History Of Bicuspid Aortic Valve Research Articles

Abstract 17436: A Diagnostic Copycat: Culture Negative Endocarditis of A Bioprosthetic Valve Presenting as ANCA Vasculitis

A 59-year-old female with a history of bicuspid aortic valve (AV) complicated by aortic stenosis and ascending aortic aneurysm s/p bioprosthetic AV and ascending aorta replacement presented with a 6-month history of weight loss, fatigue, and lower extremity rash. Initial laboratory workup identified anemia, leukopenia, and acute kidney injury with proteinuria and microscopic hematuria. Further workup included negative blood cultures, elevated inflammatory markers, elevated rheumatoid factor, hypocomplimentemia, and ANCA positivity (PR3 Ab positive). Biopsy of her palpable purpuric rash demonstrated vascular immune deposition pattern consistent with leukocytoclastic vasculitis. Renal biopsy revealed focal and crescentic glomerulonephritis with immune complex deposition. CT abdomen noted mesenteric lymphadenopathy with fluid surrounding the thoracic aortic graft. Surface echocardiogram showed bioprosthetic AV replacement with diffuse cusp thickening without stenosis or regurgitation. At this point, a multidisciplinary team offered a broad differential diagnosis of inflammatory vasculitis versus culture-negative endocarditis with plan for further testing. Follow-up whole-body and cardiac PET scan identified FDG-avid abnormalities involving the aortic graft and AV with hypermetabolic soft tissue thickening surrounding the aortic root. Transesophageal echocardiogram confirmed AV thickening with a 1 cm mobile echodensity. Additional serologic testing identified positive Bartonella henselae IgG (1:8192) and IgM (>1:20) titers. The final diagnosis was B. henselae prosthetic AV endocarditis and ascending aortic graft infection. She underwent repeat AV and ascending aortic graft replacement, with graft material positive for B. henselae PCR and was treated with a course of doxycycline and rifampin. B. henselae is a fastidious gram-negative bacterium that can cause culture negative endocarditis but is very rarely associated with aortic graft infection. This case highlights (1) a rare example of B. henselae aortic graft infection, (2) the difficulty in differentiating B. henselae endocarditis from inflammatory vasculitis, and (3) the importance of engaging multidisciplinary teams to solve difficult diagnostic cases.

Giant thoracic aorta aneurysm below an endovascular stent - An unexpected finding during linear endoscopic ultrasound.

A 50-year-old woman with a history of bicuspid aortic valve (BAV) and ascending aorta dissection was referred for endoscopic ultrasound (EUS) for suspected choledocholithiasis. Twelve years earlier she had undergone a Bentall-de Bone procedure and 7 years earlier a thoracic aorta aneurysm (TAA) was repaired with an endovascular prosthesis. EUS confirmed choledocholithiasis, however a large aneurysm (60 mm of diameter), was incidentally detected at the distal end of the aortic endoprosthesis. Computed tomography (CT) later confirmed the aneurysm, extending 4.5 cm above the renal arteries. The patient underwent a successful new endovascular repair. This rare incidental finding underscores the usefulness of a systematic approach when performing EUS, enabling the detection of significant abnormalities beyond the initial indication and allowing for early intervention in TTA patients.

