Murmurs must be fully assessed. Note their timing (i.e. systolic or diastolic), the area of greatest intensity, their loudness and the effect of various manoeuvers, such as inspiration and a Valsalva.
Systolic murmurs can be pansystolic, ejection systolic or late systolic. Pansystolic murmurs extend throughout systole beginning with the first heart sound and going right up to the second heart sound. The loudness of pitch may vary during systole and common causes include mitral regurgitation. The intensity of midsystolic murmurs (or ejection murmurs) is greatest in midsystole. The usual cause is turbulent flow through a narrow aortic or pulmonary valve. Late systolic murmurs typically occur with mitral valve prolapse or papillary muscle dysfunction.
Diastolic murmurs may be either early, where they usually have a deep crescendo quality (e.g. caused by pulmonary or aortic regurgitation), or mid-diastolic. The latter, begin later in diastole, are usually short, extending up to the first sound: they have a low-pitched quality. Their usual cause is impairment of blood flow in ventricular filling, such as caused by mitral or tricuspid stenosis. Presystolic murmurs are caused by atrial systole across a narrow valve. Continuous murmurs are caused by a patent ductus arteriosus, arteriovenous shunts and congenital aortopulmonary windows. Rare causes include a ruptured sinus of Valsalva and a coronary artery fistula
The area of intensity of a murmur is important. For example, mitral regugitation is best heard at the apex and radiates towards the axilla, while others may be heard over the entire chest wall. Conduction of an ejection systolic murmur into the carotid artery, suggests an aortic valvular origin for the lesion. Loudness of atrial murmurs is not clinically relevant and, paradoxically, more severe lesions may produce quieter murmurs.
Dynamic manoeuvers, such as inspiration, should be employed to evaluate murmurs. Inspiration increases venous return and therefore blood flow through the right side of the heart, usually accentuating right sided murmurs. A Valsalva manoeuvre changes the murmurs of HOCM and mitral valve prolapse.
The site of maximum intensity and any radiation provides information on the underlying disease. Low pitched sounds are best heard with the bell of the stethoscope and high pitched sounds with the diaphragm. Grades are from I to VI. 1: very soft. II: soft but easily audible. III: moderately loud. IV: loud with associated thrill. V: very loud plus thrill. VI: maximum loudness with thrill, heard without a stethoscope.
Figure 57 summarise the relation of murmurs to the heart sounds, and ventricular systole and diastole: the murmurs are classified by their timing, position, pitch and grade. Figure 57 also shows the typical combination of heart sounds and murmurs of some common disorders.
A pericardial friction rub may be audible over the base of the heart with the patient leaning forward; it is caused by the movement of inflamed pericardial surfaces rubbing against each other. Once fluid accumulates (figure 58), it may separate the surfaces, with the disappearance of the rub.
If the clinical features suggest tricuspid regurgitation, an attempt should be made to elicit pulsatility of the liver (figure 59). This is best done during deep inspiration with the patient supine and the examiner’s hands sandwiching the liver, accentuating the abnormal pulsation. This is an extremely useful sign, together with the systolic waves in the jugular venous pulse of tricuspid regurgitation.
The cardiac examination is completed by searching for the excess tissue fluid produced in cardiac failure. Listen over the bases of the lungs for evidence of crepitations caused by pulmonary edema (figure 60a,b).