Valve Abnormalities Research Articles

Computational study of aortic hemodynamics for patients with an abnormal aortic valve: The importance of secondary flow at the ascending aorta inlet.

Blood flow in the aorta is helical, but most computational studies ignore the presence of secondary flow components at the ascending aorta (AAo) inlet. The aim of this study is to ascertain the importance of inlet boundary conditions (BCs) in computational analysis of flow patterns in the thoracic aorta based on patient-specific images, with a particular focus on patients with an abnormal aortic valve. Two cases were studied: one presenting a severe aortic valve stenosis and the other with a mechanical valve. For both aorta models, three inlet BCs were compared; these included the flat profile and 1D through-plane velocity and 3D phase-contrast magnetic resonance imaging derived velocity profiles, with the latter being used for benchmarking. Our results showed that peak and mean velocities at the proximal end of the ascending aorta were underestimated by up to 41% when the secondary flow components were neglected. The results for helical flow descriptors highlighted the strong influence of secondary velocities on the helical flow structure in the AAo. Differences in all wall shear stress (WSS)-derived indices were much more pronounced in the AAo and aortic arch (AA) than in the descending aorta (DAo). Overall, this study demonstrates that using 3D velocity profiles as inlet BC is essential for patient-specific analysis of hemodynamics and WSS in the AAo and AA in the presence of an abnormal aortic valve. However, predicted flow in the DAo is less sensitive to the secondary velocities imposed at the inlet; hence, the 1D through-plane profile could be a sufficient inlet BC for studies focusing on distal regions of the thoracic aorta.

Minimally invasive trans-mitral septal myectomy for diffuse-type hypertrophic obstructive cardiomyopathy.

Despite excellent long-term results reported for a trans-aortic septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM), surgery for patients with diffuse hypertrophy is very challenging. In addition, a left ventricular outflow obstruction is often aggravated by an abnormal mitral valve and subvalvular apparatus. We performed video-assisted minimally invasive trans-mitral septal myectomy procedures in 3 patients with diffuse-type HOCM, who were highly symptomatic despite maximal medical therapy. Each had at least moderate mitral regurgitation (MR) due to systolic anterior motion (SAM). Using a right mini-thoracotomy, the anterior mitral leaflet was detached, through which an extended septal myectomy could easily be performed. Abnormal bridging chordae between the septum and papillary muscle (PM) were divided, then anterior mitral leaflet continuity was restored with direct closure or augmentation using a glutaraldehyde-treated autologous pericardium. A PM reorientation procedure was performed in 1 case in which both PMs were approximated and sutured onto the posterior ventricular wall. The postoperative course was uneventful in all patients, with marked improvement of symptoms in each. The peak ventricular outflow gradient decreased from 134 ± 40 to 23 ± 5mmHg with significantly diminished SAM, especially in the patient who underwent the PM reorientation procedure. During a mean follow-up period of 42 ± 14 months, no MR has been detected in any case. We believe that a minimally invasive trans-mitral septal myectomy is preferable for HOCM-patients with diffuse hypertrophy and mitral valve abnormality. Aggressive PM reorientation may also be useful for those with an abnormal PM orientation.

An unusual cause of hypoxia: getting to the heart of the matter

SummaryA 63-year-old female presented to hospital with progressive exertional dyspnoea over a 6-month period. In the year preceding her admission, she reported an intercurrent history of abdominal pain, diarrhoea and weight loss. She was found to be hypoxic, the cause for which was initially unclear. A ventilation–perfusion scan identified a right-to-left shunt. Transoesophageal echocardiography (TOE) demonstrated a significant right-to-left intracardiac shunt through a patent foramen ovale (PFO); additionally severe tricuspid regurgitation was noted through a highly abnormal tricuspid valve. The findings were consistent with carcinoid heart disease with a haemodynamically significant shunt, resulting in profound systemic hypoxia. 24-h urinary 5-hydroxyindoleacetic acid (5-HIAA) and imaging were consistent with a terminal ileal primary carcinoid cancer with hepatic metastasis. Liver biopsy confirmed a tissue diagnosis. The patient was commenced on medical therapy for carcinoid syndrome. She subsequently passed away while undergoing anaesthetic induction for valvular surgery to treat her carcinoid heart disease and PFO.

A case of isolated bicuspid pulmonary valve

SummaryOur case highlights the finding of an abnormal pulmonary valve on 2D echocardiography, confirmed to be of bicuspid morphology with 3D imaging. The use of biplane imaging both in transthoracic and transoesophageal echocardiography and routine use of three-dimensional views particularly in transoesophageal echocardiography are of incremental value in better delineating pulmonary valve anatomy.

