ends before mid-diastole. Causes of late diastolic low-pitched murmurs include mitral stenosis and tricuspid stenosis. A high-pitched late diastolic murmur suggests coronary artery stenosis. A holodiastolic murmur suggests atrial septal defect or mitral valvulitis due to acute rheumatic fever (Carey Coombs murmur).

Continuous sounds. A sound heard continuously throughout the cardiac cycle suggests one of the following:

  • a venous hum,

  • an arteriovenous fistula, or

  • pericardial friction rub.

A hepatic venous hum is a continuous, low-pitched sound. It is usually associated with severe liver disease. It should disappear with pressure over the liver (Rusconi sign). A cervical venous hum resembles the sound of a seashell placed against the ear to "hear the ocean." Cervical hums should disappear with the Valsalva maneuver or by compressing the ipsilateral jugular vein.

Arteriovenous fistulas can also produce continuous or swishing sounds. A patent ductus arteriosus is heard best at the left upper sternal border. A ruptured aneurysm of the sinus of Valsalva is heard best at the right upper sternal border. A coronary arteriovenous fistula is heard best at the left lower sternal border, and a pulmonary arteriovenous fistula is usually heard best outside the cardiac area.

A pericardial friction rub is heard best at the left lower sternal border (see above), and sounds more scratchy and swishing than continuous. A 3-component friction rub sound suggests acute pericarditis, until proven otherwise.

Change in Intensity

A crescendo (going from soft to loud) with a systolic murmur should make you think of aortic stenosis. Decrescendo murmur starts loud and diminishes in volume, and usually suggests aortic insufficiency, especially in early diastole.

A diamond-shaped murmur is caused by turbulence during systole and either increased flow across a normal valve or normal flow across an abnormal valve. Note when a diamond-shaped murmur ends. Ending before S2 is aortic stenosis; ending after S2 is pulmonic stenosis.

Quality

The quality of a murmur describes its musical or mechanical characteristics. Descriptive terms are harsh, musical, blowing, rumbling, or grinding.

Loudest Location

The loudest location is the site where the murmur is heard best. Aortic valve murmurs tend to be heard in the right second intercostal space. Pulmonic valve murmurs are best heard in the left second intercostal space. Mitral valve murmurs are loudest at the apex, and tricuspid valve murmurs are heard best at the left lower sternal border.

Radiation

As the term implies, the radiation of a murmur is the track the sound tends to travel or radiate. Aortic murmurs radiate along the aortic outflow from the left lower sternal border, to the right second intercostal space, to the right infraclavicular area. Pulmonic murmurs radiate along the pulmonary outflow tract. Mitral insufficiency murmurs radiate to the axilla or the subscapular portion of the back (especially if caused by rupture of the chordae tendineae with anterior leaflet dysfunction). Tricuspid insufficiency radiates to the venous system. Septal rupture from a myocardial infarction produces murmurs that radiate to the paravertebral area.

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