Search

The Multicenter Unsustained Tachycardia Trial (MUSTT) demonstrated that electrophysiologic testing (EP)-guided therapy significantly reduces arrhythmic death and cardiac arrest in patients with coronary artery disease, a left ventricular ejection fraction of 40% or less, nonsustained ventricular tachycardia, and inducible ventricular arrhythmia on EP testing-but only if the therapy includes an implantable defibrillator. All patients who meet the MUSTT inclusion criteria should undergo an EP test and if positive, should undergo defibrillator implantation.

BACKGROUND The coaxial design allows for thinner bipolar endocardial pacemaker leads, but recent reports have suggested a higher incidence of failure for this sophisticated configuration. OBJECTIVE To compare the long-term survival of bipolar coaxial and unipolar leads. METHODS Retrospective follow-up. RESULTS Between January 1, 1980 and June 30, 1991, 1142 bipolar coaxial leads and 1181 unipolar leads were implanted at the Cleveland Clinic. The mean follow-up was 33 ± 32 months (range 1 to 138 months). Ten bipolar coaxial leads failed (0.88%), as did 9 unipolar leads (0.76%). At 5 years the cumulative survival was 98.6% for both types of leads; however, at 10 years the survival of bipolar coaxial leads was only 92.4% compared with 98.6% of unipolar leads (P = .03; relative risk 2.7, 95% confidence interval = 1.1 to 6.9). CONCLUSIONS The sophisticated design of bipolar coaxial leads could be the cause of their increased vulnerability. The benefit- to-risk ratio of this design should be prospectively reevaluated.

The judicious use of antitachycardia pacemakers can enhance the benefits of automatic implantable cardioverter defibrillators in certain patients. Both devices were implanted in 10 highly selected patients with drug-refractory pace-terminable sustained ventricular tachycardia. During the observation period of 8 +/- 4.8 months, the automatic pacemakers detected 1,542 episodes of ventricular tachycardia and appropriately managed 1,373. The automatic implantable defibrillator was activated at least once in every patient; on two documented occasions, the defibrillator discharged because the automatic pacemaker accelerated the tachycardia. Concomitant antiarrhythmic drugs could be reduced but not withdrawn. With meticulous device programming and testing, the two systems in combination can work synergistically to manage malignant ventricular arrhythmias in carefully selected patients.

A device recall does not call for panic. Physicians should weigh the risks and benefits for the individual patient.