|Home | About | Journals | Submit | Contact Us | Français|
We report the case of a 75-year-old woman who presented with stable angina and with a quadricuspid aortic valve, which consisted of 4 equal-sized leaflets that were diagnosed incidentally upon coronary angiography. Despite the patient's advanced age, the abnormal valve was functioning almost normally.
Since the 1st case of quadricuspid aortic valve was published in 1969,1 the total number of reported cases has reached approximately 200.2 The diagnosis—more frequent in men—is commonly made between the 5th and 6th decades of life.1,2 If valve replacement is needed (due mostly to severe aortic insufficiency), that too occurs most often in the 5th or 6th decade.3 However, we report a case in which a woman's quadricuspid aortic valve was diagnosed in her 8th decade and did not result in significant valvular dysfunction, despite her advanced age.
In 2008, a 75-year-old woman was referred to our hospital for coronary angiography, because of exercise-induced chest pain and dyspnea that had begun 6 months before. She was hypertensive, hyperlipidemic, and an ex-smoker. She also had emphysema. Physical examination revealed a mild apical systolic murmur and a blood pressure of 150/80 mmHg. Electrocardiography showed anterior negative T waves. Transthoracic echocardiography, which was handicapped by a poor echocardiographic window due to the emphysema, showed that the aortic and mitral valves had undergone senile degenerative changes in association with mild aortic and moderate mitral regurgitation. Left ventricular dimensions were normal, and there was no wall-motion abnormality. The left ventricular ejection fraction was 0.65–0.70. Coronary angiography revealed multiple critical stenoses in the left anterior descending, diagonal, circumflex, and right coronary arteries. Left ventriculography in the right anterior oblique view showed normal contractions and 2+ to 3+ mitral regurgitation. Aortography was not performed. While reviewing coronary angiograms after the procedure, we noticed that the aortic valve consisted of 4 leaflets of equal size, with a “4-leaf clover” appearance (Fig. 1). Repeat transthoracic echocardiography did not show the aortic valve optimally, and the patient could not tolerate transesophageal echocardiography. Although the lesions needed coronary artery bypass surgery, we had no alternative to medical therapy, because of the severe emphysema and the patient's preference. She is still experiencing exercise-induced stable angina, partially controlled by β-blocker, nitrate, aspirin, and statin therapies.
This is one of the rare cases in which a patient with quadricuspid aortic valve presents with stable angina due to multivessel disease and is diagnosed incidentally upon coronary angiography, in the absence of symptoms or findings attributable to aortic dysfunction. As we said, the time both of diagnosis of quadricuspid aortic valve and of surgical intervention is most often in the 5th or 6th decade of life. In a comprehensive review of 186 reported cases, the mean age of the patients was 50.7 years, and only 16% of their aortic valves were functioning normally at the time of diagnosis.2 In this anomaly, the more advanced the age, the greater the likelihood of aortic insufficiency. In our patient, however, quadricuspid aortic valve did not lead to severe valvular dysfunction, despite her advanced age.
The physiopathology of the valve dysfunction in cases of quadricuspid aortic valve is poorly understood. Although stenosis is very rare, severe regurgitation due to cusp malcoaptation is common. Unequal cusp sizes can induce unequal shear stress, leading in turn to fibrosis and incomplete coaptation.4 Although aortic insufficiency is also observed in quadricuspid valves that have 4 equal cusps, we believe that in our patient the equal-sized leaflets with good coaptation most likely prevented severe regurgitation (and left ventricular dilation as well).
Most cases of quadricuspid aortic valve have been discovered incidentally at autopsy or during aortic valve surgery, and a lesser number have been detected preoperatively upon aortography or 2-dimensional echocardiography. Computed tomographic angiography and magnetic resonance imaging (MRI) are new technologies that help to identify this rare condition more frequently and more conveniently than did coronary angiography and echocardiography. The 2 newer imaging methods (especially MRI) provide high-quality images of myocardial and valvular anatomy and function and of associated coronary artery disease and anomalies.
Various embryologic mechanisms have been suggested for the origin of quadricuspid valve, including erosion of one of the valve cushions and septation of a normal valve cushion as a result of an inflammatory episode.3 Hurwitz and Roberts5 classified the quadricuspid semilunar valve into 7 types (A–G) on the basis of the size of the 4 cusps in relation to each other: the most frequent anatomic variations are 4 equal cusps, 3 equal cusps with 1 minor cusp, and 2 large cusps with 2 small cusps.3 According to the Hurwitz and Roberts classification system, our patient had the most common variant—type A, with 4 equal cusps. An echocardiographic study4 has reported the incidence of type B valves (3 equal-sized cusps and 1 smaller cusp) to be the same as that of type A, but cusps of unequal size can be found at surgery even after preoperative echocardiography has suggested cusps of similar size.
Congenital quadricuspid aortic valve is usually an isolated lesion, but several concomitant congenital abnormalities have been described. The most prevalent cardiac malformations associated with quadricuspid aortic valve are coronary artery anomalies, which have been reported in 10% of the cases1,2,6–10; ventricular septal defect and patent ductus arteriosus have also been reported.5 Because of the additional cusp, the origins of the left and right coronary artery systems may not be at their usual sites. Displacement of the origin of the right coronary artery has been reported most frequently, but there have also been reports of single coronary artery and displaced origin of the left coronary artery.1,8–10 In our patient, a long and detailed review of the coronary angiographic images indicated to us that the left coronary system originated from the left anterior sinus and that the right coronary artery originated from a relatively high and posterior takeoff point on the right posterior sinus. Certainly it is quite difficult to detect the exact site of coronary origin with use of conventional coronary angiography, especially when compared with computed tomography and MRI.
The quadricuspid aortic valve is replaced in most patients who require surgery; only a few cases of in situ surgical repair have been reported.11 In our patient, transthoracic echocardiography performed both before and after coronary angiography failed to show the quadricuspid aortic valve, primarily due to a poor echocardiographic window. More liberal use of transesophageal echocardiography, computed tomography, and MRI will reveal the actual prevalence of quadricuspid aortic valve and will provide more data about the condition.
Address for reprints: Ertan Okmen, MD, FESC, Asagi Dudullu Mah. Sinpas Aquacity, 1. Etap, Meridyen 31/5, Cekmekoy, Umraniye, 34773 Istanbul, Turkey E-mail: moc.liamtoh@ilnasadra