ANEURYSM OF THE ASCENDING AORTA SIMULATING RIGHT ATRIAL DILATATION*

Transcription

1 OCTOBER, 1969 ANEURYSM OF THE ASCENDING AORTA SIMULATING RIGHT ATRIAL DILATATION* \ ATE HAVE recently encountered I, V patients with cardiomegaly in whom the frontal, lateral and oblique roentgenograms of the chest were thought to demonstrate dilatation of the right atrium. This finding was puzzling since clinically there were no signs which correlated with right atrial enlargement. In each instance thoracic aortography revealed an unusually large aneurysm of the ascending aorta which produced a bulge above the right hemidi aphragm, thereby simulating enlargement of the right atrium. REPORT OF CASES CASE I. A 6 year old woman was admitted to the University of Iowa Hospitals because of severe pain in the right side of the chest, dyspnea, orthopnea and swelling of the ankles and abdomen. She had first complained of shortness of breath and pain in the upper back 4 years previously at which time her heart was enlarged and she was treated with digitalis and diuretics. Her symptoms worsened in spite of medication and she lost 8o pounds of weight. At the time of admission to the hospital her blood pressure was 135/45. The neck veins were distended and the liver was greatly enlarged. Examination ofthe heart revealed atrial fibrillation, gross cardiomegaly, and a systolic thrill palpable at tile apex. Loud systolic and diastolic murmurs were audible over the right second intercostal space with radiation to the entire precordium. Varicose veins were present in both lower extremities and a water hammer pulse could be felt. The clinical impression was congestive heart failure with aneurysm of the thoracic aorta, aortic stenosis and insufficiency. The electrocardiogram demonstrated atrial fibrillation and left ventricular hypertrophy. There was uncertainty concerning the etiology of the cardiac lesions with rheumatic heart disease, syphilis and arteriosclerosis being considered in the differential diagnosis. By STEVEN H. CORNELL, M.D. IOWA CITY, IOWA -4 L FIG.!. Case I. Generalized cardiomegaly with obvious left ventricular enlargement and bulging of the cardiac shadow immediately above the right hemidiaphragm suggestive of right atrial dilatation. The frontal roentgenogram of the chest (Fig. i) revealed a very large cardiac shadow with considerable enlargement to the right as well as to the left. It was thought that the upper part of the right-sided enlargement was due to a dilated ascending aorta and that the lower part was the result of an enlarged right atrium. The lateral and oblique views demonstrated enlargement both anteriorly and posteriorly. Because of uncertainty concerning the extent of the thoracic aortic aneurysm, an aortogram was obtained (Fig. 2). This revealed a very large aneurysm of the ascending aorta which nearly reached the diaphragm and accounted for all of the right-sided cardiac enlargement seen on the plain roentgenograms. Two days after the aortography surgical exploration disclosed a false aneurysm of the ascending aorta with dissection from the aortic leaflets up to the innominate artery. The * From the Department of Radiology, University of Iowa Hospitals, Iowa City, Iowa. 400

