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Heart Failure Clinics Jul 2018Echocardiography is the first step in imaging the right heart pulmonary circulation unit (RH-PCU), and the only one to allow its complete morphologic, functional, and... (Review)
Review
Echocardiography is the first step in imaging the right heart pulmonary circulation unit (RH-PCU), and the only one to allow its complete morphologic, functional, and hemodynamic analysis in all clinical scenarios. Right ventricular (RV) function is not only the consequence of its intrinsic contractile function (morphology and contractility) but also highly dependent on preload, afterload, and ventricular interdependence. Comprehensive echocardiographic examination of RH-PCU allows insight into intrinsic and extrinsic factors of RV function. Newer echocardiographic techniques allow for 3-dimensional evaluation of RV and detailed measurements of regional function using tissue Doppler or speckle tracking-based strain estimates.
Topics: Echocardiography; Heart Ventricles; Hemodynamics; Humans; Pulmonary Circulation; Ventricular Function, Right
PubMed: 29966634
DOI: 10.1016/j.hfc.2018.03.003 -
Experimental Physiology Apr 2023
Topics: Humans; Oxygen; Vasoconstriction; Iron; Hypoxia; Pulmonary Disease, Chronic Obstructive; Pulmonary Gas Exchange; Pulmonary Circulation
PubMed: 36744659
DOI: 10.1113/EP091078 -
Heart Failure Clinics Jul 2018Systemic hypertension is a risk factor for left heart failure, mostly with preserved ejection fraction. Left heart failure is a cause of pulmonary hypertension and... (Review)
Review
Systemic hypertension is a risk factor for left heart failure, mostly with preserved ejection fraction. Left heart failure is a cause of pulmonary hypertension and eventual right ventricular (RV) failure. There has been report of altered RV function in mild to moderate hypertension with preserved systolic as well as diastolic function of the left ventricle. The pathophysiology of this complication of hypertension is unclear. Preserving the RV and preventing the development of pulmonary vascular disease may be considered among the targets of optimized therapy for systemic hypertension.
Topics: Heart Failure; Heart Ventricles; Humans; Hypertension; Hypertension, Pulmonary; Pulmonary Circulation; Ventricular Dysfunction, Right; Ventricular Function, Right
PubMed: 29966624
DOI: 10.1016/j.hfc.2018.02.002 -
Circulation May 2022
Topics: Heart Atria; Heart Failure; Humans; Pulmonary Circulation; Stroke Volume; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 35605032
DOI: 10.1161/CIRCULATIONAHA.122.059810 -
Biomedical Engineering Online 2015Patients with repaired or palliated right heart congenital heart disease (CHD) are often left with residual lesions that progress and can result in significant... (Review)
Review
Patients with repaired or palliated right heart congenital heart disease (CHD) are often left with residual lesions that progress and can result in significant morbidity. However, right ventricular-pulmonary arterial evaluation and the timing of reintvervention is still subjective. Currently, it relies on symptomology, or RV imaging-based metrics from echocardiography or MR derived parameters including right ventricular (RV) ejection fraction (EF), end-systolic pressure (ESP), and end-diastolic volume (EDV). However, the RV is coupled to the pulmonary vasculature, and they are not typically evaluated together. For example, the dysfunctional right ventricular-pulmonary circulation (RV-PC) adversely affects the RV myocardial performance resulting in decreased efficiency. Therefore, comprehensive hemodynamic assessment should incorporate changes in RV-PC and energy efficiency for CHD patients. The ventricular pressure-volume relationship (PVR) and other energy-based endpoints derived from PVR, such as stroke work (SW) and ventricular elastance (Ees), can provide a measure of RV performance. However, a detailed explanation of the relationship between RV performance and pulmonary arterial hemodynamics is lacking. More importantly, PVR is impractical for routine longitudinal evaluation in a clinical setting, because it requires invasive catheterization. As an alternative, analytical methods and computational fluid dynamics (CFD) have been used to compute energy endpoints, such as power loss or energy dissipation, in abnormal physiologies. In this review, we review the causes of RV-PA failure and the limitation of current clinical parameters to quantify RV-PC dysfunction. Then, we describe the advantage of currently available energy-based endpoints and emerging energy endpoints, such as energy loss in the Pas or kinetic energy, obtained from a new non-invasive imaging technique, i.e. 4D phase contrast MRI.
Topics: Energy Metabolism; Humans; Magnetic Resonance Imaging; Pulmonary Circulation; Stroke Volume; Ventricular Dysfunction, Right
PubMed: 25602641
DOI: 10.1186/1475-925X-14-S1-S8 -
Current Heart Failure Reports Apr 2018Pulmonary hypertension due to left heart disease (PH-LHD) is the most common cause of pulmonary hypertension worldwide, yet therapies used to treat pulmonary arterial... (Review)
Review
PURPOSE OF REVIEW
Pulmonary hypertension due to left heart disease (PH-LHD) is the most common cause of pulmonary hypertension worldwide, yet therapies used to treat pulmonary arterial hypertension have failed to show efficacy in this population. Proper hemodynamic assessment and differentiation of pulmonary hypertension phenotypes is therefore critical for both current clinical practice and future research and therapeutic efforts.
