Hirose Miki, Mandour Ahmed S, Goya Seijirow, Hamabe Lina, Matsuura Katsuhiro, Yoshida Tomohiko, Watanabe Momoko, Shimada Kazumi, Uemura Akiko, Takahashi Ken, Tanaka Ryou
Department of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo, Japan.
Department of Animal Medicine (Internal Medicine), Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt.
Front Vet Sci. 2022 Jul 12;9:908829. doi: 10.3389/fvets.2022.908829. eCollection 2022.
Novel non-invasive evaluation of the intraventricular pressure differences and gradients (IVPD and IVPG) by color M-mode echocardiography (CMME) is a promising method in diastolic function evaluation. Patent ductus arteriosus (PDA) is a congenital heart defect which is associated with increased preload. The present work provides a clinical trial for the assessment of IVPD and IVPG changes in dogs before and after surgical occlusion of PDA.
A total of 12 client-owned dogs were enrolled in this study. PDA was confirmed using echocardiography, and all dogs underwent PDA occlusion. Conventional echocardiography and CMME were conducted on each patient on the operation day (Pre-PDA) and 48 h after its occlusion (Post-PDA). The total IVPD and total IVPG, as well as segmental intraventricular pressure (basal, mid-to-apical, mid, and apical) were measured from Euler's equation using specific software (MATLAB). Data were analyzed for variability and for the difference between pre- and post-PDA. The effect of PDA occlusion on the measured variables was calculated using biserial ranked correlation (rc).
There was a significant reduction in end-diastolic volume, fraction shortening, stroke volume, and mitral inflow velocities (early and late) after PDA closure. CMME was feasible in all dogs, and the CMME indices showed moderate variability, except for the apical segment of IVPD and IVPG. After PDA closure, in comparison with the pre-PDA occlusion, there was a significant reduction in total IVPD (2.285 ± 0.374 vs. 1.748 ± 0.436 mmHg; = 0.014), basal IVPD (1.177 ± 0.538 vs. 0.696 ± 0.144 mmHg; = 0.012), total IVPG (1.141 ± 0.246 vs. 0.933 ± 0.208 mmHg; = 0.032), and basal IVPG (0.578 ± 0.199 vs. 0.377 ± 0.113 mmHg; = 0.001); meanwhile, mid, mid-to-apical, and apical segments of both IVPD and IVPG showed non-significant difference. The magnitude of PDA occlusion on the measured variables was clinically relevant and associated with a large effect size on total and basal IVPD and IVPG (rc > 0.6).
The current clinical study revealed matched response of IVPD and IVPG to the reduced preload rather than left ventricular relaxation. This result is an initial step in the clinical utility of CMME-derived IVPD and IVPG measurements in the diastolic function evaluation in dogs with PDA that warrants further clinical studies.
通过彩色M型超声心动图（CMME）对心室内压力差和梯度（IVPD和IVPG）进行新型无创评估是舒张功能评估中一种有前景的方法。动脉导管未闭（PDA）是一种先天性心脏缺陷，与前负荷增加有关。本研究为评估犬类PDA手术封堵前后IVPD和IVPG的变化提供了一项临床试验。
本研究共纳入12只客户拥有的犬。通过超声心动图确诊PDA，所有犬均接受PDA封堵术。在手术当天（PDA术前）和封堵术后48小时（PDA术后）对每只犬进行常规超声心动图和CMME检查。使用特定软件（MATLAB）根据欧拉方程测量总IVPD和总IVPG以及节段性心室内压力（基底、中至心尖、中部和心尖）。分析数据的变异性以及PDA术前和术后的差异。使用双列等级相关（rc）计算PDA封堵对测量变量的影响。
PDA封堵后舒张末期容积、缩短分数、每搏输出量和二尖瓣流入速度（早期和晚期）均显著降低。CMME在所有犬中均可行，除IVPD和IVPG的心尖节段外，CMME指标显示出中等变异性。与PDA封堵术前相比，PDA封堵后总IVPD（2.285±0.374 vs. 1.748±0.436 mmHg；P = 0.014）、基底IVPD（1.177±0.538 vs. 0.696±0.144 mmHg；P = 0.012）、总IVPG（1.141±0.246 vs. 0.933±0.208 mmHg；P = 0.032）和基底IVPG（0.578±0.199 vs. 0.377±0.113 mmHg；P = 0.001）均显著降低；同时，IVPD和IVPG的中部、中至心尖部和心尖节段均无显著差异。PDA封堵对测量变量的影响程度具有临床相关性，且与对总IVPD和基底IVPD及IVPG的大效应量相关（rc>0.6）。
当前临床研究表明，IVPD和IVPG对前负荷降低而非左心室舒张的反应是匹配的。这一结果是CMME得出的IVPD和IVPG测量值在PDA犬舒张功能评估中的临床应用的初步步骤，值得进一步的临床研究。