2 VOL. 107, No. 2 Aneurysm of the Ascending Aorta 40! aneurysm was resected and a dacron graft inserted in its place. The appearance of the heart postoperatively is shown in Figure ; tile rigilt heart border is nearly normal. Cardiac arrest occurred several hours after the operation and the patient expired. At postmortem examination a long standing aortic dissection which extended down to tile common iliac arteries was found. Microscopically there was severe medial necrosis of the entire aorta. CASE II. A 57 year old woman was seen because of exertional dvspnea, orthopnea and paroxysmal nocturnal dyspnea which had increased in severity during the previous IS months in spite of treatment with digitalis and diuretics. She also complained of episodes of ankle edema and pains in the left side of the chest unrelated to exercise. A heart murmur was first heard at 26 years of age and hypertension was discovered when she was 42. Physical examination revealed the blood pressure to be 220/100 in tile arms and 145/125 in the legs. Tile femoral pulses were decreased in intensity. Loud systolic alld diastolic murmurs were Ileard over the aortic area. Clinically the patient was believed to have coarctation of tile aorta and a bicuspid aortic valve with resulting aortic stenosis and aortic insufficiency. The frontal roentgenogram of tile chest (Fig. JIG. 3. Case i. After resection of the aneurysm and insertion of a dacron graft the heart has decreased in size and the lower right contour is within normal limits. 4) defllollstrated tile heart to be enlarged to tile right as vell as to tile left. The right-sided enlargement was tilougilt to l)c due to a dilated right atrium, but tile cause for this was not apparent since tilere were no clinical signs suggestive of a rigllt-sided cardiac lesion. The ileart was enlarged retrosternally and posteriorly in tile lateral and oblique views. The.4S Fic. 2. Case I. The thoracic aortogram discloses a huge aneurysm of the ascending aorta which accounts for all of the cardiac enlargement on the right side. FIG. 4. Case ii. Cardiomegaly with enlarged left ventricle and apparent dilatation of the right atrium.

3 402 Steven H. Cornell OCTOBER, 1969 FIG. 5. Case II. Thoracic aortogram demonstrates that an aneurysm of the aortic root is responsible for the enlargement of the cardiac silhouette to the right. electrocardiogram revealed complete right bundle branch block and first degree atrioventricular block. At cardiac catheterization a lo Hg gradient was found across the aortic valve and a 64 mm. Hg gradient between the ascending and descending aorta. Angiocardiography (Fig. 5 and 6) demonstrated an aneurysm of the aortic root with mild aortic insufficiency. The coarctation of the aorta was also demonstrated. One year after cardiac catheterization the coarctation was repaired. The aneurysm of the aortic root was visualized, but not resected; this may be done at a future date depending on the patient s course. DISCUSSION Aneurysm of the aortic root has been described by several authors.7 10 These aneurysms may result from arteriosclerosis, syphilis or cystic medial necrosis. According to Najafi7 aortic insufficiency is the most common clinical manifestation and results from dilatation of the aortic valve ring or disturbance in the support of the valve cusps. Aortic insufficiency may be the cause of angina and congestive heart failure. Another frequent complication of aortic root aneurysm is dissection, which may be responsible for the presenting complaint of pain in the chest. In other cases, the dissection involves the aortic valve or coronary arteries and aggravates preexisting myocardial ischemia and aortic insufficiency. An aneurysm may also cornpress the superior vena cava and cause dilatation of the veins in the neck. Aortic root aneurysms are usually hidden within the cardiac shadow and require opacification with contrast material to be demonstrated. Windsor and Shanahan11 described 4 cases, I of which produced a bulge in the right cardiophrenic angle on the frontal roentgenogram. At operation, the aneurysm completely covered the right atrium. Cystic medial necrosis of the aorta may occur with or without the Marfan s syndrome and the etiology is not known viicroscopically there is degeneration and loss of the elastic fibers of the media with accumulation of basophihic ground substance or mucopolysaccharides.4 Merendino a nd associates6 described surgical treat- FIG. 6. Case II. In the lateral projection the coarctation of the aorta is visible in addition to the aneurysm of the aortic root.