LACTOBACILLUS ENDOCARDITIS, A SINISTER CONSEQUENCE OF AN INNOCUOUS BACTERIUM

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Lactobacillus species are gram positive rods that are part of the normal flora in gastrointestinal, oropharyngeal and genital tracts. Rarely they are implicated as causative agents of endocarditis in patients who are immunocompromised, undergo dental procedures, use probiotics or have a valvulopathy or prosthetic device. We describe the case of lactobacillus jensenii causing aortic valve endocarditis in an immunocompetent patient with a bicuspid aortic valve. It is important to recognize lactobacillus species as an emerging cause of endocarditis. Treatment involves a synergistic combination of penicillin and gentamicin. CASE PRESENTATION: 55 years old female with past medical history of bicuspid aortic valve presented to the emergency department with chief complaint of fever of 3 weeks' duration. COVID-19 testing was negative. Her medical history was significant for bicuspid aortic valve with aortic regurgitation and hyperlipidemia. Vitals signs were significant for a fever of 103 F. Physical exam was remarkable for a diastolic murmur heard best in the left third intercoastal space. Labs showed a normal blood count, and electrolytes. Patient's blood and urine cultures were obtained, and they were sent home with an oral antibiotic only to be called two days later for a positive blood culture. Blood cultures initially grew gram positive bacilli and patient was started on vancomycin and piperacillin-tazobactam pending final cultures. Due to her history of bicuspid aortic valve, endocarditis was suspected, and patient underwent transesophageal echocardiogram (TEE) which showed a 10-millimeter vegetation attached to the non-coronary cusp of aortic valve. Blood cultures came back positive for lactobacillus jensenii. Patient satisfied the Duke's criteria for endocarditis and was switched to penicillin and gentamicin. Further history did not elicit further risk factors of lactobacillus endocarditis including probiotic use, recent dental work, and immunodeficiency. Patient completed six weeks of antibiotics and had negative final blood cultures. DISCUSSION: This case highlights the importance of lactobacillus species to be a causative factor of endocarditis in patients with a predisposing risk factor. These risk factors include, in order of decreasing frequency, valvulopathy, dental procedures, probiotic use and immunosuppression. It is important to consider lactobacilli as a causative agent of infection if they are isolated on routine blood cultures in predisposed patients with a compatible clinical picture. TEE should be done if endocarditis is suspected. Lactobacilli are highly sensitive to penicillin G and synthetic penicillins. However, they are usually resistant to vancomycin. This is important as vancomycin is an integral regimen of most initial sepsis regimens. CONCLUSIONS: . REFERENCE #1: Campagne, J., J. F. Guichard, M. C. Moulhade, H. Kawski, and F. Maurier. "Lactobacillus endocarditis: a case report in France and literature review." IDCases 21 (2020): e00811. REFERENCE #2: Prendergast, B. D. "Diagnostic criteria and problems in infective endocarditis." Heart 90, no. 6 (2004): 611-613. DISCLOSURES: No relevant relationships by Muhammad Hasib Khalil, source=Web Response

506 Uneventful pseudoaneurysm of the ascending aorta with sternal erosion in pregnancy

Abstract A 36-year-old woman at 31 weeks’ gestation presented with exertional dyspnoea and palpitations. She had a history of bicuspid aortic valve treated with surgical aortic valvotomy for severe stenosis, followed by ascending aorta replacement for type A acute aortic dissection and Bentall operation with a mechanical valve for severe aortic regurgitation. Eight years after the last surgery, magnetic resonance angiography showed aortic arch aneurysm (49 mm) with a small intimal flap. Thereafter, the patient was lost to follow-up until the current admission. She was hemodynamically stable on presentation and physical examination was unremarkable apart from a mechanical second heart sound. The electrocardiogram showed sinus rhythm with left bundle branch block (Panel A). Transthoracic echocardiography revealed severe left ventricular dilation (EDV 90 ml/m2) with mild dysfunction (EF 50%), normal prosthetic aortic valve function, and aortic arch dilation (50 mm) (Panel B and C). After a multidisciplinary evaluation, elective cesarean section was performed at 34 weeks’ gestation. A post-delivery aortic computed tomography angiography revealed aortic arch aneurysm (52 mm) with intimal flap and two pseudoaneurysms of the anterior aortic wall causing sternal erosion (Panel D, E, F and G). Subsequently, the patient underwent ascending aorta and aortic arch replacement by Frozen Elephant Trunk technique with a 24 x130 mm prosthesis between the aortic root and the descending aorta. The postoperative course was uneventful, and the patient was discharged to a cardiac rehabilitation centre.

