Genetic approaches to cardiovascular disease. Supravalvular aortic stenosis, Williams syndrome, and long-QT syndrome

Supravalvular Aortic Stenosis in Homozygous Familial Hypercholesterolemia: Contemporary Management

We report a case of a patient diagnosed with homozygous familial hypercholesterolemia and progressive supravalvular aortic stenosis. Treatment with long-term low-density lipoprotein apheresis and management with novel lipid-lowering agents including an angiopoetin-like protein inhibitor led to significant low-density lipoprotein reduction. The case highlights the challenges in managing the manifestations of homozygous familial hypercholesterolemia.

Long-term surgical outcomes of congenital supravalvular aortic stenosis: a systematic review, meta-analysis and microsimulation study

OBJECTIVES

Congenital supravalvular aortic stenosis (SVAS) is a rare form of congenital outflow tract obstruction and long-term outcomes are scarcely reported. This study aims to provide an overview of outcomes after surgical repair for congenital SVAS.

METHODS

A systematic review of published literature was conducted, including observational studies reporting long-term clinical outcome (>2 years) after SVAS repair in children or adults considering >20 patients. Early risks, late event rates and time-to-event data were pooled and entered into a microsimulation model to estimate 30-year outcomes. Life expectancy was compared to the age-, sex- and origin-matched general population.

RESULTS

Twenty-three publications were included, encompassing a total of 1472 patients (13 125 patient-years; pooled mean follow-up: 9.0 (6.2) years; median follow-up: 6.3 years). Pooled mean age at surgical repair was 4.7 (5.8) years and the most commonly used surgical technique was the single-patch repair (43.6%). Pooled early mortality was 4.2% (95% confidence interval: 3.2-5.5%) and late mortality was 0.61% (95% CI: 0.45-0.83) per patient-year. Based on microsimulation, over a 30-year time horizon, it was estimated that an average patient with SVAS repair (mean age: 4.7 years) had an observed life expectancy that was 90.7% (95% credible interval: 90.0-91.6%) of expected life expectancy in the matched general population. The microsimulation-based 30-year risk of myocardial infarction was 8.1% (95% credible interval: 7.3-9.9%) and reintervention 31.3% (95% credible interval: 29.6-33.4%), of which 27.2% (95% credible interval: 25.8-29.1) due to repair dysfunction.

CONCLUSIONS

After surgical repair for SVAS, 30-year survival is lower than the matched-general-population survival and the lifetime risk of reintervention is considerable. Therefore, lifelong monitoring of the cardiovascular system and in particular residual stenosis and coronary obstruction is recommended.

Intensive Care Unit Analgosedation After Cardiac Surgery in Children with Williams Syndrome : a Matched Case-Control Study

OBJECTIVE

Cardiovascular abnormalities are common in patients with Williams syndrome and frequently require surgical intervention necessitating analgesia and sedation in a population with a unique neuropsychiatric profile, potentially increasing the risk of adverse cardiac events during the perioperative period. Despite this risk, the overall postoperative analgosedative requirements in patients with WS in the cardiac intensive care unit have not yet been investigated. Our primary aim was to examine the analgosedative requirement in patients with WS after cardiac surgery compared to a control group. Our secondary aim was to compare the frequency of major ACE and mortality between the two groups.

DESIGN

Matched case-control study.

SETTING

Pediatric CICU at a Tertiary Children's Hospital.

PATIENTS

Patients with WS and age-matched controls who underwent cardiac surgery and were admitted to the CICU after cardiac surgery between July 2014 and January 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Postoperative outcomes and total doses of analgosedative medications were collected in the first six days after surgery for the study groups. Median age was 29.8 (12.4-70.8) months for WS and 23.5 (11.2-42.3) months for controls. Across all study intervals (48 h and first 6 postoperative days), there were no differences between groups in total doses of morphine equivalents (5.0 mg/kg vs 5.6 mg/kg, p = 0.7 and 8.2 mg/kg vs 10.0 mg/kg, p = 0.7), midazolam equivalents (1.8 mg/kg vs 1.5 mg/kg, p = 0.4 and 3.4 mg/kg vs 3.8 mg/kg, p = 0.4), or dexmedetomidine (20.5 mcg/kg vs 24.4 mcg/kg, p = 0.5 and 42.3 mcg/kg vs 39.1 mcg/kg, p = 0.3). There was no difference in frequency of major ACE or mortality.

CONCLUSIONS

Patients with WS received similar analgosedative medication doses compared with controls. There was no significant difference in the frequency of major ACE (including cardiac arrest, extracorporeal membrane oxygenation, and surgical re-intervention) or mortality between the two groups, though these findings must be interpreted with caution. Further investigation is necessary to elucidate the adequacy of pain/sedation control, factors that might affect analgosedative needs in this unique population, and the impact on clinical outcomes.

Ophthalmic characteristics and retinal vasculature changes in Williams syndrome, and its association with systemic diseases

BACKGROUND

We aim to characterise the ophthalmic findings and retinal vasculature changes in patients with WS, and to analyse the correlation between ophthalmic manifestations and the associated systemic diseases.

METHODS

This retrospective case-control study included 27 WS patients and 28 age-matched healthy participants. Stellate pattern of iris, central macular thickness (CMT), foveal width, retinal vessel diameter, superficial vascular density (SVD) of macula and foveal avascular zone (FAZ) were compared between WS patients and healthy participants.

