Paroxysmal supraventricular tachycardia (PSVT) describes a group of rhythm disturbances that originate in the atria or atrioventricular (AV) junction. PSVT is characterized by rapid ventricular rate (greater than 100 beats per minute [bpm]) with sudden onset and sudden termination. In the absence of a left or right bundle branch block, QRS complexes are typically narrow, so PSVT is often referred to as narrow complex tachycardia.

PSVT can have an irregular or regular ventricular rate. The most common causes of PSVT with irregular ventricular rate are atrial fibrillation and atrial flutter. Atrial flutter with a consistent conduction pattern may appear regular instead. Common causes of PSVT with regular ventricular rate include atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT), and atrial tachycardia (AT).

PSVT can occur in any age group. Atrial fibrillation is the most common form of PSVT, with the highest incidence and prevalence. The risk of PSVT is doubled in women and increases with age.

Risk factors for PSVT include cardiac disease (myocardial infarction, heart failure, mitral valve prolapse, myocarditis, pericarditis, or structural heart disease), respiratory disease (chronic lung disease, pneumonia, pulmonary embolism, or hypoxemia), and hyperthyroidism. Many patients with PSVT have no active cardiovascular disease. PSVT is also associated with medication and substance use including caffeine, nicotine, atropine, cocaine, amphetamines, alcohol, digoxin, and ecstasy.

The underlying pathophysiology often includes a reentry circuit in the heart or triggered, enhanced, or abnormal automaticity.

Clinical presentations include palpitations, diaphoresis, dizziness, polyuria, syncope or near syncope, nausea, shortness of breath, anxiety, fatigue, and discomfort in the back, neck, or chest. Some patients are asymptomatic. Patients with coronary artery disease or structural heart disease are more likely to present with chest pain or decompensated heart failure. Persistent PSVT can cause tachycardia-induced cardiomyopathy and new-onset heart failure.