92 Aortopulmonary fistula complicating native aortic valve endocarditis

Abstract A 41-yo male with history of bicuspid aortic valve and dilatation of ascending aorta (49 mm), was transferred from a peripheral hospital with staphylococcus aureus endocarditis. On day 4 he developed fulminant pulmonary edema with a continuous murmur best heard at the left second intercostal space and impressive cardiothoracic index augmentation. TTE revealed the presence of a large aorto-pulmonary fistula (A-PF), (figure 1, left), with left to right shunt during systole and diastole (figure 1, right), between the ascending aorta and the main pulmonary artery. Despite diuretic and antibiotic therapy with cloxacillin, gentamicin and cefazolin, the patient remained in class NYHA IV, soon became inotrope dependent and he progressively developed renal dysfunction. In the ICU unit he had an episode of ventricular fibrillation and was successfully defibrillated. He underwent emergent surgery with aortic valve and ascending aorta replacement. The fistula was closed using pericardial patch. Three years postoperatively he remains well. Aortopulmonary fistula is an uncommon but highly lethal condition if untreated. The etiology of acquired A-PFs includes aneurysm rupture, trauma, aortic dissections and infective endocarditis, most commonly of a prosthetic valve. Chest pain, dyspnea and intermittent hemoptysis are frequent symptoms whereas fulminant heart failure and low cardiac output syndrome may predominate the clinical picture as in our patient. Aortopulmonary fistula is an extremely rare complication of native valve endocarditis. Abstract 92 Figure 1

1637 Percutaneous treatment of severe tricuspid regurgitation in a "bicuspid" tricuspid valve

Abstract A 72 year old female with a past medical history of bicuspid aortic valve with severe aortic regurgitation status post placement of a 21 mm Magna Ease aortic valve replacement on 6/1/16, chronic atrial fibrillation, diabetes mellitus, and severe mitral regurgitation presented with symptoms of dyspnea upon exertion. Transesophageal echocardiogram (TEE) showed normal left ventricular function with severe mitral regurgitation, severe tricuspid regurgitation and severe pulmonary hypertension. Upon close interrogation of the tricuspid valve, there was evidence of fusion with a raphe present between the septal and anterior leaflets ("a bicuspid" tricuspid valve). The patient was referred for surgical evaluation where she was deemed to be at increased surgical risk and referred for percutaneous treatment for both severe mitral and severe tricuspid regurgitation. After an uncomplicated transseptal puncture, she underwent a placement of a single MitraClip XT clip to the A2/P2 portions of the mitral valve leaflets leaving mild residual mitral regurgitation by color Doppler. Attention was then taken towards the tricuspid valve where using TEE guidance, a MitraClip XT was positioned over the central aspect of the "bicuspid" tricuspid valve with the opened clip arms perpendicular leaflet coaptation. The MitraClip XT was advanced into the right ventricle and slowly retracted to grab both TV leaflets. There was mild, residual tricuspid regurgitation by color Doppler. The mean gradient across the tricuspid valve was 1 mmHg obtained at a heart rate of 52 bpm. This case describes the first known percutaneous treatment of severe tricuspid regurgitation from a "bicuspid" tricuspid valve with a MitraClip device. Abstract 1637 Figure.

P836 Long-term survival of a rare case of pseudoaneurysm of the mitral-aortic intervalvular fibrosa as a complication of endocarditis of a bicuspid aortic valve

Abstract Introduction This is a case report of a rare condition of pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF). Case presentation The patient was a 42-year-old Filipino gentleman. He first presented to us in 2014, for routine echocardiographic examination as a part of a preoperative assessment for a non-cardiac surgery. Patient was asymptomatic and had a history of bicuspid aortic valve, which was complicated by endocarditis in 2006, and was treated with antibiotics. Echocardiography findings: Transthoracic echocardiography (TTE) showed a bicuspid aortic valve of no hemodynamic significance . A P-MAIVF was noted by Transesophageal echocardiography as a cavity expanding posteriorly into the left atrium from the left ventricular outflow tract, with a narrow neck at the junction of the aortic posterior cusp and the anterior mitral leaflet (Figure A). The cavity showed the characteristic expansion during ventricular systole, and collapse in diastole. Color flow showed the flow through the neck in systole and emptying during diastole (Figures C,D). There was mild mitral incompetence and no fistula was detected. Diagnosis was confirmed by cardiac magnetic resonance (Figure B). Follow up Because of the known complications of this condition, some of which are potentially fatal (such as rupture into the pericardium and tamponade), he was offered a surgical repair, which he had refused. Alternative conservative follow-up strategy was implemented and we had the opportunity to follow him for more than 5 years. During these years he was asymptomatic and uncomplicated. There was no change in the size of the pseudoaneurysm or its flow pattern. Conclusion This report demonstrates a rare case of P-MAIF as a complication of bicuspid aortic valve endocarditis and a long-term patient survival of a potentially fatal condition without corrective surgery. Abstract P836 Figures A,B,C,D

