Pathology of pulmonic valve stenosis and pure regurgitation

APOE-NOTCH axis governs elastogenesis during human cardiac valve remodeling

Valve remodeling is a process involving extracellular matrix organization and elongation of valve leaflets. Here, through single-cell RNA sequencing of human fetal valves, we identified an elastin-producing valve interstitial cell (VIC) subtype (apolipoprotein E (APOE)+, elastin-VICs) spatially located underneath valve endothelial cells (VECs) sensing unidirectional flow. APOE knockdown in fetal VICs resulted in profound elastogenesis defects. In valves with pulmonary stenosis (PS), we observed elastin fragmentation and decreased expression of APOE along with other genes regulating elastogenesis. Cell-cell interaction analysis revealed that jagged 1 (JAG1) from unidirectional VECs activates elastogenesis in elastin-VICs through NOTCH2. Similar observations were made in VICs cocultured with VECs under unidirectional flow. Notably, a drastic reduction of JAG1-NOTCH2 was also observed in PS valves. Lastly, we found that APOE controls JAG1-induced NOTCH activation and elastogenesis in VICs through the extracellular signal-regulated kinase pathway. Our study suggests important roles of both APOE and NOTCH in regulating elastogenesis during human valve remodeling.

Primary Severe Pulmonary and Tricuspid Valve Regurgitation in an Adult Patient

•Severe progressive PR and TR in adults without histories of cardiac surgery is rare. •Carcinoid heart disease is an important differential in isolated PR and TR. •Three-dimensional TTE is helpful in identifying morphologic abnormalities of the PV. •CCT and cardiovascular magnetic resonance also help evaluate structures near the PV.

Advances in the Treatment of Pulmonary Valve Stenosis

Pulmonary valve stenosis represents the most common congenital heart defect of dogs and appears to be increasing in prevalence due to the growing popularity of brachycephalic breeds. Current treatments include beta-blockade and balloon pulmonary valvuloplasty, though evidence-based approaches to this disease are lacking. Balloon pulmonary valvuloplasty is most effective for fused, doming valves leaving a large population of dogs with thick, dysplastic valves that fail to respond adequately to balloon dilation. Transpulmonary stent implantation is an emerging therapy to consider for dogs with valve dysplasia or who have failed balloon pulmonary valvuloplasty; current experience with transpulmonary stent implantation is provided.

Pulmonary Arterial Dilatation: Imaging Evaluation Using Multidetector Computed Tomography

Pulmonary artery dilatation comprises a heterogeneous group of disorders. Early diagnosis is important as the presentation may be incidental, chronic, or acute and life threatening depending upon the etiology. Cross-sectional imaging plays an important role, with CT pulmonary angiography being regarded as the first line investigation in the evaluation of pulmonary artery pathologies. Moreover, effects of pulmonary artery lesions on proximal and distal circulation can also be ascertained with the detection of associated conditions. Special attention should also be given to the left main coronary artery and the trachea-bronchial tree as they may be extrinsically compressed by the dilated pulmonary artery. In context of an appropriate clinical background, CT pulmonary angiography also helps in treatment planning, prognostication, and follow-up of these patients. This review mainly deals with imaging evaluation of the pulmonary arterial dilatations on CT with emphasis on the gamut of etiologies in the adult as well as pediatric populations.

Clinical-pathological correlations of BAV and the attendant thoracic aortopathies. Part 2: Pluridisciplinary perspective on their genetic and molecular origins

