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Mitral valve prolapse: A plea for unanimity
American
Heart Journal
October, 1976, V o l u m e 92, N u m b e r 4
Editorial Mitral valve prolapse" A plea for unanimity J o n a t h a n A b r a m s , M.D. Albuquerque, N. M.
Since t h e recognition in the early 1960's t h a t midsystolic clicks and late systolic m u r m u r s arise f r o m the m i t r a l valve a p p a r a t u s , a large b o d y of l i t e r a t u r e has been generated b y the m a n y fascin a t i n g aspects of this diverse clinical entity. T h e S o u t h African workers, Reid ~ and Barlow a n d associates ~, were a m o n g the first to e m p h a s i z e t h a t late systolic m u r m u r s are the result of late m i t r a l insufficiency. E a r l y r e p o r t s e m p h a s i z e d billowing ~" ~ or ballooning ~ of the m i t r a l valve, p a r t i c u l a r l y the posterior leaflet, 2. 4. ~ and very r e c e n t publications also stress these descriptive termsY M a n y series h a v e u n d e r l i n e d ' t h e relative b e n i g n i t y of the syndrome, and in fact, m o s t affected individuals are p r o b a b l y a s y m p t o m a t i c J One group has e s t i m a t e d the prevalence as high as 5 to 10 per cent of the p o p u l a t i o n J On the o t h e r h a n d , disturbing reports of sudden d e a t h ~'1 a n d life-threatening ventricular arrhythmias have appeared,~-.~. 1~-1:~occurring p e r h a p s in one per cent of affected individualsY S y m p t o m s , if present, include palpitations, chest pain, d y s p n e a a n d fatigue. Midsystolic clicks, late systolic m u r m u r s , a n d holosystolic m u r m u r s can occur in various combinations, a n d isolated clicks are quite c o m m o n . A peculiar a n d c o m m o n f e a t u r e is the e x t r e m e variability of these findings in a n y given individual, and t h e c h a r a c t e r i s t i c changes in the timing of the click From the Division of Cardiology, Dept. of Medicine, University of New Mexico, Albuquerque. Received for publication Dec. 1, 1975. Reprint requests to: Jonathan Abrams, M.D., Chief, Division of Cardiology, Dept. of Medicine, University of New Mexico, School of Medicine, Albuquerque, N. M. 87131.
October, 1976, Vol. 92, No. 4, pp. 413-415
a n d m u r m u r with p o s t u r a l alterations, a m y l nitrate, vasopressors, Valsalva m a n e u v e r , h a n d grip, etc: 7-9 ~1 M a n y s y m p t o m a t i c p a t i e n t s have inferolateral S T - T changes on the resting E C G s. ~. i,. 14., s u p r a v e n t r i c u l a r and v e n t r i c u l a r a r r h y t h m i a s are frequent, b o t h at rest and after exercise, 9..... ' a n d their presence correlates with a history of palpitations. M a n y n a m e s h a v e been used to describe this s y n d r o m e ( T a b l e I). M o s t e m p h a s i z e either the physical findings or a description of the m i t r a l valve a b n o r m a l i t y . I would like to propose t h a t only t h e t e r m mitral valve p r o l a p s e or mitral valve p r o l a p s e s y n d r o m e ( M V P ) be used by f u t u r e workers in a n effort to clarify the confusion in the literature, and to emphasize this cardinal feature. Angiographic studies h a v e clearly d e m o n s t r a t e d t h a t p r o l a p s e of the m i t r a l valve is the sine qua non of the s y n d r o m e (with or w i t h o u t m i t r a l insufficiency, which is usually mild). :~-~' ~ '~ E c h o c a r d i o g r a p h y h a s provided m u c h additional information. While it is not a l w a y s easy to obtain a high q u a l i t y echo demons t r a t i n g prolapse, 1~, " it a p p e a r s t h a t an echo showing a midsystolic posterior m o t i o n of the m i t r a l valve, with or w i t h o u t a n t e r i o r and posterior leaflet separation, or a h a m m o c k - l i k e deform i t y of the m i t r a l valve, is seen in no other cardiac conditionJ ...... T h a t prolapse can occur w i t h o u t regurgitation is clear; this is seen in individuals with only a midsystolic click, A l t h o u g h m a n y a u t h o r s h a v e stressed isolated posterior leaflet prolapse, ~ 6. s, ~2.1~. is others h a v e d e m o n s t r a t e d a n t e r i o r leaflet prolapse alone, ~6 a n d m o r e often, prolapse of b o t h leaflets2 ~. ~
American Heart Journal
413
Abrams
T a b l e I. P a r t i a l list of proposed n a m e s in the l i t e r a t u r e for M i t r a l Valve Prolapse S y n d r o m e
Click-murmur syndrome Click-late systolic murmur syndrome Systolic click syndrome Mitral click-murmur syndrome Systolic click-late systolic murmur syndrome Mid-systolic click-late systolic murmur syndrome The syndrome of mid-systolic extra sound and late systolic murmur Billowing mitral leaflet syndrome Billowing posterior mitral valve leaflet syndrome Prolapsing mitral valve leaflet syndrome Ballooning posterior leaflet syndrome Prolapsed mitral leaflet myocardiopathy Mitral valve prolapse-click syndrome Mitral valve prolapse syndrome Floppy valve syndrome Bartow's syndrome The syndrome of apical systolic click, late systolic murmur, and abnormal T-waves The syndrome of mid-systolic extra sound and late systolic murmur The auscultatory-electrocardiographic syndrome