RESULTS

Twenty-five patients (93%) had the classic stellate iris presentation. Compared with healthy controls, WS patients had decreased CMT, increased foveal width and a lower SVD of macula (all P < 0.001). Significantly decreased mean retinal arterial (117.9 ± 9.9 µm vs. 133.0 ± 6.7 µm in WS and controls, respectively; p < 0.001) and venous (158.9 ± 11.2 µm vs. 174.0 ± 8.0 µm in WS and controls, respectively; p < 0.001) outer diameters, as well as mean arterial wall thickness (11.2 ± 1.3 µm vs. 12.2 ± 0.8 µm in WS and controls, respectively; p < 0.01) were found in WS. Stellate iris grading was significantly associated with CMT, foveal width, retinal vessel diameter (all p < 0.05), and a significant increase in the odds of having hypertension (Odds ratio (OR), 5.63; P < 0.05). The severity of stellate iris in WS seemed to have the trend of increasing risk of having pulmonary stenosis, tricuspid regurgitation and mitral regurgitation.

CONCLUSIONS

This study provides the first in vivo evidence reflecting current knowledge on vessel morphology in WS patients that deficient circumferential growth is the predominant pathophysiologic changes resulting from elastin deficiency. The ophthalmic characteristics may serve as a complementary tool to diagnose and follow-up patients suffering from WS.

Frequency of QTc Interval Prolongation in Children and Adults with Williams Syndrome

QTc prolongation (≥ 460 ms), according to Bazett formula (QTcB), has been identified to be increased in Williams syndrome (WS) and suggested as a potential cause of increased risk of sudden cardiac death. The Bazett formula tends to overestimate QTc in higher heart rates. We performed a retrospective chart review of WS patients with ≥ 1 electrocardiogram (EKG) with sinus rhythm, no evidence of bundle branch blocks, and measurable intervals. A total of 280 EKGs from 147 patients with WS were analyzed and 123 EKGs from 123 controls. The QTc was calculated using Bazett formula. The average QTcB for individuals with WS and controls was 444 ± 24 ms and 417 ± 26 ms, respectively (p < 0.001). In our WS cohort 34.4% had at least 1 EKG with a QTcB ≥ 460 ms. The mean heart rate (HR) from patients with WS was significantly higher than controls (96 bpm vs 76 bpm, p < 0.001). Linear regression showed that HR contributed 27% to QTcB prolongation in the patients with WS. Patients with WS have a mean QTcB in the normal range but higher than controls, and a higher than expected frequency of QTc ≥ 460 ms compared to the general population. HR is also higher in WS and contributes modestly to the WS QTcB prolongation. Future studies are needed to assess if these findings contribute risk to sudden cardiac death but in the interim we recommend routine EKG testing, especially when starting QTc prolonging medications.

A Case of William’s Syndrome in a Ugandan Child: A Feasible Diagnosis Even in a Low-Resource Setting

Background: Williams–Beuren syndrome (WS) is a rare, complex, congenital developmental disorder including cardiovascular manifestations, intellectual disability and a peculiar cognitive and behavior profile. Supravalvular aortic stenosis (SVAS) is the most frequent cardiovascular abnormality in WS children. Data on WS patients in sub-Saharan Africa are scarce. A genetic study is usually required for a definite diagnosis, but genetic testing is often unavailable in developing countries and the combination of a typical clinical phenotype and echocardiographic profile helps to confirm the diagnosis. Case Report: We report the case of a 5-year-old Ugandan child admitted to a large no profit hospital after he was initially managed as a case of infective endocarditis. A physical examination revealed the typical features of WS. A cardiac echo showed severe SVAS (peak gradient 80 mmHg) with a normal anatomy and function of the aortic valve and mild valvular pulmonary stenosis. The child also had a moderate intellectual disability and a characteristic facies consistent with WS. Conclusion: We present the first reported case of WS in Uganda. Cardiac echo and a characteristic clinical picture could be enough to exclude more common causes of heart failure (i.e., rheumatic heart disease) and to make the diagnosis even when specific genetic tests are not available.

Supravalvar aortic stenosis: Imaging characteristics and associations on multidetector computed tomography angiography

AIM

To evaluate the imaging features and associations in patients with supravalvar aortic stenosis on multidetector computed tomography (CT) angiography.

MATERIALS AND METHODS

We retrospectively reviewed all CT angiography studies performed for evaluation of congenital heart diseases at our institution through the period from January 2014 to June 2020. Cases with supravalvar aortic stenosis were identified and classified as syndromic and nonsyndromic based on history, physical examination, and relevant investigations. The type and extent of vascular involvement and associated cardiovascular abnormalities were characterized.

RESULTS

Supravalvar aortic stenosis was identified in 26/3926 (0.66%) patients (22 males and 4 females; Age range: 2 months to 20 years). Discrete stenosis was seen in 14/26 (53.8%) patients, while diffuse involvement of the ascending aorta to varying degrees was seen in the remaining 12 (46.2%) patients. About 15/26 (57.7%) patients had pulmonary involvement at some level, namely, infundibular, valvar, supravalvar, or peripheral pulmonic stenosis while 15/26 (57.7%) patients had coronary arterial involvement either in the form of stenosis, occlusion, or ectasia. Aortic valvular abnormality including thickening, partial fusion, and adhesion of leaflet edges to the sinutubular junction causing reduced coronary inflow was seen in 15/26 (57.7%) patients. Associated ventricular septal defect, patent ductus arteriosus, and mitral valvular prolapse were seen in four (15.4%), five (19.2%), and two (7.7%) patients respectively.

CONCLUSION

Supravalvar aortic stenosis is a rare abnormality showing associated pulmonary arterial involvement, coronary arterial involvement, aortic valvular abnormalities, and associated congenital cardiac defects in the majority of cases, which may influence surgical outcomes.

Cardiovascular disease in Williams syndrome

PURPOSE OF REVIEW

Williams syndrome is a multisystem disorder seen with some regularity at most pediatric centers and usually fairly often at larger centers. Cardiovascular abnormalities, because of elastin deficiency, are the leading cause of morbidity and mortality in patients with Williams syndrome. The present article presents a review of the most recent developments regarding the cardiovascular issues in Williams syndrome.

