Heart ❤️ Core, Cardiovascular

(A) In typical atrioventricular nodal reentrant tachycardia (antegrade conduction down the slow atrioventricular nodal pathway and retrograde conduction up the fast pathway), the retrograde P wave may not be seen or may be visible early after the QRS complex. When visible, it often appears as a pseudo R wave in lead V1. (B) In atrioventricular reciprocating tachycardia, there is typically a short RP interval, with the timing and morphology of the P wave dependent on the site and conduction velocity of the accessory pathway. (C) Atrial tachycardia typically produces variable RP and PR intervals because atrioventricular conduction depends on atrioventricular nodal properties and the tachycardia rate. In atrial tachycardia, the morphology and axis of the P wave are influenced by atrial site of origin and tachycardia mechanism. Short- and long-term therapies are discussed in the text. (D) Normal sinus rhythm.

The most common types of supraventricular tachycardia are caused by a reentry phenomenon producing accelerated heart rates. Symptoms may include palpitations (including possible pulsations in the neck), chest pain, fatigue, lightheadedness or dizziness, and dyspnea. It is unusual for supraventricular tachycardia to be caused by structurally abnormal hearts. Diagnosis is often delayed because of the misdiagnosis of anxiety or panic disorder. Patient history is important in uncovering the diagnosis, whereas the physical examination may or may not be helpful. A Holter monitor or an event recorder is usually needed to capture the arrhythmia and confirm a diagnosis. Treatment consists of short-term or as-needed pharmacotherapy using calcium channel or beta blockers when vagal maneuvers fail to halt or slow the rhythm. In those who require long-term pharmacotherapy, atrioventricular nodal blocking agents or class Ic or III antiarrhythmics can be used; however, these agents should generally be managed by a cardiologist. Catheter ablation is an option in patients with persistent or recurrent supraventricular tachycardia who are unable to tolerate long-term pharmacologic treatment. If Wolff-Parkinson-White syndrome is present, expedient referral to a cardiologist is warranted because ablation is a potentially curative option