Marfan s Disease: Tricuspid and Mitral Valve Insufficiency with a Normal Aortic root

Transcription

1 Case Reports Marfan s Disease: Tricuspid and Mitral Valve Insufficiency with a Normal Aortic root Jacques Heibig, MD, FACC, FCCP,* Charles Robinson, MD, FRCP(C) and Mohammed E. Fawzy, MB, MRCP* * Consultant Cardiologists, Department of Medicine; Pathologist, Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre J Heibig, C Robinson, ME Fawzy, Marfan s Disease: Tricuspid and Mitral Valve Insufficiency with a Normal Aortic root. 1983; 3(3): KEYWORDS: Arachnodactyly, Mitral valve insufficiency, Tricuspid valve insufficiency Introduction Marfan's disease is am hereditary tissue disorder that is transmitted as an autosomal dominant trait with a variable degree of expression. In its most complete form, it is a syndrome characterized by skeletal, ocular, and cardiovascular abnormalities, as described by McKunsick and others. 1,3 Cardiovascular abnormalities are the most common causes of death, and aortic root disease is frequently encountered. 4,5 Isolated mitral and tricuspid valve involvement without associated aortic root disease is not unique but of sufficient rarity to merit recording. Case Report A 20-year-old male was referred to King Faisal Specialist Hospital after having been diagnosed elsewhere as having rheumatic heart disease. He presented with fatigue and dyspnea and was graded functional class IV according to the New York Heart Association Classification. A heart murmur was noted a few months earlier but there was no history to suggest rheumatic fever. Several memberss of the family had clinical evidence of Marian's disease. Clinical examination confirmed the typical features of the Marfan syndrome. The arm span was 1.84 meters and the height 1.72 meters. Arachnodactyly was present and the patient had a high arched palate and pectus carinatum. There was a positive "thumb sign". 3 The lenses of both eyes were dislocated upwards. The arterial blood pressure was 90/660 mm Hg; the jugular venous pressure was elevated at 15 cm of water and displayed a prominent V wave with a rapid Y descent. The arterial pulses were all present bout of low amplitude; the pulse rate was 100/min. The left ventricular thrust was hyperkinetic and deviated 2 cm to the left of the midclavicular line. There was a pansystolic murmur at the apex, grade III/VI, which was propagated to the left axilla. A different systolic murmur, increasing with inspiration, was also heard. A loud ventricular gallop was heard over the entire precordium. The liver was moderately enlarged, tender, and pulsatile. No murmur indicative of aortic valve incompetence could be heard. The ECG showed left atrial enlargement and combined right and left ventricular hypertrophy (Figure 1). The chest radiograph showed a markedly enlarged heart (Figure 2). The M-mode echocardiogram showed left and right ventricular volume overload and pansystolic prolapse of both mitral and tricuspid valves; the aortic root dimension was normal (Figure 3). Results of routine laboratory investigations were normal. Hemodynamic data indicated severe tricuspid and mitral valve incompetence, absence of end-diastolic gradient across both valves, and pulmonary hypertension. The left ventricular angiogram showed severe mitral valve insufficiency and left ventricular volume overload with increased volume in systole and diastole (Figure 4). The aortic angiogram was normal; in particular, there was no sign of aortic valve insufficiency and the aortic root dimension was normal. Because heart failure was not responsive to intensive medical therapy, both mitral and tricuspid valves were replaced with prosthetic devices. The patient did relatively well following surgery but died a few days later because of a low cardiac output syndrome. Pathology The valves appeared grossly to be "myxoid" and the chordae tendineae were stretched and thinned (Figure 5), but according to the surgical records they had not ruptured. Microscopically there was widespread fragmentation of

2 the elastic fibers and in the most myxoid areas, elastic fibers were absent (Figure 6). The zona spongiosa was prominent, with an extensive layer of myxomatous tissue that had replaced the fibrosa. The myxomatous change extended to the deformed surface and there was fibrosis of the holding surface. The stains used to demonstrate acid mucopolysaccharides were alcian blue at ph 2.5 and the colloidal iron stain. Both mitral and tricuspid valves showed striking myxoid degeneration (Figure 7). The H&E stain showed numerous bland nuclei separated by loose myxoid tissue. There was neither vascularity nor inflammation and no evidence of bacterial vegetation. Figure 1. Twelve-lead electrocardiogram showing combined left and right ventricular hypertrophy. Figure 2. Posteroanterior chest radiograph demonstrating the enlarged cardiac silhouette.

