Ventricular arrhythmias in Takayasu arteritis

Arrhythmias and conduction defects in rheumatological diseases--a comprehensive review

OBJECTIVES

To review the clinical aspects of cardiac arrhythmias and conduction disturbances in several common and less encountered adult rheumatic diseases and to underline the importance of prompt diagnosis and management in these patients.

METHODS

The PubMed database was searched for articles published between the years 1960 and 2008 for keywords referring to autoimmune diseases. All relevant English-written articles were reviewed. Most were uncontrolled series and case reports, due to the lack of prospective studies and randomized trials.

RESULTS

Rheumatologic conditions may affect the cardiovascular system and increase morbidity and mortality. Rhythm and conduction defects are usually mild but may be life-threatening; in certain diseases, such as in systemic lupus erythematosus they may resolve following therapy with corticosteroids. Conduction defects occur frequently in patients with spondyloarthropathies and in those with various forms of vasculitis. Enhanced variation of the QT interval may be a sensitive marker of a higher arrythmogenic tendency in patients with autoimmune conditions.

CONCLUSIONS

It is important to identify patients at high risk for cardiac arrhythmias. Treating such patients with arrhythmias should not differ fundamentally from other patients. Nevertheless, appropriate clinical attention and judgment should be applied to exclude the possibility that arrhythmias reflect uncontrolled myocardial inflammation.

QT dispersion in patients with Takayasu arteritis

This study was designed to test the hypothesis that myocardial involvement exists in patients with Takayasu arteritis and is associated with increased QT dispersion, which is a marker of repolarization inhomogeneity. Twenty-one consecutive patients with Takayasu arteritis and no significant coronary artery disease were included. Twelve-lead electrocardiogram and exercise-induced thallium-201 myocardial scintigraphy were performed in all patients. Ten of 21 patients (48%) had abnormal findings on scintigraphy. Patients were divided into two groups by the presence (group P, n = 10) or absence (group N, n = 11) of exercise-induced thallium-201 myocardial scintigraphic perfusion abnormalities, including permanent defects in three, reversible defects in four, and slow washout in three. The QT dispersion at rest was significantly greater in group P than that in group N (54 +/- 12 vs 40 +/- 8 msec, p < 0.005). The QTc dispersion at rest was also significantly greater in group P than in group N (59 +/- 15 vs 43 +/- 11 msec, p < 0.01). In patients with Takayasu arteritis, myocardial involvement suggested by exercise-induced thallium-201 myocardial scintigraphic perfusion abnormalities is not rare, even when no significant coronary stenosis is present on angiography. Increased baseline QT dispersion was associated with scintigraphic abnormalities and may be a useful marker of myocardial involvement in patients with Takayasu arteritis.

Usefulness of beta blocker therapy in patients with Takayasu arteritis and moderate or severe aortic regurgitation

The objective of the present study was to evaluate the benefit of beta-blocker therapy for patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. Clinical and echocardiographic evaluation was performed in 20 Japanese women in a follow-up period of 7.0 +/- 2.0 years. The patients were divided into 2 groups: Group A (n=10) patients who did not receive beta-blockers, and Group B (n=10) patients treated with long-term (5.1 +/- 1.6 years) therapeutic doses of beta-blockers. Left ventricular wall thickness increased significantly in all Takayasu patients who did not receive beta-blockers. Consequently, a remarkable increment in left ventricular mass took place (232 +/- 59 to 361 +/- 79 g; p < 0.005). In the same group, progressive worsening of the symptoms, with no reduction in the percent fractional shortening, was observed in 2 patients, while reduction of this last index was present in 1 asymptomatic patient. On the other hand, among the patients who were treated with beta-blockers, left ventricular mass still increased in 6 cases, while it clearly decreased in the other 4 cases (290 +/- 171 to 284 +/- 61 g; NS). The increment in wall thickness or left ventricular mass observed among patients with beta-blocker therapy was clearly less than the one registered among those who had not received beta-blockers. Furthermore, no worsening of the symptoms and/or left ventricular performance was observed during the follow-up period for patients receiving beta-blockers. We conclude that beta-blocker therapy can slow and even reverse the progression of left ventricular hypertrophy in patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. The mechanism still needs to be elucidated. We believe an effective reduction in the excessive afterload imposed on the left ventricle to be most likely responsible, but cardiac beta-receptor up-regulation might also be involved. Deterioration of the clinical status and/or impairment of left ventricular function were not associated with beta-blocker therapy in our patients. Therefore, these agents can be used safely alone or in addition to standard anti-hypertensive therapy when attempting to reduce excessive afterload, in spite of the presence of severe aortic regurgitation.

Emergency and critical care issues in pediatric rheumatology

The study of critical care issues in pediatric rheumatology is in its infancy, and the available literature is largely case studies and small retrospective series. A child's limited communication skills and the lack of understanding of disease consequences by both parent and child may cause both overuse and underuse of emergency services. To the extent that small case experiences in children with rheumatic diseases do not adequately reflect possible disease presentations or diagnostic and treatment options, pediatric and adult rheumatologists, intensivists, and emergency physicians should readily turn as needed to larger reported experiences in adults with similar conditions.