Bicuspid aortic valve (BAV) arises during valvulogenesis when 2 leaflets/cusps of the aortic valve (AOV) are fused together. Its clinical manifestations pertain to faulty AOV function, the associated aortopathy, and other complications surveyed in Part 1 of the present bipartite-series. Part 2 examines mainly genetic and epigenetic causes of BAV and BAV-associated aortopathies (BAVAs) and disease syndromes (BAVD). Part 1 explored the heterogeneity among subsets of patients with BAV and BAVA/BAVD, and investigated abnormal fluid dynamic stress and strain patterns sustained by the cusps. Specific BAV morphologies engender systolic outflow asymmetries, associated with abnormal aortic regional wall-shear-stress distributions and the expression/localization of BAVAs. Understanding fluid dynamic factors besides the developmental mechanisms and underlying genetics governing these congenital anomalies is necessary to explain patient predisposition to aortopathy and phenotypic heterogeneity. BAV aortopathy entails complex/multifactorial pathophysiology, involving alterations in genetics, epigenetics, hemodynamics, and in cellular and molecular pathways. There is always an interdependence between organismic developmental signals and genes-no systemic signals, no gene-expression; no active gene, no next step. An apposite signal induces the expression of the next developmental gene, which needs be expressed to trigger the next signal, and so on. Hence, embryonic, then post-partum, AOV and thoracic aortic development comprise cascades of developmental genes and their regulation. Interdependencies between them arise, entailing reciprocal/cyclical mutual interactions and adaptive feedback loops, by which developmental morphogenetic processes self-correct responding to environmental inputs/reactions. This Survey can serve as a reference point and driver for further pluridisciplinary BAV/BAVD studies and their clinical translation.

Investigation of an anatomically variant isolated bicuspid pulmonary valve: A case report

INTRODUCTION

We provide a discussion of the anatomical characteristics of the bicuspid pulmonary valve (BPV) in this paper. We performed an autopsy of an isolated BPV found in the heart of a deceased individual. The deceased was a man in his 60s and had no previous history of cardiovascular disease. The heart weighed 260 g and had mild right ventricular hypertrophy. The pulmonary valve had a fish-mouth-like shape that was convex to the pulmonary trunk and both cusps were thickened and hardened. The anterior and left semilunar cusps of the pulmonary valve were fused. Post-stenotic dilatation was noted.

CONCLUSIONS

In comparing the present case with previous reports, we found that, in human BPVs, cusps are fused in at least 2 patterns.

Pulmonic Valve Disease: Review of Pathology and Current Treatment Options

PURPOSE OF REVIEW

Our review is intended to provide readers with an overview of disease processes involving the pulmonic valve, highlighting recent outcome studies and guideline-based recommendations; with focus on the two most common interventions for treating pulmonic valve disease, balloon pulmonary valvuloplasty and pulmonic valve replacement.

RECENT FINDINGS

The main long-term sequelae of balloon pulmonary valvuloplasty, the gold standard treatment for pulmonic stenosis, remain pulmonic regurgitation and valvular restenosis. The balloon:annulus ratio is a major contributor to both, with high ratios resulting in greater degrees of regurgitation, and small ratios increasing risk for restenosis. Recent studies suggest that a ratio of approximately 1.2 may provide the most optimal results. Pulmonic valve replacement is currently the procedure of choice for patients with severe pulmonic regurgitation and hemodynamic sequelae or symptoms, yet it remains uncertain how it impacts long-term survival. Transcatheter pulmonic valve replacement is a rapidly evolving field and recent outcome studies suggest short and mid-term results at least equivalent to surgery. The Melody valve® was FDA approved for failing pulmonary surgical conduits in 2010 and for failing bioprosthetic surgical pulmonic valves in 2017 and has been extensively studied, whereas the Sapien XT valve®, offering larger diameters, was approved for failing pulmonary conduits in 2016 and has been less extensively studied. Patients with pulmonic valve disease deserve lifelong surveillance for complications. Transcatheter pulmonic valve replacement is a novel and attractive therapeutic option, but is currently only FDA approved for patients with failing pulmonary conduits or dysfunctional surgical bioprosthetic valves. New advances will undoubtedly increase the utilization of this rapidly expanding technology.