RECENT FINDINGS

Cardiovascular abnormalities occur in 80% of patients with Williams syndrome, the majority of which are arterial stenoses. The stenoses seen in Williams syndrome now appear to arise from deficient circumferential arterial growth. Pharmacological therapies aimed at improving the vascular stenoses have shown some promise in animal models. Surgical outcomes for supravalvar aortic stenosis are good at most centers. Transcatheter interventions are largely ineffective in Williams syndrome. Multilevel surgical pulmonary artery reconstruction has excellent results for peripheral pulmonary artery stenosis. Periprocedural risk stratification and management algorithms may decrease the risk of cardiovascular complications.

SUMMARY

Cardiovascular abnormalities are a major determining factor in the clinical picture and trajectory of patients with Williams syndrome. Advances in surgical techniques, medical therapeutic options, and periprocedural management hold promise for significant improvements in the cardiovascular outcomes of these patients.

Familial hypercholesterolemia supravalvular aortic stenosis and extensive atherosclerosis

Familial hypercholesterolemia is an autosomally dominant disorder caused by various mutations in low-density lipoprotein receptor genes. This can lead to premature coronary atherosclerosis and cardiac-related death. The symptoms are more severe in the homozygous type of the disease. Premature malignant atherogenesis leading to aortic root abnormalities causing supravalvular aortic stenosis is rare. Our case demonstrates the diagnostic imaging findings of the phenotype of patients who have severe elevated LDL with familial hypercolesterolemia.

Isolated supravalvular aortic stenosis with left ventricular diverticulum and cleft mitral valve: Surgical repair in adulthood

Supravalvular aortic stenosis is an uncommon but well characterized congenital narrowing of the ascending aorta above the level of the coronary arteries. It can be a familial disorder, can occur sporadically, or can be associated with Williams syndrome. We are reporting a very rare presentation of supravalvular aortic stenosis with associated left ventricular diverticulum and cleft mitral valve. Repair consisted of resection of the ascending aorta, patch augmentation of the aortic root, and mitral valve repair. Follow-up echocardiography demonstrated normal mitral and aortic valve function and a postoperative three-dimensional computed tomographic scan showed a normal shape of the reconstructed ascending aorta.

Degradation of elastic fiber and elevated elastase expression in long head of biceps tendinopathy

Tendinopathy of the long head of the biceps (TLHB) involves various types of extracellular matrix degeneration, but previous studies have not evaluated elastic fibers. The purpose of this study was to investigate elastic fiber distribution in long head of the biceps (LHB). The TLHB tendons of 16 consecutive patients (eight men and eight women; average age of 55.75 years; age range of 40-71 years) were transected and harvested. Three cadaveric LHB tendons were used as the control group. The expression of collagen type I was decreased, but type III was increased in TLHB. Disruption of elastic fibers was particularly observed in grade II specimens where the level of elastase-positive staining was significantly higher than in grade I specimens. Elastic fibers were not observed in the grade III area, implying a higher expression of elastase than in the grade I area. Results of Western blotting showed that the expression of elastin was higher in the control group and the levels of elastin significantly decreased in grades II and III of TLHB. Levels of osteopontin and elastase were increased in primary culture of human tenocytes after experiencing elastic derived peptide treatment. These results suggested that elastase may be caused by the disruption of elastic fibers in the development of chronic tendinopathy and that elastic derived peptide may enhance elastase and osteopontin expression. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1919-1926, 2017.

Rare copy number variants in a population-based investigation of hypoplastic right heart syndrome

BACKGROUND

Hypoplastic right heart syndrome (HRHS) is a rare congenital defect characterized by underdevelopment of the right heart structures commonly accompanied by an atrial septal defect. Familial HRHS reports suggest genetic factor involvement. We examined the role of copy number variants (CNVs) in HRHS.

METHODS

We genotyped 32 HRHS cases identified from all New York State live births (1998-2005) using Illumina HumanOmni2.5 microarrays. CNVs were called with PennCNV and prioritized if they were ≥20 Kb, contained ≥10 SNPs and had minimal overlap with CNVs from in-house controls, the Database of Genomic Variants, HapMap3, and Childrens Hospital of Philadelphia database.

RESULTS

We identified 28 CNVs in 17 cases; several encompassed genes important for right heart development. One case had a 2p16-2p23 duplication spanning LBH, a limb and heart development transcription factor. Lbh mis-expression results in right ventricular hypoplasia and pulmonary valve defects. This duplication also encompassed SOS1, a factor associated with pulmonary valve stenosis in Noonan syndrome. Sos1-/- mice display thin and poorly trabeculated ventricles. In another case, we identified a 1.5 Mb deletion associated with Williams-Beuren syndrome, a disorder that includes valvular malformations. A third case had a 24 Kb deletion upstream of the TGFβ ligand ITGB8. Embryos genetically null for Itgb8, and its intracellular interactant Band 4.1B, display lethal cardiac phenotypes.

CONCLUSION

To our knowledge, this is the first study of CNVs in HRHS. We identified several rare CNVs that overlap genes related to right ventricular wall and valve development, suggesting that genetics plays a role in HRHS and providing clues for further investigation. Birth Defects Research 109:16-26, 2017. © 2016 Wiley Periodicals, Inc.

Cytogenomic Aberrations in Congenital Cardiovascular Malformations

Congenital cardiovascular malformations are the most common birth defects, with a complex multifactorial etiology. Genetic factors play an important role, illuminated by numerous cytogenetically visible abnormalities, as well as submicroscopic genomic imbalances affecting critical genomic regions in the affected individuals. Study of rare families with Mendelian forms, as well as emerging next-generation sequencing technologies have uncovered a multitude of genes relevant for human congenital cardiac diseases. It is clear that the complex embryology of human cardiac development, with an orchestrated interplay of transcription factors, chromatin regulators, and signal transduction pathway molecules can be easily perturbed by genomic imbalances affecting dosage-sensitive regions. This review focuses on chromosomal abnormalities contributing to congenital heart diseases and underscores several genomic disorders linked to human cardiac malformations in the last few decades.

