Baumwart R D, Meurs K M, Raman S V
Department of Veterinary Clinical Sciences, Ohio State University College of Veterinary Medicine, Columbus, OH, USA.
J Vet Intern Med. 2009 Mar-Apr;23(2):271-4. doi: 10.1111/j.1939-1676.2008.0266.x. Epub 2008 Feb 3.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a myocardial disease characterized by fibrofatty replacement of the right ventricle and ventricular tachyarrhythmias, reported most commonly in the Boxer dog. Although ARVC is characterized as a myocardial disease, the impact of the disease on the function of the right ventricle has not been well studied.
To noninvasively evaluate the function and anatomy of the right ventricle in Boxer dogs with ARVC.
Five adult Boxer dogs with ARVC and 5 healthy size-matched hound dogs.
Magnetic resonance imaging was performed on an ECG-gated conventional 1.5-T scanner using dark blood imaging and cine acquisitions. Images were evaluated by delineation of endocardial right and left ventricular contours in the end-diastolic and end-systolic phases of each slice. Right and left end-systolic and end-diastolic volumes were generated using Simpson's rule and ejection fraction was calculated. Images were evaluated for right ventricular (RV) aneurysms and wall motion abnormalities. Spin echo images were reviewed for the presence of RV myocardial fatty replacement or scar.
RV ejection fraction was significantly lower in Boxers with ARVC compared with the controls (ARVC 34%+/- 11 control 53%+/- 10, P < .01). There was an RV aneurysm in 1 dog with ARVC but not in any of the controls. RV myocardial gross fatty changes were not observed in dogs of either group.
These findings could be interpreted to suggest that arrhythmias and myocardial dysfunction precede the development of morphological abnormalities in dogs with ARVC.
致心律失常性右室心肌病（ARVC）是一种以右心室纤维脂肪替代和室性快速心律失常为特征的心肌病，最常见于拳师犬。尽管ARVC被认为是一种心肌病，但该疾病对右心室功能的影响尚未得到充分研究。
无创评估患有ARVC的拳师犬右心室的功能和解剖结构。
5只患有ARVC的成年拳师犬和5只健康的、体型匹配的猎犬。
在一台心电门控的传统1.5-T扫描仪上进行磁共振成像，采用黑血成像和电影采集技术。通过描绘每一层舒张末期和收缩末期的心内膜右心室和左心室轮廓来评估图像。使用辛普森法则生成右心室和左心室收缩末期及舒张末期容积，并计算射血分数。评估图像是否存在右心室（RV）动脉瘤和室壁运动异常。回顾自旋回波图像以检查RV心肌脂肪替代或瘢痕的存在情况。
与对照组相比，患有ARVC的拳师犬的RV射血分数显著降低（ARVC组为34%±11，对照组为53%±10，P<.01）。1只患有ARVC的犬存在RV动脉瘤，而对照组中未发现。两组犬均未观察到RV心肌明显的脂肪变化。
这些发现可以解释为，在患有ARVC的犬中，心律失常和心肌功能障碍先于形态学异常的出现。