Milder degrees of m i t r a l insufficiency are probably correlated with selective posterior leaflet prolapse11. 1~; m o r e severe m i t r a l insufficiency is a l m o s t a l w a y s seen w h e n b o t h the anterior a n d posterior leaflets are prolapsed and incompetent2. 11 E v e n the ability of the e c h o c a r d i o g r a m to identify selective leaflet prolapse has been questioned. 1~ T h u s , the c o m m o n d e n o m i n a t o r of M V P does n o t justify the emphasis on posterior leaflet i n v o l v e m e n t . Use of the t e r m s "billowing" or " b a l l o o n i n g " is p e r h a p s m o r e aesthetic t h a n accurate. S o m e affected individuals also h a v e prolapse of the tricuspid valve. TM 20 T h e etiology of m i t r a l valve prolapse is varied. M o s t cases are idiopathic, with a high incidence of familial involvement2. 14. 21. ~2 T h e s y n d r o m e has been definitely f o u n d following d o c u m e n t e d rheum a t i c m i t r a l insufficiency. 14. ~3 While the association of midsystolic clicks and late systolic m u r m u r s in c o r o n a r y disease h a s been held to be coincidental b y some, ~ there is little d o u b t t h a t M V P h a s been f r e q u e n t l y d o c u m e n t e d in severe c o r o n a r y atherosclerotic h e a r t disease. TM 2~ M a r f a n ' s s y n d r o m e , either full-blown or forme fruste, has been suspected in some instances2 . . . . . . C e r t a i n l y the u n i f o r m finding of m y x o m a t o u s d e g e n e r a t i o n a n d increase in the a c i d - m u c o p o l y saccharide c o n t e n t of the m i t r a l valve leaflets,3. ,0. 11. 26 along with thin elongated chordae
414
tendineae, suggests an underlying connective tissue defect. T h e r e a p p e a r s to be an increased incidence of m i n o r skeletal a b n o r m a l i t i e s in m a n y affected individuals. 12. 57. 28 M V P h a s also been associated with s e c u n d u m A S D ' s a n d I H S S . 7. 1.... M a n y groups h a v e d o c u m e n t e d left v e n t r i c u l a r c o n t r a c t i o n a b n o r m a l i t i e s in p a t i e n t s with MVP, suggesting t h a t a focal or generalized cardiomyo p a t h y is a possible c o m m o n link ~2. 59-3,; others t a k e exception to this view22. 33 In all of the above conditions, the final common pathway is mitral
valve prolapse. One of the m o s t vexing aspects of M V P is the presence of chest pain a n d E C G abnormalities. T h e r e h a s been m u c h speculation a b o u t the causes of these p h e n o m e n a , a n d the m o s t p r e v a l e n t concept p o s t u l a t e s an i m b a l a n c e b e t w e e n m y o c a r d i a l oxygen supply a n d d e m a n d involving the p a p i l l a r y muscles and s u r r o u n d i n g myocardium.7. ~1.34 T h e reason for this, and its d o c u m e n t a t i o n , is obscure. A recent s t u d y d e m o n s t r a t e d congenital absence of the A-V groove b r a n c h of t h e left circumflex a r t e r y in a high p e r c e n t a g e of these p a t i e n t s 2 ~ In a n y case, M V P is clearly present in all such cases, and some suggest t h a t the prolapse itself c o n t r i b u t e s to the relative " i s c h e m i a " b y increasing tension in the p a p i l l a r y muscle. 32 M u c h is still u n k n o w n a b o u t various aspects of M V P . T h e c o m m o n utilization of the t e r m " m i t r a l valve prolapse" should result in decreased confusion in the l i t e r a t u r e and at the s a m e time e m p h a s i z e t h a t diverse etiologies can result in prolapse. I t is the prolapse of either or b o t h m i t r a l leaflets into the left a t r i u m , with or w i t h o u t valve i n c o m p e t e n c e , which results in the varied clinical sequelae. F u t u r e research hopefully will b e t t e r c h a r a c t e r i z e the m e c h a n i s m s resulting in prolapse, a n d the effects of prolapse itself. REFERENCES
1. Reid, J. V.: Mid-systolic clicks, S. Afr. Med. J. 35:353, 1961. 2. Barlow, J. B., Pocock, W. A., Marchand, P., and Denny, M.: The significance of late systolic murmurs, AM. HEARTJ. 66:443, 1963. 3. Bittar, N., and Sosa, J. A.: The billowing mitral valve leaflet, Circulation 38:763, 1968. 4. Jeresaty, R. M.: Ballooning of the mitral valve leaflets. Angiographic study of 24 patients, Radiology 100:45, 1971. 5. Criley, J. M., Louis, K. B., Humphries, J. 0., and Ross, R. S.: Prolapse of the mitral valve: Clinical and cineangiographic findings, Br. Heart J. 28:488, 1966. 6. Shappell, S. D., Orr, W., and Gunn, C. G.: The ballooning
October, 1976, Vol. 92, No. 4
Mitral valve prolapse
7.
