title: Response of pulmonary vein potentials to premature stimulation.
abstract: BACKGROUND
  Pulmonary vein potentials reflect depolarization of muscle fascicles within the myocardial sleeves that surround the pulmonary veins. The response of pulmonary vein potentials to premature stimulation has not been described.
  
  
  RESULTS
  In 31 patients with paroxysmal atrial fibrillation referred for segmental isolation of the pulmonary veins, programmed stimulation with a single atrial extrastimulus was performed from the coronary sinus. Bipolar and unipolar electrograms were recorded with a decapolar Lasso catheter positioned sequentially within the left superior, left inferior, and right superior pulmonary veins, near the ostium. Premature stimulation often resulted in greater separation of the atrial and pulmonary vein potentials recorded within the pulmonary veins, fractionation of the pulmonary vein potentials, a change in the circumferential activation sequence of the pulmonary vein potentials, and dropout of pulmonary vein potentials.
  
  
  CONCLUSIONS
  In response to premature stimulation, the muscle fascicles within the myocardial sleeves that surround the pulmonary veins display a greater degree of decremental conduction than do the myocardial fibers in the adjacent left atrium, and they display heterogeneity in conduction properties and refractoriness. Discrimination of pulmonary vein potentials from atrial electrograms is facilitated by premature stimulation.
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0022, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozaydin
authors.forename: Radmira
authors.initials: R
authors.lastname: Greenstein
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Knight
authors.forename: S Adam
authors.initials: SA
authors.lastname: Strickberger
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
mesh_terms: D000792:Angiography; D004558:Electric Stimulation; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000294:innervation / Q000502:physiology*; D009206:Myocardium / Q000473:pathology; D011667:Pulmonary Veins / Q000473:pathology / Q000502:physiology*; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology