Browsing by Author "Mandour, Ahmed S."

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Changes in the pulmonary artery wave reflection in dogs with experimentally-induced acute pulmonary embolism and the effect of vasodilator
(Mdpi, 2021-07-01) Yoshida, Tomohiko; Mandour, Ahmed S.; Matsuura, Katsuhiro; Shimada, Kazumi; El-Husseiny, Hussein M.; Hamabe, Lina; Yılmaz, Zeki; Uemura, Akiko; Tanaka, Ryou; Yılmaz, Zeki; YILMAZ, ZEKİ; Bursa Uludağ Üniversitesi/Veterinerlik Fakültesi.; 0000-0001-9836-0749; A-9637-2008
Simple Summary Pulmonary hypertension (PH) remains a fatal disease, despite the advances in disease-specific therapies. This may be because the assessment of pulmonary hemodynamics in PH has not been established. Recently, several studies have reported that the pulmonary arterial wave reflection (PAWR) might influence the right ventricular afterload and could provide additional information regarding the severity and progression of PH. However, the pathophysiology of PAWR has some unclear points particularly in the case of acute pulmonary embolism (APE). The objective of this study was to investigate, for the first time, the characteristics of PAWR in a dog model of APE using dual-tipped sensor wire. From the result of the present study, after dogs developed PH by injections of dextran microsphere, PAWR was increased significantly along with the pulmonary vascular resistance (PVR) and reduced after vasodilator administration. In addition, PAWR was significantly correlated with PVR and right ventricular fractional area of change (FAC). These results indicating that PAWR may be useful as a new evaluation method in PH and may detect changes related to right ventricular afterload earlier than pulmonary artery pressure (PAP). Pulmonary hypertension (PH) is a complex syndrome that has been frequently diagnosed in dogs and humans and can be detected by Doppler echocardiography and invasive catheterization. Recently, PAWR attracts much attention as a noninvasive approach for the early detection of PH. The present study aims to investigate the PAWR changes in acute pulmonary embolism (APE) and highlight the response of PAWR variables to vasodilator therapy in dogs. For this purpose, anesthesia and catheterization were performed in 6 Beagle dogs. After that, APE was experimentally conducted by Dextran microsphere administration, followed by vasodilator (Nitroprusside; 1 mu g/kg/min/IV) administration. The hemodynamics, echocardiography, PVR and PAWR variables were evaluated at the baseline, after APE and after administration of nitroprusside. The result showed a significant increase in PVR, PAP, tricuspid regurgitation (TR) as well as PAWR variables following APE induction compared with the baseline (p < 0.05). Vasodilation caused by administration of nitroprusside reduced the mean atrial pressure, PVR and PAWR parameters. There were a significant correlation and linear regression between PAWR indices and PVR as well as right ventricular function parameters. In conclusion, PAWR is not only correlated with PVR but also the right ventricular function parameter, which indicates that PAWR may be useful as a new evaluation method in PH, considering that PAWR can assess both right ventricular afterload and right ventricular function.
Hemodynamic effect of pimobendan following intramuscular and intravenous administration in healthy dogs: A pilot study
(Frontiers Media Sa, 2022-10-12) Enokizono, Masayuki; Mandour, Ahmed S.; Komeda, Syunta; Goya, Seijirow; Takeuchi, Aki; Katoh, Konosuke; Yairo, Akira; Yılmaz, Zeki; Shimada, Kazumi; Tanaka, Ryou; YILMAZ, ZEKİ; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/İç Hastalıkları Anabilim Dalı.; 0000-0001-9836-0749 ; A-9637-2008
BackgroundPimobendan is widely used for the treatment of dogs with heart failure via the oral route. A new injectable form of pimobendan is now available and its potential usefulness via intravenous route has been recently demonstrated in dogs. However, the cardiovascular effects of intramuscular (IM) administration of injectable pimobendan have not been investigated yet. HypothesisIM administration of pimobendan may have the same hemodynamic effect as the IV route. MethodsSix healthy Beagle dogs underwent a placebo-controlled double-blind crossover study. The early cardiovascular effects after a single dose of IM and IV injections of pimobendan (0.2 ml/kg; Pimo IM and Pimo IV, respectively) were compared to the same volume of IM placebo (Saline IM) in anesthetized dogs. Clinical [heart rate (HR) and blood pressure (BP)] and echocardiographic hemodynamic parameters [left ventricular (LV) inflow waveforms of diastolic early wave (eV), atrial systolic wave (aV), diastolic early mitral ring velocity (e '), peak velocity (pV), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR)] were monitored with 15 min intervals for 120 min. ResultsDiastolic BP decreased significantly at 30 min in Pimo IM compared to Saline IM. Mean eV and CO values significantly increased from 75 min, e ' from 60 min, pV from 75 min, and SV from 15 to 120 min, whereas SVR significantly decreased at 30-60 min in Pimo IM compared to those of Saline IM (P < 0.05). Compared with the Pimo IV, eV and pV were significantly lower at 30-60 min (P < 0.05) while SV was significantly higher at 90-105 min in Pimo IM (P < 0.05). Other hemodynamic parameters (BP, HR, SVR, CO, e ', and E/e ') did not significantly change between Pimo IM and IV. ConclusionsThe hemodynamic effect of pimobendan following IM and IV injection was described. Our results suggested that IM administration of pimobendan is equally comparable and possibly interchangeable with IV administration. This warrant further studies to investigate the clinical effectiveness of IM pimobendan in treating dogs with congestive heart failure or in heart failure cases unable to receive IV or oral administration.
