Niwano Shinichi, Kojima Jisho, Fukaya Hidehira, Sato Daisuke, Moriguchi Masahiko, Niwano Hiroe, Masaki Yoshihiko, Izumi Tohru
Department of Cardio-angiology, Kitasato University School of Medicine, Sagamihara, Japan.
Circ J. 2007 Oct;71(10):1629-35. doi: 10.1253/circj.71.1629.
Continuous rapid atrial stimulation causes atrial remodeling, but little is known about the difference in the arrhythmogenicity of the left (LA) and right atria (RA).
In 14 beagle dogs, continuous rapid pacing (400 beats/min) was delivered from the right (n=7) or left (n=7) atrial appendage (RAA or LAA) for 2 weeks. The atrial effective refractory period (ERP), ERP dispersion, and inducibility of atrial fibrillation (AF) were evaluated along the time course from 4 atrial sites: (1) RAA, (2) area close to the inferior vena cava (IVC), (3) Bachmann's bundle (BB) and (4) LA. The ERP exhibited progressive shortening at all sites, but the degree of shortening differed among them. In the RA stimulation group, ERP shortening was more prominent in the RAA and LA than in the IVC or BB. In contrast, in the LA stimulation group, ERP shortening was more prominent in the LA than in the other sites. As a result, ERP dispersion was larger in the LA stimulation group than in the RA stimulation group and the AF inducibility was higher in the LA stimulation group than in the RA stimulation group, especially at the LA site (p<0.05).
LAA stimulation was more arrhythmogenic than RAA stimulation in this model. This result may partly explain the importance of premature contractions occurring from the pulmonary veins in clinical cases of AF.
持续性快速心房刺激可导致心房重构，但关于左心房（LA）和右心房（RA）致心律失常性的差异知之甚少。
在14只比格犬中，从右心房（n = 7）或左心房（n = 7）心耳（RAA或LAA）进行持续快速起搏（400次/分钟），持续2周。从4个心房部位评估心房有效不应期（ERP）、ERP离散度和房颤（AF）的诱发性，时间过程如下：（1）RAA，（2）下腔静脉（IVC）附近区域，（3）巴赫曼束（BB）和（4）LA。所有部位的ERP均呈进行性缩短，但缩短程度在各部位之间有所不同。在右心房刺激组中，RAA和LA的ERP缩短比IVC或BB更明显。相比之下，在左心房刺激组中，LA的ERP缩短比其他部位更明显。结果，左心房刺激组的ERP离散度大于右心房刺激组，左心房刺激组的AF诱发性高于右心房刺激组，尤其是在LA部位（p<0.05）。
在该模型中，LAA刺激比RAA刺激更易致心律失常。这一结果可能部分解释了房颤临床病例中肺静脉早搏的重要性。