Role of lipoprotein (a) and LPA KIV2 repeat polymorphism in bicuspid aortic valve stenosis and calcification: a proof of concept study.

Hemodynamic valvular impairment is a frequent determinant of the natural history of bicuspid aortic valve (BAV). The role of elevated Lp(a) levels and LPA Kringle IV type 2 (KIV-2) size polymorphism in influencing aortic valve calcification and stenosis development in patients with tricuspid aortic valve was recognized. In this study, we investigate the association between Lp(a) and LPA KIV-2 repeat number, and the presence of calcification and stenosis in BAV patients. Sixty-nine patients [79.7% males; median age 45(30-53) yrs], consecutively referred to Center for Cardiovascular Diagnosis or Referral Center for Marfan syndrome or related disorders, AOU Careggi, from June to November 2014, were investigated. For each patient, clinical (ECG and echocardiography) and laboratory [Lp(a) (Immunoturbidimetric assay) and LPA KIV-2 repeat number (real-time PCR)] evaluation were performed. Patients were compared with 69 control subjects. No significant association between Lp(a) circulating levels and LPA KIV-2 repeat number and BAV was evidenced. Among BAV patients, significantly higher Lp(a) levels according to calcification degree were found [no calcifications:78(42-159)mg/L, mild/moderate: 134(69-189)mg/L; severe: 560(286-1511)mg/L, p = 0.008]. Conversely, lower LPA KIV-2 repeat numbers in subjects with more severe calcification degree were observed. Furthermore, higher Lp(a) levels in patients with aortic stenosis [214(67-501)mg/L vs 104(56-169)mg/L, p = 0.043] were also found. In conclusion, present data suggest the potential role for Lp(a) as a possible risk marker useful to stratify, among BAV patients, those with a higher chance to develop valvular calcifications and aortic stenosis.

Systematic Review of the Growth Rates and Influencing Factors in Thoracic Aortic Aneurysms

The growth rates of thoracic aortic aneurysms (TAAs) and factors influencing their expansion are poorly understood. This study aimed to review systematically published literature describing TAA expansion and examine factors that may be associated with this. A comprehensive search of MEDLINE and Embase databases was performed until 30 April 2015. Studies describing rates of TAA growth were identified and systematically reviewed. Outcomes of interest were TAA growth rates and associated factors. Study quality was assessed using Scottish Intercollegiate Guidelines Network quality checklists for cohort studies. Eleven publications, involving 1383 patients, met the eligibility criteria and were included in the review. Included studies were generally low in quality. Aneurysm measurement and growth-rate estimation techniques were inconsistently reported. Mean growth rates for all TAAs ranged from 0.2 to 4.2 mm/year. Mean growth rates for ascending and aortic arch aneurysms ranged from 0.2 to 2.8 mm/year, while those for descending and thoracoabdominal aneurysms ranged from 1.9 to 3.4 mm/year in studies reporting according to anatomical location. Large aneurysm size, distal aneurysm locations, presence of Marfan's syndrome, and bicuspid aortic valve were consistently associated with accelerated TAA growth. Presence of chronic dissection and chronic obstructive pulmonary disorder were also implicated as risk factors for faster TAA growth. Associations between medical comorbidity and aneurysm expansion were conflicting. Previous aortic surgery and anticoagulants were reported to have a protective effect on aneurysm growth in two studies. There is a shortfall in the understanding of TAA expansion rates. Existing studies are heterogeneous in methodology and reported outcomes. Identified unifying themes suggest that TAAs grow at a slow rate with large presenting diameter, distal aneurysm, and history of bicuspid aortic valve or Marfan's syndrome serving as main risk factors for accelerated aneurysm growth. High-quality studies with a standardised approach to TAA growth assessment are required.

