Pericardial Murmur

Systolic murmurs are usually midsystolic or pansystolic. Late systolic murmurs may also be heard.

Diastolic murmurs usually indicate valvular heart disease. Systolic murmurs may indicate valvular disease, but often occur when the heart is entirely normal.

A late systolic murmur usually starts in mid- or late systole and persists up to S2.

A midsystolic murmur begins after S1 and stops before S2. Brief gaps are audible between the murmur and the heart sounds. Listen carefully for the gap just before S2. It is heard more easily and, if present, usually confirms the murmur as midsystolic, not pansystolic.

A pansystolic (holosystolic) murmur starts with S1 and stops at S2, without a gap between murmur and heart sounds.

A late systolic murmur usually starts in mid- or late systole and persists up to S2.

Midsystolic murmurs most often are related to blood flow across the semilunar (aortic and pulmonic) valves. See Table 7-6, Midsystolic Murmurs (pp. __-__).

Pansystolic murmurs often occur with regurgitant (backward) flow across the atrioventricular valves. See Table 7-7, Pansystolic (Holosystolic) Murmurs (p._).

This is the murmur of mitral valve prolapse and is often, but not always, preceded by a systolic click (see p._).

Diastolic murmurs may be early diastolic, middiastolic, or late diastolic.

Crescendo Murmur

An early diastolic murmur starts right after S2, without a discernible gap, and then usually fades into silence before the next S1.

A middiastolic murmur starts a short time after S2. It may fade away, as illustrated, or merge into a late dias-tolic murmur.

A late diastolic (presystolic) murmur starts late in diastole and typically continues up to S1.

An occasional murmur, such as the murmur of a patent ductus arteriosus, starts in systole and continues without pause through S2 into but not necessarily throughout diastole. It is then called a continuous murmur. Other cardiovascular sounds, such as pericardial friction rubs or venous hums, have both systolic and diastolic components. Observe and describe these sounds according to the characteristics used for systolic and dias-tolic murmurs.

Early diastolic murmurs typically accompany regurgitant flow across incompetent semilunar valves.

Middiastolic and presystolic murmurs reflect turbulent flow across the atrioventricular valves. See Table 7-8, Diastolic Murmurs (p. __).

The combination of systolic and di-astolic murmurs, each with its own characteristics, may have similar timing. See Table 7-9, Cardiovascular Sounds With Both Systolic and Diastolic Components (p._).

■ Shape. The shape or configuration of a murmur is determined by its intensity over time.

A crescendo murmur grows louder.

A decrescendo murmur grows softer.

Pericardial Rub Murmur

A decrescendo murmur grows softer.

A crescendo-descrescendo murmur first rises in intensity, then falls.

A plateau murmur has the same intensity throughout.

A crescendo-descrescendo murmur first rises in intensity, then falls.

A plateau murmur has the same intensity throughout.

■ Location of Maximal Intensity. This is determined by the site where the murmur originates. Find the location by exploring the area where you hear the murmur. Describe where you hear it best in terms of the interspace and its relation to the sternum, the apex, or the midsternal, the midclavicular, or one of the axillary lines.

■ Radiation or Transmission from the Point of Maximal Intensity. This reflects not only the site of origin but also the intensity of the murmur and the direction of blood flow. Explore the area around a murmur and determine where else you can hear it.

■ Intensity. This is usually graded on a 6-point scale and expressed as a fraction. The numerator describes the intensity of the murmur wherever it is loudest, and the denominator indicates the scale you are using. Intensity is influenced by the thickness of the chest wall and the presence of intervening tissue.

Learn to grade murmurs using the 6-point scale below. Note that grades 4

through 6 require the added presence of a palpable thrill.

The presystolic murmur of mitral stenosis in normal sinus rhythm

The early diastolic murmur of aortic regurgitation

The midsystolic murmur of aortic stenosis and innocent flow murmurs

The pansystolic murmur of mitral regurgitation

For example, a murmur best heard in the 2nd right interspace usually originates at or near the aortic valve.

A loud murmur of aortic stenosis often radiates into the neck (in the direction of arterial flow).

An identical degree of turbulence would cause a louder murmur in a thin person than in a very muscular or obese one. Emphysematous lungs may diminish the intensity of murmurs.

Gradations of Murmurs

Grade

Description

Grade 1 Very faint, heard only after listener has "tuned in"; may not be heard in all positions

Grade 2 Quiet, but heard immediately after placing the stethoscope on the chest

Grade 3 Moderately loud

Grade 4 Loud, with palpable thrill

Grade 5 Very loud, with thrill. May be heard when the stethoscope is partly off the chest

Grade 6 Very loud, with thrill. May be heard with stethoscope entirely off the chest

■ Pitch. This is categorized as high, medium, or low.

■ Quality. This is described in terms such as blowing, harsh, rumbling, and musical.

A fully described murmur might be: a "medium-pitched, grade 2/6, blowing decrescendo murmur, heard best in the 4th left interspace, with radiation to the apex" (aortic regurgitation).

Other useful characteristics of murmurs—and heart sounds too—include variation with respiration, with the position of the patient, or with other special maneuvers.

Murmurs originating in the right side of the heart tend to change more with respiration than left-sided murmurs.

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