title: First-in-man implantation of leadless ultrasound-based cardiac stimulation pacing system: novel endocardial left ventricular resynchronization therapy in heart failure patients.
abstract: OBJECTIVE
  The importance of specific-site pacing is increasingly recognized in cardiac resynchronization therapy (CRT). Using current pacing technology, site selection is still largely limited by coronary vein anatomy, whereas left ventricular (LV) endocardial pacing using current lead technology is risky and challenging. To overcome limitations and complications with current LV pacing, the feasibility of a new technology enabling LV endocardial stimulation without the use of a lead is being evaluated in patients.
  
  
  RESULTS
  Patients presented in this report are part of the Wireless Stimulation Endocardially for CRT Trial (WiSE-CRT) study investigating the safety and performance of the WiCS(®)-LV system, an implantable cardiac pacing system capable of leadless pacing based on converting ultrasound energy to electrical energy. Three patients are presented: (i) a patient with an existing implantable defibrillator, (ii) a patient with a CRT system whose LV lead does not capture, and (iii) a CRT patient classified as a non-responder. All three patients were successfully treated. Acute electrical pacing thresholds ranged from 0.7 to 1.0 V at 0.5 ms; all patients retained captured at 6 months. Functional New York Heart Association class significantly changed (Pre: III in two patients, and IV in one patient; Post: I in one patient, II in one patient, and II-III in one patient), and LV ejection fraction increased from 23.7 ± 3.4% to 39 ± 6.2% (P < 0.017).
  
  
  CONCLUSIONS
  This report on three first-in-man cases shows that leadless endocardial pacing may be safely applied and effective, conferring short- to-mid-term symptomatic benefits. These promising findings are yet to be substantiated by larger ongoing studies.
  
  
  BACKGROUND
  http://clinicaltrials.gov/ct2/show/NCT01294527.
authors.affiliation: Division of Cardiology, Fondazione Cardiocentro Ticino, Via Tesserete 48, CH-6900 Lugano, Switzerland. angelo.auricchio@cardiocentro.org
authors.forename: Angelo
authors.initials: A
authors.lastname: Auricchio
authors.forename: Peter-Paul
authors.initials: PP
authors.lastname: Delnoy
authors.forename: François
authors.initials: F
authors.lastname: Regoli
authors.forename: Martin
authors.initials: M
authors.lastname: Seifert
authors.forename: Thanasie
authors.initials: T
authors.lastname: Markou
authors.forename: Christian
authors.initials: C
authors.lastname: Butter
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis / Q000517:prevention & control*; D006801:Humans; D008297:Male; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation; D010138:Pacemaker, Artificial; D010865:Pilot Projects; D019736:Prostheses and Implants; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis / Q000517:prevention & control*; D059015:Wireless Technology / Q000295:instrumentation*
keywords: Cardiac pacing; Cardiac resynchronization therapy; Heart failure; Left ventricle; Outcome