The contraction of the heart results in a wringing or
twisting movement that is often palpable (the apex
beat) and sometimes visible on the part of the chest
that lies in front of it—the praecordium.a The passage
of blood through the heart and its valves and on into
the great vessels of the body produces many interesting
sounds, and causes pulsation in arteries and movement
in veins in remote parts of the body. Signs of cardiac
disease may be found by examining the praecordium
and the many accessible arteries and veins of the body.
The surface anatomy of the heart and of the cardiac
valves (see Fig. 5.1) and the positions of the palpable
arteries (see Fig. 5.2) must be kept in mind during the
examination of the cardiovascular system. In addition,
the physiology of blood flow through the systemic and
pulmonary circuits needs to be understood if the cardiac
cycle and causes of cardiac murmurs are to be
understood (see Fig. 5.3).
The cardiac valves separate the atria from the
ventricles (the atrioventricular [AV] or mitral and
tricuspid valves) and the ventricles from their
corresponding great vessels. Fig. 5.4 shows the fibrous
skeleton that supports the four valves and their
appearance during systole (cardiac contraction) and
diastole (cardiac relaxation).b
The myocardium (cardiac muscle) is supplied by
the three coronaryc,1 arteries (see Fig. 5.5). The left
main coronary artery arises from the left coronary sinus
of Valsalva and divides into the left anterior descending
(LAD) artery, which supplies the anterior wall of the
heart, and the circumflex (Cx) artery, which supplies
the back of the heart. The right coronary artery (RCA)
arises from the right sinus of Valsalva and supplies the
inferior wall of the left ventricle and the right ventricle.
The coronaries are often described as the epicardial
coronary arteries. They must run over the surface of
the heart or they would be squashed during ventricular
systole.
The filling of the right side of the heart from the
systemic veins can be assessed by inspection of the
jugular veins in the neck (see Fig. 5.6) and by palpation
of the liver.2 These veins empty into the right atrium.
The internal jugular vein is deep in the
sternocleidomastoid muscle, whereas the external
jugular vein is lateral to it. Traditionally, use of the
Aortic area
Pulmonary area
Mitral area
Tricuspid
area
The areas best suited for auscultation do not
exactly correlate with the anatomical
location of the valves
FIGURE 5.1
a This is derived from the plural Latin word praecordia, meaning the parts
of the body below the heart (the entrails), but also the seat of feelings
and emotions. In Latin medical writing it means the same as in English:
the part of the body over the heart.
b Systole comes from the Greek word meaning a contraction and originally
applied to a vowel sound usually pronounced long, shortened so as to
scan. Diastole means the opposite.
c The name is from the Latin corona, which means a garland or crown. The
coronaries look like a garland draped over the surface of the heart.CHAPTER 5 THE CARdiAC ExAminATion 75
Superficial
temporal
Common
carotid
Brachial
Ulnar
Femoral
Popliteal
Radial
Posterior
RA
75%
LA
95%
PA
75%
Ao
95%
RV
75%
LV
95%
Right atrium
(RA) Mean 0–8
Right ventricle
(RV) 15–30/0–8
Left ventricle
(LV) 100–140/5–12
Left atrium
(LA) mean 1–10
Pulmonary artery
(PA) 15–30/3–12
Aorta
(Ao) 100–140/60–80
Normal pressures (mmHg) and saturations (%)
in the heart
FIGURE 5.3
external jugular vein to estimate venous pressure is
discouraged, but the right internal and external jugular
veins usually give consistent readings. The left-sided
veins are less accurate because they cross from the left
side of the chest before entering the right atrium.
Pulsations that occur in the right-sided veins reflect
movements of the top of a column of blood that extends
directly into the right atrium. This column of blood
may be used as a manometer and enables us to observe
pressure changes in the right atrium. By convention,
the sternal angle is taken as the zero point, and the
maximum height of pulsations in the internal jugular
vein, which are visible above this level when the patient
is at 45°, is measured in centimetres. In the average
person, the centre of the right atrium lies 5 centimetres
below this zero point (see Figs 5.6a and 5.7).d,1