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Journal of the American College of... Nov 2023Exercise echocardiography is used for assessment of pulmonary circulation and right ventricular function, but limits of normal and disease-specific changes remain...
BACKGROUND
Exercise echocardiography is used for assessment of pulmonary circulation and right ventricular function, but limits of normal and disease-specific changes remain insufficiently established.
OBJECTIVES
The objective of this study was to explore the physiological vs pathologic response of the right ventricle and pulmonary circulation to exercise.
METHODS
A total of 2,228 subjects were enrolled: 375 healthy controls, 40 athletes, 516 patients with cardiovascular risk factors, 17 with pulmonary arterial hypertension, 872 with connective tissue diseases without overt pulmonary hypertension, 113 with left-sided heart disease, 30 with lung disease, and 265 with chronic exposure to high altitude. All subjects underwent resting and exercise echocardiography on a semirecumbent cycle ergometer. All-cause mortality was recorded at follow-up.
RESULTS
The 5th and 95th percentile of the mean pulmonary artery pressure-cardiac output relationships were 0.2 to 3.5 mm Hg.min/L in healthy subjects without cardiovascular risk factors, and were increased in all patient categories and in high altitude residents. The 5th and 95th percentile of the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio at rest were 0.7 to 2.0 mm/mm Hg at rest and 0.5 to 1.5 mm/mm Hg at peak exercise, and were decreased at rest and exercise in all disease categories and in high-altitude residents. An increased all-cause mortality was predicted by a resting tricuspid annular plane systolic excursion to systolic pulmonary artery pressure <0.7 mm/mm Hg and mean pulmonary artery pressure-cardiac output >5 mm Hg.min/L.
CONCLUSIONS
Exercise echocardiography of the pulmonary circulation and the right ventricle discloses prognostically relevant differences between healthy subjects, athletes, high-altitude residents, and patients with various cardio-respiratory conditions. (Right Heart International NETwork During Exercise in Different Clinical Conditions; NCT03041337).
Topics: Humans; Echocardiography, Stress; Pulmonary Circulation; Exercise Test; Heart Ventricles; Hypertension, Pulmonary; Ventricular Function, Right; Ventricular Dysfunction, Right
PubMed: 37968015
DOI: 10.1016/j.jacc.2023.09.807 -
Journal of the American College of... Jun 2023The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of... (Review)
Review
The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.
Topics: Adolescent; Humans; Fontan Procedure; Heart Defects, Congenital; Pulmonary Artery; Arteriovenous Fistula; Cyanosis; Pulmonary Circulation
PubMed: 37344046
DOI: 10.1016/j.jacc.2023.04.036 -
Archivos de Cardiologia de Mexico 2022
Topics: Heart; History, Medieval; Pulmonary Circulation
PubMed: 34987236
DOI: 10.24875/ACM.M21000080 -
The Journal of Physiology Sep 2023Potassium channel subfamily K member 3 (KCNK3), encoded by the KCNK3 gene, is part of the two-pore domain potassium channel family, constitutively active at resting... (Review)
Review
Potassium channel subfamily K member 3 (KCNK3), encoded by the KCNK3 gene, is part of the two-pore domain potassium channel family, constitutively active at resting membrane potentials in excitable cells, including smooth muscle and cardiac cells. Several physiological and pharmacological mediators, such as intracellular signalling pathways, extracellular pH, hypoxia and anaesthetics, regulate KCNK3 channel function. Recent studies show that modulation of KCNK3 channel expression and function strongly influences pulmonary vascular cell and cardiomyocyte function. The altered activity of KCNK3 in pathological situations such as atrial fibrillation, pulmonary arterial hypertension and right ventricular dysfunction demonstrates the crucial role of KCNK3 in cardiovascular homeostasis. Furthermore, loss of function variants of KCNK3 have been identified in patients suffering from pulmonary arterial hypertension and atrial fibrillation. This review focuses on current knowledge of the role of the KCNK3 channel in pulmonary circulation and the heart, in healthy and pathological conditions.
