Importance of the "atrial kick" in determining the effective mitral valve orifice area in mitral stenosis

Détails

ID Serval
serval:BIB_BDB531C0D311
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Importance of the "atrial kick" in determining the effective mitral valve orifice area in mitral stenosis
Périodique
American Journal of Cardiology
Auteur(s)
Nicod  P., Hillis  L. D., Winniford  M. D., Firth  B. G.
ISSN
0002-9149 (Print)
Statut éditorial
Publié
Date de publication
02/1986
Volume
57
Numéro
6
Pages
403-7
Notes
Journal Article --- Old month value: Feb 15
Résumé
Atrial fibrillation with a rapid ventricular response in patients with mitral stenosis (MS) is often accompanied by pulmonary congestion and reduced cardiac output owing to a diminished diastolic filling period and the loss of the end-diastolic left ventricular (LV) pressure increment. To test the hypothesis that loss of atrial contraction (atrial kick) also results in a decrease in effective mitral valve orifice area, 6 patients with pure, isolated MS were studied in sinus rhythm during atrial pacing and simultaneous atrioventricular pacing. Atrial pacing at 140 beats/min caused no significant change from baseline in cardiac output or mitral valve area, but there was a decrease in LV end-diastolic volume and ejection fraction as well as an increase in left atrial pressure and mean diastolic gradient. Simultaneous atrioventricular pacing (to eliminate atrial kick) induced a decrease in cardiac output (4.4 +/- 0.9 vs 5.2 +/- 0.8 liters/min at 110 beats/min, 4.2 +/- 0.9 vs 5.1 +/- 0.9 liters/min at 140 beats/min; p less than 0.05) and LV end-diastolic volume (77 +/- 27 vs 93 +/- 29 ml at 110 beats/min, 54 +/- 17 vs 65 +/- 19 ml at 140 beats/min; p less than 0.05), an increase in left atrial pressure (28 +/- 3 vs 20 +/- 5 mm Hg at 110 beats/min, 30 +/- 4 vs 25 +/- 5 mm Hg at 140 beats/min; p less than 0.05), and a decrease in mitral valve area (1.2 +/- 0.4 vs 1.4 +/- 0.5 cm2 at 110 beats/min, 1.2 +/- 0.4 vs 1.4 +/- 0.4 cm2 at 140 beats/min; p less than 0.05). Thus, loss of atrial kick may cause pulmonary congestion and reduced cardiac output in patients with MS, partly because of a decrease in effective mitral valve area.
Mots-clé
Adult Atrioventricular Node Blood Pressure Blood Volume Cardiac Output Cardiac Pacing, Artificial/methods Female Heart Atria/*physiopathology Heart Rate Humans Male Middle Aged Mitral Valve/*physiopathology Mitral Valve Stenosis/*physiopathology *Myocardial Contraction
Pubmed
Web of science
Création de la notice
25/01/2008 15:00
Dernière modification de la notice
03/03/2018 20:59
Données d'usage