Madaric Juraj, Vanderheyden Marc, Van Laethem Christophe, Verhamme Katia, Feys Ann, Goethals Marc, Verstreken Sofie, Geelen Peter, Penicka Martin, De Bruyne Bernard, Bartunek Jozef
Cardiovascular Center, OLV Ziekenhuis, Moorselbaan 164, BE-9300 Aalst, Belgium.
Eur Heart J. 2007 Sep;28(17):2134-41. doi: 10.1093/eurheartj/ehm126. Epub 2007 May 15.
Exercise-induced mitral regurgitation (MR) bears a poor prognosis in patients with congestive heart failure (CHF). Cardiac resynchronization therapy (CRT) is associated with improved clinical outcome but its effects on exercise-induced MR remain undetermined. We investigated serial changes in functional MR in relation to left ventricular (LV) remodelling and cardiopulmonary performance after CRT.
Twenty-eight patients with CHF (LV ejection fraction 25 +/- 7%), broad QRS complex (171 +/- 27 ms), and at least mild MR [effective regurgitant orifice (ERO) 0.25 +/- 0.12 cm2] were studied with quantitative exercise echocardiography and cardiopulmonary exercise testing prior, within 1 week, and 3 months after CRT. Early after CRT, a decrease in LV dyssynchrony (from 54 +/- 21 to 19 +/- 7 ms, P < 0.001) and in MR at rest (ERO from 0.25 +/- 0.12 to 0.20 +/- 0.10 cm2, P = 0.047) was observed. However, no change in exercise-induced increase in MR was observed (ERO from 0.34 +/- 0.12 to 0.31 +/- 0.16 cm2, NS). Three months after CRT, a decrease in the mitral valve tenting area (from 3.3 +/- 1.2 to 2.0 +/- 0.6 cm2, P < 0.001) and an increase in LV sphericity index (from 1.5 +/- 0.3 to 1.8 +/- 0.5, P < 0.001) were paralleled by an attenuation of exercise-induced MR (ERO 0.19 +/- 0.06 cm(2), P = 0.001 vs. prior CRT). This was associated with an increase in LV ejection fraction (from 25 +/- 7 to 35 +/- 9%, P < 0.001), peak oxygen uptake (from 11.7 +/- 2.4 to 13.7 +/- 3.8 mL/kg/min, P = 0.001), and a decrease in Nt-pro-BNP (from 2777 +/- 1681 to 1963 +/- 1361 pg/mL, P = 0.067).
CRT is associated with acute decrease in resting MR but does not immediately attenuate exercise-induced MR. In contrast, only late, CRT-induced reversed LV remodelling and reduced mitral apparatus deformation are associated with a reduction in both resting and exercise-induced MR and with an improvement in cardiopulmonary performance.
运动诱发的二尖瓣反流（MR）在充血性心力衰竭（CHF）患者中预后较差。心脏再同步治疗（CRT）与临床结局改善相关，但其对运动诱发的MR的影响仍未明确。我们研究了CRT后功能性MR与左心室（LV）重构及心肺功能的系列变化。
对28例CHF患者[左心室射血分数25±7%，QRS波增宽（171±27毫秒），且至少有轻度MR（有效反流口面积（ERO）0.25±0.12平方厘米）]在CRT前、CRT后1周内及3个月时进行定量运动超声心动图和心肺运动试验研究。CRT后早期，观察到左心室不同步性降低（从54±21毫秒降至19±7毫秒，P<0.001）及静息时MR降低（ERO从0.25±0.12平方厘米降至0.20±0.10平方厘米，P = 0.047）。然而，运动诱发的MR增加无变化（ERO从0.34±0.12平方厘米降至0.31±0.16平方厘米，无统计学意义）。CRT后3个月，二尖瓣瓣叶帐篷样面积减小（从3.3±1.2平方厘米降至2.0±0.6平方厘米，P<0.001）及左心室球形指数增加（从1.5±0.3升至1.8±0.5，P<0.001），同时运动诱发的MR减轻（ERO为0.19±0.06平方厘米，与CRT前相比P = 0.001）。这与左心室射血分数增加（从25±7%升至35±9%，P<0.001）、峰值摄氧量增加（从11.7±2.4毫升/千克/分钟升至13.7±3.8毫升/千克/分钟，P = 0.001）及N末端脑钠肽前体降低（从2777±1681皮克/毫升降至1963±1361皮克/毫升，P = 0.067）相关。
CRT与静息MR的急性降低相关，但不能立即减轻运动诱发的MR。相反，仅在晚期，CRT诱导的左心室逆向重构及二尖瓣装置变形减轻与静息和运动诱发的MR降低以及心肺功能改善相关。
