Antisynthetase Syndrome with Anti-Pl12 Antibodies and Cardiac Involvement

Background: The antisynthetase syndrome (ASS) is a rare chronic autoimmune disorder associated with a various manifestation including myositis, interstitial lung disease, fever, Raynaud’s phenomenon, “mechanic’s hands, polyarthritis and antibody specificity. Cardiac involvement is relatively rare but possible. We report a case of ASS anti PL12 positive with cardiac manifestations.

Case report: A 36 year old woman was admitted to the Department of Cardiology in our hospital for presyncope episodes, and exertional dyspnea. Physical examination revealed signs of congestive heart failure. Her heart rate was 40 bpm with a second-degree AV block Mobitz I on the electrocardiography. Transthoracic echocardiography showed cardiomyopathy with severe biventricular dysfunction and pulmonary hypertension. Further investigations were done to identify the cause of this cardiomyopathy especially as the patient presented arthralgias for last 2 years and history suggestive of Raynaud’s phenomenon and weakness of limbs. They revealed ASS syndrome with anti PL12 antibodies, diffuse interstitial lung involvement and cardiac involvement. The patient was treated with diuretic and corticosteroid therapy (methylprednisolone 1g pulse). On 4th day of admission, patient developed a complete AV block. Permanent dual chamber pacemaker implantation was performed. The patient was initiated on Cyclophosphamide and oral prednisolone which resulted in improved muscle strength and exercise tolerance.

Conclusion: Antisynthetase syndrome is a rare inflammatory myopathy. The cardiac involvement is even rarer and it is associated with worse outcome. The cardiovascular manifestations are various. This is the first report of ASS associated with complete heart block, cardiomyopathy and pulmonary hypertension in the same patient. Given the possible severe consequences, the cardiac involvement should be considered in patients with antisynthetase syndrome and clinicians should be familiar with this entity.

Keywords: Antisynthetase syndrome; Complete heart block; Cardiomyopathy; Heart failure; Pulmonary hypertension

Abbreviations: ASS: Antisynthetase Syndrome; AV block: Atrioventricular Block; ILD: Interstitial Lung Disease