Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ 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 ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more! GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessCardiology 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessCardiology Full Site: One-Year Individual Subscription $595 USD Buy Now View All Subscription Options