A 67-year-old man had been in his usual state of health for one month, when he developed episodes of syncope. He stated that the first episodes occurred during the night, without other associated symptoms. Three days later, he had two more episodes of morning syncope with epigastric discomfort. He underwent 24-hour Holter test and was referred to the emergency department.

The Holter revealed multiple periods of transient ST elevation with second degree atrioventricular block, with a 2:1 rhythm (Figure 1), interspersed with periods of sinus rhythm (Figure 2).

Figure 1

Figure 2

A transthoracic echocardiogram revealed slightly depressed global systolic function (49% ejection fraction), without other functional or morphological dysfunctions.

Myocardial necrosis markers were negative during periods of pain and syncope, which were also observed during hospitalization.

Coronary angiography revealed a dominant right coronary artery with <30% distal lesion; the remaining arteries did not present significant lesions.

The patient initiated therapy with calcium and nitrate channel inhibitors, leading to symptom resolution.