Advanced Cardiovascular Imaging, Department of Radiology, Columbia University Medical Center, New York, New York, USA.
Am J Cardiol. 2012 Dec 1;110(11):1651-6. doi: 10.1016/j.amjcard.2012.07.036. Epub 2012 Aug 23.
Ventricular dyssynchrony significantly impairs cardiac performance. However, the independent role of interventricular dyssynchrony (interVD) and intraventricular dyssynchrony (intraVD) in the development of abnormalities of systolic and diastolic performance is unclear. Cardiac magnetic resonance imaging was performed in 39 patients with left bundle branch block and 13 healthy patients. Structural and functional parameters of the left ventricle and degrees of interVD and intraVD were measured. We found that interVD was inversely correlated with left ventricular (LV) ejection fraction (r = -0.8, p <0.0001) and positively correlated with LV end-diastolic volume (r = 0.4, p <0.01), LV end-systolic volume (r = 0.6, p <0.0001), and LV mass (r = 0.4, p <0.01), thus indicating that interVD significantly affects systolic function and favors ventricular remodeling. Multivariate analysis further confirmed that interVD was an independent predictor of systolic dysfunction. Interestingly, we found that interVD was not associated with abnormalities of diastolic performance. Conversely, we found that intraVD significantly impaired diastolic function, whereas it had no effect on systolic function. IntraVD was inversely correlated with peak filling rate (r = -0.7, p <0.0001) and 1/2 filling fraction (r = 0.4, p = 0.04) and positively correlated with time to peak filling rate (r = 0.6, p <0.0001), validated parameters of diastolic function. Multivariate analysis confirmed that intraVD was an independent predictor of diastolic dysfunction. In conclusion, our study suggests that the 2 components of ventricular dyssynchrony differently affect cardiac performance. If confirmed in prospective studies, our results may help to predict the prognosis of patients with left bundle branch block and different degrees of interVD and intraVD, particularly those subjects undergoing cardiac resynchronization therapy.
心室不同步显著损害心脏功能。然而，室间不同步（interVD）和室内不同步（intraVD）在收缩和舒张功能异常发展中的独立作用尚不清楚。对 39 例左束支传导阻滞患者和 13 例健康患者进行心脏磁共振成像。测量左心室的结构和功能参数以及 interVD 和 intraVD 的程度。我们发现 interVD 与左心室（LV）射血分数呈负相关（r = -0.8，p <0.0001），与 LV 舒张末期容积（r = 0.4，p <0.01）、LV 收缩末期容积（r = 0.6，p <0.0001）和 LV 质量（r = 0.4，p <0.01）呈正相关，这表明 interVD 显著影响收缩功能并有利于心室重构。多变量分析进一步证实 interVD 是收缩功能障碍的独立预测因子。有趣的是，我们发现 interVD 与舒张功能异常无关。相反，我们发现 intraVD 显著损害舒张功能，而对收缩功能没有影响。IntraVD 与峰值充盈率（r = -0.7，p <0.0001）和 1/2 充盈分数（r = 0.4，p = 0.04）呈负相关，与峰值充盈率时间（r = 0.6，p <0.0001）呈正相关，这是舒张功能的验证参数。多变量分析证实 intraVD 是舒张功能障碍的独立预测因子。总之，我们的研究表明，心室不同步的 2 个组成部分对心脏功能的影响不同。如果在前瞻性研究中得到证实，我们的结果可能有助于预测左束支传导阻滞患者和不同程度的 interVD 和 intraVD 的预后，特别是那些接受心脏再同步治疗的患者。