Double chamber right ventricle in Williams syndrome: a rare cardiac anomaly reported

Cardiovascular abnormality is the most consistent finding and occur in almost 80 % of all Williams syndrome (WS). Although a number of cardiovascular defects are common to WS, the majority presents in some form of arterial stenosis whereas supravalvular aortic stenosis is the most common one. Here we describe a 12 year old boy with elfin facies, presenting with urinary incontinence and a systolic murmur in right upper parasternal region. Echocardiography showed presence of double chambered right ventricle (DCRV) along with supravalvular aortic stenosis (SVAS) and coronary artery aneurysms, left pulmonary artery stenosis and multiple bladder diverticula in CT abdomen. With the clinical suspicion the diagnosis of WS was made and confirmed by fluorescent in situ hybridisation (FISH) study showing deletion in 7q11.23. Though different forms of arterial stenosis at multiple sites have been demonstrated in WS, DCRV in Williams syndrome is not reported till date in medical literature.

Williams-Beuren syndrome: computed tomography imaging review

Williams-Beuren syndrome (WBS) affects young infants and children. The underlying etiopathogenesis of this rare disease is due to the mutation of the elastin gene that is responsible for the elasticity of the arterial wall. As a result of inadequate elastin production, the major systemic arteries become abnormally rigid and can be manifested by an impediment to the blood flow. The most common cardiovascular abnormalities encountered in WBS are supravalvular aortic stenosis, pulmonary arterial stenosis, and mitral valve prolapse. Less frequently observed cardiovascular abnormalities include coarctation of the aorta, ventricular septal defect, patent ductus, subaortic stenosis, and hypertrophic cardiomyopathy. Coronary artery stenosis and severe impediment to the bi-ventricular outflow as a result of supravalvular aortic and pulmonary artery stenosis predispose patients to sudden death. Patients with progressed arterial stenosis and severe stenosis are likely to require intervention to prevent serious complications. Rarely, imaging findings may precede clinical presentation, which allows the radiologist to participate in the patient care. However, to be more prudent, the radiologist must be accustomed to the imaging characteristics of WBS as well as the patient's clinical information, which could raise the suspicion of WBS. We performed a retrospective analysis of all the available images from patients diagnosed with WBS in last 4 years at our institution, and present key imaging findings along with a review of the literature to summarize the clinically relevant features as demonstrated by multidetector computed tomography in WBS. Cross-sectional imaging plays a vital role in the diagnosis of WBS cases with equivocal clinical features. MDCT evaluation of complex cardiovascular abnormalities of WBS including coronary artery disease is feasible with modern MDCT scanners and in the future, this approach could provide accurate information for planning, navigation, and noninvasive assessment of the secondary arterial changes in WBS and thus reducing the dependence upon invasive contrast catherization techniques.

Infective endarteritis in a case of supravalvular aortic stenosis

Supravalvular aortic stenosis is the rarest form of congenital left ventricular outflow tract obstruction. It can be associated with Williams syndrome or it may be an isolated anomaly. Although infective endocarditis is common in valvular aortic stenosis, in supravalvular aortic stenosis infective endocarditis/endarteritis is rarely reported. We report a case of infective endarteritis in a case of supravalvular aortic stenosis due to resistant enterococci, causing prolonged fever. Blood culture-directed antibiotic therapy cured the infection. <Learning objective: Infective endarteritis in supravalvular aortic stenosis is a rarely reported but treatable entity. Although it may respond to empirical antibiotics, occasionally some resistant organism, causing infective endarteritis, may not respond to empirical therapy. Multiple blood culture with culture-directed antibiotic administration may be lifesaving, as in our index case.>.

Supravalvar aortic stenosis: current surgical approaches and outcomes

Supravalvar aortic stenosis (SVAS) is a congenital anomaly characterized by a discrete or diffuse narrowing of the ascending aorta. It may also be associated with right-ventricular outflow tract obstruction, aortic valve pathology and coronary ostial stenosis. While present in both familial and sporadic forms, it demonstrates a strong association with William-Beuren syndrome, both being anomalies associated with defects in the elastin gene. In this article, the authors have discussed the etiology, morphology, clinical presentation and genetic basis of SVAS. Various surgical approaches, both conventional and recent, have been discussed and demonstrated with the aid of diagrams. Single-, two- and three-sinus methods have been presented, along with a comparative analysis of early results, associated procedures, late mortality and reoperation. In conclusion, the authors have described their institutional experience of more than 40 years in the surgical management of SVAS.

Comparison of electrocardiographic QTc duration in patients with supravalvar aortic stenosis with versus without Williams syndrome

Cardiovascular abnormalities in Williams syndrome (WS) are largely attributable to elastin haploinsufficiency resulting from a large deletion of the elastin-containing region on chromosome 7q11.23. The risk of sudden death in patients with WS is 25- to 100-fold greater than that in the general population. The corrected QT (QTc) interval is prolonged in 14% of patients with WS. Patients with nonsyndromic supravalvar aortic stenosis (NSVAS) have elastin mutations resulting in elastin haploinsufficiency and a vascular phenotype nearly identical to that of WS. No previous studies have evaluated the QTc duration in NSVAS. A retrospective review of all electrocardiograms (ECGs) performed on consecutive patients with NSVAS at Arkansas Children's Hospital from January 1, 1985 to January 1, 2012 was completed. ECGs with nonsinus rhythm or unmeasurable intervals were excluded. The ECGs were read by 1 reader who was unaware of previous readings. A QTc interval of ≥460 ms was defined as prolonged. The NSVAS cohort was compared to previously published WS and control groups using the mixed model for continuous electrocardiographic variables and the generalized estimating equation for binary indicators for prolonged QTc. The generalized estimating equation used bootstrapping with 1,000 replicates. A total of 300 ECGs (median 6, range 1 to 27) from the 35 identified patients with NSVAS met the inclusion criteria. A total of 482 ECGs from patients with WS and 1,522 ECGs from controls were included. The mean age of the patients with NSVAS at ECG was 7.3 ± 6.9 years; 64% were male. The mean QTc duration was 409 ± 20 ms in the NSVAS group, 418 ± 17 ms in the control group (p <0.001), and 436 ± 27 ms in the WS group (p <0.001 compared to the control group). The prevalence of QTc prolongation was 0.3% in the NSVAS group, 2.0% in the control group (p <0.001), and 14.8% in the WS group (p <0.001 compared to controls). No patients with NSVAS died. In conclusion, cardiac repolarization is normal in patients with NSVAS. Elastin haploinsufficiency does not appear to be the etiology of QTc prolongation in patients with WS. The possible contribution of other genes on 7q11.23 to QTc prolongation in WS should be investigated.

