title: [Electrophysiological and clinical characterization of left atrial macroreentrant tachycardia].
abstract: OBJECTIVE
  We are reporting the characteristics of 9 patients with left atrial macroreentrant tachycardia, an arrhythmia not well studied in man.
  
  
  METHODS
  Mean age was 60 years and 7 were men. Tachycardia was spontaneous in 6 and induced in 3. Two had no heart disease, 2 sick sinus syndrome, 3 aortic prosthesis, 2 hypertension, 1 cardiomyopathy and 1 chronic bronchitis. Simultaneous recordings from right atrial, coronary sinus and right pulmonary artery were obtained at baseline and with atrial pacing. Macroreentrant tachycardia was diagnosed when entrainment with fusion was documented.
  
  
  RESULTS
  Cycle length was 230-440 ms (287 67). The ECG showed atypical flutter in 3 patients and P waves with flat baseline in 6. Coronary sinus activation was distal to proximal in 7. Right atrial activation was circular in 3 with previous typical flutter ablation. Entrainment from the right atrium produced long return cycles in the right atrial recordings, but equal to basal tachycardic cycle in coronary sinus recordings. Entrainment from the coronary sinus produced local return cycles equal to basal cycle in 8 and prolonged in 1. After stimulation, 4 recovered sinus rhythm, 4 went to atrial fibrillation and 1 had no change. After a follow-up of 9-19 months 5 remain in sinus rhythm treated with antiarrhythmic drugs and/or atrial pacing.
  
  
  CONCLUSIONS
  Left atrial macroreentrant tachycardia is associated with organic heart disease. The ECG most frequent pattern tends to show P waves with flat baseline at a relatively slow rate. Most circuits turn clockwise in anterior view. Atrial stimulation is not very effective for cardioversion to sinus rhythm. The prognosis of long term rhythm is uncertain.
authors.affiliation: Servicio de Cardiología, Hospital Universitario de Getafe, Madrid, Spain.
authors.forename: Carina P
authors.initials: CP
authors.lastname: Cantale
authors.forename: Francisco
authors.initials: F
authors.lastname: García-Cosío
authors.forename: María A
authors.initials: MA
authors.lastname: Montero
authors.forename: Agustín
authors.initials: A
authors.lastname: Pastor
authors.forename: Ambrosio
authors.initials: A
authors.lastname: Núñez
authors.forename: Antonio
authors.initials: A
authors.lastname: Goicolea
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013615:Tachycardia, Sinoatrial Nodal Reentry / Q000503:physiopathology*
vernacular_title: Caracterización electrofisiológica y clínica de la taquicardia macrorreentrante auricular izquierda.