A 50-year-old airline pilot complained of severe, intense, precordial, crushing sensation with pain radiating to the left shoulder and down the inside of the left arm, triggered by an off-duty tennis match. The chest discomfort brought on by the exertion was relieved by rest. Emergency room examination resulted in the following information:
Heart rate (HR) 98 b/min
Blood pressure (BP) 160/110 mm Hg
ECG: ventricular extrasystole arrhythmia (premature ventricular contraction [PVC]) as well as S-T segment depression and decreased R wave height.
The following day an exercise tolerance test was performed to test the functional response to graded stress. This symptom-limited test gave an ischemic ECG response during exercise, characterized by a downward-sloping S-T segment. Mild exertion resulted in chest pain, which was relieved by sublingual nitroglycerin. Coronary angiography showed lumenal obstruction >70% (88%) in three major coronary vessels, including the left anterior interventricular (descending) coronary artery. Nitroglycerin, beta-blockers, and calcium channel blockers were tried as pharmacologic therapy. Angioplasty, the procedure in which a balloon-tipped catheter is inserted into the partially obstructed vessels, was able to increase coronary flow to near normal values.
1a. What is the term for the chest pain experienced by this individual?
1b. What is the cause of this pain?
2. What is the site of action for each of the pharmacologic drug therapies?
a. Nitroglycerin:
b. Beta-blockers:
c. Calcium channel blockers:
3. Describe the gross anatomy of normal coronary arteries.
4. Describe angioplasty. State the pros and cons of its use.
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