Systemic Diseases and Heart Block

Systemic diseases can cause heart block owing to the involvement of the myocardium and thereby the conduction system. Younger patients (<60) with heart block should be evaluated for an underlying systemic disease. These disorders are classified into infiltrative, rheumatologic, endocrine, and hereditary neuromuscular degenerative diseases. Cardiac amyloidosis owing to amyloid fibrils and cardiac sarcoidosis owing to noncaseating granulomas can infiltrate the conduction system leading to heart block. Accelerated atherosclerosis, vasculitis, myocarditis, and interstitial inflammation contribute to heart block in rheumatologic disorders. Myotonic, Becker, and Duchenne muscular dystrophies are neuromuscular diseases involving the myocardium skeletal muscles and can cause heart block.

Risk of Arrhythmia Among New Users of Hydroxychloroquine in Rheumatoid Arthritis and Systemic Lupus Erythematosus: A Population-Based Study

OBJECTIVES

We assessed the association between hydroxychloroquine (HCQ) initiation and risk of arrhythmia among patients with incident rheumatoid arthritis (RA) or with incident systemic lupus erythematosus (SLE).

METHODS

All patients with incident RA or SLE and no arrhythmic events, not receiving antiarrhythmic medications, and not receiving HCQ prior to the index date of disease in British Columbia, Canada, between January 1996 and December 2014 were identified from administrative databases. We identified patients who were dispensed HCQ prescriptions (HCQ initiators) or were not dispensed HCQ prescriptions (HCQ noninitiators) during each study year; groups were matched 1:1 by propensity scores using baseline confounders on demographics, comorbidities, medications, and health care utilization. Outcomes were any new arrhythmias, atrial fibrillation, abnormal electrocardiograms, including long QT syndrome and conduction disorder, and other unspecified arrhythmias during follow-up. We used cause-specific Cox proportional hazards models with death as a competing event to assess the association between HCQ initiation and the outcomes.

RESULTS

We identified 11,518 propensity score-matched patients with RA or SLE in each group. Over the mean follow-up of 8 years, there were 1,610 and 1,646 incident arrhythmias in the HCQ initiator group and the noninitiator group, respectively, with crude incidence rates of arrhythmia of 17.5 and 18.1 in 1,000 persons per year, respectively. The adjusted cause-specific hazard ratio (cHR) for patients who received HCQ was 0.96 (95% confidence interval [95% CI] 0.89-1.03) compared with HCQ noninitiators, and the cHRs for patients who took HCQ and had arrhythmia subtypes of atrial fibrillation, abnormal electrocardiograms, and other unspecified arrhythmias were 0.93 (95% CI 0.83-1.04), 0.98 (95% CI 0.87-1.11), and 0.95 (95% CI 0.84-1.07), respectively.

CONCLUSION

Risk of any type of arrhythmia was not increased among new users of HCQ.

Chronic rheumatologic disorders and cardiovascular disease risk in women

Cardiovascular disease (CVD) is a major health threat to women worldwide. In addition to traditional CVD risk factors, autoimmune conditions are increasingly being recognized as contributors to adverse CVD consequences in women. Chronic systemic autoimmune and inflammatory disorders can trigger premature and accelerated atherosclerosis, microvascular dysfunction, and thrombosis. The presence of comorbid conditions, duration of the autoimmune condition, disease severity, and treatment of underlying inflammation are all factors that impact CVD risk and progression. Early identification and screening of CVD risk factors in those with underlying autoimmune conditions may attenuate CVD in this population. Treatment with non-steroidal anti-inflammatory drugs, corticosteroids, disease modifying agents and biologics may influence CVD risk factors and overall risk. Multi-disciplinary and team-based care, clinical trials, and collaborative team-science studies focusing on systemic autoimmune conditions will be beneficial to advance care for women.

Management of Complete Heart Block in a Pregnant Woman with Systemic Lupus Erythematosus-Associated Complications: Treatment Considerations and Pitfalls

We present a case of a pregnant woman with systemic lupus erythematosus (SLE) who was diagnosed with asymptomatic complete heart block (CHB) during pregnancy. To evaluate possible risks and benefits of pacemaker (PM) implantation, a multidisciplinary counselling board was held. Its recommendation was to perform PM implantation to prevent intra-uterine growth restriction from insufficient cardiac output using a fluoroscopic protective shield. The procedure was performed without complications and established permanent pacing on onwards ECG examinations. The patient subsequently gave birth to a healthy newborn. After a retrospective clinical case evaluation and review of relevant literature, a presumptive association between CHB and the primary diagnosis was proposed. Above that, pregnant women with SLE who develop hypertension are commonly treated with methyldopa, which may cause conduction abnormalities. Clinical recommendations for young female patients expecting pregnancy are lacking in this area. Careful diagnostic and treatment approaches should be used in the management of possible SLE-related complications in women of child-bearing age, focusing on preventable events.

