title: Effect of diltiazem and metoprolol on left atrial appendix functions in patients with nonvalvular chronic atrial fibrillation.
abstract: OBJECTIVE
  Thrombo-embolic events are the important cause of mortality and morbidity in patients with chronic atrial fibrillation (CAF). The origin of thromboembolism is often the left atrial appendix (LAA). Flow rate velocity (FRV) inside the LAA is the major determinant of thrombus formation. The aim of our study was to investigate the effects of diltiazem and metoprolol used for ventricular rate control on FRV of the LAA in CAF patients and thus to evaluate the positive or negative effects of these two drugs on thromboembolic events.
  
  
  METHODS
  Sixty-four patients were included in the study. All patients were suffering from CAF for more than a year. The patients were allocated to two groups according with agent used for rate control- metoprolol (Group 1; n=31) and diltiazem (Group 2; n=33). Transesophageal echocardiography was applied to all patients and LAA FRV was measured by a pulse wave Doppler in the 1/3 proximal portion of the LAA. The measurements were repeated after applying 5 mg metoprolol to Group 1 and 25 mg diltiazem to Group 2 via venous cannula.
  
  
  RESULTS
  In Group 1 after metoprolol LAA flow velocity changed from 0.25 +/- 0.90 m/s to 0.25 +/- 0.10 m/s (p>0.05). In group 2 after diltiazem left atrial appendix FRV decreased from 0.21 +/- 0.9 m/s to 0.19 +/- 0.6 m/s (p>0.05).
  
  
  CONCLUSIONS
  In patients with CAF metoprolol used for ventricular rate control had no effect on LAA flow velocity and the observed decrease in LAA flow rate velocity with intravenous diltiazem was insignificant.
authors.affiliation: Department of Cardiology, Medical School, Firat University, Elaziğ, Turkey. ilgink@yahoo.com
authors.forename: Ilgin
authors.initials: I
authors.lastname: Karaca
authors.forename: Naci
authors.initials: N
authors.lastname: Coşkun
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yavuzkir
authors.forename: Erdoğan
authors.initials: E
authors.lastname: Ilkay
authors.forename: Necati
authors.initials: N
authors.lastname: Dağli
authors.forename: Ahmet
authors.initials: A
authors.lastname: Işik
authors.forename: Mehmet
authors.initials: M
authors.lastname: Balin
authors.forename: Mehmet
authors.initials: M
authors.lastname: Akbulut
authors.forename: Nadi
authors.initials: N
authors.lastname: Arslan
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000502:physiology; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000187:drug effects*; D001783:Blood Flow Velocity / Q000187:drug effects; D002908:Chronic Disease; D004110:Diltiazem / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008875:Middle Aged; D013923:Thromboembolism / Q000517:prevention & control; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D014665:Vasodilator Agents; D004110:Diltiazem; D008790:Metoprolol