In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.
COVID-19 and Cardiology Read more

The implanted cardioverter-defibrillator 20 years ago and now: What does the future hold?

EHRA 2018 Congress News

Director of Cardiac Pacing & Tachyarrhythmia Devices, Professor Bruce Wilkoff (Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA) has spent much of his career investigating ways to improve pacemakers and defibrillators, with a particular focus on device reliability and lead extraction. Looking back on a lifetime of experience in this area, he gives his thoughts on how far cardiac devices have come and what lies ahead.

Implantable Cardioverter \ Defibrillator
Arrhythmias and Device Therapy

wilkoff_bruce-2015.jpgWhat attracted you to the field of electrophysiology?

Having studied biomedical engineering before my medical degree, I was always interested in the technical aspects of medicine and I became fascinated by pacemakers. There were no defibrillators when I did my medical and electrophysiology training. So it was a welcome, but steep, learning curve when my first real introduction to them came in 1986—around the time implanted cardioverter-defibrillators (ICDs) received US FDA approval—when I joined the Cleveland Clinic and had to present findings at the World Congress of Cardiology from the first 25 patients who had received implants at the clinic.

What is your greatest achievement in electrophysiology?

For about 30 years I’ve been working on finding ways to manage the morbidity associated with pacemaker and ICD therapy and I would like to think it is an area to which I have made significant contributions. Much of the time has been spent developing the tools and techniques for transvenous lead extraction in order to fix broken or infected leads, developing metrics to determine what makes a lead good or bad and finding ways to reduce device infections.

Don’t miss!
Learn more about lead extraction from Prof. Wilkoff and other experts in this afternoon’s How-to session
Today, 16:30 – 18:00; Wenckebach.

How have ICDs changed the lives of patients?

The integration, twenty years ago, of pacemaker and defibrillator therapy made a dramatic difference to the outcomes of patients, although we are still trying to find the best way to combine these components and to understand which patients to pace and how best to pace them. Back in 1986, you needed to survive two cardiac arrests to be considered for an implanted defibrillator. By 1998, we had started to identify patients with coronary artery disease (CAD)—those who had suffered a heart attack and had inducible ventricular tachycardia—who were candidates for primary prevention device implantation. Not too long afterwards, studies like SCD-HeFT1 demonstrated that many patients with cardiomyopathy, irrespective of CAD, were good candidates for ICDs. It was after this that the dual-chamber devices really took off and began to be used widely. However, in the early 2000s I headed the DAVID trial,2 which showed that pacing the right ventricle in patients with no indication for pacing actually worsened outcomes, and this was a substantial change to the thinking at that time. The next big development in this area, cardiac resynchronisation therapy (CRT), altered practice again. Currently, up to 40% of patients receive CRT with their ICD therapy. Already, the next steps in CRT are being explored. The AdaptResponse trial,3 of which I’m the principal investigator, is looking at the benefits of CRT using algorithm-derived left ventricular fusion pacing compared with conventional CRT in patients with normal atrioventricular conduction. Another area in which we have seen significant advances is the programming of devices. Originally, shocking was considered to be the most important intervention during ventricular tachycardia. We now understand that minimising the number of shocks the patient receives is key and we have learned how to programme devices to give the best survival with the fewest shocks.

What is the biggest challenge ahead for ICDs?

We need to further address the morbidity associated with these devices.

In ICDs we have one of the most dramatically effective life-saving therapies—if we want them to save more lives, we have to reduce morbidity.

We have already discussed that correct device programming can reduce the number of shocks, and therefore pain, and improve the patient experience. Another way we can reduce pain and the impact of the device on quality of life is by eliminating, or at least reducing, the number of leads, and we are already seeing the early steps of pacing without leads or with subcutaneous leads. We also need to work on developing devices that are less likely to fail. I think that making this invasive therapy less invasive and more reliable is where the future lies.


  1. Bardy GH, et al. N Engl J Med 2005;352:225–37.
  2. Wilkoff BL, et al. JAMA 2002;288:3115–23.
  3. Filippatos G, et al. Eur J Heart Fail 2017;19:950–7.