title: Safety of symptom-limited exercise testing in a big cohort of a modern ICD population.
abstract: BACKGROUND
  Exercise may predispose to ventricular arrhythmias especially in patients with congestive heart failure. As therapy with implanted cardioverter-defibrillators (ICDs) has become standard medical care, there is an emerging number of exercise tests that need to be performed in patients with ICDs. In contrast, little is known about the safety of symptom-limited exercise testing in these patients.
  
  
  RESULTS
  400 ICD patients performed symptom-limited exercise treadmill testing. 200 patients performed a ramp protocol with an initial workload of 0 W increased by 15 W every minute. Another 200 ICD patients did a slightly modified ramp protocol with again an initial workload of 0 W but with an increased capacity of 15 W every 2 min. The study population consists mainly of patients with ischemic (63%) and non-ischemic (34%) heart disease. Atrial fibrillation was present in 16% of the subjects. The mean ejection fraction was 28 ± 8, and 78% of the patients had an ejection fraction below 30%. In this cohort of patients, no sustained ventricular arrhythmias and no deaths occurred during or after exercise testing. No inappropriate shock delivery was observed. The modified ramp protocol resulted in a prolonged exercise time with equal exercise capacity but does not result in an enhanced susceptibility for ventricular arrhythmias.
  
  
  CONCLUSIONS
  Symptom-limited exercise treadmill testing in heart failure patients with ICDs is a safe procedure. The use of a ramp protocol is sufficient in terms of safety and is easy to perform in general practice. The exercise duration in heart failure patients with ICDs does not predict serious adverse events.
authors.affiliation: Department of Cardiology, Krankenhaus der Barmherzigen Brueder Trier, Nordallee 1, 54290, Trier, Germany. f.voss@bk-trier.de.
authors.forename: Frederik
authors.initials: F
authors.lastname: Voss
authors.affiliation: Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Schueler
authors.affiliation: Department of Cardiology, Krankenhaus der Barmherzigen Brueder Trier, Nordallee 1, 54290, Trier, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lauterbach
authors.affiliation: Department of Cardiology, Diakonie-Klinikum Schwaebisch Hall, Diakoniestr. 10, 74523, Schwaebisch Hall, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bauer
authors.affiliation: Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
authors.affiliation: Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
authors.forename: Ruediger
authors.initials: R
authors.lastname: Becker
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications; D017147:Defibrillators, Implantable; D005080:Exercise Test / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Exercise test; ICD; Ventricular arrhythmias