Management of patients after catheter ablation of ventricular tachycardia

Radiofrequency catheter ablation of postinfarction ventricular tachycardia: long-term success and the significance of inducible nonclinical arrhythmias

BACKGROUND

Radiofrequency (RF) catheter ablation is effective therapy for monomorphic ventricular tachycardia (VT) in patients without structural heart disease. In patients with postinfarction VT; however, this procedure has been used predominantly as adjunctive therapy, targeting only the patient's clinically documented arrhythmia. By targeting all inducible, sustained VT morphologies, we sought to determine the utility of RF catheter ablation as a primary cure in patients who present with hemodynamically tolerated VT.

METHODS AND RESULTS

RF ablation was attempted in 35 patients with a previous myocardial infarction and recurrent, hemodynamically tolerated VT. A mean of 3.9+/-2.7 VTs were induced per patient (range, 1 to 10). The clinically documented arrhythmia was successfully ablated in 30 of 35 patients (86%), and on follow-up electrophysiological testing, 11 patients had no inducible VT and were discharged without other therapy. Nineteen patients had inducible "nonclinical" arrhythmias on follow-up testing, and the majority underwent cardiac defibrillator implantation. Freedom from recurrent arrhythmias, including sudden death, was 91% in patients without inducible VT and 53% in patients with persistently inducible "nonclinical" arrhythmias (P<.05; mean follow-up, 17+/-12 and 12+/-11 months, respectively).

CONCLUSIONS

In patients with well-tolerated VT, RF catheter ablation may be useful as a primary cure if no other ventricular arrhythmias are inducible on follow-up testing. Ablation of all hemodynamically tolerated arrhythmias should be attempted in patients with multiple inducible VT morphologies because of the high rate of recurrence of unablated VTs in these patients.

Challenges of device therapy for ventricular tachycardia in the rate range of sinus rhythm

A method is described for patient-activated detection of ventricular tachycardia, under circumstances in which automatic algorithms fail. We present a case of a patient with an implanted defibrillator (Jewel PCD) who presented with symptomatic exercise-induced ventricular tachycardia that was only marginally faster than the preceding sinus tachycardia. Programming the sudden onset criterion avoided delivery of therapy into sinus tachycardia, but failed to detect ventricular tachycardia. Brief application of a magnet resulted in successful detection and therapy. This method is device-specific and requires a co-operative, insightful patient. The benefits and risks of such an approach are discussed.

Nonpharmacological therapy of ventricular tachyarrhythmias: observations in 554 patients

It has been shown that conventional antiarrhythmic drug treatment is debatable, and there is growing interest in nonpharmacological techniques. We studied the outcome of 554 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) who underwent nonpharmacological techniques from March 1980 to June 1994 at our institution. Catheter ablation was performed in 51 patients (G1), map guided surgery in 147 (G2), and cardioverter defibrillator implantation (ICD) in 356 (G3). During a mean follow-up of 37 +/- 12 (< 1-137) months, incidence of sudden death (G1 4%, G2 6%, G3 3%) and cardiac death (G1 7%, G2 16%, G3 8%) were relatively low, and there was no significant differences between G1-G3. VT/VF recurrences occurred more frequently in G1 (57%) than in G2 (18%) (P < 0.01). ICD discharges occurred in 69% of patients. We conclude that nonpharmacological techniques lead to low sudden death rates; however, there is a high rate of recurrence in G1. Risk stratification is necessary to select the ideal therapy for each individual patient.

The future of arrhythmia surgery

The future of arrhythmia surgery is discussed in light of the 25 years of historical developments that have led to the present explosion in antiarrhythmic therapies and technologies. The role of the arrhythmia surgeon in these developments is outlined, along with a number of exciting near-term and far-term developments that will continue to revolutionize therapeutic interventions for arrhythmia problems.