BACKGROUND: Thoracoscopy is a minimally invasive method used in diagnosis and treatment of many disorders in animals, however, its application in smaller species is limited in literature which can be contributed to the challenges faced while performing a minimally invasive procedure in smaller mammals. OBJECTIVES: Evaluating the feasibility and ideal port placement considering heart as the target organ in rabbit. Also, the impact of ventilation protocol on rate of mortality was evaluated. METHODS: Twenty New Zealand white rabbits were used in this experiment. Approaches used for the introduction of the camera were Para-xiphoid and intercostal space, the optimal spot for insertion of the second trocar relative to the camera was also evaluated, lung damage and rate of mortality were assessed under two different mechanical ventilation modes of pressure-controlled and volume-controlled. RESULTS: Surgical view gained through the para-xiphoid approach is rather panoramic and spatial than the direct intercostal view, maneuver on the heart with an instrument is easier when the 5th intercostal space is used for the second trocar. With the help of PCV, lungs sustain less damage and atelectasis can be avoided till the end of the procedure and therefore, less mortality is experienced. CONCLUSIONS: Using the Para-xiphoid approach and the correct ventilation protocol provides sufficient working space under good vison, which makes the rabbit thoracoscopic heart model a practical model that can be used in many cardiac experiments.

BACKGROUND: One of the important parts of the cardiovascular system is the cardiac vessels. Ultrasonography which is the method of choice for evaluating the heart and vessels in all living animals can also be used in this fish. OBJECTIVES: This study was conducted to make a full understanding of the anatomic and echocardiographic characteristics of these vessels in beluga and suggest standard methods of ultrasonography for this species. METHODS: In this study, a total of 10 immature belugas were selected. The transducer was placed on the ventral surface of the body, between pectoral fins and transverse and sagittal images were obtained. By moving the anterior and posterior regions the vessels were investigated. After the ultrasound examination, anatomic studies were performed. Length and diameter of the vascular compartment were measured and analyzed by SPSS 16 software and Paired Sample T – method (P>0.05). RESULTS: In ultrasonography, blood flow was visible because of the movement of echoic particles. Two precardiac vessels joining between the liver lobes constituted and common vascular compartment before entering the sinus venosus. In the anatomical study, the ventral aorta was bifurcate near the gills. The right liver adjacent to the vessel was shorter and wider than the left one. Moreover, the common vascular compartment was shorter and wider than the liver adjacent to the vessels. The ventral aorta was longer and wider than the right precardiac vessel and common vascular compartment but was shorter than the left precardiac vessel (P>0.05). CONCLUSIONS: Due to lacing thorough anatomic and ultrasonographic studies concerning the cardiac vessels in this species, this study can be a cornerstone for further researches of this kind. In this study the long left precardiac vessel is named Common cardinal vein and wide right vessel is named Hepatic vein.

BACKGROUND: Nowadays, due to widespread usage of anti-pain drugs, more attention is being paid to tramadol, although it has only been recognized  rather recently in veterinary medicine. Therefore, evaluation of its effects on various organs is a principal issue. OBJECTIVES: The aim of present study was to investigate cardiac function change following administration of tramadol using electrocardiography and echocardiography. METHODS: Five healthy dogs aged 3-5 years and weighting 20-26 kg were selected for study. To check the health of animals, clinical and laboratory examinations were performed. Then animals were kept for 2 weeks and vaccination and anti parasite therapy were prescribed for them. This study was conducted in 3 stages and ECG and echocardiography were recorded: before tramadol injection, immediately after injection and one hour after that. Parametric data analysis of variance with repeated measure was conducted using SPSS version 20. RESULTS: Along evaluated parameters, only left ventricular volume in end-diastole and end-systole, time interval between the Q wave to aortic valve closure, stroke volume and ejection fraction showed significant difference between the three stages. CONCLUSIONS: In conclusion, tramadol shows remarkable anti-pain effects with low cardiac side-effects in comparison to other opioid drugs. However, more studies are needed due to the importance of this subject.

BACKGROUND: Echocardiography is a noninvasive technique that is an important tool in diagnosis of cardiac diseases. Interoperation of the results of the echocardiography is dependent on having anatomical knowledge of the heart. OBJECTIVES: The aim of this study was to prepare the anatomical slices according to the related views in echocardiography. These sections can be used as a model for teaching of echocardiography. METHODS: Six dogs euthanized for purposes rather than the present study were used. The hearts were dissected and then dilated and fixed using formalin 10%. Fixed hearts were then cut to obtain representative slices corresponding to long and short axes of right parastenal standard echocardiographic views which were taken from three healthy dogs. After that, both anatomical and ultrasound images were correlated. RESULTS: The external and internal morphology of the heart were suitable for this study. The comparison of the anatomical slices with related echocardiograms showed a high level of correlation. In the long axis views, the four chambers, the atrioventricular valves and the cardiac septum were visible. The left ventricular outflow and aortic valve were represented in deeper views. The short axis series showed two ventricles and their internal morphology. CONCLUSIONS: The slices of hearts which were fixed using formalin may be used for echocardiography interoperation

