They both had chest pain last month. Mr A was a middle-aged man with
recent chest discomfort who had called up from overseas on Wednesday for an
appointment on Saturday. He had intended to fly in on Friday but unfortunately,
he never made it as he died of a sudden heart attack on Friday.
The stars were shining brighter
for Mr B. He had exertional chest discomfort for the last two months and
finally decided to come for an assessment of his heart a fortnight ago. Tests
performed confirmed the presence of significant blockage of all the three major
arteries of the heart.
Ever so often, when you are
jogging, playing your game of tennis or while you are enjoying your game of
golf, you may have felt that discomfort in the chest and you are wondering
whether to dismiss it or take it as a warning of underlying heart disease. This
is a common dilemma.
Typical angina
Chest pain is the most common
complaint encountered by family physicians, cardiologists and emergency-room
physicians. What distinguishes the chest pain due to underlying blockage of the
heart arteries (angina pectoris) from other types of chest pain are the
characteristics of the pain.
The term angina pectoris is
derived from the Latin word angina ("infection of the throat"), the
Greek ankhone ("strangling"), and the Latin pectus
("chest"), and can therefore be translated as "a strangling
feeling in the chest".
Typically, it is described as
tightness over the central or left anterior chest, which may occasionally radiate
down the left arm. It is aggravated by physical exertion and relieved by rest.
Occasionally, it presents itself as increasing shortness of breath or neck
tightness on physical exertion without any chest pain.
The heart muscle receives blood
through three major heart (coronary) arteries which carry oxygenated blood to
the heart muscle cells (myocytes). During rest, the myocytes take up about 75
per cent of the oxygen content that is present in the blood flowing through the
heart arteries. Hence, during exercise, the increased demand for oxygen is met
primarily through increased blood flow through the heart arteries. If there is
an obstruction to blood flow as a result of narrowing of the heart arteries,
the oxygen supply may be unable to meet the increased demand, resulting in an
environment where there is insufficient oxygen. This results in the activation
of cellular pathways which operate in an oxygen-scarce environment, resulting
in the production of chemicals such as lactic acid. The build-up of these
chemicals stimulate nerve endings that cause the sensation of pain.
Angina or heartburn?
Heartburn is an uncomfortable
feeling of burning or warmth in the central chest, which may radiate to the
neck, throat and jaw. It can mimic angina and present itself as chest
tightness. Unlike angina, it is not due to heart disease, but is a result of
backflow of acid from the stomach into the oesophagus. It is typically
aggravated by lying down or bending over soon after a meal and relieved by
standing up, drinking water and taking antacids. It is present in about
one-third of adults, especially in pregnant women. It can sometimes be
difficult to distinguish it from angina, the main distinguishing factor being
that heartburn is not related to exertion.
Angina in the young
Angina can occur in the young as
a result of inherited conditions. While the major heart arteries of the heart
lie on the surface of the heart in the majority, in some, the artery may take a
course where a segment of the artery may be embedded in the heart muscle
(myocardial bridging) and hence the embedded segment may be compressed by the
heart muscle bands during contraction of the heart. If a long segment is
embedded deeply into the heart muscle, the obstruction to flow may be
significant enough to cause angina during vigorous physical exertion.
Another rare cause of mechanical
obstruction is the abnormal origin and course of the heart artery, where a
segment of it is wedged between the main artery arising from the heart (aorta)
and the lung artery (pulmonary artery). During heavy physical exertion, the
pulsations of the two large arteries may result in compression of the heart
artery to the extent that it causes angina. On rare occasions, these two
inherited causes of heart artery obstruction can cause sudden death during
vigorous physical exertion in the young.
Angina not related to exertion
While angina is typically
associated with physical exertion, there is an uncommon variety called coronary
vasospasm or Prinzmetal's angina. This condition is due to transient
constriction of the heart artery secondary to abnormalities in the regulation
of the smooth muscle in the wall of the artery.
Mdm C had typical angina except
that it was not related to exertion and she had a negative stress test for
heart disease. Her diagnosis was eventually confirmed when she recorded her
electrocardiogram (electrical pattern of heart or ECG) with a portable ECG
monitor during angina. The recorded ECG resembled an acute heart attack and was
associated with life-threatening heart rhythms.
The confirmation of coronary
vasospasm allowed the institution of measures that averted the possibility of
sudden death.
Chest pain but not angina
Understanding angina will help to
distinguish the types of chest pain that do not need urgent medical attention.
Chest pain is usually not angina if it can be localised to a single site on the
chest using two fingers, is sharp, pulling or pinprick in nature, and not
aggravated by exertion.
However, if you have risk factors
for heart disease and have a family history of heart disease, do remember that
having no chest pain does not mean there is no heart disease. After all, about
70 per cent of the patients who arrived at the emergency department with an
acute heart attack never had chest pain previously.
Dr Lim is medical director at the
Singapore Heart, Stroke & Cancer Centre. He is also editor-in-chief, Heart
Asia (a journal of the British Medical Journal Publishing Group); chairman,
scientific advisory board, Asia Pacific Heart Association; and honorary
professor and senior medical adviser, Peking University Heart Centre.
This series is brought to you by
the Heart, Stroke and Cancer Centre. It is produced on alternate Saturdays.
Dr Michael Lim
The Business Times
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