The advantages of live/real time three-dimensional transesophageal echocardiography during assessments of pulmonary stenosis

This report sought to compare live/real-time three-dimensional transesophageal echocardiography (3D-TEE) with two-dimensional transesophageal echocardiography (2D-TEE) and to determine whether there are advantages to using 3D-TEE on patients with pulmonary stenosis (PS). Sixteen consecutive adult patients (50 % male and 50 % female; mean age 33 ± 13.4 years) with PS and indications of TEE were prospectively enrolled in this study. Following this, initial 2D-TEE and 3D-TEE examinations were performed, and 3D-TEE images were analyzed using an off-line Q-lab software system. Finally, the 2D-TEE and 3D-TEE findings were compared. In the present study, 3D-TEE allowed us to obtain the en face views of pulmonary valves (PVs) in all but one patient. While this patient was without a PV due to a previous tetralogy of Fallot operation, we could detect the type of PV in the other 15 (93.7 %) patients by using 3D-TEE. Due to poor image quality, the most stenotic area was not measurable in only one (6.2 %) of the patients. In eight (50 %) of the patients, severity and localization of stenosis were more precisely determined with 3DTEE than with 2D-TEE. The PVs' maximal annulus dimensions were found to be significantly larger when they were measured using 3D modalities. This study provides evidence of the incremental value of using 3D-TEE rather than 2D-TEE during assessments of PS, specifically in cases where special conditions (pregnancy, pulmonary regurgitation, and concomitant atrial septal defects) cause recordings of the transvalvular peak gradient to be inaccurate. Therefore, 3D-TEE should be used as a complementary imaging tool to 2D-TEE during routine echocardiographic examinations.

Native Cardiac Valve Pathology

Anatomy of the native cardiac valves, reasons for surgical excision and examination, and a summary of the gross examination and documentation are presented. Aortic stenosis, aortic valve regurgitation, tricuspid and pulmonary valve pathology, mitral stenosis, and mitral insufficiency are each presented with an overview, focused anatomy, and discussion of pathologic diagnosis by gross examination and histology.

Acquired pulmonary artery stenosis in four dogs

CASE DESCRIPTION

4 dogs with acquired pulmonary artery stenosis (PAS) were examined for various clinical signs. One was a mixed-breed dog with congenital valvular PAS that subsequently developed peripheral PAS, one was a Golden Retriever with pulmonary valve fibrosarcoma, one was a Pembroke Welsh Corgi in which the left pulmonary artery had inadvertently been ligated during surgery for correction of patent ductus arteriosus, and one was a Boston Terrier with a heart-base mass compressing the pulmonary arteries.

CLINICAL FINDINGS

All 4 dogs were evaluated with 2-dimensional and Doppler echocardiography to characterize the nature and severity of the stenoses; other diagnostic tests were also performed.

TREATMENT AND OUTCOME

The mixed-breed dog with valvular and peripheral PAS was euthanized, surgical resection of the pulmonic valve mass was performed in the Golden Retriever, corrective surgery was performed on the Pembroke Welsh Corgi with left pulmonary artery ligation, and the Boston Terrier with the heart-base mass was managed medically.

CLINICAL RELEVANCE

Acquired PAS in dogs may manifest as a clinically silent heart murmur, syncope, or right-sided heart failure. The diagnosis is made on the basis of imaging findings, particularly results of 2-dimensional and Doppler echocardiography. Treatment may include surgical, interventional, or medical modalities and is targeted at resolving the inciting cause.

Unusual echocardiographic views of bicuspid and tricuspid pulmonic valves

The pulmonary artery is typically seen on transthoracic echocardiography in its longitudinal axis. Therefore, short axis views of the pulmonic valve leaflets are not generally obtained, and the distinction between tricuspid and bicuspid pulmonic valves is difficult or impossible. Bicuspid pulmonic valve is one cause of pulmonic stenosis, which is especially common in tetralogy of Fallot. Presented here are 2 patients in whom the orientation of the pulmonary artery was unusual, and the pulmonic valve was seen en face. The first patient had tetralogy of Fallot and a bicuspid pulmonic valve. The severe obstruction to right ventricular outflow was infundibular. The second patient had severe stenosis of a tricuspid pulmonic valve, which was treated with balloon valvuloplasty. These unusual views of the pulmonic valve leaflets were obtained because of anterior displacement of the pulmonary artery, and precise anatomic delineation of the problem in each case was possible with transthoracic echocardiography.