Search results for "Coronary circulation"
showing 5 items of 75 documents
Echocardiographic assessment of coronary microvascular dysfunction: Basic concepts, technical aspects, and clinical settings
2021
Abstract Coronary flow reserve is the capacity of the coronary circulation to augment the blood flow in response an increase in myocardial metabolic demands and has a powerful prognostic significance in different clinical situations. It might assess with invasive and noninvasive technique. Transthoracic echocardiography Doppler is an emerging diagnostic technique, noninvasive, highly feasible, safe for patient and physician, without radiation, and able to detect macrovascular and microvascular anomalies in the coronary circulation. This review aims to describe the benefit and limits of echocardiographic assessment of coronary flow reserve.
Coronary venous therapy to improve microvascular dysfunction.
2021
The coronary circulation is a complex system in which vascular resistances are determined by an interplay of forces in at least three compartments: the epicardial, the microvascular, and the venous district. Cardiologists, and particularly interventional cardiologists, normallly place the focus of their attention on diseases of the epicardial coronary circulation as possible causes of coronary syndromes and neglect the importance of the other two compartments of coronary circulation. The study of the coronary microcirculation, an increasingly recognized source of ischemia, has long been disregarded, but is witnessing a revival since the (re-)introduction of diagnostic tools in the better eq…
Effect of coronary perfusion rate on the hydrolysis of exogenous and endogenous acetylcholine in the isolated heart
1977
1. The effect of perfusion rate on the hydrolysis of acetylcholine in isolated chicken hearts was studied by measuring both the spontaneous and the evoked output of endogenous acetylcholine into the perfusate in response to vagal stimulation and the arterio-venous difference of exogenous acetylcholine. 2. A decrease in the perfusion rate from 30 to 20 and 10 ml/min caused a graded and significant decline of both the spontaneous overflow of acetylcholine and the overflow evoked by stimulation of both vagus nerves (20 Hz, 1 ms, 40V) for 20 min. The spontaneous and evoked overflow at 30 ml/min were 2 and 3 times, respectively, the overflow at 10 ml/min. 3. Physostigmine (10−6M) raised both the…
Ischemia in patients with no obstructive coronary artery disease: classification, diagnosis and treatment of coronary microvascular dysfunction
2020
Patients with coronary microvascular dysfunction represent a widespread population, and despite the good prognosis, many of them, because of the angina symptoms, have a poor quality of life with strong limitations in their daily activities. In 2017, a new classification of microvascular dysfunction as well as a new definition of ischemia in patients with no obstructive coronary artery disease became available. This new definition improves Kemp's initial work, where cardiac X syndrome was initially described. This work summarizes the last updates on the subject with particular attention to the new classification of microvascular dysfunction, with particular attention to microvascular and vas…
Intracoronary Infusion of Thioflavin-S to Study Microvascular Obstruction in a Model of Myocardial Infarction
2015
Abstract Introduction and objectives Microvascular obstruction exerts deleterious effects after myocardial infarction. To elucidate the role of ischemia-reperfusion injury on the occurrence and dynamics of microvascular obstruction, we performed a preliminary methodological study to accurately define this process in an in vivo model. Methods Myocardial infarction was induced in swine by means of 90-min of occlusion of the mid left anterior descending coronary artery using angioplasty balloons . Intracoronary infusion of thioflavin-S was applied and compared with traditional intra-aortic or intraventricular instillation. The left anterior descending coronary artery perfused area and microvas…