First-degree heart block is a minor manifestation of acute rheumatic fever. Second and third degree heart block and junctional rhythms occur less commonly. We report patients presenting with these latter three electrocardiographic abnormalities and investigate their diagnostic utility.

Patients admitted to our centre meeting the 2014 New Zealand Rheumatic Fever Guideline Diagnostic Criteria for rheumatic fever over a 5-year period from January 2010 to December 2014 were identified. Clinical, haematologic, electrocardiographic, and echocardiographic records were reviewed. Electrocardiograms (ECG) were considered abnormal if there was second- or third-degree atrioventricular block or junctional rhythms. Comparative data from patients with advanced conduction abnormalities without a diagnosis of rheumatic fever during the same time period were reviewed.

A total of 201 patients met inclusion criteria for rheumatic fever. Of these, 17 (8.5%) had transient abnormalities of atrioventricular conduction, 5 (2.5%) with second or third-degree atrioventricular block, and 12 (6%) junctional rhythms. The remaining 173 (86%) patients had evidence of rheumatic valvulitis at presentation. Only one patient without rheumatic fever was found to have advanced conduction abnormalities over the study period, from a total of 3702 ECG.

This large contemporary cohort of acute rheumatic fever shows that 8.5% of cases had either advanced atrioventricular block or junctional rhythms both highly suggestive of the diagnosis in our population.