Pulmonary stenosis is a predictor of unfavorable outcome after surgery for supravalvular aortic stenosis

We sought to evaluate whether the presence of pulmonary stenosis (PS), amongst other factors, influences the mortality and the rate of reoperations in the long-term follow-up of patients with supravalvular aortic stenosis (SVAS). We identified all patients with SVAS from our surgical database. The patients with multi-level aortic stenosis or concomitant cardiac procedures were excluded from this study. Follow-up (100 %) was conducted between 2008 and 2010. Twenty-six patients underwent surgery for SVAS between 1974 and 2006. Seventeen patients (65 %) were diagnosed with Williams-Beuren-Syndrome, six (17 %) had a diffuse form of SVAS and 10 (39 %) had PS. No patient had a surgical or interventional procedure for PS at the initial operation or during follow-up. There was no statistically significant association between PS and WBS (p = 0.30) or diffuse form of SVAS (p = 0.13). Patients with PS were operated at younger age (p = 0.028). Median follow-up time was 14.6 years. Overall mortality was 11.5 %. One patient with preoperatively severely decreased LV-function died 27 days postoperatively. Two late deaths occurred 7 and 10 years after the initial operation. Reoperations were required in 4 patients (15 %), 4-19 years after the original operation, due to aortic arch stenosis, supravalvular restenosis or poststenotic aortic dilatation. PS was found to be a risk factor for reoperation (p = 0.005) and for the combined reoperation/death end-point (p = 0.003). PS in patients with SVAS is a risk factor for reoperations in the aortic region and might be considered an indicator of the severity of the arterial disease and a predictor of an unfavourable outcome.

Extended single-patch repair of supravalvar aortic stenosis: a simple and effective technique

BACKGROUND

The optimal surgical procedure for repair of supravalvar aortic stenosis (SVAS) remains uncertain. Proponents of multisinus repair techniques suggest improved outcomes compared with the single-patch technique. We evaluated the outcomes after an extended single-patch technique for relief of SVAS.

METHODS

A cross-sectional retrospective analysis was performed of all SVAS patients who underwent repair from 1996 to 2009. Patient, procedural, and hospital course data were obtained through a review of the medical records. At follow-up, patients were evaluated for residual SVAS gradient, valvar aortic stenosis, aortic insufficiency, and need for reintervention.

RESULTS

Twenty-two patients (mean age, 2.4 ± 2.4 years) underwent repair of SVAS (discrete form, 59%). Mean preoperative peak gradient was 77 ± 27 mm Hg (range, 20 to 139 mm Hg). There were no hospital deaths. Median postoperative length of stay was 5 days (range, 3 to 68 days). Mean follow-up was 4.1 ± 3.5 years (range, 0.7 to 13 years). Follow-up Doppler echocardiography revealed a peak left ventricular outflow tract gradient of 10 ± 12 mm Hg (range, 0 to 41 mm Hg). No patient had significant valvar aortic stenosis or insufficiency. Two patients (9%) required catheter-based reintervention that was unrelated to the SVAS repair.

CONCLUSIONS

This study demonstrates that a simple, extended single-patch technique for repair of SVAS provides excellent medium-term results. A durable reduction in gradient with low complication and recurrence rates can be achieved without the need for more complicated multisinus patch repairs.

Extended replacement of a calcified ascending aorta in adulthood sporadic, diffuse type, supravalvular aortic stenosis

The diffuse variant of supravalvular aortic stenosis (SVAS) is one of the most rare congenital vascular pathological conditions of adulthood. Due to its rarity, surgical treatment of this clinical entity is still a matter of debate because of the variable degree of aortic narrowing, presence of multilevel obstruction, and age at presentation, all factors that strongly influence the disease prognosis. We report a case of an adult patient with an extremely calcified diffuse SVAS who underwent successful replacement of the ascending aorta through the interposition of a tubular prosthesis. Six months' follow-up showed complete relief of the aortic gradient and an improvement in clinical performance.

Long-term outcome of large artificial patch aortic repair for diffuse stenosis in Williams syndrome

There have been only a few reports concerning the long-term results of a surgical procedure using a large artificial patch for patients with Williams syndrome. Twelve years have passed since a patient with William's syndrome underwent a surgery with a patch angioplasty for the diffuse supravalvular aortic stenosis and deformities of the neck branch arteries. The patient had a well-balanced aortic growth without stenotic or aneurysmal changes, which was confirmed during the time of the second surgery when replacing the mitral valve. This technique of using a large patch has proven to be safe for Williams syndrome patients with diffuse supravalvular aortic stenosis in the long term.

