Permanent Junctional Reciprocating Tachycardia

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Commonly observed in children

• Heart rate may vary from 120 to 250 bpm

• Tachycardia cardiomyopathy may occur because the tachycardia tends to be incessant

• This is a reentrant tachycardia and quite sensitive to autonomic manipulation

• Tachycardia tends to slow down with age because retrograde conduction through the accessory pathway tends to slow down

GENERAL CONSIDERATIONS

• This is reentrant arrhythmia induced by a retrogradely conducting (concealed) decremental accessory pathway

• It may occur in the perioperative period in infants and children

• The perioperative form is self-limiting; however, heart rates > 200 bpm may cause marked hypotension

• The idiopathic form can persist for years, leading to tachycardia cardiomyopathy

• P waves precede the QRS complexes (long RP tachycardia)

• The P waves are inverted in inferior leads

• The pathway causing this type of orthodromic reciprocating tachycardia is commonly located at or near the os of the coronary sinus

• Drug therapy does not control this arrhythmia secondary to prolonged conduction property of the accessory pathway, although rate control can be achieved

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Palpitations

• Shortness of breath

• Features of congestive heart failure

PHYSICAL EXAM FINDINGS

• Elevated jugular venous distention

• S₃ may be heard during sinus rhythm

• Bilateral pulmonary rales

DIFFERENTIAL DIAGNOSIS

• Automatic atrial tachycardia

• Atypical atrioventricular nodal reentrant tachycardia

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, basic metabolic panel

ELECTROCARDIOGRAPHY

• ECG shows a narrow QRS with inverted P waves in the inferior leads

• Outpatient cardiac monitor is used to detect and document rhythm disturbance

IMAGING STUDIES

• Echocardiogram to evaluate left ventricular function

DIAGNOSTIC PROCEDURES

• Electrophysiologic study to define mechanism of rhythm disturbance and determine suitability for ablation

TREATMENT

CARDIOLOGY REFERRAL

• Patients suspected to have this disorder should be referred to an electrophysiologist

HOSPITALIZATION CRITERIA

• Patients in active heart failure

• After ablation for 24 hours

MEDICATIONS

• Drug therapy is frequently not helpful

• Class IC drug or amiodarone may achieve rate control

• Digoxin has no effect, and verapamil may accelerate the tachycardia

• Beta blockers may control heart rate in adults

THERAPEUTIC PROCEDURES

• Radiofrequency ablation is successful in 95% of patients

SURGERY

• Not required

MONITORING

• ECG monitoring in the hospital

DIET AND ACTIVITY

• General healthy lifestyle

ONGOING MANAGEMENT

HOSPITAL DISCHARGE CRITERIA

• Adequate treatment of ...