Thyrotoxicosis-Related Left Main Coronary Artery Spasm Presenting As Acute Coronary Syndrome

Abstract

Thyrotoxicosis can cause acute chest pain without ST changes in EKG due to coronary artery spasm. Its diagnosis can be particularly challenging as the symptoms may mimic acute coronary syndrome. The diagnosis of coronary artery spasm is confirmed by coronary angiography. The use of intracoronary nitroglycerin can relieve spasms and reveal the true extent of coronary artery disease. We present a case of a perimenopausal woman with newly diagnosed hyperthyroidism who presented with chest pain. Coronary angiography showed spasm of the left anterior descending artery which was relieved by intracoronary nitroglycerin. Hyperthyroidism is associated with a spectrum of cardiovascular manifestations ranging from relatively benign palpitations to cardiac arrest. Rarely, it has been associated with episodic angina which indicates myocardial ischemia secondary to coronary artery spasm. Thyrotoxicosis-induced coronary artery spasm is a rare condition. Coronary artery spasm might masquerade as acute coronary syndrome, and coronary angiography is usually necessary to rule out myocardial infarction. In patients with risk factors for developing thyrotoxicosis-induced coronary artery spasm, any stenosis found on coronary angiography must not be assumed to be coronary artery disease only, and the possibility of coronary artery spasm must be explored. Our case emphasizes the use of intraprocedural nitroglycerin in these patients, which can relieve the spasm and reveal the true extent of coronary artery disease. Restoration of euthyroidism is the cornerstone of management and abates the need for long-term coronary vasodilator medications. Early diagnosis and optimal management have a favorable prognosis in these patients.

Keywords: acute coronary syndrome; angiography; cardiac catheterization; chest pain; coronary vasospasm; euthyroidism; graves' disease; hyperthyroidism; thyrotoxicosis.

Figure 1. Ostial Left Main coronary artery spasm (RAO-CRA projection) [Blue Arrow]

IC-nitro: intra coronary nitroglycerin, RAO-CRA: right anterior oblique-cranial

Figure 2. Ostial left main artery post IC-nitro (RAO-CRA projection) [Blue Arrow]

IC-nitro: intra coronary nitroglycerin, RAO-CRA: right anterior oblique-cranial

Figure 3. Left Coronary Artery post-IC nitro (LAO-CAU projection)

IC-nitro: intra coronary nitroglycerin, LAO-CAU: left anterior oblique-caudal

Figure 4. RCA (LAO projection)

RCA: right coronary artery