Stenosis of the thoracic aorta in Williams syndrome

Williams syndrome (WS) is a multisystem congenital disorder affecting 1/8000 live births. Our objective was to review our experience with stenosis of the thoracic aorta (STA) in these patients. A retrospective review was undertaken of consecutive WS patients at The Children's Hospital of Philadelphia from January 1, 1980, through December 31, 2007. WS was diagnosed by an experienced medical geneticist and/or by fluorescence in situ hybridization. Stenosis was diagnosed with either echocardiography or cardiac catheterization. Freedom from intervention was determined using Kaplan-Meier analysis. From a total cohort of 270 patients, 37 (14%) patients with STA were identified and comprised the study group. Age at presentation was 2.1 + or - 4.0 years, and follow-up was 11.8 + or - 12.6 years (range 0-51). Long-segment STA was more common (89%) than discrete STA. Severity of STA was mild in 18, moderate in 10, and severe in 9 patients. Branch pulmonary artery stenosis was seen in 62% (23 of 37) of STA patients, and supravalvar aortic stenosis was seen in 54% (20 of 37) STA patients. Nine (24%) patients underwent intervention for STA: 8 cases were severe, and 1 case was moderate. Restenosis resulting in reintervention occurred in 5 of 9 (56%) patients, with 4 of 5 (80%) patients undergoing multiple reinterventions. Freedom from intervention was 89, 82, and 73% at 1, 5, and 20 years, respectively. One patient died. STA is common in WS and is generally the long-segment type. In patients with STA, interventions are common and usually occur by 5 years of age. Reintervention for STA occurs frequently.

Cardiovascular abnormalities, interventions, and long-term outcomes in infantile Williams syndrome

OBJECTIVE

To determine the prevalence of cardiovascular abnormalities (CVA) and outcomes in patients with Williams syndrome presenting before 1 year of age.

STUDY DESIGN

A retrospective review was undertaken of consecutive patients with WS at our institution from January 1, 1980, through December 31, 2007. WS was diagnosed by an experienced medical geneticist and/or by fluorescence in situ hybridization. CVA were diagnosed with the use of echocardiography, cardiac catheterization, or computerized tomographic angiography. Freedom from intervention was determined using Kaplan-Meier analysis.

RESULTS

The study group was 129 patients with CVA. Age at presentation was 127 +/- 116 days, with follow-up of 8.0 +/- 7.5 years (0 to 42 years). The most common lesions were peripheral pulmonary artery stenosis (62%) and supravalvar aortic stenosis (57%). Other CVA were common. CV interventions were performed in 29%, with 58% of those before 1 year. Freedom from intervention was 85%, 73%, and 66% at 1, 5, and 25 years, respectively. Four patients died.

CONCLUSIONS

CVA are the most common manifestations of infantile Williams syndrome and occur with greater frequency than previously reported. In those with CVA, interventions are common and usually occur by 5 years of age. Most of these patients do not require intervention on long-term follow-up, and overall mortality is low.

Diffuse supravalvular aortic stenosis: surgical repair in adulthood

We present the case of a 54-year-old woman in which a diffuse congenital supravalvular aortic stenosis (SVAS) was associated with a severe aortic valve incompetence and heavy calcification of the aortic annulus. Repair consisted in resection of the ascending aorta, patch augmentation of the hypoplastic aortic root and annulus, placement of a 20 mm Dacron tubular graft (Vascutek, Renfrewshire, UK) and aortic valve replacement with a mechanical prosthesis (Sorin, Turin, Italy). Follow-up echocardiography demonstrated normal prosthetic valve function and a postoperative three-dimensional computed tomographic scan showed a normal shape of the reconstructed ascending aorta.

Surgery for supravalvular aortic stenosis - the three-patch technique

The objective of this paper is to describe the three-patch technique for repair of supravalvular aortic stenosis (SVAS). Supravalvular aortic stenosis is a rare malformation as a result of an abnormal thickening of the aortic wall. SVAS may present in two forms: a localized form (affecting only the aortic sinotubular junction) and a diffuse form, where the aortic arch and its side branches are also affected. Since 1960, multiple surgical techniques have been described with the aim of relieving the aortic narrowing and restoring the aortic root. We present the three-patch technique as originally developed by Brom. After transection of the aorta at the sinotubular junction, three longitudinal incisions are made into the three sinuses. The aortic root geometry is then restored by placement of three separate patches of autologous pericardium in the opened sinuses. Brom's technique provides a complete and symmetric restoration of the aortic anatomy. The technique is illustrated by angiographies, surgical drawings, videos and a review of the literature. The results of the three-patch technique are good and our long-term experience will be described.

Bilateral semilunar valve dysplasia in a patient with inverted duplication 2p25-22

Here we report a patient with partial trisomy 2p and congenital dysplasia of the semilunar valves. To our knowledge, this is the first case of 2p duplication with developmental defects of both semilunar valves and suggests that genes on this region contribute to the formation of the semilunar valves.

Functional consequences of methionine oxidation of hERG potassium channels

Reactive species oxidatively modify numerous proteins including ion channels. Oxidative sensitivity of ion channels is often conferred by amino acids containing sulfur atoms, such as cysteine and methionine. Functional consequences of oxidative modification of methionine in human ether à go-go related gene 1 (hERG1), which encodes cardiac I(Kr) channels, are unknown. Here we used chloramine-T (ChT), which preferentially oxidizes methionine, to examine the functional consequences of methionine oxidation of hERG channels stably expressed in a human embryonic kidney cell line (HEK 293) and native hERG channels in a human neuroblastoma cell line (SH-SY5Y). ChT (300 microM) significantly decreased whole-cell hERG current in both HEK 293 and SH-SY5Y cells. In HEK 293 cells, the effects of ChT on hERG current were time- and concentration-dependent, and were markedly attenuated in the presence of enzyme methionine sulfoxide reductase A that specifically repairs oxidized methionine. After treatment with ChT, the channel deactivation upon repolarization to -60 or -100 mV was significantly accelerated. The effect of ChT on channel activation kinetics was voltage-dependent; activation slowed during depolarization to +30 mV but accelerated during depolarization to 0 or -10mV. In contrast, the reversal potential, inactivation kinetics, and voltage-dependence of steady-state inactivation remained unaltered. Our results demonstrate that the redox status of methionine is an important modulator of hERG channel.

