CONGENITAL HEART DISEASE

     CONGENITAL HEART DISEASE  - A        CONGENITAL HEART DISEASE - B

     CONGENITAL HEART DISEASE  - C        CONGENITAL HEART DISEASE - D

     CONGENITAL HEART DISEASE  - E      

  CONGENITAL HEART DISEASE  - D

CONGENITAL AORTIC REGURGITATION

B.J.M. Delemarre, MD Department of Cardiology, Hospital Leyenburg, the Hague, The Netherlands

   Introduction

   Etiology and clinical presentation
   Diagnosis
   Treatment
   CONCLUSION
   References

Introduction

Abnormal aortic valve development is one of the most threatening congenital heart diseases. Like a thief in the night, the patient might be struck by endocarditis after a visit to the dentist without using endocarditis prophylaxis. After all, he or she did not know the aortic valve was abnormal and hence leaking or stenotic, as the hemodynamic conditions are well tolerated and there were no symptoms (Figure 1). In particular this scenario holds for congenital aortic regurgitation.

Etiology and clinical presentation

Congenital aortic valve regurgitation as isolated condition is rare and results from abnormal aortic valve development. The isolated condition has been described in mono-, bi- and tetracuspid valves (Figure 2). More often, congenital aortic regurgitation results from other congenital heart diseases like subvalvular aortic membrane, subarterial ventricular septal defect, aneurysm of the sinus of Valsalva, as part of the Marfan syndrome or resulting from medication used by the mother during pregnancy (1-3).

Fig.1

Fig. 1. Echocardiographic recording of a 21 year old patient admitted with endocarditis. This male patient developed fever 8 weeks after a visit to the dentist and became ill. Transesophageal echocardiography showed a bicuspid aortic valve with a paravalvular abscess(*). Short axis, panel A; Long axis, panel B. The patient was operated and a homograft implanted.

Sometimes the murmur is detected immediately after birth, but, as the valve regurgitation itself is often well tolerated, it might remain unnoticed until adulthood (4,5). Therefore, the natural history of 3).

Fig. 2

Fig. 2. Transesophageal recording of a quadricuspid aortic valve in diastole (panel A) and systole (panel B). This 35 year-old woman had no symptoms and only trivial aortic regurgitation.

the disease in younger patients is mainly influenced by the development of endocarditis. In the older patient early valve degeneration determines the clinical course. As mentioned before, the regurgitation is well tolerated and the patients do not have any complaints. In severe cases the regurgitation may lead to symptoms of heart failure, pounding headache, or nocturnal angina pectoris. This latter condition is caused by the diminished coronary perfusion pressure induced by a slow heart rate. Due to the long lasting diastole, the pressure within the left ventricle rises while the pressure in the aorta falls, hence coronary perfusion pressure fails and the subendocardial layers become anoxic.

Diagnosis

The diagnosis is made during auscultation by the characteristic diastolic decrescendo murmur. A soft first heart sound and a positive Durozier phenomenon indicate more severe regurgitation. The electrocardiogram may show left ventricular hypertrophy and a left ventricular diastolic strain pattern, represented by “T” wave inversion in the left precordial leads. These abnormalities however do not reflect the severity of the disease and cannot be used to guide intervention. The diagnosis is confirmed using color Doppler echocardiography by a regurgitant jet originating from the aortic valve. The severity of the regurgitation might be determined by the same characteristics as used in adult patients. An increase in left ventricular volume reflected by an increase of end systolic diameter to values equal with the corresponding normal end diastolic diameter for that age is an ominous sign. In addition, a short pressure half time of the regurgitant signal together with diastolic flow reversal in the abdominal aorta are hallmarks of severe aortic regurgitation. All these features however might be encountered in asymptomatic patients. In the past, cardiac catheterization was performed to exclude other associated abnormalities, but with modern echocardiographic equipment and pediatric transesophageal scope, this is no longer necessary.

Treatment

Medication in the treatment of these patients is restricted to afterload reduction. In particular treatment with nifedipine has been described to diminish the rate of progression of aortic valve regurgitation and to postpone valve replacement (6). Recently it has been suggested that treatment of factors known to induce coronary artery disease, may also have adverse effects on the rate of progression of valvular heart disease (7). The main problem in the treatment of patients with congenital aortic regurgitation is optimum timing of intervention. As the hemodynamic effect are well tolerated, one has to pay attention to signs of left ventricular dysfunction, during regular follow up (8). Nowadays, valve reconstruction is hardly performed and the long term results of these operations are not well known. The place of aortic root replacement by an aortic homograft is still undetermined. The treatment of choice is valve replacement by either the autologous pulmonary valve in a Ross procedure or replacement by a mechanical valve (9). Tissue valves have the advantage of not needing oral anticoagulant therapy, but primary valve failure by calcification and valve deterioration especially in young patients prevent their general use (10). The problem of surgical intervention at a younger age is that the patients might outgrow their valve and thus often a re-operation with additional risks is required (11). Therefore, operation is deferred as long as possible and performed at the moment the patient develops symptoms. During the operation, aortic tissue has to be investigated for abnormalities in the elastic and fibromuscular tissue, as these patients tend to develop ascending aorta dilatation and even dissecting aneurysms (12). After the operation, the patients have to be followed to monitor signs of patient valve mismatch. In the younger patients, pannus formation may also lead to an increase in gradients across the valve prosthesis. In additio, during follow up the diameter of the ascending aorta has to be monitored for dilatation and subsequent dissection of the aorta thoracalis.

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2. Van der Lee C, Roos-Hesselink JW, Bogers AJJC, McGhie JS, Spitads ESC. 
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3. Ando J, Kobayashi T, Sato R, Yasuda K. Congenital aortic regurgitation observed in
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    congenital bicuspid aortic valve: assessment and follow up by 
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9. Stelzer P, Elkins R. Pulmonary autograft: an American experience. 
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10. Hammermeister K, Sethi GK, Henderson WG, Grover FI., Oprian C, 
      Rahimtoola S. Outcomes 15 years afb:er valve replacement with a 
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11. Pibarot P, Dumesnil JG. Hemodynamic and clinical hnpact
      of prosthesis-patient mismatch in the aortic valve position and its prevention. 
      J Am Coll Cardiol 2000;36:1131 –1141.

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      Peterson KL. Familial aortic dissecting aneurysm. J Am Coll Cardiol 1989;
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Correspondence to: Dr. BJM Delemarre, Department of Cardiology, Hospital Leyenburg, the Hague, The Netherlands