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Revista Portuguesa de Cardiologia Jan 2020
Topics: Blood Viscosity; Coronary Artery Disease; Hemorheology; Humans; Microcirculation; Microvascular Angina
PubMed: 32156447
DOI: 10.1016/j.repc.2020.02.004 -
Biomedicine & Pharmacotherapy =... Aug 2023Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the... (Review)
Review
Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the pathophysiological mechanism of CMD is still limited at present, which greatly restricts its clinical diagnosis and treatment. Studies have shown that CMD is closely related to a variety of cardiovascular diseases, can aggravate the occurrence and development of cardiovascular diseases, and is closely related to a poor prognosis in patients with cardiovascular diseases. Improving coronary microvascular remodelling and increasing myocardial perfusion might be promising strategies for the treatment of cardiovascular diseases. In this paper, the pathogenesis and functional assessment of CMD are reviewed first, along with the relationship of CMD with cardiovascular diseases. Then, the latest strategies for the treatment of CMD and cardiovascular diseases are summarized. Finally, urgent scientific problems in CMD and cardiovascular diseases are highlighted and future research directions are proposed to provide prospective insights for the prevention and treatment of CMD and cardiovascular diseases in the future.
Topics: Humans; Cardiovascular Diseases; Coronary Circulation; Myocardial Ischemia; Microcirculation
PubMed: 37321056
DOI: 10.1016/j.biopha.2023.115011 -
Function (Oxford, England) 2023When exercising humans increase their oxygen uptake (V̇O) 20-fold above rest the numbers are staggering: Each minute the O transport system - lungs, cardiovascular,... (Review)
Review
When exercising humans increase their oxygen uptake (V̇O) 20-fold above rest the numbers are staggering: Each minute the O transport system - lungs, cardiovascular, active muscles - transports and utilizes 161 sextillion (10 ) O molecules. Leg extension exercise increases the quadriceps muscles' blood flow 100-times; transporting 17 sextillion O molecules per kilogram per minute from microcirculation (capillaries) to mitochondria powering their cellular energetics. Within these muscles, the capillary network constitutes a prodigious blood-tissue interface essential to exchange O and carbon dioxide requisite for muscle function. In disease, microcirculatory dysfunction underlies the pathophysiology of heart failure, diabetes, hypertension, pulmonary disease, sepsis, stroke and senile dementia. Effective therapeutic countermeasure design demands knowledge of microvascular/capillary function in health to recognize and combat pathological dysfunction. Dated concepts of skeletal muscle capillary (from the Latin meaning 'hair') function prevail despite rigorous data-supported contemporary models; hindering progress in the field for future and current students, researchers and clinicians. Following closely the 100th anniversary of August Krogh's 1920 Nobel Prize for capillary function this Evidence Review presents an anatomical and physiological development of this dynamic field: Constructing a scientifically defensible platform for our current understanding of microcirculatory physiological function in supporting blood-mitochondrial O transport. New developments include: 1. Putative roles of red blood cell aquaporin and rhesus channels in determining tissue O diffusion. 2. Recent discoveries regarding intramyocyte O transport. 3. Developing a comprehensive capillary functional model for muscle O delivery-to-V̇O matching. 4. Use of kinetics analysis to discriminate control mechanisms from collateral or pathological phenomena.
Topics: Humans; Oxygen; Microcirculation; Capillaries; Oxygen Consumption; Muscle, Skeletal; Mitochondria
PubMed: 37168497
DOI: 10.1093/function/zqad013 -
Clinical & Experimental Optometry Sep 2023The conjunctival microcirculation is an accessible complex network of micro vessels whose quantitative assessment can reveal microvascular haemodynamic properties.... (Review)
Review
The conjunctival microcirculation is an accessible complex network of micro vessels whose quantitative assessment can reveal microvascular haemodynamic properties. Currently, algorithms for the measurement of conjunctival haemodynamics use either manual or semi-automated systems, which may provide insight into overall conjunctival health, as well as in ocular and systemic disease. These algorithms include functional slit-lamp biomicroscopy, laser doppler flowmetry, optical coherence tomography angiography, orthogonal polarized spectral imaging, computer-assisted intravitral microscopy, diffuse reflectance spectroscopy and corneal confocal microscopy. Furthermore, several studies have demonstrated a relationship between conjunctival microcirculatory haemodynamics and many diseases such as dry eye disease, Alzheimer's disease, diabetes, hypertension, sepsis, coronary microvascular disease, and sickle cell anaemia. This review aims to describe conjunctival microcirculation, its characteristics, and techniques for its measurement, as well as the association between conjunctival microcirculation and microvascular abnormalities in disease states.
Topics: Humans; Blood Flow Velocity; Microcirculation; Conjunctiva; Hemodynamics; Slit Lamp Microscopy
PubMed: 36641840
DOI: 10.1080/08164622.2022.2151872 -
Hypertension (Dallas, Tex. : 1979) Mar 2022Microcirculation and macrocirculation are tightly interconnected into a dangerous cross-link in hypertension. Small artery damage includes functional (vasoconstriction,... (Review)
Review
Microcirculation and macrocirculation are tightly interconnected into a dangerous cross-link in hypertension. Small artery damage includes functional (vasoconstriction, impaired vasodilatation) and structural abnormalities (mostly inward eutrophic remodeling). These abnormalities are major determinants of the increase in total peripheral resistance and mean blood pressure (BP) in primary hypertension, which in the long term induces large artery stiffening. In turn, large artery stiffening increases central systolic and pulse pressures, which are further augmented by wave reflection in response to the structural alterations in small resistance arteries. Finally, transmission of high BP and flow pulsatility to small resistance arteries further induces functional and structural abnormalities, thus leading to increased total peripheral resistance and mean BP, thus perpetuating the vicious circle. Hyperpulsatility, in addition to higher mean BP, exaggerates cardiac, brain, and kidney damages and leads to cardiovascular, cerebral, and renal complications. The dangerous cross-link between micro and macrocirculation can be reversed into a virtuous one by ACE (angiotensin-converting enzyme) inhibitors, sartans, and calcium channel blockers. These three pharmacological classes are more potent than β-blockers and diuretics for reducing arterial stiffness and small artery remodeling. The same ranking was observed for their effectiveness at reducing left ventricular hypertrophy, preserving glomerular filtration rate, and preventing dementia, suggesting that they can act beyond brachial BP reduction, by breaking the micro/macrocirculation vicious circle.