Diagnosis and management of medical problems in adults with Williams–Beuren syndrome

Williams-Beuren syndrome (WBS) is a multi-system disorder that requires ongoing management by a primary care physician familiar with the natural history and common medical problems associated with the condition. Some abnormalities are unique to WBS, such as the elastin arteriopathy that often manifests as supravalvar aortic stenosis and hypertension. Still other features, such as diverticulosis, are seen in the general population but tend to present earlier in WBS. Life long monitoring of the cardiovascular and endocrine systems is essential to the clinical management of individuals with Williams-Beuren syndrome. Constipation should be aggressively managed, and symptoms of abdominal pain should prompt an evaluation for diverticulosis/diverticulitis. While the mean IQ of WBS is in the mild mental retardation range, difficulties with attention and anxiety are more likely to negatively impact independent functioning in the adult with WBS. There is no evidence for decline in cognitive ability over time, but adaptive functioning may be improved with treatment of anxiety by both behavior and medical modalities.

Successful reconstructive surgery for isolated mitral insufficiency associated with Williams syndrome: report of a case

Isolated mitral insufficiency requiring surgical correction is extremely rare in Williams syndrome (WS). We report the case of a 25-year-old man with WS, who suffered congestive heart failure caused by severe mitral insufficiency and atrial fibrillation. We found extensive anterior leaflet prolapse, but no other cardiovascular disorders such as supra-aortic or pulmonary arterial stenosis. He underwent successful radical valve repair with a concomitant Cox-maze procedure. This reconstructive procedure was appropriate and effective surgical treatment for isolated mitral valve disease associated with WS.

Supravalvular and valvular aortic stenosis in heterozygous familial hypercholesterolemia

OBJECTIVES

To report calcified aortic stenosis due to hypercholesterolemia in two siblings.

CASE PRESENTATION AND INTERVENTION

A 13-year-old boy with a history of dyspnea on exertion and a systolic murmur of aortic stenosis was referred to our center. Echocardiography showed combined valvular and supravalvular aortic stenoses with a good left ventricle systolic function and severe left ventricular hypertrophy. Two years later his 17-year-old sister was referred to the clinic with similar symptoms. Severe valvular aortic stenosis was detected by echocardiography. Selective coronary angiography showed significant involvement. The father had a history of hypercholesterolemia and confirmed coronary artery disease involving 3 vessels. Angiography showed anterioapical and inferiobasal hypokinesis with preserved left ventricle systolic function. The mother and the other two siblings did not have hyperlipidemia, thereby indicating heterozygous familial hypercholesterolemia in the two affected siblings. The siblings were managed with atrovastatin and nicotinic acid and cholestyramine was added stepwise. The father was treated with lovostatin.

CONCLUSION

This report shows that severe hyperlipidemia in very young patients may be a risk factor for valvulopathy.

Arrhythmia and neuronal/endothelial myocyte uncoupling in hyperhomocysteinemia

Elevated levels of homocysteine (Hcy) known as hyperhomocysteinemia (HHcy) are associated with arrhythmogenesis and sudden cardiac death (SCD). Hcy decreases constitutive neuronal and endothelial nitric oxide (NO), and cardiac diastolic relaxation. Hcy increases the iNOS/NO, peroxynitrite, mitochondrial NADPH oxidase, and suppresses superoxide dismutase (SOD) and redoxins. Hcy activates matrix metalloproteinase (MMP), disrupts connexin-43 and increases collagen/elastin ratio. The disruption of connexin-43 and accumulation of collagen (fibrosis) disrupt the normal pattern of cardiac conduction and attenuate NO transport from endothelium to myocyte (E-M) causing E-M uncoupling, leading to a pro-arrhythmic environment. The goal of this review is to elaborate the mechanism of Hcy-mediated iNOS/NO in E-M uncoupling and SCD. It is known that Hcy creates arrhythmogenic substrates (i.e. increase in collagen/elastin ratio and disruption in connexin-43) and exacerbates heart failure during chronic volume overload. Also, Hcy behaves as an agonist to N-methyl-D-aspartate (NMDA, an excitatory neurotransmitter) receptor-1, and blockade of NMDA-R1 reduces the increase in heart rate-evoked by NMDA-analog and reduces SCD. This review suggest that Hcy increases iNOS/NO, superoxide, metalloproteinase activity, and disrupts connexin-43, exacerbates endothelial-myocyte uncoupling and cardiac failure secondary to inducing NMDA-R1.

Severe coronary artery disease in the absence of supravalvular stenosis in a patient with Williams syndrome

Williams syndrome is a complex syndrome comprising developmental abnormalities, craniofacial dysmorphic features, and cardiac anomalies. The most common cardiac anomaly is supravalvular aortic stenosis. We report a case of a 6-year-old girl with Williams syndrome who presented with decompensated heart failure due to ischemic cardiomyopathy. Her only significant cardiac anomaly was severe stenosis of the left main coronary artery. She subsequently died despite surgical revascularization. Isolated coronary anomalies are rare in Williams syndrome but should be considered especially in the presence of heart failure or ischemia.

