Rare or unusual causes of chronic, isolated, pure aortic regurgitation

Quadricuspid Aortic Valve and Associated Abnormalities in a Dog

An 11-month-old, female Scottish terrier was presented with a history of a heart murmur. The electrocardiogram showed signs of left ventricular enlargement, and radiography confirmed generalized cardiomegaly. Echocardiography revealed four equally sized aortic valve cusps. A ventricular septal defect, with systolic left-to-right shunting, and aortic regurgitation into both ventricles were also present. The dog was free of clinical signs 1 year after diagnosis.

Valvular Heart Disease

Aortic regurgitation (AR) is characterized by diastolic reflux of blood from the aorta into the left ventricle (LV). Acute AR typically causes severe pulmonary edema and hypotension and is a surgical emergency. Chronic severe AR causes combined LV volume and pressure overload. It is accompanied by systolic hypertension and wide pulse pressure, which account for peripheral physical findings, such as bounding pulses. The afterload excess caused by systolic hypertension leads to progressive LV dilation and systolic dysfunction. The most important diagnostic test for AR is echocardiography. It provides the ability to determine the cause of AR and to assess the severity of AR and its effect on LV size, function, and hemodynamics. Many patients with chronic severe AR may remain clinically compensated for years with normal LV function and no symptoms. These patients do not require surgery but can be followed carefully for the onset of symptoms or LV dilation/dysfunction. Surgery should be considered before the LV ejection fraction falls below 55% or the LV end-diastolic dimension reaches 55 mm. Symptomatic patients should undergo surgery unless there are excessive comorbidities or other contraindications. The primary role of medical therapy with vasodilators is to delay the need for surgery in asymptomatic patients with normal LV function or to treat patients in whom surgery is not an option. The goal of vasodilator therapy is to achieve a significant decrease in systolic arterial pressure. Future therapies may focus on molecular mechanisms to prevent adverse LV remodeling and fibrosis.

Sudden deterioration of aortic regurgitation due to rupture of a raphal cord on the conjoined cusp

A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.

Images in cardiology. Non-invasive detection of quadricuspid aortic valve

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Congenital quadricuspid aortic valve anomaly associated with hypertrophic non-obstructive cardiomyopathy: a case report and review of the literature

A case is reported of a 38 year old woman without known cardiac congenital abnormality but a history of well controlled arterial hypertension who was admitted to hospital after successful resuscitation at home following cardiac arrest. There was no evidence of myocardial infarction on 12-lead electrocardiogram but there were signs of left ventricular hypertrophy. Transoesophageal echocardiography revealed a rare quadricuspid aortic valve (QAV) malformation with concomitant mild aortic regurgitation. The left ventricle showed a massive concentric hypertrophy without obstruction. The patient was eventually transferred in a persistent vegetative state to a home care facility. A review of the literature revealed 70 cases of QAV diagnosed by transthoracic or transoesophageal echocardiography (26 cases), at necropsy (25), during surgery (15), and during angiography (4). The present case is the first report of QAV associated with non-obstructive hypertrophic cardiomyopathy.

Pathology of aortic valve stenosis and pure aortic regurgitation: a clinical morphologic assessment--Part II

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant aortic valves. Part I discussed stenotic aortic valves and Part II discusses causes of purely regurgitant aortic valves. In over 95% of stenotic aortic valves, the etiology is one of three types: congenital (primarily bicuspid), degenerative, and rheumatic. Other rare causes included active infective endocarditis, homozygous type II hyperlipoproteinemia, and systemic lupus erythematosis. The causes of pure aortic regurgitation are multiple but can be separated into diseases affecting the valve (normal aorta) (infective endocarditis, congenital bicuspid, rheumatic, floppy), diseases affecting the walls of aorta (normal valve) (syphilis, Marfan's dissection), disease affecting both aorta and valve (abnormal aorta, abnormal valve) (ankylosing spondylitis), and disease affecting neither aorta nor valve (normal aorta, normal valve) (ventricular septal defect, systemic hypertension). Diseases affecting the aortic valve alone are the most common subgroup of conditions producing purely regurgitant aortic valves.

Congenital aortic regurgitation: natural history and management

OBJECTIVES AND BACKGROUND

Congenital aortic regurgitation is rare as an isolated lesion. We describe seven children with no physical features of the Marfan syndrome in the patients or their families and no other cardiac lesions who had congenital valvular aortic regurgitation.

METHODS

From 1954 to the present, seven children with auscultatory and physiologic characteristics of aortic regurgitation were evaluated for a total of 108 patient-years. We report on their natural history, clinical and laboratory findings, management and outcome.

RESULTS

In five of the seven children congenital aortic regurgitation was diagnosed in infancy. In four, progressive severity of the regurgitation led to valve replacement at age 3, 10, 15 and 20 years, respectively, and to resection of an aneurysm of the ascending aorta in the 10-year old patient. Two patients had cystic medial necrosis on aortic biopsy. One of these patients died after reoperation for dissecting aneurysm of the thoracic aorta at 22 years of age; the other died after dissection and rupture of the ascending aorta at age 25 years. After obstructing pannus developed, the 3-year old patient underwent replacement of the St. Jude valve at age 10 years. The other three patients were asymptomatic at last follow-up at age 8, 10 and 20 years, respectively.

CONCLUSIONS

Supportive management is recommended until it becomes necessary to intervene surgically when regurgitation becomes severe. The need for surgical treatment is indicated by the appearance of a diastolic thrill, left ventricular strain on the electrocardiogram or other evidence of left ventricular dysfunction on the echocardiogram or exercise stress testing by treadmill or radionuclide cineangiocardiography. Close follow-up of these patients is important to detect progression of aortic regurgitation, especially in the presence of cystic medial necrosis.