From the Guidelines
Atrial ectopic tachycardia secondary to permanent junctional reciprocating tachycardia (PJRT) that is heritable is diagnosed based on the presence of a concealed accessory pathway with slow retrograde conduction, typically presenting with incessant tachycardia. The diagnosis of PJRT is made based on the characteristic electrocardiogram (ECG) findings, including a narrow QRS complex and a retrograde P wave, as described in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1. Some key points to consider in the diagnosis and management of PJRT include:
- The presence of a concealed accessory pathway with slow retrograde conduction, which is a hallmark of PJRT 1
- The typical presentation with incessant tachycardia, which can lead to tachycardia-induced cardiomyopathy if left untreated 1
- The use of antiarrhythmic medications, such as beta-blockers, calcium channel blockers, or class IC antiarrhythmics, as initial treatment options 1
- The consideration of catheter ablation of the accessory pathway for refractory cases, with success rates exceeding 90% 1
- The importance of genetic testing in cases with a strong family history or associated congenital heart disease, as PJRT can have heritable components 1 It is essential to note that while PJRT can have heritable components, it is not typically considered a primarily genetic disorder, and the pathophysiology involves abnormal electrical circuits or focal triggers rather than primarily genetic ion channel dysfunction 1.
From the Research
Diagnosis of Atrial Ectopic Tachycardia
- Atrial ectopic tachycardia, secondary to permanent junctional reciprocating tachycardia (PJRT), that is heritable can be diagnosed using electrophysiological findings and long-term follow-up of patients with the permanent form of junctional reciprocating tachycardia treated by catheter ablation 2.
- The electrocardiographic hallmarks of PJRT include an RP interval > PR with inverted P waves in leads II, III, aVF and V3-V6 3.
- During tachycardia, retrograde ventriculo-atrial conduction occurs over an accessory pathway with decremental conduction properties, located predominantly in the posteroseptal zone 3, 4.
Location of Accessory Pathway
- The location of the accessory pathway in patients with PJRT can be determined using radiofrequency catheter ablation, with the majority of pathways located in the posteroseptal zone 3, 4, 5.
- Other locations of the accessory pathway include right midseptal, right posterior, right lateral, left posterior, left lateral, left posterolateral, left anterolateral, left posteroseptal, middle cardiac vein, and left coronary cusp 4, 5.
Treatment and Outcomes
- Radiofrequency catheter ablation is a safe and effective treatment for patients with PJRT, with a high success rate and low recurrence rate 2, 6, 3, 4, 5.
- The treatment can also improve left ventricular systolic function in patients with tachycardia-induced cardiomyopathy (TIC) 6, 3, 4, 5.
- Long-term follow-up results show that radiofrequency catheter ablation can provide a high overall long-term success rate, with none of the patients having recurrence after repeat ablations 5.