TY - JOUR
T1 - Altered mitral valve kinematics with atrioventricular and ventricular pacing
AU - Langer, Frank
AU - Tibayan, Frederick A.
AU - Rodriguez, Filiberto
AU - Timek, Tomasz
AU - Zasio, Mary K.
AU - Liang, David
AU - Daughters, George T.
AU - Ingels, Neil B.
AU - Miller, D. Craig
PY - 2005
Y1 - 2005
N2 - Background and aim of the study: Pacing-induced mitral regurgitation contributes to the 'pacemaker syndrome', which usually is observed with ventricular (V) pacing, but has also been reported with atrioventricular (AV) sequential pacing. Effects of different pacing modes on 3-D kinematics of the mitral apparatus are incompletely understood. Methods: Radio-opaque markers were placed on the left ventricular (LV) and mitral apparatus including the annulus, leaflets and papillary muscles of eight sheep. Hemodynamic and 3-D dynamic marker geometry were obtained one week later with biplane videofluoroscopy (60 Hz) during atrial (pacing site = left atrium), AV-sequential (140 ms interval) and (anterolateral LV epicardial) ventricular pacing. Results: Compared with A-pacing (*p <0.05): 1) The regurgitant fraction increased with both AV- and V-pacing (A: 6 ± 3%, AV: 13 ± 3%*, V: 15 ± 2%*); 2) AV and V-pacing delayed closure at the leaflet center (A: 21 ± 10 ms, AV: 52 ± 5 ms*, V: 92 ± 6 ms*) and posterior commissure (A: 17 ± 10 ms, AV: 46 ± 8 ms*, V: 94 ± 6 ms*). V-pacing delayed valve closure at the anterior commissure (A: 27 ± 9 ms, V: 94 ± 6 ms*); 3) The end-diastolic leaflet opening angle was greater with AV- and V-pacing (anterior mitral leaflet (AML): A: 32 ± 2°, AV: 41 ± 4°*, V: 46 ± 4°*, posterior mitral leaflet (PML): A: 56 ± 4°, AV: 62 ± 3°*, V: 68 ± 3°*); 4) 'Effective' end-diastolic PML midline length was reduced with AV- and V-pacing (A: 11.2 ±0.7 mm, AV: 10.0 ± 0.4 mm*, V: 10.2 ± 0.3 mm*), as was the distance from each papillary muscle (PM) tip to the AML edge ('effective' chordal length) close to the commissures (anterior PM-AML: A: 31.5 ±1.8 mm, AV: 30.5 ± 1.9 mm*, V: 29.7 ± 1.8 mm*; posterior PM-AML: A: 33.7 ± 1.8 mm, AV: 33.1 ± 1.9 mm*, V: 32.8 ± 1.9 mm*). Conclusion: Both ventricular and AV-sequential-pacing resulted in a more widely opened valve at end-diastole and leaflet dyssynchrony with delayed mitral valve closure and early systolic mitral regurgitation. These alterations which result in pacing-induced mitral regurgitation may be clinically important in patients with impaired LV function.
AB - Background and aim of the study: Pacing-induced mitral regurgitation contributes to the 'pacemaker syndrome', which usually is observed with ventricular (V) pacing, but has also been reported with atrioventricular (AV) sequential pacing. Effects of different pacing modes on 3-D kinematics of the mitral apparatus are incompletely understood. Methods: Radio-opaque markers were placed on the left ventricular (LV) and mitral apparatus including the annulus, leaflets and papillary muscles of eight sheep. Hemodynamic and 3-D dynamic marker geometry were obtained one week later with biplane videofluoroscopy (60 Hz) during atrial (pacing site = left atrium), AV-sequential (140 ms interval) and (anterolateral LV epicardial) ventricular pacing. Results: Compared with A-pacing (*p <0.05): 1) The regurgitant fraction increased with both AV- and V-pacing (A: 6 ± 3%, AV: 13 ± 3%*, V: 15 ± 2%*); 2) AV and V-pacing delayed closure at the leaflet center (A: 21 ± 10 ms, AV: 52 ± 5 ms*, V: 92 ± 6 ms*) and posterior commissure (A: 17 ± 10 ms, AV: 46 ± 8 ms*, V: 94 ± 6 ms*). V-pacing delayed valve closure at the anterior commissure (A: 27 ± 9 ms, V: 94 ± 6 ms*); 3) The end-diastolic leaflet opening angle was greater with AV- and V-pacing (anterior mitral leaflet (AML): A: 32 ± 2°, AV: 41 ± 4°*, V: 46 ± 4°*, posterior mitral leaflet (PML): A: 56 ± 4°, AV: 62 ± 3°*, V: 68 ± 3°*); 4) 'Effective' end-diastolic PML midline length was reduced with AV- and V-pacing (A: 11.2 ±0.7 mm, AV: 10.0 ± 0.4 mm*, V: 10.2 ± 0.3 mm*), as was the distance from each papillary muscle (PM) tip to the AML edge ('effective' chordal length) close to the commissures (anterior PM-AML: A: 31.5 ±1.8 mm, AV: 30.5 ± 1.9 mm*, V: 29.7 ± 1.8 mm*; posterior PM-AML: A: 33.7 ± 1.8 mm, AV: 33.1 ± 1.9 mm*, V: 32.8 ± 1.9 mm*). Conclusion: Both ventricular and AV-sequential-pacing resulted in a more widely opened valve at end-diastole and leaflet dyssynchrony with delayed mitral valve closure and early systolic mitral regurgitation. These alterations which result in pacing-induced mitral regurgitation may be clinically important in patients with impaired LV function.
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M3 - Article
C2 - 15974520
AN - SCOPUS:24344507258
SN - 0966-8519
VL - 14
SP - 286
EP - 294
JO - Journal of Heart Valve Disease
JF - Journal of Heart Valve Disease
IS - 3
ER -