Indian Pacing Electrophysiol. J.

ISSN 0972-6292


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Indian Pacing Electrophysiol. J. 2012;12(3):xx-xx           Case Report

An Unusual Case of Third-Degree Atrioventricular Block in Association with Acute Exacerbation of Systemic Lupus Erythematosus

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Hemant Boolani, Yeruva Madhu Reddy, David Shanberg and Dhanunjaya Lakkireddy

Section of Electrophysiology, Division of Cardiology, Bloch Heart Rhythm Center, Mid America Cardiology, University of Kansas Hospital & Medical Center, Kansas City, KS 66160

Address for Correspondence: Dhanunjaya Lakkireddy MD, FACC, FHRS, Director, Center for Excellence in Atrial Fibrillation & EP Research, Bloch Heart Rhythm Center, Mid America Cardiology @ University of Kansas Hospitals, 3901 Rainbow Blvd, Kansas City, KS 66160. Email: dlakkireddy@gmail.com

Abstract

Systemic lupus erythematosus presenting as third-degree atrioventricular heart block is rare.  Cardiac manifestations of systemic lupus erythematosus can range from inflammatory conditions like pericarditis, myocarditis and endocarditis to accelerated atherosclerosis and premature coronary artery disease. Conduction abnormalities, especially congenital atrioventricular blocks, are seen in offspring of patients suffering with systemic lupus erythematosus. These blocks are associated with the presence of anti-Ro (anti-SSA) antibodies. Cardiac conduction abnormalities and arrhythmias have been reported in less than one-tenth of all adult patients suffering from systemic lupus erythematosus. We describe a patient with systemic lupus erythematosus who presented with third-degree AV block. The incidence and mechanism of third-degree atrioventricular block in adult patients suffering with systemic lupus erythematosus remains unknown.

Keywords: Third-degree Atrioventricular Block, Complete Heart Block, Systemic Lupus Erythematosus

Introduction

Systemic lupus erythematosus (SLE) is an autoimmune disorder that can affect multiple organ systems. It is associated with significant cardiovascular involvement, ranging from asymptomatic heart disease or mild to severe life-threatening cardiovascular conditions. Cardiovascular disease is a significant cause of morbidity and mortality in these patients.[1]  The most frequent cardiovascular manifestations of SLE are pericarditis, myocarditis, coronary artery disease, and congestive heart failure.[1]  Conduction disturbances and arrhythmias have been documented in less than 10% of all SLE patients. [1] Incidence of a third-degree atrioventricular (AV) block in adults suffering with SLE patient is rare.  We present a patient with SLE who developed a rare third-degree AV block.

Case Report

 A 29 year old Hispanic female was brought to the emergency department with complaints of nausea, vomiting, diaphoresis and shortness of breath for three days prior to presentation.  Her past medical history included SLE, complicated by lupus nephritis, antiphospholipid syndrome, and hemolytic anemia. She was diagnosed eleven years ago.  Her antibody profile was positive for anti-nuclear antibody (ANA) and anti double stranded DNA antibodies. Her treatment regimen included cyclophosphamide and corticosteroids for a duration of two years. Her SLE symptoms have been in remission for the past seven years.  She also suffered from hypertension and Raynaud's syndrome, both treated with a calcium channel blocker. She had a history of ventricular septal defect repair as a neonate.

On arrival to the emergency room she was hypotensive with a blood pressure of 70/42 mm of Hg and the electrocardiogram showed normal sinus rhythm at 80 beats per minute (BPM) with complete heart block and a junctional escape rhythm at the rate of 50 BPM with right bundle branch block and left posterior fascicular block (Figure 1).  Initial laboratory tests showed an alanine aminotransferase of 759 U/L, aspartate aminotransferase of 661 U/L, serum creatinine of 1.9 mg/dL, and blood urea nitrogen of 49 mg/dL.  Cardiac enzymes were elevated with troponin-I of 27 ng/mL and creatine kinase-MB of 29 ng/mL. The International Normalized Ratio was 14.0.  The leukocyte count was 14 K/uL, hemoglobin was 8.8 gm/dL, hematocrit was 26%, and the platelet count was 243 K/uL.  The direct Coomb's test was positive.



Figure 1: 12 lead electrocardiogram showing normal sinus rhythm at 80 BPM with complete heart block and a junctional escape rhythm at the rate of 50 BPM on day one of hospitalization.


She was diagnosed with an acute exacerbation of SLE complicated by sepsis and multi-organ involvement including acute myocarditis. She was started on methylprednisolone, broad spectrum antibiotics and hemodynamic support with pressors.  A cardiology consult was sought for complete heart block and plans were made to implant a temporary trans-venous pacemaker. While preparing the patient for trans-venous pacemaker placement, the patient went into asystole.  The patient was resuscitated and placed on ventilatory support and a temporary trans-venous pacemaker was inserted.