Association of Hydroxychloroquine Dose With Adverse Cardiac Events in Patients With Systemic Lupus Erythematosus

OBJECTIVE

To determine whether hydroxychloroquine (HCQ) dose is associated with adverse cardiac outcomes in patients with systemic lupus erythematosus (SLE).

METHODS

Patients with SLE taking HCQ and with ≥1 echocardiogram followed at a tertiary care center in the Bronx, New York between 2005 and 2021 were included. The HCQ weight-based dose at the HCQ start date was the main exposure of interest. The outcome was incident all-cause heart failure with reduced ejection fraction (HFrEF), life-threatening arrhythmia, or cardiac death. We used Fine-Gray regression models with death as a competing event to study the association of HCQ dose with the outcome. Due to a significant interaction between smoking and HCQ exposure, models were stratified by smoking status. Propensity score analysis was performed as a secondary analysis.

RESULTS

Of 294 patients, 37 (13%) developed the outcome over a median follow-up time of 7.9 years (interquartile range [IQR] 4.2-12.3 years). In nonsmokers (n = 226), multivariable analysis adjusted for age, body mass index, hypertension, chronic kidney disease, diabetes mellitus, and thromboembolism showed that higher HCQ weight-based doses were not associated with an increased risk of the outcome (subdistribution hazard ratio [HR] 0.62 [IQR 0.41-0.92], P = 0.02). Similarly, higher baseline HCQ doses were not associated with a higher risk of the outcome among smokers (n = 68) (subdistribution HR 0.85 [IQR 0.53-1.34] per mg/kg, P = 0.48). Propensity score analysis showed comparable results.

CONCLUSION

Higher HCQ doses were not associated with an increased risk of HFrEF, life-threatening arrhythmia, or cardiac death among patients with SLE and may decrease the risk among nonsmokers.

Systemic Diseases and Heart Block

Systemic diseases can cause heart block owing to the involvement of the myocardium and thereby the conduction system. Younger patients (<60) with heart block should be evaluated for an underlying systemic disease. These disorders are classified into infiltrative, rheumatologic, endocrine, and hereditary neuromuscular degenerative diseases. Cardiac amyloidosis owing to amyloid fibrils and cardiac sarcoidosis owing to noncaseating granulomas can infiltrate the conduction system leading to heart block. Accelerated atherosclerosis, vasculitis, myocarditis, and interstitial inflammation contribute to heart block in rheumatologic disorders. Myotonic, Becker, and Duchenne muscular dystrophies are neuromuscular diseases involving the myocardium skeletal muscles and can cause heart block.

Heart Rate Variability in Women with Systemic Lupus Erythematosus: Association with Health-Related Parameters and Effects of Aerobic Exercise

Abnormal heart rate variability (HRV) has been observed in patients with systemic lupus erythematosus (SLE). In a combined cross-sectional and interventional study approach, we investigated the association of HRV with inflammation and oxidative stress markers, patient-reported outcomes, and the effect of 12 weeks of aerobic exercise in HRV. Fifty-five women with SLE (mean age 43.5 ± 14.0 years) were assigned to either aerobic exercise (n = 26) or usual care (n = 29) in a non-randomized trial. HRV was assessed using a heart rate monitor during 10 min, inflammatory and oxidative stress markers were obtained, psychological stress (Perceived Stress Scale), sleep quality (Pittsburg Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory), and quality of life (36-item Short-Form Health Survey) were also assessed. Low frequency to high frequency power (LFHF) ratio was associated with physical fatigue (p = 0.019). Sample entropy was inversely associated with high-sensitivity C-reactive protein (p = 0.014) and myeloperoxidase (p = 0.007). There were no significant between-group differences in the changes in HRV derived parameters after the exercise intervention. High-sensitivity C-reactive protein and myeloperoxidase were negatively related to sample entropy and physical fatigue was positively related to LFHF ratio. However, an exercise intervention of 12 weeks of aerobic training did not produce any changes in HRV derived parameters in women with SLE in comparison to a control group.