Abstract 335: Mechanical Valve Thrombosis and Therapy

Background: Obstruction of prosthetic heart valves may be caused by thrombus formation and/or pannus in-growth. Thrombosis is more likely with inadequate anticoagulation and associated with more acute onset of symptoms. Case: A 36 year old female with a history of bicuspid aortic valve, now with a mechanical aortic valve (21mm Carbomedics Top-Hat) presented with sudden onset of exertional dyspnea and orthopnea (NYHA Class III). She had been compliant with anticoagulation, with bi-monthly INRs ≥2.5. On admission, her INR was 3.14. Physical exam revealed pedal edema and 3/6 crescendo-decrescendo murmur radiating to the carotids. Transthoracic echocardiogram (TTE) showed a left ventricular ejection fraction of 45-50% and a prosthetic aortic valve with significantly increased transvalvular gradients (peak gradient of 68 and mean gradient of 43 mmHg). Transesophageal echocardiogram revealed restricted motion of one of the leaflets without obvious vegetations or masses. Fluoroscopy in multiple views confirmed prosthetic valve dysfunction with only one functioning leaflet. Decision-making: Given the sudden onset of symptoms, thrombosis was suspected as the most likely etiology. The patient opted against re-do surgery, thus a decision was made to attempt thrombolysis. After several hours of an unfractionated heparin (UH) drip, thrombolysis with Alteplase was attempted with a 10mg IV bolus followed by a 90mg infusion. The infusion was breviated due to severe abdominal pain and concern for bleeding, but her hemodynamics and hematocrit remained stable. The efficacy of the therapy was assessed by repeat TTE and fluoroscopy. TTE showed a peak gradient of 37.5 and a mean gradient of 17mmHg (within the normal range for this valve type). Fluoroscopy showed good motion of both valve leaflets. She showed significant clinical improvement. UH infusion was continued as a bridge to a new higher INR goal of 3.5 (3.0-4.0). Conclusion: This case demonstrates the importance of including valve thrombosis in the differential diagnosis of valve malfunction even in the setting of uninterrupted anticoagulation with goal INR. It also stresses good history taking and building a contextualized, patient-relevant differential diagnosis.

Abstract 18729: Prosthetic Valve Positioning - Not a Static Question

A 65-year-old female with a history of bicuspid aortic valve s/p AVR with a Medtronic Hall mechanical valve presented with chest pain. Her recent history was notable for one week of intermittent substernal chest pain present when lying in the left lateral position. Initial ECG, obtained during an episode of chest pain, revealed 2 mm ST segment depression in the anterolateral leads and ST segment elevation in lead aVR. The ECG changes normalized with cessation of her chest pain. Laboratory evaluation showed an INR of 3.5 (on warfarin), and normal cardiac biomarkers. Chest imaging, including CT angiography, was unremarkable. Physical examination demonstrated a normal jugular venous pressure, a mechanical second heart sound, and a II/VI crescendo-decrescendo systolic murmur at the right upper sternal border. Transthoracic echocardiography (TTE) revealed normal biventricular systolic function and a mechanical valve in the aortic position, associated with mild aortic regurgitation. Valve fluoroscopy revealed an aortic monoleaflet mechanical prosthesis with normal opening and closing angles in the supine position, but with closing restriction when in the left lateral decubitus position (closing angle 46 degrees, associated with recurrent chest pain and ischemic ECG changes). Transesophageal echocardiography (TEE) showed moderate aortic stenosis, mild aortic regurgitation, and multiple linear echodensities on the aortic prosthesis. These echogenicities were felt to represent thrombi, and the patient was treated with 5 doses of tPA and intravenous heparin. Subsequent TEE and valve fluoroscopy revealed improved prosthetic leaflet motion in supine and lateral decubitus positions. This case describes an unusual presentation of mechanical aortic valve thrombosis. The contiguous association of the mechanical valve with the coronary ostia can contribute to ischemic complications, in this case positionally induced. It also highlights the value of timely valve fluoroscopy and the consideration of patient maneuvers to delineate valve function. Current guidelines support the use of thrombolytic therapy for small, left-sided thrombi, with recent literature suggesting that slowly infused low-dose tPA provides the optimal risk-benefit profile.