Echocardiogram revealed severely depressed left ventricular function, with an ejection fraction of 30% without regional wall motion abnormalities, bi-atrial enlargement, and pulmonary artery systolic pressure of 45 mm of Hg.  Electrocardiogram showed persistence of complete heart block with ventricular paced rhythm at 70 BPM.  The patient's renal failure worsened and renal replacement therapy was initiated. With continuation of previously initiated therapy, her condition gradually improved.

On day seven, the electrocardiogram showed resolution of the complete heart block with normal sinus rhythm at the rate of 79 BPM, a PR interval of 170 milliseconds and persistence of right branch bundle block with left posterior fascicular block.  Her hemodynamic condition continued to improve and she was weaned off pressor support. On day eight, her endo-tracheal tube was removed. She was placed on appropriate treatment regimen for her heart failure. The trans-venous temporary pacemaker was removed on day nine. On day ten, the electrocardiogram revealed normal sinus rhythm with a sinus rate of 62 BPM and right branch bundle block with left posterior fascicular block (Figure 2).  Repeat echocardiogram showed mild improvement in her left ventricular function (ejection fraction of 40%). Heart failure therapy was optimized. Patient continued to improve and remained in normal sinus rhythm.  She was discharged home on day twenty-seven.



Figure 2:  12 lead electrocardiogram showing normal sinus rhythm with right bundle branch block and left posterior fascicular block on day ten of hospitalization.

At one year follow-up, the patient had no symptoms of heart failure and the electrocardiogram was unchanged showing normal sinus rhythm and right bundle branch block with left posterior fascicular block. Her left ventricular ejection fraction had improved to 50-55%.

Discussion

Systemic lupus erythematosus (SLE) presenting as third-degree AV block in an adult patient is not very common. To date only a handful of cases have been described.  This report represents the 16th case of non-congenital and non-anti-malarial therapy induced third-degree AV block in SLE patients.  Acute exacerbation of SLE was the possible cause of third-degree AV block in this case.  It has been widely established that congenital third-degree AV block is seen in neonates of mothers in whom anti-Ro/SSA and anti-La/SSB antibodies are positive.[2, 3]  Conduction defects have been described more often in anti-Ro positive than anti-Ro negative SLE patients. It has been noted that AV block in adults suffering from SLE was associated with anti- U1 ribonucleaoprotein antibodies and not anti-Ro/La antibodies.[2, 3]  The exact mechanism by which these antibodies affect conduction system of the heart is still unclear.

Hydroxychloroquine and chloroquine, used in the management of SLE and other autoimmune disorders, are known to cause cardiotoxicity and conduction abnormalities.[4]  Our patient had no history of hydroxychloroquine or chloroquine use.

It is postulated that small vessel vasculitis in acute settings and infiltration of the conduction system by fibrous or granulation tissue in chronic settings in patients with SLE, may affect the cardiac conduction system adversely, causing conduction abnormalities including complete heart block.  In a case series of eight autopsies, abnormal histology of the cardiac conduction system was seen in patients with SLE.[5]  In our opinion, resolution of the third-degree AV block in our patient was most likely associated with treatment of acute exacerbation of SLE.

In conclusion, acute exacerbation of SLE can present as myocarditis with conduction tissue disorders including complete heart block. Significant insights into the pathologic and molecular basis of AV heart block are required to further understand the underlying pathology and therapeutic measures that may improve outcomes in such patients.

References

1. Ansari, A. and P.H. Larson, Heart disease in systemic lupus erythematosus: diagnosis and management. Tex Heart Inst J, 1985. 12(1):9-21.

2. Seferovic, P.M., et al., Cardiac arrhythmias and conduction disturbances in autoimmune rheumatic diseases. Rheumatology (Oxford), 2006. 45 Suppl 4:iv39-42.

3. Fonseca, E., M. Crespo, and J.A. Sobrino, Complete heart block in an adult with systemic lupus erythematosus. Lupus, 1994. 3(2):129-31.

4. Keating, R.J., et al., Hydroxychloroquine-induced cardiotoxicity in a 39-year-old woman with systemic lupus erythematosus and systolic dysfunction. J Am Soc Echocardiogr, 2005. 18(9):981.

5. James, T.N., C.E. Rupe, and R.W. Monto, Pathology of the Cardiac Conduction System in Systemic Lupus Erythematosus. Ann Intern Med, 1965. 63: 402-10.

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