Role of two-dimensional speckle-tracking echocardiography in early detection of left ventricular dysfunction in dogs
(Mdpi, 2021-08-07) Hamabe, Lina; Mandour, Ahmed S.; Shimada, Kazumi; Uemura, Akiko; Yılmaz, Zeki; Nagaoka, Kentaro; Tanaka, Ryou; YILMAZ, ZEKİ; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/İç Hastalıkları Anabilim Dalı.; 0000-0001-9836-0749; A-9637-2008
Simple Summary Two-dimensional speckle-tracking echocardiography represents an advanced imaging technique that allows the analysis of global and regional myocardial function, cardiac rotation and synchronicity using deformation imaging. It has gained growing importance over the last decade, especially in human medicine as a method of evaluating myocardial function. This review aims to give an overview of the current understanding of this technique and its clinical applicability in the field of veterinary medicine with a focus on early detection of left ventricular dysfunction in dogs. Two-dimensional speckle-tracking echocardiography (2D-STE) is an advanced echocardiographic technique based on deformation imaging that allows comprehensive evaluation of the myocardial function. Clinical application of 2D-STE holds great potential for its ability to provide valuable information on both global and regional myocardial function and to quantify cardiac rotation and synchronicity, which are not readily possible with the conventional echocardiography. It has gained growing importance over the past decade, especially in human medicine, and its application includes assessment of myocardial function, detection of subclinical myocardial dysfunction and serving as a prognostic indicator. This review illustrates the fundamental concepts of deformation analysis and gives an overview of the current understanding and its clinical application of this technique in veterinary medicine, with a focus on early detection of left ventricular (LV) dysfunction in dogs.
The utility of intraventricular pressure gradient for early detection of chemotherapy-induced subclinical cardiac dysfunction in dogs
(Mdpi, 2021-04-08) Matsuura, Katsuhiro; Shiraishi, Kenjirou; Mandour, Ahmed S.; Sato, Kotomi; Shimada, Kazumi; Goya, Seijirow; Yoshida, Tomohiko; Kitpipatkun, Pitipat; Hamabe, Lina; Uemura, Akiko; Yılmaz, Zeki; Ifuku, Mayumi; Iso, Takeshi; Takahashi, Ken; Tanaka, Ryou; YILMAZ, ZEKİ; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/İç Hastalıkları Anabilim Dalı.; 0000-0001-9836-0749; A-9637-2008
Simple SummaryCardiotoxicity is a serious side effect of doxorubicin in cancer patients due to the risk of development of heart failure. Early detection of doxorubicin-induced cardiomyopa-thy (DXR-ICM) has become a major objective to reduce heart failure in cancer patients. Echocar-diography is the gold standard method to diagnose cardiac diseases when cardiac dysfunction is prominent; however, it still cannot predict or early diagnose heart failure before functional de-cline. The intraventricular blood flow is characterized by intraventricular pressure gradients (IVPG) that created due to the suction of blood by the ventricles. Currently, advanced imaging techniques allow non-invasive assessment of IVPG from color M-mode echocardiography (CMME) after image processing for the clinical setting. Studies revealed that IVPG indices are promising for the early diagnosis of cardiac dysfunction. In this study, we aimed to investigate the usefulness of IVPG to detect cardiac function changes after DXR administration in dogs.Early detection of doxorubicin (DXR)-induced cardiomyopathy (DXR-ICM) is crucial to improve cancer patient outcomes and survival. In recent years, the intraventricular pressure gradient (IVPG) has been a breakthrough as a sensitive index to assess cardiac function. This study aimed to evaluate the usefulness of IVPG for the early detection of chemotherapy-related cardiac dysfunction. For this purpose, six dogs underwent conventional, speckle tracking, and color M-mode echocardiography concomitantly with pressure-and-volume analysis by conductance catheter. The cardiac function measurements were assessed before DXR administration (baseline, Pre), at the end of treatment protocol (Post), and at 1.5 years follow-up (Post2). The result showed a significant reduction in the left ventricular end-systolic pressure-volume (Emax: 4.4 +/- 0.7, 6.1 +/- 1.6 vs. 8.4 +/- 0.8 mmHg/mL), total-IVPG (0.59 +/- 0.12, 0.62 +/- 0.15 vs. 0.86 +/- 0.12 mmHg), and mid-IVPG (0.28 +/- 0.12, 0.31 +/- 0.11 vs. 0.48 +/- 0.08 mmHg), respectively in Post2 and Post compared with the baseline (p < 0.05). Mid-to-apical IVPG was also reduced in Post2 compared with the baseline (0.29 +/- 0.13 vs. 0.51 +/- 0.11). Meanwhile, the fraction shortening, ejection fraction, and longitudinal strain revealed no change between groups. Total and mid-IVPG were significantly correlated with Emax (R = 0.49; p < 0.05, both) but only mid-IVPG was a predictor for Emax (R-2 = 0.238, p = 0.040). In conclusion, this study revealed that impairment of contractility was the initial changes observed with DXR-ICM in dogs and only IVPG could noninvasively detect subclinical alterations in cardiac function. Color M-mode echocardiography-derived IVPG could be a potential marker for the early detection of doxorubicin cardiomyopathy.