Morphology of the cardiovascular system in greater rhea (Rhea americana americana Linnaeus, 1758)

Greater rheas have been the subject of scientific studies in the various areas of veterinary and biology in order to obtain essential information for their captivity management. The aim of this study was to describe the morphology of the greater rhea heart. The 20 animals were incised in sagittal plane, then fixed in 3.7% formaldehyde and dissected after 72 h. In addition, samples from the cardiovascular system were collected, processed for hematoxylin-eosin and Gomori Trichrome Staining. The heart is conical in shape, dark red when fresh and is located between the hepatic lobes. It has two atria and two ventricles, and four valves (left and right atrioventricular, aortic and pulmonary). The aorta and pulmonary trunk emerge at the heart base, while the ostia of the cranial and caudal vena cava emerged from the right atrium and the right and left pulmonary veins and the left coronary vein from the left atrium. From the aorta artery, the right and left coronary arteries arose, which originated, respectively, the superficial and conal branches and the profuse, left ventricular and superficial branches, being responsible for the irrigation of the heart. Microscopically the heart was constituted by simple pavement epithelium, rich in loose connective tissue. The aorta and pulmonary arteries were composed of the intima, middle and adventitial tunics. Thus, it is concluded that the morphological findings of greater rhea resemble those described for other birds such as ostrich and Gallus gallus domesticus.

Fatal myopericarditis complicated with coronary vein perforation under the triple antithrombotic therapy: a case report

Background Acute pericarditis generally follows a mild clinical course and is rarely fatal. Coronary vein involvement is rarely reported. Case summary We report an autopsy case of cardiac tamponade from idiopathic myopericarditis due to coronary venous perforation under the triple antithrombotic therapy. A 69-year-old man was admitted to our hospital with abnormal findings on electrocardiography, bloody pericardial effusion, and mild elevation of troponin I. Oral anti-inflammatories were started and the patient followed a benign course. However, on hospital Day 5, he suddenly suffered cardiogenic shock with pulseless electric activity due to cardiac tamponade under the combination use of the dual antiplatelet drugs and an anticoagulant drug. He died despite intense medical treatment. Autopsy revealed cardiac tamponade caused by perforation in the coronary venous wall. To the best of our knowledge, this is the first description of fatal myopericarditis as a complication of coronary venous perforation. Discussion The aetiology and mechanism remain unknown; however, we should take care for this rare complication in patients with acute myopericarditis and bloody effusion under the triple antithrombotic therapy.

Left coronary cusp ablation to eliminate epicardial substrates – a novel strategy for left ventricular summit ventricular tachycardia ablation

Background Catheter ablation of LV summit VT can be challenging due to possible subepicardial or intramural site of origin and its close proximity to the major coronary vessels. Objective Local electrograms monitoring inside LV summit communicating vein potentially defines arrhythmogenic substrates and facilitates ablation from the adjacent anatomical structures. Results We experienced two cases of LV summit VT with epicardial local abnormal ventricular activities (Epi-LAVA) recorded from distal bipolar electrode of the 2F microcatheter in communicating vein close to the superior portion of LV summit. During sinus rhythm, Epi-LAVA displayed isolated late fractionated potentials in the first case but had initial fractionated potentials fused with terminal portion of far-field ventricular signals and late isolated potentials exhibiting 2:1 conduction in the second case. Epi-LAVA represented earliest ventricular signals during VT in both cases. Pace mapping at Epi-LAVA sites yielded single QRS morphology with excellent pacemap score and induced VT. Our strategy was to perform ablation at the facing site of Epi-LAVA aiming to eliminate the potentials transmurally. Radiofrequency (RF) energy was applied above and under the left coronary cusp opposite to Epi-LAVA sites using 3.5-mm tip open-irrigation catheter with a power of 30–35 W for 60 seconds under real-time intracardiac echocardiograhic guidance. VT was slowed and terminated in 1 second. Repeat ablation delayed and completely abolished Epi-LAVA followed by noninducibility of VT. Anatomical proximity of the left coronary cusp semilunar insertion and subepicardial or intramural site of origin possibly dictates successful ablation. Epi-LAVA from coronary vein mapping serve as a new landmark of the ablation target with a measurable procedural endpoint. Conclusion Elimination of epicardial substrates with RF energy application at the left coronary cusp can be a novel strategy for LV summit VT ablation. Funding Acknowledgement Type of funding source: None

MDCT of unique drainage of the anterior interventricular coronary vein into the left atrium: two case reports

Pre-procedural CT mapping of the coronary venous system is advised by the current guidelines before many interventional procedures. The published literature for variants of the coronary venous system is scarce. The variant of anterior interventricular vein (AIV) drainage into the left atrium is extremely rare. In this paper, we present multidetector CT findings of two cases of anomalous drainage of the anterior interventricular vein into the left atrium.

Contrast-free high-resolution 3D magnetization transfer imaging for simultaneous myocardial scar and cardiac vein visualization

Objective To develop a three-dimensional (3D) high-resolution free-breathing magnetization transfer ratio (MTR) sequence for contrast-free assessment of myocardial infarct and coronary vein anatomy. Materials and methods Two datasets with and without off-resonance magnetization transfer preparation were sequentially acquired to compute MTR. 2D image navigators enabled beat-to-beat translational and bin-to-bin non-rigid motion correction. Two different imaging sequences were explored. MTR scar localization was compared against 3D late gadolinium enhancement (LGE) in a porcine model of myocardial infarction. MTR variability across the left ventricle and vessel sharpness in the coronary veins were evaluated in healthy human subjects. Results A decrease in MTR was observed in areas with LGE in all pigs (non-infarct: 25.1 ± 1.7% vs infarct: 16.8 ± 1.9%). The average infarct volume overlap on MTR and LGE was 62.5 ± 19.2%. In humans, mean MTR in myocardium was between 37 and 40%. Spatial variability was between 15 and 20% of the mean value. 3D whole heart MT-prepared datasets enabled coronary vein visualization with up to 8% improved vessel sharpness for non-rigid compared to translational motion correction. Discussion MTR and LGE showed agreement in infarct detection and localization in a swine model. Free-breathing 3D MTR maps are feasible in humans but high spatial variability was observed. Further clinical studies are warranted.