8.
9. 10.
11. 12.
13. 14.
15. 16.
17. 18. 19.
20.
posterior leaflet syndrome: Minnesota multiphasic personality inventory profiles in symptomatic and asymptomatic groups, Chest 66:6, 1974. O'Rourke, R. A., Crawford, M. H., Johnson, A. D., et al.: Prolapsing mitral valve leaflet syndrome-University of California, San Diego (Specialty conference), West J. Med. 122:217, 1975. Barlow, J. B.,~ Bossman, C. K., Pocock, W. A., and Marchand, P.: Late systolic murmurs and non-ejection ("mid-late") systolic clicks. An analysis of 90 patients, Br. Heart J. 30:203, 1968. Hancock, E. W., and Cohn, K.: The syndrome associated with mid-systolic click and late systolic murmur, Am. J. Med. 41:183, 1966. Marshall, C. E., and Shappell, S. D.: Sudden death and ballooning posterior leaflet syndrome. Detailed anatomic and histochemical investigation, Arch. Pathol. 98:134, 1974. Jeresaty, R. M.: Mitral valve prolapse-click syndrome, Progr. Cardiovasc. Dis. 1 5:623, 1973. Gooch, A. S., Vicencio, F , Maranhao, V., and Goldberg, H.: Arrhythmias and left ventricular asynergy in the prolapsing mitral leaflet syndrome, Am. J. Cardiol. 29:611, 1972. Sloman, G., Wong, M., and Walker, J.: Arrhythmias on exercise in patients with abnormalities of the posterior leaflet of the mitral valve, AM. HEART g. 83:312, 1972. Pocock, W. A., and Barlow, J. B.: Etiology and electrocardiographic features of the billowing posterior mitral leaflet syndrome. Analysis of a further 130 patients with a late systolic m u r m u r or non-ejection systolic click, Am. J. Med. 51:731, 1971. Popp, R. L., Brown, O. R., Silverman, J. F., and Harrison, D. C.: Echocardiographic abnormalities in the mitral valve prolapse syndrome, Circulation 49:428, 1974. Kerber, R. E., Isaess, D. M., and Hancock, E. W.: Echocardiographic patterns in patients with the syndrome of systolic click and late systolic murmur, N. Engl. J. Med. 284:691, 1971. Dillon, J. C., Haine, C. L., Chang, S., and Feigenbaum, H.: Use of echocardiography in patients with prolapsed mitral valve, Circulation 43:503, 1971. King, J. F., and Dunn, M.: Mitral-valve leaflets and systolic clicks. (Letter to Ed.) N. Engl. J. Med. 284:1329, 1971. Gooch, A. S., Maranhao, V., Scampardonis, G., Cha, S. D., and Yang, S. S.: Prolapse of both mitral and tricuspid leaflets in systolic murmur-click syndrome, N. Engl. J. Med. 287:1218, 1972. Ainsworth, R. P., Hartmann, A. S., Aker, U., and Schad, N.: Tricuspid valve prolapse with late systolic tricuspid insufficiency, Radiology 107:309, 1973.
American Heart Journal
21. 22.
23. 24.
25.
26.
27.
28. 29.
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32. 33. 34.
