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Angina
Pectoris
Angina pectoris refers to pain originating from the chest (Figure
3).
This pain
was first recognized as a clinical identity by Heberden in 1772,
who defined the "agchonč" (the Greek root means
"a rope to hang") on the chest ("pectoris")
as "a strangling sensation with a feeling of anxiety"
(Heberden, 1772).
How does the
sense of pain originate directly from the heart?
In normal
hearts undergoing stress, such as occurs in exercise, lactate
and other metabolic substances are usually produced, at increasing
rates, before oxygen supply and demand become metabolically imbalanced.
The cardiorespiratory threshold that ultimately limits the exercise
is determined by the onset of unpleasant sensations such as fatigue,
shortness of breath, muscle tension, and weakness induced by these
metabolically active substances (Jones
and Killian, 2000). Despite these unpleasant sensations, if
the heart is normal we do not sense that pain is originating from
the heart.
In contrast,
a patient with advanced coronary artery disease who exercises
may experience a crushing, constrictive, suffocating discomfort
or pain. The pain usually occurs in the upper substernal area,
sometimes radiating to adjacent areas (predominantly left side)
such as the arms, neck, throat, and the lower jaw. The sense of
pain can occur before the person feels fatigue or shortness of
breath.
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