Radiofrequency-Triggered Pacemakers: Uses and Limitations

Abstract

Seven patients with either recurrent paroxysmal supraventricular tachycardia (five), alternatinng bradycardiatachycardia (one), or ventricular tachycardia (one) underwent insertion of permanent radiofrequency-triggered pacemakers. Follow-up evaluation (36 +/- 24 months, mean +/- SD) revealed that arrhythmias were well controlled in five of seven patients, although three of the five required medication to decrease frequency of arrhythmias. Overdrive pacing was ineffective in one patient with Wolff-Parkinson-White syndrome who had recurrent bouts of atrial fibrillation or atrial flutter. One additional patient with ventricular tachycardia became refractory to overdrive atrial pacing. These studies document the long-term effectiveness of radiofrequency pacemakers in some patients with recurrent refractory arrhythmias. Careful patient selection and electrophysiologic studies are mandatory before implantation of a permanent radiofrequency pacemaker. Physicians must be aware of both the benefits and possible limitations of radiofrequency pacemakers in order to choose between pacemaker versus surgical intervention in patients with cardiac arrhythmias refractory to standard drug therapy.

Remote regulation of glucose homeostasis in mice using genetically encoded nanoparticles

“…Additionally, gene therapies for certain disorders require tight regulation 28 or the ability to titrate transgene expression to biological response 29 . In this report, we have shown that ferritin tethered to TRPV1 can effectively modulate transgene expression in stem cell implants and in tissue with virally mediated transgene delivery in response to RF and magnetic fields, both of which have been used in clinical practice for setting pacemakers 8 and treating depression 30 , respectively. Finally, because TRPV1 gates Ca 2+ , it is possible this system could regulate the activity of neurons as TRPV1 activation by chemical ligands has previously been shown to modulate neural activity 31 .…”

“…Radio waves, which freely penetrate tissue, are already used clinically to control pacemakers and other devices 8 . Recent reports have demonstrated remote radio wave activation of engineered cells in vivo using extracellular nanoparticles 9,10 and a modified temperature-sensitive channel to control transgene expression 9 .…”

The third decade of cardiac pacing. Multiprogrammable pulse generators.

“…Pacing techniques needing the active participation of the patient (or close relative) when the tachycardia develops outside hospital require an alert, intelligent patient with a positive attitude, who understands his condition and symptoms. '9 20 The need for active patient intervention is a distinct disadvantage if the tachycardia occurs after or during sleep, or is associated with syncope, dizziness, chest pain, or unawareness before haemodynamic deterioration. The various autonomic and compensatory reflex mechanisms triggered at the onset of the tachycardia may make its termination more difficult if allowed to continue for more than a few seconds.2' For this reason many investigators consider that the ideal antitachycardia pacemaker should automatically turn itself on when the tachycardia starts and switch itself off automatically when the tachycardia ends.22 Precise electrophysiological characterisation of reentry tachycardia is essential before using these complex and potentially dangerous devices.…”

Patient‐activated anti‐tachycardia pacing in adult congenital heart disease

“…[3][4][5][6][7] A third management strategy is atrial antitachycardia pacing (ATP). When ATP technology was first developed, many ATP devices required patient activation to delivery therapy, [8][9][10] but as technology advanced, most included automatic tachycardia detection. Early experience with atrial ATP in pediatric and congenital heart disease was complicated by proarrhythmic effects and inability to provide rate-responsive pacing or AV sequential pacing.…”