A 35 year old man presents with breathlessness, palpitations, dizziness, and retrosternal chest pain for 15 minutes. The pain was moderate in intensity, and tightening in character. He experienced 3 similar episodes 3, 6, and 8 weeks ago. These occurred respectively during a board meeting, when he was called upon to deliver a speech, and while waiting for co-workers in the lunch room. During these episodes, he had a severe urge to just drop things and leave the place. Because of this, he has avoided such situations for the past month, as he is highly worried of a serious outcome. His medical and surgical histories are unremarkable. There is no family history of cardiac disease, or of sudden deaths at a young age. He has a good relationship with his family, but as a senior manager, is currently stressed at work. He drinks in moderation, does not smoke, and strongly denies using controlled substances.
The rate is 80 bpm, with a sinus rhythm. No abnormalities are noted. Serial ECGs turn out to be normal, even though the patient continues to complain of palpitations throughout.
Random Plasma Glucose: 100 mg/dL (80-120)
The echocardiogram appears completely normal with no evidence of structural or valvular defects. The left ventricular ejection fraction is >70%
TSH: 3.8 mU/L (0.4-4.5) Free T3: 5.5 pmol/L (3.5 - 6.5) Free T4: 17 pmol/L (10 - 23)