Topics: Humans; Pulmonary Circulation; Atrial Fibrillation; Pulmonary Arterial Hypertension; Membrane Potentials; Lung; Potassium Channels, Tandem Pore Domain
PubMed: 37477289
DOI: 10.1113/JP284936 -
Comprehensive Physiology Mar 2020The pulmonary blood-gas barrier represents a remarkable feat of engineering. It achieves the exquisite thinness needed for gas exchange by diffusion, the strength to... (Review)
Review
The pulmonary blood-gas barrier represents a remarkable feat of engineering. It achieves the exquisite thinness needed for gas exchange by diffusion, the strength to withstand the stresses and strains of repetitive and changing ventilation, and the ability to actively maintain itself under varied demands. Understanding the design principles of this barrier is essential to understanding a variety of lung diseases, and to successfully regenerating or artificially recapitulating the barrier ex vivo. Many classical studies helped to elucidate the unique structure and morphology of the mammalian blood-gas barrier, and ongoing investigations have helped to refine these descriptions and to understand the biological aspects of blood-gas barrier function and regulation. This article reviews the key features of the blood-gas barrier that enable achievement of the necessary design criteria and describes the mechanical environment to which the barrier is exposed. It then focuses on the biological and mechanical components of the barrier that preserve integrity during homeostasis, but which may be compromised in certain pathophysiological states, leading to disease. Finally, this article summarizes recent key advances in efforts to engineer the blood-gas barrier ex vivo, using the platforms of lung-on-a-chip and tissue-engineered whole lungs. © 2020 American Physiological Society. Compr Physiol 10:415-452, 2020.
Topics: Animals; Bioengineering; Blood-Air Barrier; Humans; Lung; Lung Diseases; Pulmonary Circulation; Pulmonary Gas Exchange
PubMed: 32163210
DOI: 10.1002/cphy.c190026 -
Current Opinion in Pulmonary Medicine Sep 2021While there has been a longstanding interest in metabolic disease in pulmonary hypertension, publications in the last several years have translated basic science... (Review)
Review
PURPOSE OF REVIEW
While there has been a longstanding interest in metabolic disease in pulmonary hypertension, publications in the last several years have translated basic science findings to human disease and even led to recently published studies of metabolic therapy in pulmonary arterial hypertension that are discussed here.
RECENT FINDINGS
Progress has been made in four key areas including mechanisms of insulin resistance in pulmonary arterial hypertension, the role of obesity in pulmonary vascular disease, novel clinical trials targeting metabolism in pulmonary hypertension, and the role of metabolism in chronic thromboembolic pulmonary hypertension.
SUMMARY
: Insulin resistance in pulmonary arterial hypertension is primarily in the lipid axis. There are systemic manifestations of insulin resistance including right ventricular lipotoxicity. Obesity is associated with elevation of right ventricular systolic pressure even in a healthy population and therapies in pulmonary arterial hypertension that target metabolism hold promise for improving exercise, right ventricular function, and visceral adiposity. Finally, there are emerging data that chronic thromboembolic pulmonary hypertension is similarly characterized by metabolic alterations, though the specific metabolites may be different from pulmonary arterial hypertension.
Topics: Heart Ventricles; Humans; Hypertension, Pulmonary; Pulmonary Arterial Hypertension; Pulmonary Artery; Pulmonary Circulation; Ventricular Function, Right
PubMed: 34127621
DOI: 10.1097/MCP.0000000000000794 -
Seminars in Respiratory and Critical... Dec 2023The right ventricle plays a pivotal role in patients with pulmonary hypertension (PH). Its adaptation to pressure overload determines a patient's functional status as... (Review)
Review
The right ventricle plays a pivotal role in patients with pulmonary hypertension (PH). Its adaptation to pressure overload determines a patient's functional status as well as survival. In a healthy situation, the right ventricle is part of a low pressure, high compliance system. It is built to accommodate changes in preload, but not very well suited for dealing with pressure overload. In PH, right ventricular (RV) contractility must increase to maintain cardiac output. In other words, the balance between the degree of RV contractility and afterload determines stroke volume. Hypertrophy is one of the major hallmarks of RV adaptation, but it may cause stiffening of the ventricle in addition to intrinsic changes to the RV myocardium. Ventricular filling becomes more difficult for which the right atrium tries to compensate through increased stroke work. Interaction of RV diastolic stiffness and right atrial (RA) function determines RV filling, but also causes vena cava backflow. Assessment of RV and RA function is critical in the evaluation of patient status. In recent guidelines, this is acknowledged by incorporating additional RV parameters in the risk stratification in PH. Several conventional parameters of RV and RA function have been part of risk stratification for many years. Understanding the pathophysiology of RV failure and the interactions with the pulmonary circulation and right atrium requires consideration of the unique RV anatomy. This review will therefore describe normal RV structure and function and changes that occur during adaptation to increased afterload. Consequences of a failing right ventricle and its implications for RA function will be discussed. Subsequently, we will describe RV and RA assessment in clinical practice.
