犬心房颤动模型中心房大小及排空功能的重塑

Remodeling of atrial dimensions and emptying function in canine models of atrial fibrillation.

作者信息

Shi Y, Ducharme A, Li D, Gaspo R, Nattel S, Tardif J C

机构信息

Department of Medicine, Montreal Heart Institute and University of Montreal, 5000 Belanger Street East, Montreal, Quebec, H1T 1C8, Canada.

出版信息

Cardiovasc Res. 2001 Nov;52(2):217-25. doi: 10.1016/s0008-6363(01)00377-7.

DOI:10.1016/s0008-6363(01)00377-7

PMID:11684069

Abstract

OBJECTIVES

Atrial tachycardia-induced remodeling (ATR) and ventricular tachypacing-induced heart failure (HF) create experimental substrates for atrial fibrillation (AF), and both have been reported to produce atrial dilation and hypocontractility. The relative importance of changes in atrial size and contractility in the two models is unknown. This study compared changes in atrial dimensions and emptying in ATR versus HF dog models and related them to AF promotion.

METHODS

In ATR dogs (n=11), the right atrium (RA) was paced at 400/min for 42 days. In HF dogs (n=10), the right ventricle was paced at 240 bpm for 2 weeks, followed by 3 weeks at 220 bpm. Transthoracic echocardiography was performed at baseline and weekly thereafter. At a terminal electrophysiological study, RA effective refractory period (ERP) was recorded and AF induced repeatedly by atrial burst pacing to measure mean AF duration (DAF).

RESULTS

Left atrial (LA) systolic area increased by 10.0% in ATR versus 48.2% in HF dogs (P=0.008), with significant time-dependent changes in HF (P=0.0001), but not ATR (P=0.16). LA diastolic area increased over time in both groups (P=0.004, 0.0001 for ATR and HF respectively), but increases were much larger in CHF (80.2%) compared to ATR (24.2%, P=0.0002). Similar findings were obtained for RA. Fractional area shortening (FAS) decreased by 19.4% (ATR) versus 41.8% (HF, P=0.007) in LA and 13.7% (ATR) versus 33.7% (HF, P=0.03) in RA. RA ERP correlated with DAF in ATR dogs (r=-0.79, P<0.001), but not in HF dogs (r=0.20, P=NS). DAF and diastolic areas of RA and LA were highly correlated (r=0.71, 0.77; P<0.01 for each) in HF dogs, but not in ATR dogs (r=-0.18, 0.29; P=NS).

CONCLUSIONS

Remodeling of atrial size and emptying function is much greater in HF than in ATR. Whereas in ATR, electrophysiological remodeling is of prime importance in AF promotion, structural remodeling (as reflected in changes in atrial size and contraction) appears much more important in HF-induced AF.

摘要

目的

房性心动过速诱导的重塑（ATR）和室性快速起搏诱导的心力衰竭（HF）为心房颤动（AF）创造了实验基础，并且据报道两者都会导致心房扩张和收缩功能减退。在这两种模型中，心房大小和收缩性变化的相对重要性尚不清楚。本研究比较了ATR与HF犬模型中心房尺寸和排空的变化，并将其与AF的诱发相关联。

方法

在ATR犬（n = 11）中，右心房（RA）以400次/分钟的频率起搏42天。在HF犬（n = 10）中，右心室以240次/分钟的频率起搏2周，随后以220次/分钟的频率起搏3周。在基线时及之后每周进行经胸超声心动图检查。在终末电生理研究中，记录RA有效不应期（ERP），并通过心房猝发起搏反复诱发AF以测量平均AF持续时间（DAF）。

结果

与HF犬相比，ATR犬的左心房（LA）收缩面积增加了10.0%，而HF犬增加了48.2%（P = 0.008），HF犬有显著的时间依赖性变化（P = 0.0001），而ATR犬没有（P = 0.16）。两组的LA舒张面积均随时间增加（ATR和HF分别为P = 0.004、0.0001），但与ATR（24.2%）相比，CHF组增加幅度更大（80.2%，P = 0.0002）。RA也有类似的发现。LA的面积缩短分数（FAS）在ATR组降低了19.4%，而在HF组降低了41.8%（P = 0.007）；RA的FAS在ATR组降低了13.7%，而在HF组降低了33.7%（P = 0.03）。在ATR犬中，RA ERP与DAF相关（r = -0.79，P < 0.001），但在HF犬中不相关（r = 0.20，P = 无统计学意义）。在HF犬中，DAF与RA和LA的舒张面积高度相关（r = 0.71、0.77；每组P < 0.01），但在ATR犬中不相关（r = -0.18、0.29；P = 无统计学意义）。