title: Transmyocardial laser revascularization: epicardial ECG detection provides efficient R-wave triggering during mobilization of the heart.
abstract: OBJECTIVE
  In order to achieve an accurate intraoperative ECG detection, a new technique in detecting the trigger-signal was developed. In contrast to the traditional three-lead ECG-configuration, the left leg electrode was connected to a transient epicardial pacemaker electrode on the left-ventricular surface.
  
  
  BACKGROUND
  The Holmium:YAG-Laser for Transmyocardial Laser Revascularization (TMLR) is R-wave-triggered, providing the release of energy only during the refractory period of the heart cycle. However, an exact ECG-triggering during mobilization of the apex and/or posterior wall is difficult to achieve by using conventional ECG-configuration, therefore increasing the risk for mistriggering and induction of arrhythmias during TMLR.
  
  
  METHODS
  Two groups of patients, all undergoing stand alone TMLR-procedures via left minithoracotomy, were compared. Ten patients were operated with the conventional ECG configuration (group 1) and ten patients with the modified epicardial ECG configuration (group 2).
  
  
  RESULTS
  In patients of group 1, as a result of a loss of the trigger signal or due to the triggering of artifacts, the incidence of correctly triggered QRS-complexes was 56% of all documented QRS-complexes. In contrast, an excellent triggering was observed in 98% (p < 0.001) in group 2, resulting in a reduction of laser operative time by 35% (p < 0.001) and a decrease in the incidence of intraoperative ventricular fibrillation (0 vs. 3).
  
  
  CONCLUSIONS
  In conclusion, this new ECG configuration is a simple but effective method in achieving an excellent ECG signal during all stages of TMLR. As a consequence, a reduction in operative time and incidence of ventricular fibrillation can be achieved.
authors.affiliation: Department of General Surgery, General Hospital, University of Vienna, Austria. nerminovich@hotmail.com
authors.forename: Thomas
authors.initials: T
authors.lastname: Wild
authors.forename: Nermin
authors.initials: N
authors.lastname: Serbecic
authors.forename: Sven Christoph
authors.initials: SC
authors.lastname: Beutelspacher
authors.forename: Meinhard
authors.initials: M
authors.lastname: Ploner
authors.forename: Zeno
authors.initials: Z
authors.lastname: Deckert
authors.forename: Rainald
authors.initials: R
authors.lastname: Seitelberger
mesh_terms: D000368:Aged; D004562:Electrocardiography / Q000379:methods*; D004594:Electrophysiology / Q000379:methods; D006321:Heart / Q000502:physiology; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009204:Myocardial Revascularization / Q000379:methods*; D010496:Pericardium; D016896:Treatment Outcome