NOT YOUR TYPICAL PSEUDO-SEVERE AORTIC STENOSIS

Calcific aortic stenosis (AS) is the most common valve abnormality encountered in developing countries. In the majority of patients, stenosis severity is easily identified by a low valve area and high mean gradient. However, a subset of patients are found to have a low mean gradient despite a low

Cardiovascular Imaging Techniques in Systemic Rheumatic Diseases

The risk of cardiovascular (CV) events and mortality is significantly higher in patients with systemic rheumatic diseases than in the general population. Although CV involvement in such patients is highly heterogeneous and may affect various structures of the heart, it can now be diagnosed earlier and promptly treated. Various types of assessments are employed for the evaluation of CV risk such as transthoracic or transesophageal echocardiography, magnetic resonance imaging (MRI), and computed tomography (CT) to investigate valve abnormalities, pericardial disease, and ventricular wall motion defects. The diameter of coronary arteries can be assessed using invasive quantitative coronarography or intravascular ultrasound, and coronary flow reserve can be assessed using non-invasive transesophageal or transthoracic ultrasonography (US), MRI, CT, or positron emission tomography (PET) after endothelium-dependent vasodilation. Finally, peripheral circulation can be measured invasively using strain-gauge plethysmography in an arm after the arterial infusion of an endothelium-dependent vasodilator or non-invasively by means of US or MRI measurements of flow-mediated vasodilation of the brachial artery. All of the above are reliable methods of investigating CV involvement, but more recently, introduced use of speckle tracking echocardiography and 3-dimensional US are diagnostically more accurate.

Menarche, menopause, and pregnancy data in untreated females and females treated with agalsidase alfa in the Fabry Outcome Survey

Mucopolysaccharidosis (MPS) type III, Sanfilippo Syndrome, is an autosomal recessive lysosomal storage disorder. MPS I and II patients often develop cardiac involvement leading to early mortality, however there are limited data in MPS III. The objective of this study is to describe cardiac abnormalities in a large group of MPS III patients followed in a longitudinal natural history study designed to determine outcome measures for gene transfer trials.A single center study of MPS III patients who were enrolled in the Nationwide Children's Hospital natural history study in 2014. Two cardiologists reviewed all patient echocardiograms for anatomic, valvular, and functional abnormalities. Valve abnormalities were defined as abnormal morphology, trivial mitral regurgitation (MR) with abnormal morphology or at least mild MR, and any aortic regurgitation (AR). Abnormal left ventricular (LV) function was defined as ejection fraction < 50%. Group comparisons were assessed using two-sample t-tests or Wilcoxon rank sum tests for continuous variables and chi-square or Fisher's exact tests for categorical variables.Twenty-five patients, 15 Type A and 10 Type B MPS III, underwent 45 echocardiograms. Fifteen patients (60%) demonstrated an abnormal echocardiographic finding with age at first abnormal echocardiogram within the study being 6.8 ± 2.8 years. Left-sided valve abnormalities were common over time: 7 mitral valve thickening, 2 mitral valve prolapse, 16 MR (8 mild, 8 trivial), 3 aortic valve thickening, and 9 AR (7 mild, 2 trivial). Two patients had asymmetric LV septal hypertrophy. No valvular stenosis or ventricular function abnormalities were noted. Incidental findings included: mild aortic root dilation (2), bicommissural aortic valve (1), and mild tricuspid regurgitation (3).Individuals with Sanfilippo A and B demonstrate a natural history of cardiac involvement with valvular abnormalities most common. In short-term follow up, patients demonstrated only mild progression of abnormalities, none requiring intervention. Valvular disease prevalence is similar to MPS I and II, but appears less severe. These findings raise no specific concerns for gene transfer trials in patients in this age range.

