A 71 year-old woman was admitted to our hospital because of chest pain. She had been suffering from diabetes mellitus since age 30. Electrocardiography and echocardiography showed left ventricular hypertrophy. Coronary angiography showed significant stenosis at the left anterior descending artery, and we performed percutaneous coronary intervention successfully. We diagnosed her case as familial hypertrophic cardiomyopathy with angina pectoris because she has had many relatives with heart disease, though not diabetes nor deafness. After 8 years, her electrocardiography changed gradually and drastically, becoming precordial lead to QS pattern, and she also had mild deafness, suggesting mitochondrial disease. We investigated mitochondrial 3243 mutation and found two percentage heteroplasmy. Combined with cardiac magnetic resonance imaging that showed extensive myocardial defect, we confirmed the diagnosis of her disease as mitochondrial cardiomyopathy. We speculated her angina not only representing diabetic atherosclerosis but also implicating vascular smooth muscle dysfunction due to mitochondrial disease. Precordial QS pattern may suggest a diagnosis of mitochondrial cardiomyopathy.

An early repolarization（ER）pattern in the ECG has been recognized as a risk factor for ventricular fibrillation（VF）for the last several decades. Meanwhile, vasospastic angina（VSA）is a unique form of ischaemic heart disease and patients with VSA occasionally develop life-threatening ventricular arrhythmias. However, it is unclear whether ER pattern and its characteristics are associated with life-threatening ventricular arrhythmias in VSA patients. In addition, the long-term prognosis of VSA patients with ER pattern and the mechanism of ER pattern in patients with VSA have not been fully elucidated. We retrospectively evaluated 265 consecutive VSA patients, including 21 with VF history. ER pattern was observed in 64 patients（24.2%）. Prevalence of ER pattern was higher in patients with VF history than in those without（P = 0.001）. ER was independently associated with VF history（P = 0.001）. During long-term follow-up（5.5±3.3 years）, there was higher incidence of VF recurrence in cases with ER pattern. Furthermore, cases with day-to-day variation of ER pattern showed a higher incidence of VF recurrence during follow-up（Log-rank, P = 0.008）. Therefore, the higher prevalence of ER pattern in patients with VF history suggests that ER pattern may be a marker for vulnerability to VF in VSA. The presence of ER pattern, especially with day-to-day variation, may be a predictor of VF. In this review, the role and potential mechanisms of ER in patients with VSA are reviewed and discussed according to our results and the literatures.