A Complicated Case of Triple Valve Infective Endocarditis in an IV Drug User with a Bicuspid Aortic Valve Requiring Three Separate Salvage Operations: A Case Report and Literature Review.

Infective endocarditis (IE) is an infection of the endocardium that involves valves and adjacent mural endocardium or a septal defect. Local complications include severe valvular insufficiency, which may lead to intractable congestive heart failure and myocardial abscesses. If left untreated, IE is generally fatal. Diagnosing IE can be straightforward in patients with the typical oslerian manifestations such as bacteremia, evidence of active valvulitis, peripheral emboli, and immunologic vascular phenomena. In the acute course, however, the classic peripheral stigmata may be few or absent, particularly among intravenous drug abuse (IVDA) patients in whom IE is often due to a S. aureus infection of right-sided heart valves. We present a complicated case of a very aggressive native aortic valve MSSA (methicillin sensitive Staphylococcus aureus) IE in a young adult male with a past medical history of bicuspid aortic valve and IV drug abuse. His clinical course was complicated by aortic valve destruction and development of third-degree AV block, as well as an aorto-left atrial fistula requiring emergent operation for AV replacement and patch repair. The patient required two reoperations for recurrent endocarditis and its complications.

A spontaneously closed, acquired supravalvular Gerbode defect mimicking an unruptured sinus of Valsalva aneurysm

A 40-year-old man who had a past history of bicuspid aortic valve (BAV) presented with low-grade fever for 6 weeks and rapidly progressive dyspnoea for 1 day. He was hypothermic (35.9°C) with a blood pressure of 75/53 mmHg and a pulse rate of 106/min. On cardiac auscultation, there was a Grade 3/6 diastolic murmur at the right upper sternal border. A transoesophageal echocardiography (TEE) was undertaken due to suboptimal transthoracic echocardiographic (TTE) imaging quality and suspected infective endocarditis (IE), which demonstrated multiple irregular-shaped, oscillating vegetations ( Panel …

Predictors of aortic events after aortic valve replacement for bicuspid valve stenosis

We would like to congratulate the authors on their study [1]. A controversial area in cardiac surgery is addressed in a very scientific and academic way. The authors use data from stenotic bicuspid aortic valve (BAV) patients operated on from 1995 to 2000 who underwent aortic valve replacement (AVR) without ascending aorta replacement. Inclusion criteria were aortic diameter between 40 and 50 mm. This historic cohort allows the authors to evaluate long-term aortic events (15-year follow-up) and include patients with aortic diameter between 45 and 50 mm, who at that time were not included in the US guidelines for ascending aorta replacement. Adverse aortic events were experienced in 8 of 153 patients (5.3%) with a mean progression rate of 0.5 mm/patient-year. Cox-regression analysis was performed including only two preoperative variables, hypertension and ascending aorta diameter. No statistical predictors of adverse aortic events were identified. It has been previously reported that aortic dilatation in BAV patients is hereditary [2] and related to its configuration (anterior–posterior vs right–left) [3]. Our group has found body surface area (BSA) and family history of BAV and/or aortopathy to be independent predictors for aortic dilatation [4]. Have the authors taken into account these variables (BAV configuration, family history of BAV and/or aortopathy, BSA) in their regression analysis? Pharmacological treatments such as use of statins and beta-blockers have shown to be protective of aneurysmal dilatation [5, 6]. Taking into account the large cohort the authors are analysing, it would be extremely interesting to know if either is protective of adverse aortic events. Finally, we consider this study as contributing significantly to such a debated topic and therefore congratulate the authors for their endeavour.