Sinus node disfunction in an adolescent with systemic lupus erythematosus

Cardiac involvement in systemic lupus erythematosus (SLE) is well documented. The pericardium, myocardium and endocardium, as well as the coronary arteries, the valves and the conduction system can all be affected. While pericarditis is common, arrythmias are less frequently described.We present a 13-year-old male, who had fatigue, anorexia, weight loss, myalgias and arthralgias for four months. On physical examination, we identified bradycardia (heart rate 31-50 bpm), oral and nasal ulcers and polyarthritis. The laboratory results showed hemolytic anemia, hypocomplementemia, antinuclear and anti-dsDNA antibodies, hematuria and non-nephrotic proteinuria. Renal function was normal. Lupus nephritis class II was diagnosed by kidney biopsy. On the transthoracic echocardiogram we identified a minimal pericardial effusion, suggesting pericarditis, and, on the electrocardiogram, we detected sinus arrest with junctional rhythm, denoting sinus node dysfunction. The patient was diagnosed with juvenile SLE with cardiac, renal, musculoskeletal and hematologic involvement. Disease remission and cardiac rhythm control were obtained with steroids and mycophenolate mofetil. Currently, the patient is asymptomatic, with normal sinus rhythm.We described an adolescent with SLE who had sinus node dysfunction upon diagnosis. Other cases have been reported in adults but none in juvenile SLE. All SLE patients should have a thorough cardiac examination to promptly diagnose and treat the innumerous cardiac manifestations of this disease.

A case of complete atrioventricular block in secondary hemophagocytic syndrome/hemophagocytic lymphohistiocytosis recovered by plasma exchange and cytokine absorbing therapy with AN69ST continuous hemodiafiltration

We report a case of incipient systemic lupus erythematosus (SLE) that rapidly progressed to complete atrioventricular block (cAVB). A 20-year-old man was admitted with facial erythema, painless oral aphtha, polyarthritis, and myalgia of each extremity. On admission, he developed first-degree atrioventricular block, pericarditis, pleuritis, renal failure, hemophagocytic lymphohistiocytosis, neurophychiatric SLE (left cerebellar infarction), and Staphylococcus aureus bacteremia. He was subsequently diagnosed with SLE based on several positive findings on immunological tests (including positive for antinuclear antibody). Despite immediate glucocorticoid pulse therapy and plasma exchange (PE) along with antibiotic, he developed cAVB that required temporary pacing on day 2. Because it was thought that hypercytokinemia exacerbated pericarditis, which progressed to myocarditis and cAVB, we decided to PE and cytokine-adsorbing therapy with AN69ST-continuous hemodiafiltration (CHDF). Other than renal failure, his organ dysfunctions improved with the multidisciplinary therapy. CAVB improved and temporary pacing was no longer required on day 11. Even a first-degree atrioventricular block can rapidly progress to cAVB; therefore, strict attention to electrocardiogram is necessary in severe SLE cases. When presenting with organ dysfunctions caused by hypercytokinemia such as severe SLE cases or SLE with severe infection cases, use of the combination of PE and AN69ST-CHDF might be beneficial.

Complete heart block in lupus

Conduction abnormalities are uncommon in adult patients with lupus. We present a young woman with recurrent syncope caused by third-degree atrio-ventricular block as the initial manifestation of lupus and review 31 additional cases of systemic lupus erythematosus patients that have been described previously with complete heart block. Heart blocks occurred almost exclusively in females. The median age was 37 years. In 24 cases heart blocks were diagnosed in patients with established lupus. In only five patients, including the patient presented here, heart blocks were diagnosed before the lupus diagnosis. Syncope was the most common presenting symptom of heart block. Electrocardiographic findings prior to heart block episodes were reported in 17 cases: eight had normal findings, but nine had already variant forms of atrioventricular or intraventricular conduction defects. Anti-nuclear antibody tests were reported in 25 cases and were all positive. Anti-DNA antibodies were also common and were positive in 16 of 19 cases (84%). Anti-La and anti-Ro antibodies were less common (13% and 35%, respectively). Three patients died, all prior to 1975. Heart block resolved in 10 cases. Follow-up was reported in four of these cases and heart block recurred in three of them. A permanent pacemaker was the eventual treatment in 22 cases. The etiology of lupus-associated complete heart block is not clear. It is probably variable, possibly related to effects of autoantibodies reacting with the conduction system, myocardial disease and adverse effects of antimalarials. Insertion of a permanent pacemaker seems to be the preferable method of treatment.

[Cardiac arrhythmias in patients with chronic autoimmune diseases]

Chronic inflammation due to autoimmune diseases is associated with a higher rate of supraventricular and ventricular arrhythmias leading to an increased risk for cardiovascular morbidity and mortality. Involvement of the cardiac conduction system is common in patients with chronic autoimmune diseases, although the penetrance of clinical signs and symptoms is variable and complete heart block with need for therapy is rare. The combination of the increased prevalence of structural cardiovascular disease and the direct impact of inflammatory mechanisms on cardiac electrophysiology seems to be responsible for the higher rate of tachyarrhythmias. In particular, fibroblast activation, gap junction impairment via changes in connexin composition and abnormalities in intracellular calcium-handling are mentioned. Electrocardiographic markers of an increased arrhythmogenic potential in patients with chronic autoimmune disorders may include prolonged P‑wave duration as well as abnormal QTc interval and reduced heart rate variability. Thus, minimizing the inflammatory burden through tight control of disease activity may help reduce the arrhythmic load.