3 Figure 3. M-mode echocardiogram. Sweep from the aortic root to the left ventricular cavity demonstrating the normal site of the aortic root, the enlarged LA and LV cavities, and the pansystolic prolapse of mitral valve. Figure 4. Left ventricular angiogram in the right anterior oblique position showing severe mitral valve incompetence. A portion of left auricular appendage showed normal muscle, endocardium and subendocardial tissues. Discussion Based on necropsy material, Roberts and Honig have classified the findings in 18 adults with the Marfan syndrome into three groups. 5 Group 1 had a fusiform ascending aorta with marked elastic fiber degeneration. The aortic and mitral valves were "stretched" or prolapsed and showed increased acid mucopolysaccharide. Group 2 had aortic dissection with no prior valve insufficiency. Group 3 consisted of two patients who had floppy prolapsed mitral valves with markedly dilated mitral annuli but a normal aorta and aortic valve. Analysis of 151 previously reported necropsies on Marfan patients found that 22 percent had an isolated or a predominant mitral regurgitation;

4 in these, mitral valve dilatation with or without leaflet prolapsed appeared to be the major cause of mitral regurgitation. 5 These necropsy findings are consistent with clinical studies such as that of Pyeritz et al., showing that in 50 consecutive patients with typical Marfan syndrome, 84 percent had aortic root enlargement demonstrated by M-mode echocardiography and 6 percent were found to have a murmur indicative of mitral valve regurgitation only. 3,6 Figure 5. Stretched and thinned chordae tendineae. Figure 6. Fragmented elastic fibers of mitral valve.

5 Figure 7. Myxoid degeneration in tricuspid valve (colloidal iron stain). The present case might thus fall into Roberts and Honig's group 3. Apart from the unusual involvement of the tricuspid valve, 7,8 the main feature of interest in our case is the apparent complete lack of involvement of the aortic valve and aortic root. Unfortunately, necroscopy was not obtained but visual inspection at surgery indicated lack of aortic disease. It is, however, possible that there was microscopic evidence of Marfan stigmata of both the aortic valve and aorta. REFERENCES 1. Payvandi MN, Kerber RE, Phelps C, et al.: Cardiac, skeletal and opthalmologic abnormalities in relatives of patients with the Marfan syndrome. Circulation 55(5): Hirst AE Jr, Gore I: Marfan's syndrome: a review. Prog Cardiovasc Dis 16: Pyeritz RE, McKusick VA: The Marfan syndrome: diagnosis and management. TV Engl J Med 300(14): / Murdoch JL, Walker BA, Halpern BL, et al.: Life expectancy and causes of death in the Marfan syndrome. N Engl J Med 286: Roberts WC, Honig HS: The spectrum of cardiovascular disease in the Marfan Syndrome: a clinico morphologic study of 18 necroscopy patients and comparison to 151 previously reported necrospy patients. Am Heart J 104(1): McKusick VA: The cardiovascular aspects of Marfan's syndrome: a heritable disorder of connective tissue. Circulation 11(3): Shankar KR, Hultgren MK, Lauer RM, et al.: Lethal tricuspid and mitral regurgitation in Marfan's syndrome. Am J Cardiol 20: Saponaro A, Russo R, Dragagna G, et al.: Insufficienza mitralica isolata nella sindrome di Marfan completa. Minerva Cardioangiol 24(5):