A 65-year-old male patient was referred to our outpatient clinic for cardiac evaluation because of an asymptomatic continuous murmur. Four years ago, a grade 2/6 systolic cardiac murmur had been coincidentally detected, but it had not been investigated so far. The patient was completely asymptomatic. There was no relevant past medical history or significant family history. His cardiovascular risk profile was favourable.
Case Description and Test Results
Blood pressure was 110/50 mmHg with a pulse rate of 72 beats per minute. The patient had a to-and-fro murmur, grade 5/6 systolic and 3/6 diastolic, which was most strongly audible over the left sternal border. A right ictus was palpable with lateral displacement of the left ictus. Jugular venous distention and peripheral oedema were absent. Laboratory results were normal. An electrocardiogram (ECG) showed sinus rhythm with left ventricular hypertrophy. Chest X-ray revealed cardiac enlargement.
On transthoracic echocardiography (TTE), a dilated left ventricle with normal systolic function was noticed. The right ventricle showed mild dilatation and normal systolic function. A significant left-to-right shunt was detected near the interventricular septum. Because of systolic turbulent flow in the right atrium, the exact origin of the shunt was difficult to determine.
To further elucidate the flow anomaly in the right atrium, a transoesophageal echocardiography (TOE) was performed. It showed a rupture of the right sinus of Valsalva to the right ventricle with a diameter of 1,7 cm at the most, resulting in a significant left-to-right shunt. The aortic root itself was not dilated, except for the small localised sacculation of the sinus, pending in the right atrium. A trileaflet aortic valve was noted. There was no atrial or ventricular septal defect (see Figures 1 and 2).
Magnetic resonance imaging (MRI) was performed. Two jets were visualised, both originating from the dilated right sinus of Valsalva to the right ventricle (see Figure 3). The first jet was pointed towards the right ventricle wall, the second towards the tricuspid valve. The left-to-right shunt was quantified as Qp:Qs ratio of 1,38:1. Again, volume overload with biventricular dilatation and increased cardiac output were noted.
Cardiac catheterisation revealed a hyperdynamic circulation with a dilated left ventricle, but normal systolic function. The capillary wedge pressure was increased. Right heart catheterisation revealed mild pulmonary hypertension. Oximetry confirmed a left-to-right shunt at the right ventricular level. Angiography of the ascending aorta confirmed a slight aneurysmal dilatation of the right sinus of Valsalva with left-to-right shunting resulting in immediate filling of the right ventricle after contrast injection in the right coronary sinus. Coronary angiography revealed no significant coronary artery disease.
Despite the fact that the patient did not have any complaints, a surgical correction was proposed. Rigorous endocarditis prophylaxis and exercise restriction were advised.
Discussion
A Rare Cardiac Anomaly
A rupture of a sinus of Valsalva is a rare cardiac anomaly, mostly occuring in aneurysmal dilated sinuses. This cardiac lesion can be congenital or acquired. A congenital lack of continuity in the media, between the aorta and annulus fibrosus of the aortic valve, may initiate aneurysm formation or, less frequently, infection or degeneration processes may affect an aortic sinus.
Acquired aneurysms have been associated with trauma, atherosclerosis, infective endocarditis, syphilis, Marfan syndrome and collagen vascular disorders.1 In the case described above, although unproven, the origin of the ruptured sinus is considered congenital, since laboratory tests were negative and our patient did not have any sign of connective tissue disease or history of trauma.