4 VOL. 507, No. 2 Aneurysm of the Ascending Aorta 403 ment of 20 patients with cystic medial necrosis of the ascending aorta, 12 ofwhom had no evidence of Marfan s syndrome. All patients had aneurysmectomy and 19 also had surgical correction of their aortic valve. These authors point out that the ascending portion of the aorta is subjected to the greatest stress and is therefore most likely to enlarge and dissect. Ferlic et al.3 did aneurysmorrhaphy or graft replacement in 7 patients with aortic insufficiency secondary to cystic medial necrosis and replaced the aortic valve by a ball valve prosthesis. Chapman et al.2 reported a group of 16 similar cases who were operated using total cardiopulmonary bypass. Austen and Blennerhassett described a case of giant cell aortitis causing an aneurysm of the ascending aorta with aortic insufficiency. This was successfully repaired using a prosthetic graft and aortic valve. It was pointed out by Steinberg and Halpern8 that aneurysms of the thoracic aorta may be difficult to differentiate from tumors or other mediastinal masses on plain roentgenograms of the chest. Angiography can differentiate between these. More recently Malcolm and associates5 described aneurysms of the descending thoracic aorta which were situated on the right side of the chest. In i of their cases the aneurysm could be seen in the right cardiophrenic angle on the frontal chest roentgenogram but was not large enough to be mistaken for a right atrium. Aneurysms of the ascending aorta tend to produce a bulge along the right upper cardiac margin and their recognition is usually not difficult. On the other hand, aneurysms of the aortic root frequently do not protrude outside of the cardiac shadow. It is unusual for an aneurysm to produce a bulge immediately above the right hem idiaphragm as was the case in our 2 patients. The only similar case described in the literature of which we are aware is that of Windsor and Shanahan. Cystic medial necrosis with dissection was responsible for the aneurysm in our first patient. In the second patient there was a coarctation of the aorta but the precise etiology of the aneurysm has not been established. SUMMARY In 2 patients an aneurysm of the ascending thoracic aorta simulated enlargement of the right atrium on the plain roentgenograms. In each case the correct diagnosis was made by thoracic aortography. Department of Radiology University of Iowa Hospitals Iowa City, Iowa REFERENCES 1. AU5TEN, W. G.. and BLENNERHASSETT, J. B. Giant-cell aortitis causing aneurysms of ascending aorta and aortic regurgitation New England 7. Mcd., 1965, 272, CHAPMAN, D. W., BEAZLEY, H. L., 1ETERSON P. K., WEBB, J. A., and COOLEY, D. A. Annulo-aortic ectasia with cystic medial necrosis: diagnosis and surgical treatment. Am. 7. Cardiol., 1965, 16, FERLIC, R. M., Gooi-r, B., EDWARDS, J. E., and LILLEHEI, C. N. Aortic valvular insufficiency associated with cystic medial necrosis: surgical and pathologic considerations. Ann. Surg., 1967, 165, GORE, I. Blood and lymphatic vessels. In: Pathology. Volume I. Edited by W. A. D. Anderson. C. V. Mosby Company, St. Louis, 1966, p MALCOLM, J. A., LAWRENCE, L. R., and PRIN- CIPATO, D. J. Aortic aneurysms of right side. New York 7. Med., 1967, 67, MERENDINO, K. A., \VINTER5CHEID, L. C., and DILLARD, I). H. Cystic medial necrosis with and without Marfan s syndrome: surgical experience with 20 patients and note about modified bicuspidization operation. S. C/in. NorthAmerica, 1967,47, NAJAFI, H. Aortic root aneurysm: diagnosis and treatment. J.A.M.I1., 1966, z#{231}, STEINBERG, I., and HALPERN, M. Arteriosclerotic aneurysms of thoracic aorta: intravenous and selective visualization. AM. J. ROENTGENOL., RAD. THERAPY & NUCLEAR MED., 1964, 92, STEINBERG, I. Aneurysms of thoracic aorta: review of diagnostic and etiologic features. Am. 7. Cardiol., 1958, i, WHEAT, M. W., JR., and BARTLEY, T. D. Aneurysms of aortic root. Dis. Chest, 1965, 47, I I. WINDSOR, H. M., and SHANAHAN, M. X. Unusual aneurysms of root of aorta. 7. Thoracic & Cardiovasc. Surg., 1967,53,

5 This article has been cited by: 1. Richard J. Keene, Robert E. Steiner, E.J.G. Olsen, Celia Oakley Aortic root aneurysm Radiographic and pathologic features. Clinical Radiology 22:3, [CrossRef]