Skip to Main Content

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

  • Ventricular tachycardia occurs with no evidence of structural heart disease

  • Lack of structural heart disease is defined by normal findings on ECG, echocardiogram, and coronary angiography

GENERAL CONSIDERATIONS

  • Tachycardia may be caused by triggered activity (typically left or right ventricular outflow tract tachycardia) or reentry (typically left ventricular tachycardia)

  • Triggered outflow tract tachycardias are dependent on cyclic adenosine monophosphate and often respond to IV adenosine

  • MRI may be abnormal and show ventricular fatty deposits or frank right ventricular dysplasia, which is a hallmark of arrhythmogenic right ventricular dysplasia (ARVD)

  • The idiopathic left ventricular tachycardia is more often induced by atrial pacing and is sensitive to verapamil

  • Sudden death is rare, and implantable cardioverter-defibrillator (ICD) is not always required since cure rate with ablation can be high

  • Overall, the arrhythmia carries a benign prognosis

  • These tachycardias are generally monomorphic

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

  • Palpitations

  • Syncope

  • Presyncope

PHYSICAL EXAM FINDINGS

  • Normal physical exam findings

DIFFERENTIAL DIAGNOSIS

  • Intramyocardial reentrant ventricular tachycardia

  • ARVD

  • Mahaim tachycardia

  • Tachycardia following repair of tetralogy of Fallot

DIAGNOSTIC EVALUATION

LABORATORY TESTS

  • Thyroid-stimulating hormone

  • Comprehensive metabolic panel

ELECTROCARDIOGRAPHY

  • ECG to assess morphology of the QRS during VT

  • Left bundle branch block (LBBB), inferior axis with a late R/S precordial transition suggests right ventricular outflow tract (RVOT) origin

  • Right bundle branch block (RBBB), left or superior axis suggests left posterior fascicle in origin

  • RBBB, right inferior axis suggests left anterior fascicle in origin

  • Exercise stress test may be used to initiate tachycardia

  • Signal-averaged ECG may be helpful (unremarkable in RVOT and ventricular tachycardia and abnormal in ARVD)

IMAGING STUDIES

  • MRI of the heart to exclude right ventricular dysplasia and to assess for any ventricular scar (substrate for VT)

DIAGNOSTIC PROCEDURES

  • Electrophysiology study to establish mechanism and determine suitability for ablation

TREATMENT

CARDIOLOGY REFERRAL

  • All patients require evaluation by a cardiac electrophysiologist

HOSPITALIZATION CRITERIA

  • Following syncope

MEDICATIONS

  • Beta blockers, metoprolol 50 mg PO twice daily to a maximum usual dosage of 200 mg/day; or verapamil, start 180 mg/day, next dose 360 mg/day

  • Class IA, IC, or III antiarrhythmic agents

  • In acute conditions, in the emergency room, adenosine can be used to terminate ventricular tachycardia

THERAPEUTIC PROCEDURES

  • Radiofrequency ablation in appropriate cases

SURGERY

  • Generally not required

MONITORING

  • ECG monitoring in hospital

DIET AND ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.