Congenital aneurysms are often associated with other cardiac anomalies, including ventricular septal defect (VSD) and aortic valve dysfunction. Less common associated lesions are pulmonary stenosis, a bicuspid aortic valve, mitral insufficiency with or without prolapse, a coarctation of the aorta, a patent ductus arteriosus and tricuspid insufficiency.1–4
Because of the congenital weakness, the sinus gradually gives way under the aortic pressure to form an aneurysm. Rupture of an aneurysm of a sinus of Valsalva usually occurs between the first and the fourth decade of life. Recently, a rupture was described in an octogenerian, but in the literature very few articles describe this lesion in patients over 60 years of age.2,5
Unruptured sinus of Valsalva aneurysms are frequently asymptomatic and consequently seldom diagnosed. Sometimes prominent murmurs are generated, as blood flows in and out of an unruptured aneurysmal pouch. Cases of right ventricular outflow obstruction, coronary artery compression with infarction, conduction disturbances, endocarditis and thrombus within the aneurysmal cavity have also been reported.4
The most frequent complication of an aneurysm of the sinus of Valsalva is rupture. More than 90 % of the shunts originate in the right or non-coronary sinus and shunt into the right ventricle or right atrium. Rarely, rupture is into the left atrium, left ventricle, pericardial cavity or pulmonary artery.1
A rupture can be immediately fatal when going to the pericardium or if a complete heart block develops. A large, acute intracardiac rupture leads to a sudden volume overload with subsegment development of frank pulmonary oedema. Smaller, subacute perforations are often better tolerated. As a result of progressive volume overload, both ventricles may dilate, thereby leading to decreased diastolic and systolic heart function. Most patients have a gradual onset of symptoms, including shortness of breath, fatigue, palpitations, chest pain and syncope.4,6,7
Few cases are described of patients with a ruptured sinus being completely asymptomatic. Only a loud continuous murmur may be found, as it was the case in our patient.2,4 The same auscultatory findings may occur in a variety of conditions, including patent ductus arteriosus, coronary arteriovenous fistula or VSD combined with aortic regurgitation.
Diagnostic Tools
Several non-invasive diagnostic tools are available to diagnose a ruptured sinus of Valsalva, including echocardiography, multislice computed tomography (MSCT) and MRI. The diagnostic work-up for a pre-cordial continuous murmur mostly consists of echocardiography.
TTE with colour Doppler can correctly establish the diagnosis of a ruptured aneurysm in 75 % of patients.3 However, TTE images are often suboptimal, resulting in imprecise delineation of the anatomy and anatomic relations of the aneurysm and associated lesions. These limitations were obviously present in our case, in which the exact origin of the shunt was difficult to determine.
TOE has become the gold standard for the diagnosis of this lesion. Associated with colour Doppler, TOE precisely defines the location, morphology, size, associated lesions and complications of the defect.3,7 It was very accurate for establishing a diagnosis in our patient.
When congenital abnormalities of the thoracic aorta are suspected in an asymptomatic patient, confirmation of this abnormality can be made by MRI, allowing precise evaluation of the aortic root and thoracic aorta. Besides the morphologic information, the flow rate and amount of flow can be determined, facilitating the calculation of the Qp:Qs ratio. Cardiac volumes and function can also be assessed.8
The development of a new generation of CT scanners, especially for MSCT, has created a range of opportunities in the field of non-invasive CT-based angiography.9
Because surgery had been suggested, and also because of our patient’s age, it was decided to make an invasive evaluation. Cardiac catheterisation with coronary and aortic angiography can still play a role in providing exact haemodynamic data and identifying associated conditions, especially coronary artery disease.
Management
Little is known about the natural history of an unruptured, asymptomatic sinus of Valsalva aneurysm, therefore the optimal management is controversial. However, when an unruptured aneurysm becomes symptomatic, surgical intervention is needed. Ruptured aneurysms, both symptomatic and asymptomatic, require an early, corrective procedure. Acute lesion enlargement and the possibility of endocarditis form a permanent threat. Eventually, all patients with a sufficient shunt will develop progressive congestive heart failure. A mean survival period of 3,9 years in patients with untreated ruptured sinus of Valsalva aneurysms has been reported.1
An early, aggressive approach is recommended to prevent clinical deterioration.1,2,4,6 Operative procedures include simple plication, patch repair, aortic root replacement and aortic valve replacement/repair. Peri-operative mortality is about 3.9 %, mostly in the setting of pre-existing sepsis or endocarditis.1 Again this emphasises the need for strict endocarditis prophylaxis. After repair, patients’ life-expectancy approximates that of the healthy population.6 Recently, the percutaneous transcatheter closure of ruptured sinus of Valsalva aneuysms using an Amplatzer™ duct occluder has been reported, which allows to obviate open heart surgery in some carefully selected cases, but experience and follow-up are very limited.10
Despite the fact that our patient was completely asymptomatic, a surgical repair was proposed to prevent progression to severe cardiac failure, further rupture and possible endocarditis. A percutaneous closure seemed impossible because of the location of the lesion. Since rupture often – but not always – follows physical stress, exercise restriction was recommended.
Conclusion
A rupture of a sinus of Valsalva has to be taken into account in the differential diagnosis of a continuous heart murmur, even though the patient looks healthy and is asymptomatic. Clinical suspicion has to be confirmed by imaging investigations. Repair, mostly by surgery, is indicated.