Endothelin-1 Concentrations in Pericardial Fluid Are More Elevated in Patients with Ischemic Heart Disease Than in Patients With Nonischemic Heart Disease

There is epidemiologic evidence that the prognosis of patients with nonischemic heart failure is better than that for patients with ischemic heart failure. In addition, studies have revealed that patients with ischemic heart failure show a poorer response to medical therapy. However, the pathophysiologic difference between ischemic and nonischemic heart disease is unclear. To clarify this point, we measured atrial natriuretic peptide, brain natriuretic peptide, angiotensin II, endothelin (ET)-1. interleukin-1beta interleukin-6. tumor necrosis factor (TNF)-alpha soluble TNF receptor I, and soluble TNF receptor II concentrations in plasma and pericardial fluid in patients with ischemic or nonischemic heart disease undergoing cardiac surgery. The pericardial ET-1 concentration in patients with ischemic heart disease was statistically greater than that in patients with nonischemic heart disease (about 1.5-fold), although no difference was found in the plasma ET-1 concentration. These findings suggest that the production and secretion of ET-1 from the myocardium in patients with ischemic heart disease are augmented to a greater extent than in patients with nonischemic heart disease. This result may lead to a greater understanding of the pathophysiology of ischemic heart disease.

Drug-induced long QT in isolated rabbit Purkinje fibers: importance of action potential duration, triangulation and early afterdepolarizations

In the present study, we investigated three drug-induced long-QT syndromes in isolated rabbit Purkinje fibers in order to identify the relationship of action potential duration (APD), triangulation of action potentials (APD(90)-APD(40)) and early afterdepolarizations. Isolated rabbit Purkinje fibers were superperfused in Tyrode solution with solvent, indapamide (1 x 10 (-4) M, an I(ks) blocker mimicking long QT1), dofetilide (1 x 10 (-9), 1 x 10 (-8) or 1 x 10 (-7) M, an I(kr) blocker mimicking long QT2) or anthopleurin (1 x 10 (-8) M, an inhibitor of the inactivation of the I(Na(+)) current mimicking long QT3) (n=8 per group) for 25 min, and stimulated at 1 Hz for 20 min and at 0.2 Hz for another 5 min. Indapamide did not change APD and triangulation or elicit early afterdepolarizations even in the presence of beta-adrenergic stimulation with isoproterenol. Dofetilide concentration-dependently prolonged APD(90), increased triangulation and elicited early afterdepolarizations. Anthopleurin markedly increased APD(90) as well as triangulation and elicited early afterdepolarizations. The induction of early afterdepolarizations by dofetilide and anthopleurin was associated with a prolongation of APD(90) or an increase in triangulation, but not with a change in APD(40). Moreover, the degree of the increase in the triangulation was larger than that of APD(90) in long QT2 (dofetilide-induced) and long QT3 (anthopleurin-induced) models in isolated rabbit Purkinje fibers. Our present study indicates that rabbit Purkinje fibers can be used as long QT2 (dofetilide-mimicking) and LQT3 (anthopleurin-mimicking) syndrome models, and confirms that drug-induced long QT1 (indapamide-mimicking) is absent. Our present study also shows the relationship between a prolongation of APD(90) or increase in triangulation and the induction of early afterdepolarizations with dofetilide (I(kr) blocker) and anthopleurin (I(Na) modulator) in isolated rabbit Purkinje fibers.

Cardiovascular manifestations in 75 patients with Williams syndrome

OBJECTIVE

The prevalence and types of various cardiovascular diseases in different age groups as well as the outcomes of cardiac surgery and other interventions were assessed in a population of 75 Williams syndrome (WS) patients aged 4 months to 76 years (median 22.7 years).

STUDY DESIGN

The diagnosis of WS was in each case confirmed by the clinical phenotype and by a FISH test showing elastin hemizygosity. Clinical and operative data were collected from all hospitals where the patients had been treated.

RESULTS

Cardiovascular symptoms were evident in 35 of 75 (47%) WS children at birth. During follow up, 44 of 75 (53%) WS patients were found to have cardiovascular defects. Among them, the definitive diagnosis was made before 1 year of age in 23 (52%) infants, between 1 year and 15 years of age in 14 (32%) children, and older than 15 years of age in 7 (16%) adults. Multiple obstructive cardiovascular diseases were found in six infants. Supravalvular aortic stenosis (SVAS) was diagnosed in 32/44 (73%), pulmonary arterial stenosis (PAS) in 18/44 (41%), aortic or mitral valve defect in 5/44 (11 %) of cases, and tetralogy of Fallot in one (2%) case. Altogether, 17/44 (39 %) underwent surgery or intervention. Surgery was most frequently performed in the infant group (6% v 21% v 0%, p=0.004). After 1 year of age, seven patients underwent SVAS relief and two cases PAS relief. Postoperatively there was no mortality (median follow up time 6.9 years). Arterial hypertension was found in 55% of adults. In three adults, arterial vasculopathy was not diagnosed until necropsy.

CONCLUSIONS

Our data indicate the following in WS. Cardiac symptoms are common in neonates. Heart disease diagnosed in infancy frequently requires operation. After 1 year of age, PAS tends to improve and SVAS to progress. Life long cardiac follow up is necessary because of the risks of developing vasculopathy or arterial hypertension.

Supravalvular aortic stenosis and peripheral pulmonary stenosis coexisting with a straight thoracic spine

Supravalvular aortic stenosis (SVAS) is recognized in cases of Williams syndrome and in sporadic cases not associated with other features of the syndrome. It is also well recognized as associated with peripheral pulmonary stenosis (PPS). A male patient was diagnosed as having PPS at the age of 1 year and 8 months, and was found at the age of 18 years to have SVAS. Cardiac catheterization showed that he had a localized type of SVAS and regression of the PPS. Chest X-ray showed that he did not have the normal thoracic curvature. His 19-year-old sister had also been diagnosed with PPS, and his 43-year-old mother was known to have a harsh systolic cardiac murmur of unknown etiology. Cardiac magnetic resonance imaging showed a localized type of SVAS in his mother also, though not in his sister, both of whom had a somewhat straight thoracic spine, most noticeably in the mother, though not to the degree observed in the patient. This case appears to be familial, though it is not clear whether this skeletal abnormality is an unknown phenotypic feature of this cardiovascular disease.