RESUMO
BACKGROUND: Episodic symptoms, often reported during exertion, complicate the assessment of suspected supraventricular tachycardia (SVT). OBJECTIVE: To examine the diagnostic sensitivity of graded exercise testing in young patients with documented SVT or ventricular preexcitation. METHODS: A single-centre retrospective review identified 53 patients (5.1 to 17.5 years of age) with structurally normal hearts who had undergone 65 graded treadmill exercise tests in the setting of either documented SVT with normal resting electrocardiograms (n=30) or ventricular preexcitation (n=23). Twenty-five patients (13 pre-excited and 12 nonpreexcited) had exercise-related symptoms. SVT induction during exercise testing was assessed in relation to pre-excitation and the patient's history of exercise-induced symptoms. RESULTS: SVT was induced during six of the 65 exercise tests performed in three of 53 patients (overall sensitivity 5.7%). All three patients had a history of exercise- induced symptoms, and two had ventricular preexcitation. SVT was induced in 12% of patients with exercise- related symptoms. No other rhythm disturbances occurred during exercise testing. CONCLUSION: The diagnostic yield of graded exercise testing in patients with suspected SVT is limited, even among those with exercise related symptoms.