Ypenburg Claudia, Lancellotti Patrizio, Tops Laurens F, Bleeker Gabe B, Holman Eduard R, Piérard Luc A, Schalij Martin J, Bax Jeroen J
Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
J Am Coll Cardiol. 2007 Nov 20;50(21):2071-7. doi: 10.1016/j.jacc.2007.08.019. Epub 2007 Nov 7.
The purpose of this study was to evaluate the relationship between dyssynchrony involving the mitral valve apparatus and the acute improvement in mitral regurgitation (MR) after cardiac resynchronization therapy (CRT). The effect of interruption of CRT at 6 months' follow-up on dyssynchrony and MR was also evaluated.
Mitral regurgitation may improve acutely after CRT, but the precise mechanism is not fully understood.
Out of 63 consecutive patients with baseline MR, 25 patients showed an acute reduction in MR severity immediately after CRT. This selected group of 25 patients (age 68 +/- 10 years, left ventricular ejection fraction 23 +/- 8%) was evaluated in the current study. Echocardiography including speckle tracking strain analysis was performed at baseline, after CRT initiation, and during interruption of CRT at 6 months' follow-up to study the relationship between dyssynchrony between the papillary muscles and severity of MR.
According to the inclusion criteria, all patients showed an immediate improvement in MR after CRT (vena contracta width decreased from 0.54 +/- 0.15 cm to 0.39 +/- 0.13 cm; p < 0.001), accompanied by an improvement in mitral deformation indexes. Furthermore, dyssynchrony between the papillary muscles decreased from 169 +/- 69 ms to 25 +/- 26 ms (p < 0.001). Importantly, these beneficial effects were maintained at 6 months' follow-up, but acute loss of resynchronization (from 26 +/- 28 ms to 134 +/- 51 ms; p < 0.001) was observed after interruption of CRT, with an acute recurrence of MR and worsening in mitral deformation indexes.
Cardiac resynchronization therapy can acutely reduce MR in patients with dyssynchrony involving the papillary muscles; interruption of CRT at 6 months' follow-up, however, resulted in acute loss of resynchronization with recurrence of MR.
本研究旨在评估涉及二尖瓣装置的不同步与心脏再同步治疗（CRT）后二尖瓣反流（MR）急性改善之间的关系。还评估了6个月随访时中断CRT对不同步和MR的影响。
CRT后二尖瓣反流可能会急性改善，但其确切机制尚未完全了解。
在63例基线存在MR的连续患者中，25例患者在CRT后立即出现MR严重程度的急性降低。本研究对这组选定的25例患者（年龄68±10岁，左心室射血分数23±8%）进行了评估。在基线、CRT开始后以及6个月随访CRT中断期间进行了包括斑点追踪应变分析在内的超声心动图检查，以研究乳头肌之间的不同步与MR严重程度之间的关系。
根据纳入标准，所有患者在CRT后MR均立即改善（缩流颈宽度从0.54±0.15 cm降至0.39±0.13 cm；p<0.001），同时二尖瓣变形指数也有所改善。此外，乳头肌之间的不同步从169±69 ms降至25±26 ms（p<0.001）。重要的是，这些有益效果在6个月随访时得以维持，但在CRT中断后观察到急性再同步丧失（从26±28 ms增至134±51 ms；p<0.001），同时MR急性复发且二尖瓣变形指数恶化。
心脏再同步治疗可使涉及乳头肌不同步的患者急性减轻MR；然而，在6个月随访时中断CRT会导致急性再同步丧失及MR复发。