Cardiac Manifestations of Idiopathic Hypereosinophilic Syndrome

Hypereosinophilic syndromes (HES) have heterogenous clinical presentations and can cause significant morbidity, including cardiac complications and thromboembolic events. Characterizing cardiac manifestations in HES will aid the evaluation and management of these patients. A retrospective review of electronic medical records (January 2002 to June 2017) was performed for adult patients with a diagnosis of idiopathic HES. Each chart review detailed symptoms at clinical presentation, eosinophil counts, troponin levels, and echocardiographic findings. The study was approved by the institutional review board. Twenty-one patients were identified for review, consisting of 10 males and 11 females. Symptom duration at time of initial presentation ranged from 1 to 156 months (average 29.3 months). Eosinophil counts ranged from 1090 to 62,160 eosinophils per microliter at the time of initial presentation. Thirteen (62%) patients presented with cardiovascular symptoms, including chest pain, dyspnea on exertion, or lower extremity edema. Eight (38%) patients had elevated troponin levels and two additional patients had elevated LDH with no troponin levels drawn. Eleven (52%) patients demonstrated valve abnormalities on echocardiogram including one patient with thrombus formation in the left ventricular endocardium. Four (19%) patients had ejection fractions less than 45%. Maintenance therapies included the following: 7 patients (33%) prednisone and hydroxyurea, 5 patients (24%) prednisone and interferon, 5 patients (24%) prednisone only, and 4 patients (19%) mepolizumab. Cardiac symptoms and abnormalities are frequently seen with idiopathic HES. Prompt, comprehensive cardiovascular evaluation is essential to reduce HES-associated cardiac morbidities.

Cathepsin B inhibition attenuates cardiovascular pathology in mucopolysaccharidosis I mice

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder with multisystemic features, including heart enlargement, heart valve dysfunction, and aortic stiffness and dilatation. Previous studies have shown that MPS I mice overexpress cathepsin B (CtsB) in multiple tissues, including those from the cardiovascular system. Here, we hypothesized that inhibition of CtsB could ameliorate cardiac function parameters, as well as aorta and valve abnormalities found in MPS I.First, we found that total elastase activity in an MPS I aorta is elevated. Following that, we demonstrated that CtsB leaks from the lysosome in MPS I human fibroblasts, possibly acting as a degradative agent of extracellular matrix components from the aorta, cardiac muscle, and heart valves. We then used a CtsB inhibitor in vivo in the MPS I mouse model. After 4 months of treatment, partial inhibition of CtsB activity in treated mice reduced aortic dilatation, as well as heart valve thickening, and led to improvements in cardiac function parameters, although none of these were completely normalized. Based on these results, we conclude that lysosomal alterations in this disease promote leakage of CtsB to outside the organelle, where this protein can have multiple pathological roles. CtsB inhibition improved cardiovascular parameters in MPS I mice and can have a potential benefit in this disease.

Pulmonary Valve Morphology in Patients with Bicuspid Aortic Valves

The aortic and pulmonary valve share a common developmental origin from the embryonic arterial trunk. Bicuspid aortic valve is the most common congenital anomaly and can occur isolated as well as in association with other congenital heart disease (CHD). Data on pulmonary valve morphology in these cases are scarce. In this study, we aimed to determine pulmonary valve morphology in hearts with BAV associated with CHD. In 83 post-mortem heart specimens with BAV and associated CHD, pulmonary valve morphology was studied and related to BAV morphology. In 14/83 (17%) hearts, the pulmonary valve was affected, bicuspid in 8/83 (10%), dome-shaped in 3/83 (4%) and atretic in 3/83 (4%). In specimens with a bicuspid pulmonary valve, 5/8 (63%) had a strictly bicuspid aortic valve (without raphe), 2/3 hearts (67%) with dome-shaped pulmonary valves and 2/3 hearts (67%) with atretic pulmonary valves had BAV without raphe. Six out of eight (75%) specimens with a bicuspid pulmonary valve had a perimembranous ventricular septal defect (VSD). 4/8 (50%) specimens with a bicuspid pulmonary valve were associated with chromosomal abnormalities: 3 (38%) had trisomy 18 and 1 (13%) had trisomy 13. In BAV with associated CHD, abnormal pulmonary valve morphology was observed in 17% of the hearts. The majority of hearts with abnormal pulmonary valve morphology had a Type B bicuspid aortic valve (without raphe). Bilateral semilunar valvular disease is associated with Type B BAVs and in many cases related to chromosomal abnormalities. As this study was performed in post-mortem specimens with high frequency of associated CHD, caution is warranted with application of these results to the general BAV population.

Early and long-term outcomes of mitral valve repair for Barlow's disease: a single-centre 16-year experience.

