Spasojević Kosić Lj, Trailović D R, Krstić N
Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia.
Department of Equine, Small Animal, Poultry and Wild Animals Diseases, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia.
Iran J Vet Res. 2017 Winter;18(1):43-48.
By causing numerous changes in the cardiovascular system, ageing leads to a decreased threshold for clinical manifestation of heart disease. The aim of this study was to define the existence of cardiac structural and functional changes in healthy dogs of different age. Radiographic, electrocardiographic (ECG) and echocardiographic examinations of 20 clinically healthy German Shepherd dogs were performed in order to define the values of relevant parameters. Afterwards, the values of cardio examinations were compared between young and old dogs and statistically analyzed. The ECG recordings did not show the appearance of clinically significant arrhythmias, nor was their appearance significantly different between dogs of different age. Statistically significant differences in QRS duration (P<0.05) and R wave amplitude (P<0.05) existed between groups, but all values were within the range of ECG reference values for healthy dogs. Concerning structural changes, the left ventricle wall thickness at end-diastole (LVWd) and end-systole (LVWs), and the relative wall thickness (RWT) between young and old dogs differed significantly (P<0.001, P<0.05, P<0.05, respectively). These differences in heart structure were not accompanied by systolic dysfunction, estimated by a left ventricle shortening fraction. The diastolic wall stress index (WSID) was significantly decreased in old dogs (P<0.05). Young and old dogs showed similar electrical and systolic function. Old dogs had different cardiac structure compared to the young dogs, which could result in diastolic function change.
衰老通过引起心血管系统的众多变化，导致心脏病临床表现的阈值降低。本研究的目的是确定不同年龄健康犬心脏结构和功能变化的存在情况。对20只临床健康的德国牧羊犬进行了放射学、心电图（ECG）和超声心动图检查，以确定相关参数的值。之后，比较了年轻犬和老年犬的心脏检查值并进行了统计分析。心电图记录未显示出具有临床意义的心律失常，不同年龄的犬之间其出现情况也无显著差异。各组之间QRS波时限（P<0.05）和R波振幅（P<0.05）存在统计学显著差异，但所有值均在健康犬心电图参考值范围内。关于结构变化，年轻犬和老年犬之间舒张末期左心室壁厚度（LVWd）、收缩末期左心室壁厚度（LVWs）以及相对壁厚度（RWT）存在显著差异（分别为P<0.001、P<0.05、P<0.05）。这些心脏结构上的差异并未伴有通过左心室缩短分数评估的收缩功能障碍。老年犬的舒张期壁应力指数（WSID）显著降低（P<0.05）。年轻犬和老年犬表现出相似的电功能和收缩功能。与年轻犬相比，老年犬的心脏结构不同，这可能导致舒张功能改变。
