A heartfelt beginning: Myopericarditis revealing mixed connective tissue disease

Vigneshvarprashanth Umapathy¹, S Aravindakumar², B Senthilkumar³

¹Resident Internal Medicine, Kauvery Hospitals, Trichy, Tamil Nadu, India

²Chief Consultant Interventional Cardiologist, Kauvery Hospitals, Trichy, Tamil Nadu, India

³Consultant Rheumatologist, Kauvery Hospitals, Trichy, Tamil Nadu, India

Background

Myopericarditis, a complication of acute pericarditis, is characterized by extension of pericardial inflammation to the myocardium, which can manifest as an elevated troponin level and ECG changes (mainly ST-segment elevation). The classical ECG finding of myopericarditis include widespread concave ST elevation with PR depression in all leads except aVR and V1 were there may be reciprocal ST depression and PR elevation. The most common cause is infection which is often viral and the other causes of myopericarditis can be neoplastic, autoimmune, post MI and postsurgical. The key challenge in managing myopericarditis is excluding the presence of an acute coronary syndrome. Here we present a case which is a rare cause of myopericarditis.

Case Presenation

A 39-year-old lady who is a known diabetic presented with acute onset chest pain and dyspnoea. On examination, she was oriented, tachypnoeic and hypoxic. ECG was suggestive of infero-postero-lateral wall myocardial infarction (IW/PW/LWMI). ECHO revealed hypokinesia of the inferior, posterior and lateral walls with mild left ventricular dysfunction and mild pulmonary artery hypertension. Cardiac biomarker (Troponin-T) was positive and a diagnosis of acute coronary syndrome was considered. But intriguingly, the coronary angiogram (CAG) revealed normal coronaries.

After stabilizing, on taking a detailed history she revealed a history of evening rise of temperature, loss of weight, fatigue, rash over the malar area and hyperpigmentation of hands. Autoimmune work-up (Tab.1) was done after ruling out ongoing infection as the cause for her worsening. Antinuclear antibody was strongly positive, antibody to U1-nRNP / Sm# showed 3+, and serum C3 and C4 levels were normal.

She was diagnosed with mixed connective tissue disease (MCTD) and was manged with systemic corticosteroids and immunosuppressants (azathioprine and hydroxychloroquine). She improved and is doing well in subsequent follow-ups.

Tab. 1: Autoimmune workup of our patient

ANA (nucleus granular)	Strong positive
Antibody to U1-nRNP / Sm#	3+
C3	Normal
C4	Normal

*ANA: Antinuclear antibody

Fig (1): ECG minicking infero-postero-lateral wall myocardial infarction

Fig (2): Coronary angiography (CAG) showing normal coronaries

Fig (3): CTPA showing cardiomegaly with dilated pulmonary artery and congestive bilateral lung fields

Discussion

Our patient had sudden onset chest pain and dyspnoea, which, when combined with the ECG and ECHO findings, suggested a myocardial infarction. But it was the underlying MCTD which caused the havoc.

MCTD is an autoimmune illness that shares characteristics with systemic lupus erythematosus (SLE), polymyositis, and systemic sclerosis. It is associated with positive autoantibodies against U1-nRNP. In MCTD, myocarditis or myopericarditis is extremely uncommon. Only a meagre of MCTD cases with myocarditis or myopericarditis has been reported worldwide (Tab. 2).

It has been found that between 15% and 65% of patients with MCTD had cardiac involvement, among which about 40% of the patients had pericarditis, and around 30% had mitral valve prolapse, which were the most commonly seen cardiac symptoms. Conduction abnormalities and pulmonary hypertension were among the additional symptoms.¹ However, myocarditis in MCTD is unusual.

Tab. 2: A literature review of myocarditis in mixed connective tissue disease (MCTD) patients

Author	Study year	Age (years)	Sex	Myocarditis onset	Final outcome
Lash et al.2	1986	25	F	11 years	Died
		42		12 years	Survived
		44		10 years	Died
Whitlow et al.3	1980	24	F	2 years	Died
Hammann et al.4	1999	30	F	5 years	Survived
Shinkawa et al.5	2016	34	F	2 years	Survived
Grossman et al.6	1981	35	F	1 year	Died
Faieley et al.7	2014	53	M	Unknown	Survived
Nunoda et al.8	1986	55	F	Unknown	Survived
Our patient	2023 (Present study)	39	F	Initial manifestation (few months of non-specific symptoms)	Survived

Conclusion

MCTD can present with acute onset chest pain which can mimic myocardial infarction leading to therapeutic confusion. Clinicians should keep myocarditis in mind as a potentially serious complication of MCTD.

References

Ungprasert P, Wannarong T, Panichsillapakit T, Cheungpasitporn W, Thongprayoon C, Ahmed S, Raddatz DA. Cardiac involvement in mixed connective tissue disease: a systematic review. International journal of cardiology. 2014 Feb 15;171(3):326-30.
Lash AD, Wittman AL, Quismorio Jr FP. Myocarditis in mixed connective tissue disease: clinical and pathologic study of three cases and review of the literature. InSeminars in arthritis and rheumatism 1986 May 1 (Vol. 15, No. 4, pp. 288-296). WB Saunders.
Whitlow PL, Gilliam JN, Chubick A, Ziff M. Myocarditis in mixed connective tissue disease. Arthritis & Rheumatism: Official Journal of the American College of Rheumatology. 1980 Jul;23(7):808-15.
Hammann C, Genton CY, Delabays A, Bischoff Delaloye A, Bogousslavsky J, Spertini F. Myocarditis of mixed connective tissue disease: favourable outcome after intravenous pulsed cyclophosphamide. Clinical rheumatology. 1999 Jan;18:85-7.
Shinkawa Y, Yagita M, Fujita M. Myocarditis in mixed connective tissue disease: a case report. J Clin Case Rep. 2016 Jan 26;6(679):2.
Grossman LA, Li JKH: Myocardial involvement in mixed connective tissue disease. NY State J Med 81:379- 381, 1981.
Fairley SL, Herron B, Wilson CM, Roberts MJ. Acute fulminant necrotising lymphocytic myocarditis in a patient with mixed connective tissue disease: a rapid clinical response to immunosuppression. The Ulster Medical Journal. 2014 May;83(2):119.
Nunoda S, Mifune J, Ono S, Nakayama A, Hifumi S, Shimizu M, Takahashi Y, Tanaka T. An adult case of mixed connective tissue disease associated with perimyocarditis and massive pericardial effusion. Japanese heart journal. 1986;27(1):129-35.

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A heartfelt beginning: Myopericarditis revealing mixed connective tissue disease