The Role of Cardiac Ganglia in the Prevention of Coronary Atherosclerosis: An Analytical Examination of Cholesterol-fed Rabbits

Background: The heart is innervated by the autonomic nervous system, which contributes to the control of the heart's rhythm and coronary circulation. It has been suggested that the cardiac fibers of the vagus nerve play important roles in controlling circulatory functions and in protecting against atherosclerotic pathologies in coronary arteries. Aims: To investigate the presence of atherosclerotic differences in the coronary arteries of cholesterol-fed rabbits by measuring the density of cardiac ganglia neurons. Study Design: Animal experiment. Methods: This study was conducted using 45 male rabbits. Over a period of 16 weeks, they were kept on an atherogenic diet of water ad libitum and high fat (8.6%) containing saturated fatty acids with 205 mg/kg of cholesterol (1%) per day. Then, their hearts were removed and examined by histopathological methods. Atherosclerotic plaques of the main coronary arteries were examined using the Cavalieri method. Atherosclerosis index values (AIVs) were estimated as the wall surface area/plaque surface area, and the results were analyzed with the Kruskal-Wallis and Mann-Whitney U tests. Results: While the average atherosclerosis index value was estimated to be ≤8% in 21 animals, the atherosclerosis index value was 9-20% in animals with minor plaque detection (n=11) and ≥20% in animals with major plaque detection (n=10). Increased atherosclerosis index values were more common in animals with low neuron densities than in animals with high neuron densities (p<0.017). Conclusion: The low neuron density of the cardiac ganglia in cholesterol-fed rabbits is associated with an increased atherosclerotic plaque incidence and volume.

Giant Right Ventricular Mass Protruding into the Pulmonary Artery during Systole.

Myxomas are the most common primary cardiac tumors in adults and mainly originate in the left atrium with a slight female predominance. Only 3%-4% of myxomas are detected in the right ventricle. Although these tumors are histologically benign, they can lead to several catastrophic complications such as embolization or obstruction of blood flow at the mitral or tricuspid valve orifices. We report a rare case of right ventricular myxoma presented with near-syncope attacks and worsening dyspnea.

Neurogenic Stress Cardiomyopathy Following Subarachnoid Hemorrhage Is Associated with Vagal Complex Degeneration: First Experimental Study.

BACKGROUND: Neurogenic stunned myocardium (NSM) is a devastating complication of subarachnoid hemorrhage (SAH). The most widely accepted mechanism in the pathogenesis of NSM and takotsubo cardiomyopathy is catecholamine-mediated direct myocardial injury. The aim of this study is to examine if there is any effect of sympathetic overactivity of the stellate ganglions on myocardial tissues, secondary to vagal complex degeneration in SAH-induced NSM. MATERIALS AND METHODS: This study was conducted on 25 New Zealand female rabbits. After the examination, all animals were assigned into 3 groups randomly: a control group (n = 5), a sham group (n = 5), and a study group (n = 15) that was subjected to experimental SAH with double injection of blood into the cisterna magna. After 7 animals exhibited NSM, all animals were killed. Their brains, vagal complexes, stellate ganglions, and hearts were extracted and examined by histopathologic methods. Degenerated nodose ganglion neurons and stellate ganglion neuron densities were compared with degenerated myocardial tissue/normal myocardial tissue ratios, and the results were analyzed with the Mann-Whitney U test. RESULTS: Three rabbits in the study group died immediately after the second injection of blood. NSM developed in 7 animals after 1 to 5 days, which was diagnosed with transthoracic echocardiography. Interestingly, the animals that developed NSM had more stellate ganglia neurons and more degenerated neuron densities of nodose ganglia (P < 0.001). CONCLUSIONS: NSM and takotsubo cardiomyopathy may be induced by vagal complex degeneration and sympathetic overactivity, which originated from more neurons, including stellate ganglia and more degenerated neuron densities of nodose ganglia.

Spontaneous Early Resolution of an Iatrogenic Type A Aortic Dissection Following Coronary Angiography.

A 74-year-old man was admitted with the diagnosis of non-ST-elevation myocardial infarction. During right coronary angiography, a coronary artery dissection extending into the proximal ascending aorta was noticed without hemodynamic compromise. Immediate computed tomography angiography showed no evidence of dissection in the ascending aorta. The patient remained hemodynamically stable with medical therapy alone. This case report highlights the importance of medical therapy in patients with uncomplicated iatrogenic aortic dissection.