RECENT FINDINGS
Substantial recent efforts have sought to improve the hemodynamic characterization of pulmonary hypertension for both diagnostic and prognostic purposes. These efforts include identifying occult LHD using provocative maneuvers as well as sub-classifying PH-LHD based on the presence or absence of a pre-capillary component. How to best define the pre-capillary component remains controversial as several studies have drawn conflicting conclusions. The lack of standardization of hemodynamic measurements as well as measurement fidelity concerns may explain some of the discrepant results. Non-hemodynamic methods of PH-LHD classification may also have an emerging role. Despite recent advances, therapeutic studies have largely remained disappointing. In this review, we discuss the nuances and controversies surrounding diagnostic and prognostic hemodynamic characterization of PH-LHD as well as summarize the recent therapeutic efforts and ongoing challenges in this population.
Topics: Disease Management; Focus Groups; Humans; Hypertension, Pulmonary; Monitoring, Physiologic; Patient Selection; Pulmonary Circulation; Pulmonary Wedge Pressure; Vascular Resistance
PubMed: 29417467
DOI: 10.1007/s11897-018-0377-9 -
American Journal of Obstetrics &... Jan 2021The Fontan operation was first performed in 1968 and is a palliative procedure for children born with single ventricle forms of congenital heart disease. Today, 70,000... (Review)
Review
The Fontan operation was first performed in 1968 and is a palliative procedure for children born with single ventricle forms of congenital heart disease. Today, 70,000 patients worldwide have Fontan circulation today, half of them women, and with an expected 30-year survival of >80%, this population is expected to double in the next 20 years. The Fontan operation surgically redirects systemic venous blood return directly to the pulmonary circulation, bypassing the single ventricle. This abnormal anatomy results in significant challenges for the cardiovascular system and is marked by a sustained, abnormally elevated systemic venous pressure combined with decreased cardiac output. As more women with Fontan circulation reach childbearing age, understanding the unique risks of pregnancy to the mother and fetus and how to best provide clinical care for these women during pregnancy is imperative. However, there are limited clinical data to guide counseling and management in this population. This expert review offers an analysis of the literature about Fontan circulation during pregnancy and describes our center's current multidisciplinary approach to care for these women in the preconception, antepartum, intrapartum, and postpartum periods.
Topics: Child; Female; Fontan Procedure; Heart Defects, Congenital; Humans; Postpartum Period; Pregnancy; Pulmonary Circulation; Univentricular Heart
PubMed: 33451613
DOI: 10.1016/j.ajogmf.2020.100257 -
Journal of Biomechanical Engineering Feb 2022Pulmonary hypertension (PH) is a progressive disease that is characterized by a gradual increase in both resistive and reactive pulmonary arterial (PA) impedance....
Pulmonary hypertension (PH) is a progressive disease that is characterized by a gradual increase in both resistive and reactive pulmonary arterial (PA) impedance. Previous studies in a rodent model of PH have shown that reducing the hemodynamic load in the left lung (by banding the left PA) reverses this remodeling phenomenon. However, banding a single side of the pulmonary circulation is not a viable clinical option, so-using in silico modeling-we evaluated if the banding effect can be recreated by replacing the proximal vasculature with a compliant synthetic PA. We developed a computational model of the pulmonary circulation by combining a one-dimensional model of the proximal vasculature with a zero-dimensional line transmission model to the 12th generation. Using this model, we performed four simulations: (1) Control; (2) PH; (3) PH with a stenosis in the left PA; and (4) PH with proximal vessel compliance returned to Control levels. Simulations revealed that vascular changes associated with PH result in an increase in pulse pressure (PP), maximum pressure (Pmax), maximum wall shear stress (WSS), and maximum circumferential stress (σθθ) relative to controls, in the distal circulation. Banding the left PA reduced these measurements of hemodynamic stress in the left lung, but increases them in the right lung. Furthermore, left PA banding increased reactive PA impedance. However, returning the proximal PA compliance to Control levels simultaneously decreased all measures of hemodynamic stress in both lungs, and returned reactive PA impedance to normal levels. In conclusion, if future in vivo studies support the idea of hemodynamic unloading as an effective therapy for PH, this can be surgically achieved by replacing the proximal PA with a compliant prosthesis, and it will have the added benefit of reducing reactive right ventricular afterload.
