[A case of systemic lupus erythematosus with interstitial myocarditis leading to sudden death]

A 29-year-old female with systemic lupus erythematosus (SLE) was admitted because of exertional dyspnea in January, 1996. The diagnosis of SLE was made on the basis of malar rash, discoid rash, polyarthritis, leukopenia, positive antinuclear antibody and focal glomerulonephritis in 1991. She did not have any cardiac symptoms in 1994, when the electrocardiogram (ECG) abnormalities, such as poor R wave progression and right axis deviation, were present. On admission, she developed congestive heart failure without any signs of active SLE. Laboratory findings were unremarkable. There were new ECG abnormalities, such as left atrial overload and low voltage in limb leads. Chest roentgenogram showed mild pulmonary congestion and marked cardiomegaly. Echocardiography showed enlargement and diffuse hypokinesis of the left ventricle. Cardiac catheterization confirmed that the coronary arteries were normal and that the left ventricular function was poor (ejection fraction, 21%). Myocardial biopsy obtained from left ventricle revealed interstitial fibrosis. After furosemide, digoxin and captril were administered with predonisolone (PSL), her symptoms gradually improved. Since the Holter monitoring showed nonsustained ventricular tachycardia, the doses of PSL and mexiletine were increased up to 20 mg and 300 mg daily, respectively. Unexpectedly, she was found dead in her hospital room in May, 1996. The postmortem findings of the heart revealed mild infiltration of inflammatory cells, predominantly lymphocytes, and plasma cells, and interstitial fibrosis, which were consistent with interstitial myocarditis. In this case ECG abnormalities preceded cardiac symptoms, which may suggest that myocarditis subclinically developed. Serum creatinine kinase levels had not been elevated throughout the entire course. While several cases of acute myocarditis associated with a flare of SLE have been reported, there were few cases regarding interstitial myocarditis that chronically progress and can be fatal. This case is thought to be suggestive of elucidating the pathogenesis of lupus myocarditis.