BACKGROUND: Caspian miniature horse is an Iranian breed of the horse. Some anatomical studies such as topography of the heart have been conducted in recent years. Objectives: Regarding the importance of SA node in regulating the rhythmic contraction of heart, the present study was performed to demonstrate the position of the SA node and its arterial supply. Methods: 4 excised hearts of Caspian miniature horse were used for this study.  The coronary arteries in two horses were injected with a mixture of gelatin and choromopaque and the other two with colored rodopas. The gelatin injected specimens were used for contrast radiography and the rodopas injected specimens were macerated in HCl and the cast  studied for arterial branches. Terminal sulcus and location of SA node was macroscopically detected and separated for histological investigation. Results: Our study showed that the SA node is a small mass of transformed cardiac muscle. It is situated under the epicardium of the right ventricle between the cranial vena cava and the right auricle. The blood is supplied by a few branches separated from the right auricular branch of the proximal branch of left atrial artery. The latter itself is a branch of the left circumflex artery of the left coronary artery.

AbstractBACKGROUND: Beluga (Huso huso) is one of the sturgeons and currently is cultured artificially in Iran with different goals. The cardiovascular system is one of the important systems of the body, and heart is the most important organ in this system. So far, few studies have been done on the heart of sturgeons.OBJECTIVES: This study was done to determine the exact structure of beluga different parts of the heart septum using echocardiographic and histologic techniques. METHODS: Six immature male belugas (2.5 years old) were investigated in this study. For echocardiography, probe was placed on the ventral surface of body, between pectoral fins. At first, macroscopic morphologic studies of different parts of heart were done at the topographic place of them. For histological studies, usual methods of fixation and hematoxylin and eosin (H&E) coloring were used. Prepared slides were studied by light microscope.RESULTS: All parts of the heart including the sinus venosus, atrium, ventricle, conus arteriosus and pericardium were clearly visible in different probe moves. The pericardium were covered surround heart`s structures having homogenous echo pattern. Sinus venosus had a very thin septum without any expansion and contraction. Atrium had a completed muscular septum with expansion and contraction. Ventricle muscular septum had two layers: an external compact layer and an internal spongy layer. Conus arteriosus was composed of obvious muscular septum and connective tissue. Histological studies showed three layers in beluga heart including epicardium, myocardium and endocardium. In overall, the histological findings were matched with the results of echocardiography. CONCLUSIONS: This study is the first investigation on echocardiographic feature of different parts of beluga heart. These results were coordinated with histological findings. Normal information and findings of this study can be used for investigation of various anatomic or pathologic changes in beluga heart in different research projects.

BACKGROUND: Myocardial bridge (MB) is generally defined as a superfacial muscular band that forms sporadic or multiple across the coronary artery in dog, cat, sheep, and human. OBJECTIVES: From the view of embryology MB is a preformatted structure with coronary artery during  forming. The type of study in human is during sonography and angiography examination, but in veterinary science the study on MB is  done after death examination. METHODS: This study was performed on over 50 sheep hearts that were prepared from slaughterhouse of Shahr e kord. First, pericardium was opened and the heart brought out of the pericardial cavity and then the hearts were studied with concentrated light and lens on both sides. After the M B recognition,  their length and width were measured by a ruler. In both sides of the heart,the MB was  divided into 1/3 proximal, 1/3 middle and 1/3 distal. In all of the studied hearts, only 10 samples (20%) had M B. RESULTS: The average length of recognised MBs was 1.55±1.17 (SD) cm and  with width of 1.09±.092 (SD) cm. The positive samples were transferred to histology laboratory for preparation of cross section of heart and were stained with  H&E staining.CONCLUSIONS: The longitudinal section showed the long fibers of myocardium with continual narrow fibers and intercalated discs were located between them.

Hemodynamic effects of spontaneous ventilation, intermittent positive-pressure ventilation (IPPV), and high-frequency oscillatory ventilation (HFOV) were compared in 6 dogs during halothane anesthesia. Anesthesia was induced with IV thiamylal Na and was maintained with halothane (end-tidal concentration, 1.09%). During placement of catheters, dogs breathed spontaneously through a conventional semiclosed anesthesia circuit. Data were collected, and dogs were mechanically ventilated, using IPPV or HFOV in random order. Ventilation was adjusted to maintain PaCO2 between 38 and 43 mm of Hg during IPPV and HFOV. Cardiac index, aortic blood pressure, and maximum rate of increase of left ventricular pressure were significantly (P less than 0.05) less during HFOV than during spontaneous ventilation, whereas right atrial and pulmonary artery pressure were significantly greater during HFOV than during spontaneous ventilation. During IPPV, only the maximum rate of increase of left ventricular pressure was significantly less than that during spontaneous ventilation.