Background: Ectopic atrial tachycardia (EAT) is an uncommon arrhythmia that is notoriously difficult to control. It is often associated with tachycardia induced cardiomyopathy and can be misdiagnosed as sinus tachycardia secondary to viral myocarditis. Medical management to control heart rate (HR) can be challenging and radiofrequency ablation (RFA) may offer definitive management.
Iva bradine is a selective funny current (If) inhibitor that is most frequently used for rate control in adults with systolic heart failure and chronic angina.
Methods: We report a series of six patients with EAT successfully treated with ivabradine in our paediatric cardiology centre. Patient demographics, 12-lead ECGs, Holter monitor results and transthoracic echocardiograms were reviewed.
Results: The median age at starting ivabradine was 10.5 years (range 2 months to 14 years) and three patients were female.
In all six patients, ivabradine treatment was started as an adjuvant to another antiarrhythmic. For one patient ivabradine subsequently became their only antiarrhythmic agent.
Four patients had incessant ectopic atrial tachycardia. Three of these patients were known to have reduced LV function (FS <28%) prior to starting ivabradine. In all three cases the LV function improved with heart rate control. These three patients also had mean HR reduction of 41% when comparing Holter monitor results prior to and after commencing ivabradine.
All six patients had structurally normal hearts though one patient had severe mitral regurgitation secondary to rheumatic heart disease.
Rate control was achieved in all six patients.
There were no reported side effects any of our patients after starting ivabradine.
Discussion: Ivabradine is not commonly used in the treatment of EAT and there is little published data for this indication. Our case series has demonstrated significant rate and rhythm improvement when ivabradine was added to more conventional therapies for the treatment of EAT. Ivabradine should be considered as an adjuvant therapy in children with incessant tachycardia, such as EAT, when standard medical management is unsuccessful.