Following mitral valve repair for Barlow's disease, recurrent mitral regurgitation (MR) is believed to occur frequently and is mainly attributed to disease progression. Between January 2000 and December 2015, 180 patients (40% women, mean age 58.7 ± 13.5 years) with Barlow's disease underwent mitral valve repair. To provide a longitudinal assessment of mitral valve repair durability, a multistate model for interval-censored observations (4 states: 1, Grade 0/1+ MR; 2, Grade 2+ MR; 3, Grade 3+/4+ MR; 4, reintervention/death) was developed. The mechanism of recurrent MR was assessed echocardiographically. Early mortality was 1.7%. After hospital discharge, 6 late reinterventions were performed. With death as a competing risk, the 10-year overall reintervention-free survival and reintervention rates were 79.8% (95% confidence interval 72.7-87.6%) and 4.5% (95% confidence interval 2.0-10.2%), respectively. Echocardiographic follow-up was available for 165 (93%) of hospital survivors with a total of 480 examinations. The incidence of both recurrent Grade 2+ and Grade 3+/4+ MR was relatively low up to 10 years after surgery. Grade 2+ MR did not always progress to higher regurgitation grade during the follow-up period. Grade 3+/4+ regurgitation was highly associated with valve-related morbidity and mortality. Recurrent MR (≥Grade 2+) was predominantly related to the technical aspects of valve repair. Despite the complex valve abnormalities observed in patients with Barlow's disease, mitral valve repair can be performed with good early and late outcomes and low rates of recurrence of MR up to 10 years after surgery. Early and late valve repair durability is good and remains stable over time, suggesting that underlying disease progression has limited clinical significance.

心脏瓣膜病遗传学

心脏瓣膜病伴有显著的发病率和死亡率，并且常是由于先天性畸形引起心脏瓣膜结构和功能异常，导致瓣口狭窄或关闭不全所致的。然而，成年人心脏瓣膜病患病率日益增加，不仅是因为老龄化日益严重，而且还因为先天性心脏瓣膜缺陷儿童的医疗和外科护理的改善。人类基因组计划的成功和遗传技术的重大进展，加上我们对心脏瓣膜发育的了解越来越多，导致人们发现许多心脏瓣膜疾病的遗传因素。这些发现使用各种方法，包括家族性瓣膜病的检查和全基因组关联研究，以调查散发病例。本综述将讨论这些发现及其在瓣膜性心脏病治疗中的意义。 Valvular heart disease is associated with significant morbidity and mortality, and is often caused by congenital malformations resulting in abnormal cardiac valve structure and function, resulting in stenosis or insufficiency of the valve. However, the prevalence of valvular heart disease in adults is increasing, not only because of the growing aging, but also because of the improvement of medical and surgical care for children with congenital heart valve defects. The success of genomics project and the great progress of genetic technology, and our increasing understanding of cardiac valve development have led to the discovery of many genetic factors of heart valve disease. These findings use a variety of methods, including familial valvular disease examination and genome wide association studies to investigate sporadic cases. This review will discuss these findings and their significance in the treatment of valvular heart disease.

Percutaneous Mitral Valve Interventions and Heart Failure.

Mitral regurgitation (MR) is the most frequent Valvular Heart Disease (VHD) and is an important cause of heart failure. MR can be caused by primary valve abnormality (Degenerative MR/Primary MR) or it can be secondary to cardiomyopathy (Functional MR/Secondary MR). Medical management alleviates symptoms but does not alter the progression of the disease. Current guidelines recommend surgery for moderate-to-severe (Grade>3) MR in patients with symptoms or evidence of left ventricular dysfunction. Despite current practice guidelines, the majority of patients with severe MR do not undergo surgery. The reasons include high surgical risk from advanced age or multiple comorbidities, and a lack of clear data supporting valve surgery for secondary MR with LV dysfunction. The recent emergence of percutaneous interventional approaches in treating MR has expanded therapeutic options for patients who are at high risk for conventional Mitral Valve (MV) surgery. In this chapter, we will review the novel advancements in the field of percutaneous MV interventions that could potentially become the standard of care for patients with MR and heart failure.

Right heart dilatation in a fetus with an abnormal foramen ovale valve: an indicator of interatrial communication restriction.

