Junctional Ectopic Tachycardia Clinical Presentation

Updated: Sep 13, 2016
  • Author: M Silvana Horenstein, MD; Chief Editor: Stuart Berger, MD  more...
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Presentation

History

In general, postoperative junctional ectopic tachycardia (JET) occurs in the hospital with rapid hemodynamic instability, whereas congenital JET may have a more insidious course before producing signs of congestive heart failure.

Postoperative JET usually begins 6-72 hours following cardiopulmonary bypass surgery for repair of congenital heart lesions. It is usually identified during monitoring in the ICU. A fall in blood pressure and cardiac output usually occurs concomitantly.

The onset of congenital JET is often insidious. The clinical presentation of congenital JET may occur from birth to age 4 weeks. However, sporadic cases of intrauterine tachycardia have been reported in infants who presented with JET at birth. Prolonged moderate tachycardia may not be recognized until myocardial dysfunction and signs of congestive heart failure ensue. Heart rate variability is decreased; the heart rate is very regular except for occasional sinus capture beats.

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Physical

Patients with congenital JET present with moderate tachycardia and signs of congestive heart failure. If VA dissociation has occurred, which is usually the case, cannon waves may be present in the jugular venous pulse, and the intensity of the first heart sound varies.

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Causes

The speculative causes of postoperative JET are discussed in Pathophysiology. The one fairly uniform finding is a preceding cardiopulmonary bypass surgery.

The cause of congenital JET is unknown. A family history of JET has been reported in 50-55% patients. It appears that patients with the angiotensin-converting enzyme insertion/deletion (ACE D/D) polymorphism have a greater than 2-fold increase in the incidence of postoperative JET. Therefore, it is hypothesized that the renin-angiotensin-aldosterone system plays an important role in the etiology of JET. [7]

Postoperative JET occurs more often after tetralogy of Fallot repair. [8] It has been associated with resection of muscle bundles, increased traction through the right atrium for relief of right ventricular outflow tract obstruction, and with higher bypass temperatures.

The nonparoxysmal form of junctional tachycardia, which may be a triggered arrhythmia, is observed following digoxin overdose.

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