A stethoscope can be used to detect rales, crackling
noises that are caused by the movement of excess
fluid in the lungs. This can help locate where fluid
has accumulated. By listening to breathing sounds or
thumping the chest, a physician can usually tell when
fluid from the lungs has leaked (pleural effusion) into
the chest cavity. The fluid will also appear as a cloudy
area on X-rays. The stethoscope can also detect the
sounds of the heart chambers filling and emptying
and the heart valves opening and closing throughout
the cardiac cycle. Abnormal variations in these
sounds can aid the physician in diagnosing and mon-
itoring heart failure, because the condition is asso-
ciated with one or two abnormal sounds in addition
to the two sounds usually heard with the healthy
heart. Another symptom, blueness of the skin (called
cyanosis) accompanied by coolness and moisture,
most often in the fingers and toes, indicates low levels
of oxygen in the blood (called hypoxia). Edema is
detected by pressing the finger against the ankle or
skin and noting how long it takes the depression to
refill. Liver enlargement is felt by examining the ab-
domen. The neck vein may also be distended. (See
box, “Signs of Heart Failure During an Examina-
tion.”)
A number of sophisticated diagnostic techniques
may also be employed to diagnose and monitor heart
failure and heart function. The two main noninvasive