Foramen ovale (FO) valve with a shape or motion abnormality is frequently detected during routine obstetric ultrasonic examinations. However, the hemodynamics mechanism of this entity remains unclear. The purpose of the study is to determine the relevance of interatrial communication restriction and resultant morphological modifications. We reviewed the echocardiographic records of fetuses with isolated abnormal FO valve evaluated between January of 2010 and december of 2016. The size (DFO) of the FO orifice, opening angle (α) of the FO valve, and dimensions of cardiac chambers, FO channel outlet (DOUT) and inferior vena cava (DIVC) were measured. We evaluated their (DFO, DOUT, α) relationships to the diameters of RA and DIVC. Five hundred and seventy normal fetuses were selected to establish the normal range of the DOUT/DIVC ratio so as to provide a criterion for restriction. An abnormal FO valve was identified in 89 fetuses without congenital heart disease, with restriction noted in 62 fetuses (45 fetuses with RA dilatation, 12 fetuses with RA and RV dilatation, and 5 fetuses with no RA dilatation). There were no significant correlations between RA/LA and DFO/DIVC, RA/ LA and α. RA/LA was negatively correlated with DOUT/DIVC (R2=0.97, p<0.01). For a fetus with an abnormal FO valve, right heart dilatation could be considered as an indicator of interatrial communication restriction, which could be assessed by evaluating the FO channel outlet. The degree of right atrium dilatation indicates the severity of the restriction.

Mitral valve prolapse: an underestimated cause of sudden cardiac death-a current review of the literature.

Mitral valve prolapse (MVP) is a common valve abnormality in general population. Despite the general belief of a benign disorder, several articles since the 1980s report sudden cardiac death (SCD) in MVP patients, with a substantial percentage of asymptomatic young individuals. The problem is to detect those patients at increased risk and implement methods that are suitable to prevent cardiac arrest. This review investigates the correlation between MVP and SCD, the understanding of the pathophysiology, the strategies for detecting those at risk and treatment options. A complete literature survey was performed using PubMed database search to gather available information regarding MVP and SCD. A total of 33 studies met selection criteria for inclusion in the review. MVP is an underrated cause of arrhythmic SCD. The subset of patients with malignant MVP who may be at greater risk for SCD is characterized by young women with bileaflet MVP, biphasic or inverted T waves in the inferior leads, and frequent complex ventricular ectopic activity with documented ventricular bigeminy or ventricular tachycardia (VT) and premature ventricular contractions (PVCs) configurations of outflow tract alternating with fascicular origin or papillary muscle. MVP is a common condition in the general population and is often encountered in asymptomatic individuals. The existing literature continues to generate significant controversy regarding the association of MVP with ventricular arrhythmias and SCD. Early echocardiography and cardiac magnetic resonance (CMR) are essential, as is a greater understanding of the potential electrophysiological processes of primary arrhythmogenesis and the evaluation of the genetic substrate.

Pulmonary artery aneurysm secondary to congenital pulmonic valve stenosis

Pulmonary artery (PA) aneurysms are uncommon and often diagnosed post-mortem. Theyare characterized by a PA/aorta diameter ratio greater than 2 on transthoracic echocardiographyor a pulmonary artery diameter greater than 4 or 5 cm on computed tomography. The mostcommon conditions associated with pulmonary artery aneurysm are congenital heart defectswith left-to-right shunts and pulmonic valve abnormalities. There are also numerous causesof acquired pulmonary artery aneurysms, including infection, vasculitis, pulmonary arterialhypertension, trauma, neoplasm and pulmonary embolism. Symptoms of PA aneurysm areusually non-specific, and physical examination findings are variable depending on the underlyingcause. Work-up includes various imaging modalities, transthoracic echocardiography, and rightheart catheterization. The gold standard treatment is surgery, but in select patients, conservativemanagement with close monitoring can be pursued.

A whole-heart motion-correction algorithm: Effects on CT image quality and diagnostic accuracy of mechanical valve prosthesis abnormalities

BackgroundWe aimed to determine the effect of a whole-heart motion-correction algorithm (new-generation snapshot freeze, NG SSF) on the image quality of cardiac computed tomography (CT) images in patients with mechanical valve prostheses compared to standard images without motion correction and to compare the diagnostic accuracy of NG SSF and standard CT image sets for the detection of prosthetic valve abnormalities. MethodsA total of 20 patients with 32 mechanical valves who underwent wide-coverage detector cardiac CT with single-heartbeat acquisition were included. The CT image quality for subvalvular (below the prosthesis) and valvular regions (valve leaflets) of mechanical valves was assessed by two observers on a four-point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent). Paired t-tests or Wilcoxon signed rank tests were used to compare image quality scores and the number of diagnostic phases (image quality score≥3) between the standard image sets and NG SSF image sets. Diagnostic performance for detection of prosthetic valve abnormalities was compared between two image sets with the final diagnosis set by re-operation or clinical findings as the standard reference. ResultsNG SSF image sets had better image quality scores than standard image sets for both valvular and subvalvular regions (P < 0.05 for both). The number of phases that were of diagnostic image quality per patient was significantly greater in the NG SSF image set than standard image set for both valvular and subvalvular regions (P < 0.0001). Diagnostic performance of NG SSF image sets for the detection of prosthetic abnormalities (20 pannus and two paravalvular leaks) was greater than that of standard image sets (P < 0.05). ConclusionApplication of NG SSF can improve CT image quality and diagnostic accuracy in patients with mechanical valves compared to standard images.

