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C HAP TE R 1 0 / History Taking and Physical Examination 237

as three-component (atrial systole, ventricular systole, and ventric- variety of physiologic or pharmacologic maneuvers can be used to
ular diastole), two-component (ventricular systole and diastole), or alter circulatory dynamics: respiration, postural changes, the Val-
one-component (ventricular systole) rubs. One-component rubs salva maneuver, postextrasystolic beats, isometric exercise, and va-
8
may be difficult to differentiate from a murmur. Rubs are best soactive agents. Table 10-7 summarizes the auscultatory effects of
heard either with the patient sitting upright and leaning forward these maneuvers.
with the breath expelled (most appropriate for the patient with an Respiration affects blood flow. Inspiration increases venous re-
acute myocardial infarction) or with the patient on his or her turn to the right heart, increasing right ventricular diastolic pres-
hands and knees in bed or on the examination table (useful in a sure, stroke volume, and ejection time. Pulmonary vascular im-
nonacute situation). A pericardial friction rub can be heard with or pedance is reduced, with increases in pulmonary vascular
without a pericardial effusion. Pericardial friction rubs can be dif- capacitance. With a normal respiratory rate, blood return to the
ferentiated from pleural friction rubs by having the patient hold his left ventricle is reduced, resulting in decreased left ventricular di-
or her breath. astolic pressure, stroke volume, and ejection time. Transmission of
Pericardial friction rubs are common in postoperative cardiac the augmented right ventricular volume to the left ventricle is de-
patients. Also, a respirophasic squeak may be heard that is related layed by three to four cardiac cycles in the pulmonary vasculature.
to mediastinal or pleural tubes. Air in the mediastinum produces All of the auscultatory events generated by the right heart are aug-
a crunching sound (Hamman’s sign) during auscultation of the mented during inspiration. 33 The use of the Müller maneuver
precordium. (sustained inspiratory effort against a closed glottis) further aug-
ments the auscultatory effects of inspiration. Expiration increases
Dynamic Auscultation. Dynamic auscultation can be used venous return to the left heart, increasing left ventricular diastolic
to aid in the interpretation of heart sounds and murmurs. A pressure, stroke volume, and ejection time. 6

Table 10-7 ■ AUSCULTATORY EFFECTS OF PHYSIOLOGIC AND PHARMACOLOGIC MANEUVERS
Maneuver Effect Maneuver Effect
Inspiration Physiologically splits S 2 Valsalva maneuver
Attenuates left ventricular S 3 and S 4 , mitral
opening snap, and pulmonic ejection sound Phase II (strain) Attenuates S 3 and S 4
A
Narrows A 2 –P 2 interval
Accentuates right ventricular S 3 and S 4 , tricuspid Phase III (release) Widens A 2 –P 2 interval
A
opening snap, and right heart murmurs
Phase IV (overshoot) Returns to baseline or transiently accentuates
S 3 and S 4
Hastens and accentuates click-murmur of mitral Postextrasystolic beats Augments murmurs of aortic and pulmonic stenosis,
valve prolapse tricuspid and aortic regurgitation, and hypertrophic
obstructive cardiomyopathy
Expiration Paradoxically splits S 2 Delays click-murmur of mitral valve prolapse
Accentuates left ventricular S 3 and S 4 , mitral
opening snap, and left heart murmurs
Attenuates right ventricular S 3 and S 4 , and Isometric exercise Accentuates left ventricular S 3 and S 4 and murmurs
tricuspid opening snap of aortic regurgitation, rheumatic mitral
regurgitation
Lying down Widens split S 2 in all respiratory phases Ventricular septal defect, mitral stenosis
Augments first right, then left, ventricular Attenuates murmur of aortic stenosis
Delays click-murmur of mitral valve prolapse
S 3 and S 4
Augments most systolic murmurs
Diminishes systolic murmur of hypertrophic Amyl nitrate Augments opening snaps; S 3 ; and murmurs of
obstructive cardiomyopathy aortic, pulmonic, mitral, and tricuspid stenosis, and
tricuspid regurgitation
Delays and attenuates click-murmur of mitral Diminishes murmurs of mitral and aortic regurgitation,
valve prolapse ventricular septal defect, and Austin Flint
Sudden standing Narrows split S 2 in all respiratory phases Hastens click-murmur of mitral valve prolapse
Diminishes first right, then left, ventricular
S 3 and S 4
Diminishes most systolic murmurs
Accentuates systolic murmur of hypertrophic
obstructive cardiomyopathy
Hastens and accentuates click-murmur of mitral Methoxamine and Accentuates murmurs of aortic and mitral
valve prolapse phenylephrine regurgitation, and ventricular septal defect
Squatting Augments right and left ventricular S 3 and S 4 , Diminishes murmurs of hypertrophic obstructive
and most murmurs cardiomyopathy and aortic stenosis
Delays click-murmur of mitral valve prolapse Delays click-murmur of mitral valve prolapse

Adapted from Braunwald, E. (1984). The physical examination. In E. Braunwald (Ed.). Heart disease: A textbook of cardiovascular medicine (2nd ed., pp. 35—38). Philadelphia: WB
Saunders.