Topics: Humans; Hypertension, Pulmonary; Heart Ventricles; Pulmonary Circulation; Heart Failure; Stroke Volume; Ventricular Function, Right; Ventricular Dysfunction, Right
PubMed: 37487527
DOI: 10.1055/s-0043-1770117 -
Clinical Journal of Gastroenterology Oct 2019Liver cirrhosis is associated with multiple vascular syndromes affecting almost all body systems. Many of these syndromes are directly related to impaired liver function... (Review)
Review
Liver cirrhosis is associated with multiple vascular syndromes affecting almost all body systems. Many of these syndromes are directly related to impaired liver function and sometimes reversible after liver transplantation while others arise secondary to portal hypertension and ascites. Altered expression of angiogenic and vasoactive compounds (most importantly nitric oxide), endothelial dysfunction, dysregulated neurohormonal control, and systemic inflammatory state play differential roles in mediating homeostatic instability and abnormal vasogenic response. Important vascular features encountered in liver disease include portal hypertension, splanchnic overflow, abnormal angiogenesis and shunts, portopulmonary syndrome, hepatopulmonary syndrome, and systemic hyperdynamic circulation. Redistribution of effective circulatory volume deviating from vital organs and pooling in splanchnic circulation is also encountered in liver patients which may lead to devastating outcomes as hepatorenal syndrome. Etiologically, vascular syndromes are not isolated phenomena and vascular dysfunction in one system may lead to the development of another in a different system. This review focuses on understanding the pathophysiological factors underlying vascular syndromes related to chronic liver disease and the potential links among them. Many of these syndromes are associated with high mortality, thus it is crucial to look for early biomarkers for these syndromes and develop novel preventive and therapeutic strategies.
Topics: Collateral Circulation; Hepatopulmonary Syndrome; Hepatorenal Syndrome; Humans; Hypertension, Portal; Hypertension, Pulmonary; Liver Circulation; Liver Cirrhosis; Pulmonary Circulation; Splanchnic Circulation; Syndrome; Vascular Diseases; Vasodilation
PubMed: 30980261
DOI: 10.1007/s12328-019-00956-0 -
Heart Failure Clinics Jan 2021Right heart and pulmonary circulation disorders are generally caused by right ventricle (RV) pressure overload, volume overload, and cardiomyopathy, and they are... (Review)
Review
Right heart and pulmonary circulation disorders are generally caused by right ventricle (RV) pressure overload, volume overload, and cardiomyopathy, and they are associated with distinct clinical courses and therapeutic approaches, although they often may coexist. Cardiac magnetic resonance (CMR) provides a noninvasive accurate and reproducible multiplanar anatomic and functional assessment, tissue characterization, and blood flow evaluation of the right heart and pulmonary circulation. This article reviews the current status of the CMR, the most recent techniques, the new parameters and their clinical utility in diagnosis, prognosis, and therapeutic management in the right heart and pulmonary circulation disorders.
Topics: Cardiomyopathies; Humans; Hypertension, Pulmonary; Magnetic Resonance Imaging, Cine; Magnetic Resonance Spectroscopy; Pulmonary Circulation; Ventricular Function, Right
PubMed: 33220887
DOI: 10.1016/j.hfc.2020.08.006 -
Current Opinion in Cardiology Nov 2020Pulmonary hypertension is a common phenomenon in heart failure patients that is highly relevant for morbidity and outcome. Although postcapillary in nature, the... (Review)
Review
PURPOSE OF REVIEW
Pulmonary hypertension is a common phenomenon in heart failure patients that is highly relevant for morbidity and outcome. Although postcapillary in nature, the pathophysiology of pulmonary hypertension in patients with heart failure with reduced or preserved ejection fraction is complex, and decisions about management strategies remain challenging.
RECENT FINDINGS
Recently, the hemodynamic definitions and subclassification of postcapillary pulmonary hypertension have been revisited. The distinction between isolated postcapillary pulmonary hypertension (IpcPH) and combined post and precapillary pulmonary hypertension (CpcPH) and their definition are essential. Novel data on the prognostic impact of hemodynamic variables and right ventricular function highlight the importance of cardiopulmonary interaction in patients with left-sided heart failure (LHF). Furthermore, the impact of management strategies including medical therapy, remote hemodynamic monitoring, and interventional approaches on hemodynamics and outcome has recently been investigated. Here, we critically review recent developments and future considerations in this field, and highlight distinct treatment strategies targeting the underlying left heart condition, the pulmonary circulation, and/or impaired right ventricular function.
SUMMARY
Detailed hemodynamic characterization and proper phenotyping are essential for prognostication and the management of patients with pulmonary hypertension associated with LHF, both in clinical practice and when addressing research questions.
Topics: Heart Failure; Hemodynamics; Humans; Hypertension, Pulmonary; Pulmonary Circulation; Ventricular Dysfunction, Right; Ventricular Function, Right
PubMed: 32969856
DOI: 10.1097/HCO.0000000000000791