Echocardiographic Screening of Rheumatic Heart Disease in American Samoa.

While rheumatic heart disease (RHD) is a treatable disease nearly eradicated in the United States, it remains the most common form of acquired heart disease in the developing world. This study used echocardiographic screening to determine the prevalence of RHD in children in American Samoa. Screening took place at a subset of local schools. Private schools were recruited and public schools underwent cluster randomization based on population density. We collected survey information and performed a limited physical examination and echocardiogram using the World Heart Federation protocol for consented school children aged 5-18years old. Of 2200 students from two private high schools and two public primary schools, 1058 subjects consented and were screened. Overall, 133 (12.9%) children were identified as having either definite (3.5%) or borderline (9.4%) RHD. Of the patients with definitive RHD, 28 subjects had abnormal mitral valves with pathologic regurgitation, three mitral stenosis, three abnormal aortic valves with pathologic regurgitation, and seven borderline mitral and aortic valve disease. Of the subjects with borderline disease, 77 had pathologic mitral regurgitation, 12 pathologic aortic regurgitation, and 7 at least two features of mitral valve disease without pathologic regurgitation or stenosis. Rheumatic heart disease remains a major cause of morbidity and mortality worldwide. The prevalence of RHD in American Samoa (12.9%) is to date the highest reported in the world literature. Echocardiographic screening of school children is feasible, while reliance on murmur and Jones criteria is not helpful in identifying children with RHD.

Re-evaluation of hypoplastic left heart syndrome from a developmental and morphological perspective

BackgroundHypoplastic left heart syndrome (HLHS) covers a spectrum of rare congenital anomalies characterised by a non-apex forming left ventricle and stenosis/atresia of the mitral and aortic valves. Despite many studies, the causes of HLHS remain unclear and there are conflicting views regarding the role of flow, valvar or myocardial abnormalities in its pathogenesis, all of which were proposed prior to the description of the second heart field. Our aim was to re-evaluate the patterns of malformation in HLHS in relation to recognised cardiac progenitor populations, with a view to providing aetiologically useful sub-groupings for genomic studies.ResultsWe examined 78 hearts previously classified as HLHS, with subtypes based on valve patency, and re-categorised them based on their objective ventricular phenotype. Three distinct subgroups could be identified: slit-like left ventricle (24%); miniaturised left ventricle (6%); and thickened left ventricle with endocardial fibroelastosis (EFE; 70%). Slit-like ventricles were always found in combination with aortic atresia and mitral atresia. Miniaturised left ventricles all had normally formed, though smaller aortic and mitral valves. The remaining group were found to have a range of aortic valve malformations associated with thickened left ventricular walls despite being described as either atresia or stenosis. The degree of myocardial thickening was not correlated to the degree of valvar stenosis. Lineage tracing in mice to investigate the progenitor populations that form the parts of the heart disrupted by HLHS showed that whereas Nkx2–5-Cre labelled myocardial and endothelial cells within the left and right ventricles, Mef2c-AHF-Cre, which labels second heart field-derived cells only, was largely restricted to the endocardium and myocardium of the right ventricle. However, like Nkx2–5-Cre, Mef2c-AHF-Cre lineage cells made a significant contribution to the aortic and mitral valves. In contrast, Wnt1-Cre made a major contribution only to the aortic valve. This suggests that discrete cardiac progenitors might be responsible for the patterns of defects observed in the distinct ventricular sub-groups.ConclusionsOnly the slit-like ventricle grouping was found to map to the current nomenclature: the combination of mitral atresia with aortic atresia. It appears that slit-like and miniature ventricles also form discrete sub-groups. Thus, reclassification of HLHS into subgroups based on ventricular phenotype, might be useful in genetic and developmental studies in investigating the aetiology of this severe malformation syndrome.

An abnormal tricuspid valve in the human cadaveric heart – A case report

An abnormal tricuspid valve in the human cadaveric heart – A case report