Topics: Blood Pressure; Humans; Hypertension; Microcirculation; Pulse Wave Analysis; Vascular Resistance; Vascular Stiffness
PubMed: 34984924
DOI: 10.1161/HYPERTENSIONAHA.121.17962 -
Minerva Cardioangiologica Aug 2019Coronary microcirculatory dysfunction (CMD) is a major cause of myocardial ischemia that influences the outcomes of patients with coronary artery disease. The mechanisms... (Review)
Review
Coronary microcirculatory dysfunction (CMD) is a major cause of myocardial ischemia that influences the outcomes of patients with coronary artery disease. The mechanisms of CMD are heterogeneous and may result from a spectrum of biological and cardiovascular risk factors that may affect also the microcirculation of other vital organs. Microcirculatory dysfunction of the brain, known as cerebral small vessel disease, is increasingly being recognized as a cause of cognitive decline and neurodegenerative disorders. Despite microvascular dysfunction of the heart and the brain may share underlying pathophysiological mechanisms (endothelial dysfunction, thrombosis, vascular remodeling and capillary rarefaction), the evidence about the potential link between both pathological processes is scarce. In this paper we discuss the mechanisms of microvascular dysfunction of the heart and the brain, their clinical impact on cardiac events, cognitive decline and neurodegenerative disorders, and the potential link between both vascular target organs at the level of the microcirculation.
Topics: Cerebral Small Vessel Diseases; Cerebrovascular Circulation; Cognitive Dysfunction; Coronary Artery Disease; Coronary Circulation; Humans; Microcirculation; Myocardial Ischemia; Neurodegenerative Diseases; Risk Factors
PubMed: 29687698
DOI: 10.23736/S0026-4725.18.04701-1 -
Trends in Endocrinology and Metabolism:... Mar 2020Chest pain with non-obstructive coronary artery disease (NOCAD) occurs more frequently in women than in men and is mainly related to coronary microvascular disease... (Review)
Review
Chest pain with non-obstructive coronary artery disease (NOCAD) occurs more frequently in women than in men and is mainly related to coronary microvascular disease (CMD). The majority of CMD patients are postmenopausal women, suggesting a role for lack of estrogens in the development and progression of CMD. Patients are often discharged without a clear treatment plan due to the limited understanding of etiology and diagnostic parameters of CMD and have significantly higher rates of future cardiovascular events. Thus, there is a need for a better understanding of the underlying biology, and CMD-specific diagnostic tests and therapies. In this article, we reviewed recent studies on CMD, estrogen action in coronary microvasculature, and diagnosis and treatment options for CMD in postmenopausal women.
Topics: Coronary Artery Disease; Estrogens; Female; Humans; Male; Microcirculation; Postmenopause; Receptors, Estrogen; Sex Characteristics; Signal Transduction
PubMed: 31787492
DOI: 10.1016/j.tem.2019.11.001 -
Arteriosclerosis, Thrombosis, and... Jan 2020
Topics: Coronary Stenosis; Humans; Microcirculation; Myocardial Ischemia
PubMed: 31869270
DOI: 10.1161/ATVBAHA.119.313579 -
Microcirculation (New York, N.Y. : 1994) Apr 2021
Topics: Microcirculation
PubMed: 33629399
DOI: 10.1111/micc.12688 -
Current Opinion in Critical Care Aug 2019Adequate tissue perfusion is of utmost importance to avoid organ failure in patients with cardiogenic shock. Within the recent years, the microcirculation, defined as... (Review)
Review
PURPOSE OF REVIEW
Adequate tissue perfusion is of utmost importance to avoid organ failure in patients with cardiogenic shock. Within the recent years, the microcirculation, defined as the perfusion of the smallest vessels, has been identified to play a crucial role. Microcirculatory changes may include capillary flow disturbances as well as changes in the density of perfused vessels. Due to the availability of new technologies to assess the microcirculation, interesting new data came up and it is the purpose of this review to summarize recent studies in the field.
RECENT FINDINGS
Nowadays, an increasing number of studies confirm parameters of the microcirculation, derived by intravital microscopy, to represent strong outcome predictors in cardiogenic shock. In addition, microcirculation as read-out parameter in innovative clinical studies has meanwhile been accepted as serious endpoint. Treatment strategies such as mechanical assist devices, blood pressure regulating agents or fluids use tissue perfusion and microcirculatory network density as targets in addition to clinical perfusion evaluation and decreasing serum lactate levels.
SUMMARY
The parameter most frequently used to detect tissue malperfusion is serum lactate. Novel, noninvasive methods to quantify microvascular perfusion have the potential to guide treatment in terms of optimizing organ perfusion and oxygenation probably paving the way for an individualized therapy.
Topics: Humans; Microcirculation; Shock, Cardiogenic
PubMed: 31135392
DOI: 10.1097/MCC.0000000000000630