Indications for diagnosis and/or determining prognosis:
(1) history of persistent palpitations
(2) history of recurrent syncope of undetermined etiology
(3) history of presyncope with impaired left ventricular function
(4) investigation of arrhythmias with narrow QRS complexes
(5) investigation of tachycardia with wide QRS complexes of undetermined cause
(6) investigation of ventricular arrhythmias
(7) sustained ventricular tachycardia or cardiac arrest not explained by acute myocardial infarction, drug toxicity or electrolyte imbalance
(8) testing of an implanted cardioverter defibrillator (ICD)
(9) second degree atrioventricular block (for evaluation of need for permanent pacemaker)
(10) symptomatic hypertrophic cardiomyopathy (prognostic)
(11) investigation of nonsustained ventricular tachycardia occurring more than 3 weeks after an acute myocardial infarction and with low (<= 35%) left ventricular ejection fraction (page 625, to identify risk factors for sudden cardiac arrest)
Indications for management:
(1) radiofrequency ablation of accessory conduction pathways
(2) radiofrequency ablation of paroxysmal supraventricular or junctional tachycardias
(3) radiofrequency ablation of atrial flutter or fibrillation
(4) radiofrequency ablation of venticular arrhythmias
Contraindications:
(1) severe aortic stenosis
(2) unstable coronary artery disease
(3) severe stenosis of the left main coronary artery
(4) severe electrolyte imbalances
