Paroxysmal Supraventricular Tachycardia

Excerpt

Paroxysmal supraventricular tachycardia (PSVT) manifests as intermittent episodes of regular, sudden-onset, and spontaneously terminating tachycardia. The incidence of this tachyarrhythmia is approximately 2.5 per 1000 in the general population, commonly encountered in emergency departments, and often affects individuals without underlying structural heart disease. PSVT is the characteristic feature of atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT), and focal atrial tachycardia. AVNRT is the most common cause of PSVT in adults, followed by AVRT and atrial tachycardia. Although patients with PSVT usually exhibit recurring palpitations, at times, PSVT may present with atypical symptoms such as shortness of breath, dizziness, chest pain, and syncope. This is particularly notable in older individuals with existing structural heart conditions. Noncardiac symptoms, such as tinnitus, burping, chilling, sweating, absence-like seizures, panic attacks, and asthma-like attacks, have also been reported in patients with PSVT.

A 12-lead electrocardiogram (ECG) is the most important initial investigation for patients presenting with PSVT. The common electrocardiographic findings include narrow complex tachycardia with a 1:1 atrioventricular association. However, AVNRT may present with atrioventricular or ventriculoatrial dissociation and atrial tachycardia commonly has a 2:1 atrioventricular conduction. Treatment options include adenosine, beta-adrenergic antagonists, calcium channel blockers, vagal maneuvers, and rarely electrical cardioversion. Over the past few decades, catheter ablation has emerged as the most effective and safest treatment option for PSVT and is associated with improved quality of life.