BACKGROUND: The clinical conditions of various diseases, including coronary artery disease, are determined by genetics and the environment. Previous investigations noted the significance of genetic mutations and polymorphisms in cases of coronary spasm.

CASE REPORT: We report on monozygotic identical twins who almost simultaneously presented with vasospastic angina. The 58-year-old younger twin was admitted to our hospital because of persistent chest pain. An electrocardiogram showed an inverted T wave in the left precordial leads. Coronary angiographies revealed a short left main trunk (LMT) and 50% stenosis at the proximal portion of the left anterior descending artery (LAD). Infusion of acetylcholine to his left coronary artery caused marked vasoconstriction associated with a sensation of chest oppression. Nitroglycerine completely reversed this response. Based on these findings, we diagnosed Twin A with vasospastic angina. At nearly the same time, his identical twin brother was diagnosed with vasospastic angina at another hospital. Comparison of both coronary angiograms indicated similar structure of coronary vessels, including short LMT and mild stenosis at the proximal portion of LAD.

CONCLUSIONS: These 2 cases highlight the importance of genetic factors in the pathogenesis of vasospastic angina. It may be important for individuals to receive medical attention if their identical twin presents with vasospastic angina.

Keywords: Coronary Vasospasm - therapy, Angina Pectoris - therapy, Diseases in Twins, Twins, Monozygotic