Intermittent Cardiogenic Shock in a Man With Mechanical Prosthesis of the Aortic Valve

Intermittent dysfunction of prosthetic aortic valve is a rare but life-threatening condition that may be difficult to recognize. Here, we present a case of 64-year-old man with a history of bicuspid aortic valve that had been replaced with a Medtronic-Hall prosthesis 15 years earlier. Until his current illness, he was fit, with good function of the valve and well maintained anticoagulation. After several days of progressive intermittent breathlessness, he experienced severe anginal chest pain, orthopnea, and dizziness that proceeded into an electromechanical dissociation. Circulation was restored after a brief resuscitation, intubation, and the administration of vasopressors by emergency medical services personnel. On admission to the intensive care unit, he had sinus rhythm with intraventricular conduction defect (Figure 1), stable blood pressure on vasopressors, and was ventilated for pulmonary edema (Figure 2). Nongated chest computed tomography scan ruled out an aortic dissection, and no particular abnormality was observed in the area of …

Bicuspid aortic valve disease: the role of oxidative stress in Lrp5 bone formation

The bicuspid aortic valve is a common congenital cardiac anomaly, having a prevalence of 0.9% to 1.37% in the general population and a male preponderance ratio of 2:1. The recognition of a bicuspid aortic valve is clinically relevant because of its association with aortic stenosis or regurgitation, aortic aneurysm or dissection, and infective endocarditis. Although some patients with a bicuspid aortic valve may go undetected without clinical complications for a lifetime, the vast majority will require intervention, most often surgery, at some point. In fact, the natural history of bicuspid aortic valve is that of valve calcification and progressive stenosis that typically occur at a faster rate than in tricuspid aortic valves. This pattern of presentation supports the hypothesis that shear stress in patients with congenitally abnormal aortic valves may contribute to an earlier leaflet calcification. However, there is emerging research data showing that the valve calcification process might have a similar pathophysiologic process to that of vascular atherosclerosis. This review focuses on the current knowledge of the cellular mechanisms of bicuspid aortic valve.

Subaortic Pseudoaneurysm of the Left Ventricle Complicating Staphyloccal Endocarditis*

Subaortic pseudoaneurysms are rare but can be a cause of sudden death in young individuals. This case report involves a 20-year-old Vietnamese male who died suddenly from rupture of a subaortic pseudoaneurysm with resultant hemopericardium with tamponade. He had a history of bicuspid aortic valve with recent but healed Staphylococcal endocarditis. A review of the literature reveals few similar cases and enlightens the association between aortic bicuspid valve, endocarditis, and subvalvular aortic aneurysm. The pathogenesis as well as recent studies that identified aneurysm predisposing genes in patients with bicuspid aortic valve will be discussed.

Vieussens’ Ring

58-year-old man with a history of bicuspid aortic valve and severe childhood bacterial endocarditis presented to the Radiology Department for further investigation into the complex perivalvular anatomy seen on echocardiography and for assessment of the ascending aorta. Magnetic resonance imaging demonstrated a normal-caliber ascending aorta and a large perivalvular cavity. In addition, however, it showed dilated tortuous coronary arteries and an unusual appearance of the right coronary artery (RCA) origin (Figures 1 through 3). Phase-contrast imaging demonstrated retrograde flow within the mid RCA, presumably caused by large collaterals from the left coronary circulation. An ECG-gated computed tomography (CT) scan was performed to help further delineate the anatomy. This showed that the large perivalvular space communicated with the left ventricular outflow tract and aortic root through numerous fenestrations. The RCA origin was severely stenotic. Distally, the RCA was supplied by numerous collaterals from the left coronary circulation, as implied by magnetic resonance imaging. One collateral pathway included a long, tortuous connection from the left circumflex coronary artery through an obtuse marginal branch traveling around the inferior aspect of the heart and communicating through an acute marginal branch with the RCA. The other major collateral pathway passed from the left anterior descending artery across the right ventricular outflow tract to the RCA through the right conus artery. This second collateral is also known by its eponymous name of Vieussens’ collateral pathway.1,2 Also identified in this study is a significant stenosis of the right conus branch near its origin from the RCA, which affected its capacity to act as a collateral pathway. It is postulated that the clinically documented episode of severe bacterial endocarditis in childhood probably resulted in a perivalvular abscess, leading to the formation of a perivalvular cavity and stenosis of the RCA origin. This in turn eventually led to the formation of these impressive collateral pathways. Disclosures