Paroxysmal supraventricular tachycardia (PSVT) primarily includes atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT). Clinically, these are characterized by regular and rapid tachycardia with sudden onset and termination. The electrocardiogram typically shows normal QRS complex morphology and regular RR intervals. The common mechanism is reentry; in AVNRT, the reentrant circuit is located within the AV node, while in AVRT, the circuit involves the AV junction, accessory pathways, atria, and ventricles, and is closely related to pre-excitation syndromes.
To be continued