Topics: Hemodynamics; Humans; Hypertension, Pulmonary; Pulmonary Artery; Pulmonary Circulation; Vascular Resistance
PubMed: 34251418
DOI: 10.1115/1.4051719 -
Cardiology in the Young Oct 2023Pulmonary arterial compliance, the dynamic component of pulmonary vasculature, remains inadequately studied in patients with left to right shunts. We sought to study the... (Review)
Review
INTRODUCTION
Pulmonary arterial compliance, the dynamic component of pulmonary vasculature, remains inadequately studied in patients with left to right shunts. We sought to study the pulmonary arterial compliance in patients with left to right shunt lesions and its utility in clinical decision-making.
MATERIALS AND METHODS
In this single-centre retrospective study, we reviewed cardiac catheterisation data of consecutive patients of left to right shunt lesions catheterised over one year. In addition to the various other parameters, pulmonary arterial compliance was calculated, as indexed pulmonary flow (Qpi) / (Heart rate × pulse pressure in the pulmonary artery). RC time was also calculated, as the product of pulmonary arterial compliance and pulmonary vascular resistance index. Patients were divided into "operable," "borderline," and "inoperable" based on the decision of the treating team, and the pulmonary arterial compliance values were evaluated in these groups to study if it can be utilised to refine the operability decision.
RESULTS
298 patients (Median age 16 years, 56% <18 years) with various acyanotic shunt lesions were included. Overall, the pulmonary arterial compliance varied with Qpi, pulmonary artery mean pressure, and pulmonary vascular resistance index, but did not vary with age, type of lesion, or transpulmonary gradients. The median pulmonary arterial compliance in patients with normal pulmonary artery pressure (Mean pulmonary artery pressure less than 20 mmHg) was 4.1 ml/mmHg/m (IQR 3.2). The median pulmonary arterial compliance for operable patients was 2.67 ml/mmHg/m (IQR 2.2). Median pulmonary arterial compliance was significantly lower in both inoperable (0.52 ml/mmHg/m, IQR 0.34) and borderline (0.80 ml/mmHg/m, IQR 0.36) groups when compared to operable patients (p < 0.001). A pulmonary arterial compliance value lower than 1.18 ml/mmHg/m identified inoperable patients with high sensitivity and specificity (95%, AUC 0.99). However, in borderline cases, assessment by this value did not agree with empirical clinical assessment.The median RC time for the entire study population was 0.47 S (IQR 0.30). RC time in operable patients was significantly lower than that in the inoperable patients (Median 0.40 IQR 0.23 in operable, 0.73 0.25 in inoperable patients (p < 0.001).
CONCLUSIONS
Addition of pulmonary arterial compliance to the routine haemodynamic assessment of patients with shunt lesions may improve our understanding of the pulmonary circulation and may have clinical utility.
Topics: Humans; Adolescent; Pulmonary Artery; Pulmonary Circulation; Hypertension, Pulmonary; Retrospective Studies; Vascular Resistance
PubMed: 36325920
DOI: 10.1017/S1047951122003341 -
The Canadian Journal of Cardiology Apr 2015Pulmonary hypertension (PH) in left heart disease, classified as group II, is the most common form of PH that occurs in approximately 60% of cases of reduced and... (Review)
Review
Pulmonary hypertension (PH) in left heart disease, classified as group II, is the most common form of PH that occurs in approximately 60% of cases of reduced and preserved left ventricular ejection fraction. Although relatively much is known about hemodynamic stages (passive or reactive) and their consequences on the right ventricle (RV) there is no consensus on the best hemodynamic definition of group II PH. In addition, the main pathways that lead to lung capillary injury and impaired biology of small artery remodelling processes are largely unknown. Typical lung manifestations of an increased pulmonary pressure and progressive RV-pulmonary circulation uncoupling are an abnormal alveolar capillary gas diffusion, impaired lung mechanics (restriction), and exercise ventilation inefficiency. Of several classes of pulmonary vasodilators currently clinically available, oral phosphodiesterase 5 inhibition, because of its strong selectivity for targeting the cyclic guanosine monophosphate pathway in the pulmonary circulation, is increasingly emerging as an attractive opportunity to reach hemodynamic benefits, reverse capillary injury, and RV remodelling, and improve functional capacity. Guanylate cyclase stimulators offer an additional intriguing opportunity but the lack of selectivity and systemic effects might preclude some of the anticipated benefits on the pulmonary circulation. Future trials will determine whether new routes of pharmacologic strategy aimed at targeting lung structural and vascular remodelling might affect morbidity and mortality in left heart disease populations. We believe that this therapeutic goal rather than a pure hemodynamic effect might ultimately emerge as an important challenge for the clinician.
Topics: Humans; Hypertension, Pulmonary; Pulmonary Circulation; Pulmonary Wedge Pressure; Vascular Remodeling; Ventricular Dysfunction, Left
PubMed: 25840093
DOI: 10.1016/j.cjca.2014.10.012