The relationship between disease-related characteristics and conduction disturbances in ankylosing spondylitis

Objectives: Ankylosing spondylitis (AS) is associated with an increased cardiovascular (CV) risk. Conduction disturbances (CD) may explain the CV burden, as they are independently associated with cardiac disease. The aim of this study was (1) to determine the prevalence of CD in AS, and (ii) to evaluate the relationship between CD and demographic and AS-related characteristics. Methods: A rheumatological evaluation assessing demographic and AS-related characteristics and a resting standard 12-lead electrocardiogram (ECG) were performed in 131 consecutive AS patients. Results: A first-degree atriciventricular (AV) block was found in six (4.6%) patients. One (0.8%) patient suffered from a complete right bundle branch block (RBBB) and one (0.8%) patient had a left anterior hemiblock. A prolonged QRS (pQRS) interval was observed in 38 (29.2%) patients, including those with a complete or incomplete BBB. Age, disease duration, and body mass index (BMI) were significantly associated with the PR interval, and male gender, disease duration, and the Bath Ankylosing Spondylitis Metrology Index (BASMI) with the QRS interval. In multivariate analyses, disease duration remained independently associated with both the PR and the QRS intervals. Conclusion: Intraventricular CD is highly prevalent in AS, particularly in patients with long-standing disease. Further research is needed to determine whether intraventricular CD contribute to the increased CV risk and long-term CV mortality in AS.