Trikhun Ploypanut, Surachetpong Sirilak Disatian, Sutayatram Saikaew, Buranakarl Chollada
Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand.
Department of Medicine, Faculty of Veterinary Science, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok 10330, Thailand.
Vet World. 2020 Nov;13(11):2436-2442. doi: 10.14202/vetworld.2020.2436-2442. Epub 2020 Nov 14.
Pulmonic stenosis (PS) is the most common congenital heart disease in dogs. This condition causes right ventricle (RV) overload and disrupts overall systolic function. The aim of this study was to examine the alterations of cardiac electrical activity and mechanical function in dogs with PS compared to normal healthy dogs.
The ventricular systolic function of dogs with PS was studied. Dogs were divided into two groups, PS (n=13) and control (CONT) (n=12). Measurements of blood pressure, electrocardiography (ECG), and echocardiography were performed.
PS dogs had exercise intolerance, with six experiencing syncope. ECG of PS dogs showed higher amplitudes of P, S, and T waves (p<0.01), and a lower R:S ratio (p<0.001) with longer QRS duration (p<0.001) compared to CONT dogs. Echocardiography demonstrated that the pulmonic flow velocity and pressure gradient (PG) between the RV and the pulmonary artery of PS dogs were significantly higher than CONT dogs (p<0.001). The RV free wall thickness to the left ventricular posterior wall thickness ratio and the right atrium to the left atrium diameter ratio was higher (p<0.001), while interventricular septum (IVS) was thicker (p<0.01) in PS dogs compared with CONT dogs (p<0.001). The systolic function in PS dogs showed higher pulmonic valve velocity time integral (PVVTI) value (p<0.001) and longer pulmonic valve ejection time (ET) (p<0.05) than CONT dogs. However, aortic valve VTI (AVVTI) value and aortic valve ET were not significantly different between the groups, although fractional shortening in PS dogs was higher. In PS dogs, PG showed a significant positive correlation with PVVTI: AVVTI ratio (p<0.05).
PS had prolonged pulmonic valve opening. The thickening of the RV wall and IVS can cause a detrimental reduction of the left ventricular preload in PS dogs.
肺动脉狭窄（PS）是犬类最常见的先天性心脏病。这种病症会导致右心室（RV）负荷过重，并扰乱整体收缩功能。本研究的目的是检查患有PS的犬与正常健康犬相比，心脏电活动和机械功能的改变。
对患有PS的犬的心室收缩功能进行了研究。犬被分为两组，PS组（n = 13）和对照组（CONT）（n = 12）。进行了血压、心电图（ECG）和超声心动图测量。
患有PS的犬运动不耐受，其中6只出现晕厥。与CONT组犬相比，PS组犬的心电图显示P波、S波和T波振幅更高（p < 0.01），R:S比值更低（p < 0.001），QRS持续时间更长（p < 0.001）。超声心动图显示，PS组犬的肺动脉血流速度以及右心室与肺动脉之间的压力梯度（PG）显著高于CONT组犬（p < 0.001）。与CONT组犬相比，PS组犬的右心室游离壁厚度与左心室后壁厚度比值以及右心房与左心房直径比值更高（p < 0.001），而室间隔（IVS）更厚（p < 0.01）。PS组犬的收缩功能显示肺动脉瓣速度时间积分（PVVTI）值更高（p < 0.001），肺动脉瓣射血时间（ET）更长（p < 0.05），高于CONT组犬。然而，尽管PS组犬的缩短分数更高，但两组之间主动脉瓣VTI（AVVTI）值和主动脉瓣ET并无显著差异。在PS组犬中，PG与PVVTI:AVVTI比值呈显著正相关（p < 0.05）。
PS导致肺动脉瓣开放时间延长。右心室壁和室间隔增厚会导致患有PS的犬左心室前负荷有害性降低。
