Which pharmacological agents are considered first-line for the long-term management of patients with frequent SVT episodes?

For the long-term management of patients experiencing frequent episodes of supraventricular tachycardia (SVT), standard beta-blockers (excluding sotalol) are considered first-line pharmacological agents unless contraindicated, according to UK clinical guidelines. This recommendation is based on their efficacy in rhythm control and rate control in arrhythmias including SVT and atrial fibrillation, which share pathophysiological mechanisms with SVT ¹.

If beta-blockers are contraindicated or ineffective, alternative antiarrhythmic drugs such as class 1c agents (e.g., flecainide or propafenone) may be considered, provided there is no underlying ischaemic or structural heart disease ¹.

For patients with left ventricular impairment or heart failure, amiodarone is recommended as a second-line agent due to its efficacy despite its side effect profile ¹.

Additionally, dronedarone may be used as a second-line option after beta-blockers, particularly in patients with cardiovascular risk factors but without left ventricular systolic dysfunction or heart failure ¹.

In paediatric populations and specific SVT subtypes, pharmacologic management often includes beta-blockers and class 1c agents, consistent with adult recommendations, but tailored to the individual patient’s arrhythmia type and comorbidities (Luedtke et al., 1997).

Overall, the UK guidelines prioritize beta-blockers as first-line agents for long-term rhythm control in frequent SVT episodes, with other antiarrhythmics reserved for specific clinical scenarios or intolerance, a position supported by clinical pharmacology literature (Luedtke et al., 1997) ¹.