The Microcirculation and Clinical Disease
John H. Barker, Gary L. Anderson, Michael D. Menger in Clinically Applied Microcirculation Research, 2019
More subtle or low-grade chronic derangement is usually only detectable by investigation, and the majority of these tests are clinical research tools rather than methods used in current clinical practice. Organ-specific methodologies in current use are referred to in the relevant chapters and examples only are summarized here. An estimation of pulmonary capillary pressure may be obtained from the pulmonary “wedge” pressure, obtained by advancing a catheter into the pulmonary artery until it wedges in a distal artery. An estimate of alveolar permeability may be obtained by measuring the transfer factor — the disappearance of carbon monoxide from inhaled air, a freely diffusible molecule with avidity for hemoglobin. Access to filtrate (urine) makes renal microvascular function more accessible to clinical investigation and techniques exist for estimating the clearance of various solutes, renal plasma flow, and glomerular filtration rates.34 The selectivity of the glomerular barrier can be assessed both in terms of charge and molecular size using appropriate molecular probes. The retina is one of the few vascular beds that is routinely observed in clinical practice. The development of vitreous fluorophotometry provides the means to quantitative retinal vessel barrier function35 and laser scanning ophthalmoscopy enables detailed analysis of microvascular perfusion in the macular region.36
Clinical Cases
S. J. Copley, J. P. Kanne, D. M. Hansell in Thoracic Imaging, 2014
ii. Transthoracic echocardiography is used as a screening test to estimate the tricuspid valve regurgitant flow velocity, as an indirect measure of pulmonary arterial pressure. However, direct pressure measurements at cardiac catheterisation are more accurate. Pressure measurements at cardiac catheterisation confirmed the diagnosis in the current case with a high pulmonary vascular resistance, no evidence of a left-to-right shunt and normal pulmonary wedge pressure. Further imaging investigations should include ventilation–perfusion scintigraphy or a CT pulmonary angiogram (CTPA) to exclude chronic thromboembolic disease or interstitial lung disease. An image from the CTPA (19c) shows the enlarged central pulmonary artery, which should normally be approximately the same diameter as the ascending thoracic aorta. In this case, there was no evidence of chronic thromboembolic disease and no other clinically discernible cause of pulmonary hypertension such as underlying lung disease or left-to-right shunt. A diagnosis of IPAH was made.
Cardiac Damage from Left Ventricular Hypertrophy to Heart Failure
Giuseppe Mancia, Guido Grassi, Konstantinos P. Tsioufis, Anna F. Dominiczak, Enrico Agabiti Rosei in Manual of Hypertension of the European Society of Hypertension, 2019
Subendocardial ischemia, typically seen in patients with LVH even in the presence of normal epicardial arteries, can deteriorate diastolic filling. Conversely, since most of the coronary flow occurs in diastole, alterations of myocardial relaxation or compliance may affect blood supply. Diastolic abnormalities may be observed early in the natural history of hypertension and may also be demonstrated in normotensive subjects with parental hypertension (82,83). A few studies, using different techniques, showed that diastolic LV performance significantly influences exercise capacity in hypertensive patients with LVH (84–87). Brogan et al. (75) and Fagard et al. (88), who defined diastolic dysfunction on the basis of left ventricular end diastolic pressure or pulmonary wedge pressure, respectively, found an association between diastolic dysfunction and subsequent incidence of heart failure or cardiovascular events.
Levosimendan: mechanistic insight and its diverse future aspects in cardiac care
Published in Acta Cardiologica, 2023
Md Sayeed Akhtar, Md Quamrul Hassan, Aisha Siddiqui, Sirajudeen S. Alavudeen, Obaid Afzal, Abdulmalik S.A Altamimi, Syed Obaidur Rahman, Mallika Khurana, Mohamed Jawed Ahsan, Arun Kumar Sharma, Fauzia Tabassum
Lack of evidence and inconsistencies between different LEVO-HF related studies conducted around the globe have major concerns in clinical use. LEVO exerts its cardiac cardiodynamic effects by three key processes: Inotropic impact, improved endothelial functions, and cardiac protection. The CO and cardiac stroke volume has been well improved in decompensated HF. Concurrent to the reduction in incident of HF, pulmonary wedge pressure, SVR, and pulmonary vascular resistance has been also improved by LEVO administration. Uniquely, it directly maintains myocardial functioning devoid of any sympathetic activities. Cardiac pleiotropy of LEVO added additional benefits in preventing occurrence of cardiomyopathy followed by AHF. LEVO can be also beneficial in both non-cardiac surgery as well as renal complications associated with HF. Surprisingly, its active metabolites greatly possess similar cardio dynamic properties and thus efficacy of LEVO remains preserved throughout many days. However, in contrast to this evidence, LEVO also not exhibited advantage over dobutamine in clinical practice as discussed above. Keeping these facts in mind, overseeing more satisfactory meta-analysis is mandatory to find any conclusive clarity and applicability about LEVO in HF issues.
Overview of Impella and mechanical devices in cardiogenic shock
Published in Expert Review of Medical Devices, 2018
Hymie Habib Chera, Menachem Nagar, Nai-Lun Chang, Carlos Morales-Mangual, George Dous, Jonathan D. Marmur, Muhammad Ihsan, Paul Madaj, Yitzhak Rosen
CS is one of the major clinical presentations of acute heart failure. The characteristic features of CS include a pulmonary wedge pressure (PWP) which is more than 18 mmHg, cardiac index less than 2.2 L/min/m2 [3], and persistent organ hypoperfusion causing oliguria and cold, clammy extremities. Non-ischemic etiologies of LV or right ventricular (RV) dysfunction such as myopericarditis, acute decompensation secondary to chronic systolic dysfunction, acute and progressive valvular disease, and Takotsubo cardiomyopathy remain common and contribute to the progression of CS [4].
An update on current and emerging treatments for pulmonary arterial hypertension in childhood and adolescence
Published in Expert Review of Respiratory Medicine, 2019
Julie Wacker, Robert Weintraub, Maurice Beghetti
The definition of PH is a mean pulmonary artery pressure (mPAP) ≥25 mmHg assessed by a right heart catheterization [5]. In addition, in order to be classified as PAH, pulmonary wedge pressure should be lower than 15 mmHg, and indexed pulmonary vascular resistance (PVRi) should be elevated (>3 Woods Units (WU)·m2).
Related Knowledge Centers
- Acute Respiratory Distress Syndrome
- Pulmonary Circulation
- Atrium
- Pulmonary Edema
- Cardiac Output
- Heart Failure
- Pulmonary Artery Catheter