title: Role of transesophageal echocardiography in the evaluation of patients with clinical pacemaker syndrome.
abstract: OBJECTIVE
  The goal of this study was to investigate the possible role of transesophageal echocardiography in the evaluation of patients with clinical pacemaker syndrome.
  
  
  BACKGROUND
  Several reports on transthoracic echocardiographic features of ventricular pacing were described; however, no previous study of transesophageal echocardiography has been undertaken in patients at the severe end of pacemaker syndrome who need reprogramming of dual-chamber pacing for symptom relief.
  
  
  METHODS
  Twelve patients with ventricular-inhibited pacemakers (VVI) with clinical symptomatic pacemaker syndrome (group I) and 10 patients with VVI without pacemaker syndrome (group II) were prospectively studied. The two groups were pacemaker dependent and had persistent ventriculoatrial conduction. Transesophageal echocardiographic parameters were assessed in group II and within 6 hours before reprogramming to the DDD mode in group I. Follow-up transesophageal echocardiographic study was performed 28+/-5 days after reprogramming in group I.
  
  
  RESULTS
  All patients in group I had subjective improvements of symptoms after DDD reprogramming. The atrial reverse flow velocities of pulmonary veins in group I before reprogramming were significantly higher in group II (39.3+/-11.4 versus 15.7+/-13.5 cm/sec, p < 0.0001). Spontaneous echo contrast in the descending aorta was detected in all patients from group I before reprogramming. The prevalence of significant mitral regurgitation (> or = moderate) was significantly higher in group I before reprogramming than in group II (67% versus 8%, p = 0.01). Significant mitral regurgitation and spontaneous echo contrast in the descending aorta in group I disappeared after reprogramming to the DDD mode.
  
  
  CONCLUSIONS
  Transesophageal echocardiography provides physiologic, pacemaker-related hemodynamic changes in paced patients. Significantly higher atrial reverse flow velocities of pulmonary veins, increased frequency of spontaneous echo contrast in the descending aorta, and significant mitral regurgitation are peculiar echocardiographic findings in patients with VVI with clinical pacemaker syndrome.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Republic of China.
authors.forename: T M
authors.initials: TM
authors.lastname: Lee
authors.forename: S F
authors.initials: SF
authors.lastname: Su
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lin
authors.forename: W J
authors.initials: WJ
authors.lastname: Chen
authors.forename: M F
authors.initials: MF
authors.lastname: Chen
authors.forename: C S
authors.initials: CS
authors.lastname: Liau
authors.forename: Y T
authors.initials: YT
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D016279:Atrial Function, Left; D001783:Blood Flow Velocity; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006329:Heart Conduction System; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000000981:diagnostic imaging; D013577:Syndrome