A 72-year-old man presents to the clinic for his annual exam. For the past few months, he has pain in his chest with physical activity. The pain goes away after he takes a break. He reports no chest pain while he is resting, and the pain is not worsening. His past medical history is notable for hypertension, type 2 diabetes mellitus, and hyperlipidemia. His medications include amlodipine, atorvastatin, and metformin. His temperature is 36.5°C (97.7°F), blood pressure is 132/80 mmHg, pulse is 74/min, respirations are 14/min, and oxygen saturation is 98% on room air. He has a regular rate and rhythm, normal S1 and S2, and no murmurs, rubs, or gallops. His anterior, lateral, and posterior chest are non-tender to palpation. His electrocardiogram is shown in Figure A. Troponin I level is < 0.017 ng/mL. Which of the following is the most likely diagnosis?
Stable angina
Costochondritis
ST elevation myocardial infarction
Unstable angina
Stable angina
This patient who presents with exertional chest pain that is relieved with rest without increasing frequency or intensity of chest pain, a normal electrocardiogram (ECG), and normal troponin level most likely has stable angina.

Angina pectoris is chest pain secondary to myocardial ischemia and is most commonly caused by atherosclerosis, though it can be caused by any etiology leading to narrowing of the coronary arteries. The pain tends to be substernal, dull, squeezing, or pressure-like and can also radiate to the neck or arm. It may also be associated with shortness of breath, dizziness, lightheadedness, nausea/vomiting, or diaphoresis. In stable angina, the chest pain is precipitated by exertion or stress and is consistently relieved with rest or nitroglycerin. ECG tends to be normal, and troponin I levels are not elevated. Treatment of stable angina includes beta blockers and nitrates (for episodes of pain), as well as therapy to prevent disease progression disease progression which may include antiplatelet therapy (aspirin), lipid-lowering medications, and glycemic control. Lifestyle measures are also the mainstay of therapy and may include smoking cessation, exercise, and dietary modification.

Joshi and de Lemos review stable angina. They note the optimal management of this condition. They recommend lifestyle interventions, lipid-lowering therapy, and antiplatelets to reduce morbidity and mortality.

Figure A shows an electrocardiogram with regular rate and rhythm. Every P wave is followed by a narrow QRS complex, which is consistent with normal sinus rhythm.

Incorrect Answers:
Answer A: Costochondritis presents with pain of the chest wall that can be sharp, aching, or pressure-like and typically worsens with cough or deep breathing. It is typically caused by injury to the chest, physical strain, or can be associated with inflammatory conditions such as arthritis. On exam, the pain can be reproduced with palpation of the chest wall, in particular, the costochondral junction. This patient's chest pain is associated with exertion and relieved with rest, and his pain is not reproduced upon palpation of the chest wall. Thus, he is unlikely to have costochondritis.

Answer B: Non-ST elevation myocardial infarction presents similarly to unstable angina with substernal chest pain that is new-onset, accelerating, or occurring at rest, without ST elevations on ECG. However, ST depressions or T wave inversions may be present on ECG, and troponin I and creatine kinase-MB isoenzyme (CK-MB) would be elevated, indicating myocardial injury.

Answer C: ST-elevation myocardial infarction presents with acute onset substernal chest pain that can radiate to the neck, arm, shoulders, or jaw and is sometimes associated with diaphoresis, nausea/vomiting, shortness of breath, lightheadedness, or anxiety. ECG shows ST elevations in a vascular distribution, and troponin I and CK-MB levels are elevated. This patient's ECG does not show ST elevations, and his symptoms are more consistent with stable angina.

Answer E: Unstable angina is characterized by substernal chest pain occurring at rest or occurring with more severity, longer duration, or increasing frequency. ECG may be normal or show ST depression or T wave inversion, and the troponin level is not elevated. It is caused by incomplete coronary artery occlusion by a thrombus or atherosclerosis, commonly due to a ruptured plaque with subsequent clot formation. This patient's chest pain is exertional, does not occur at rest, and is consistently relieved with rest, and thus would be consistent with stable angina.

Bullet Summary:
Stable angina is characterized by exertional chest pain that is not changing in quality or quantity and is relieved with rest.