Fundamentals of Anatomy and Physiology

The Cardiovascular Circulatory System 339

Common Disease, Disorder, or Condition

Disorders of the Cardiovascular System continued

Incompetent Heart Valve^
An incompetent heart valve produces serious leakage of blood. Once the valve
closes, blood still flows through it but in the reverse direction. This produces a swishing
sound after the valve closes. An incompetent atrioventricular valve produces the sound
after the first thump of a heartbeat while an incompetent semilunar valve produces the
sound after the second thump of a heartbeat. An incompetent tricus-pid valve causes
the blood to flow back into the right atrium and superior and infe-rior venae cavae
producing a swelling in the periphery of the body. An incompetent bicuspid valve causes
the blood to flow back into the left atrium and the pulmonary veins and lungs causing
lung congestion and swelling.

Angina Pectoris^
Angina pectoris is also called cardiac pain. Minor symptoms are occasionally misdi-
agnosed as indigestion by the layman while major symptoms precede an actual heart
attack. It results in episodes of pain in the thoracic region caused by a lack of -oxygen to
the muscle cells of the heart. The pain can progress along the jaw, neck, shoulder, and
down the left arm. It causes an individual to experience chest pressure and feelings of
suffocation and possible death. These attacks are usually caused by buildup of plaque
in the coronary arteries (atherosclerosis) or by spasms of these arteries. Symptoms can
be relieved by nitroglycerin tablets, which cause the coronary arteries to dilate allowing
more oxygen-carrying blood to reach the heart. Symptoms seem to be related to
overexertion, emotional stress, and eating certain foods. Moderate exercising, not
smoking, weight control, avoidance of fatty foods, and low blood pressure are
preventative measures that can inhibit the development of this condition.

Mitral Valve Prolapse Syndrome^
Mitral valve prolapse (MVP) syndrome develops when one or both of the bicuspid/mi-
tral cusps project back into the left atrium during contraction of the ventricles. This
condition can be acquired due to bacterial endocarditis or rheumatic fever, or it can be
congenital. Surgery may be performed to replace the defective valve with an artificial
valve.

Myocardial Infarction^
Myocardial infarction is also known as a heart attack. It results from the death of a
portion of the heart muscle cells caused by an obstruction or blockage of a coronary
artery. This occurs due to plaque buildup (atherosclerosis), a coronary spasm, or a
thrombus (unwanted clotting in the artery). The first symptom is a great crushing
pressure in the chest (occasionally referred to by the patients as an elephant sit-ting on
their chest) with accompanying pain radiating down the left arm. This is followed by
nausea, clamminess, shortness of breath, turning ashen in color, and feeling faint.
Other symptoms include a heightened heartbeat rate, low blood pres-sure, low pulse
rate, elevated temperature, and an irregular heartbeat rate. If oxy-gen-carrying blood is
supplied to the heart within 20 minutes, permanent damage to the heart is prevented.
However, if lack of oxygen occurs for a longer period of