Rizzon, P., Biasco, G., Brindicci, G., and Mauro, F.: Familial syndrome of mid-systolic click and late systolic murmur, Br. Heart J. 35:245, 1973. Shell, W. E., Walton, J. A., Clifford, M. E., and Willis, P. W.: The familial occurrence of the syndrome of midlate systolic click and late systolic murmur, Circulation 39:327, 1969. Steinfeld, L., Dimich, I., Rappaport, H., and Baron, M.: Late systolic m u r m u r of rheumatic mitral insufficiency, Am. J. CardioL 35:397, 1975. Steelman, R, B., White, R. S., Hill, J. C., et al: Midsystolic clicks in arteriosclerotic heart disease. A new facet in the clinical syndrome of papillary muscle dysfunction, Circulation 44:503, 1971. Aranda, J. M., Befeler, B., Lazzara, R., Embi, A., and Machado, H.: Mitral valve prolapse in coronary artery disease. Clinical, hemodynamic, and angiographic correlations, Circulation 52:245, 1975. Roberts, W. C., Dangel, J. C., and Bulkley, B. H.: Nonrheumatic valvular cardiac disease: A clinical pathologic survey of 27 different conditions causing valvular dysfunction, in Likoff, W., Editor: Cardiovasc. Clin. 5:379, 1973. Bon Tempo, C. P., Ronan, J. A., de Leon, A. C., and Twigg, H. L.: Radiographic appearance of the thorax in systolic click-late systolic m u r m u r syndrome, Am. J. Cardiol. 36:27, 1975. Salomon, J., Shah, P., and Heinle, R. A.: Thoracic skeletal abnormalities in idiopathic mitral valve prolapse, Am. J. Cardiol. 36:32, 1975. Ehlers, K. H., Engle, M. A., Levin, A. R., Grossman, H., and Fleming, R. J.: Left ventricular abnormality with late mitral insufficiency and abnormal electrocardiogram, Am J. Cardiol. 26:333, 1970. Liedtke, A. J., Gault, J. H., Leaman, D. M., and Blumenthal, M. S.: Geometry of left ventricular contraction in the systolic click syndrome. Characterization of a segmental myocardial abnormality, Circulation 47:27, 1973. Gentzler, R. D., Gault, J. H., Liedtke, A. J., McCann, W. D., Maun, R. H., and Hunter, A. S.: Congenital absence of the left circumflex artery in the systolic click syndrome, Circulation 52:490, 1975. Jeresaty, R. M.: Etiology of the mitral valve prolapse-click syndrome, Am. J. Cardiol. 36:110, 1975. Nutter, D. O., Wickliffe, C., Gilbert, C. A., Moody, C., and King, S. B., III: The pathophysiology of idiopathic mitral valve prolapse, Circulation 52:297, 1975. LeWinter, M. M., Hoffman, J. R., Shell, W. E., Karliner, J. S., and O'Rourke, R. A.: Phenylepherine-induced atypical chest pain in patients with prolapsing mitral valve leaflets, Am. J. Cardiol. 34:12, 1974.
41 5
Heart Journal
October, 1976, V o l u m e 92, N u m b e r 4
Editorial Mitral valve prolapse" A plea for unanimity J o n a t h a n A b r a m s , M.D. Albuquerque, N. M.
Since t h e recognition in the early 1960's t h a t midsystolic clicks and late systolic m u r m u r s arise f r o m the m i t r a l valve a p p a r a t u s , a large b o d y of l i t e r a t u r e has been generated b y the m a n y fascin a t i n g aspects of this diverse clinical entity. T h e S o u t h African workers, Reid ~ and Barlow a n d associates ~, were a m o n g the first to e m p h a s i z e t h a t late systolic m u r m u r s are the result of late m i t r a l insufficiency. E a r l y r e p o r t s e m p h a s i z e d billowing ~" ~ or ballooning ~ of the m i t r a l valve, p a r t i c u l a r l y the posterior leaflet, 2. 4. ~ and very r e c e n t publications also stress these descriptive termsY M a n y series h a v e u n d e r l i n e d ' t h e relative b e n i g n i t y of the syndrome, and in fact, m o s t affected individuals are p r o b a b l y a s y m p t o m a t i c J One group has e s t i m a t e d the prevalence as high as 5 to 10 per cent of the p o p u l a t i o n J On the o t h e r h a n d , disturbing reports of sudden d e a t h ~'1 a n d life-threatening ventricular arrhythmias have appeared,~-.~. 1~-1:~occurring p e r h a p s in one per cent of affected individualsY S y m p t o m s , if present, include palpitations, chest pain, d y s p n e a a n d fatigue. Midsystolic clicks, late systolic m u r m u r s , a n d holosystolic m u r m u r s can occur in various combinations, a n d isolated clicks are quite c o m m o n . A peculiar a n d c o m m o n f e a t u r e is the e x t r e m e variability of these findings in a n y given individual, and t h e c h a r a c t e r i s t i c changes in the timing of the click From the Division of Cardiology, Dept. of Medicine, University of New Mexico, Albuquerque. Received for publication Dec. 1, 1975. Reprint requests to: Jonathan Abrams, M.D., Chief, Division of Cardiology, Dept. of Medicine, University of New Mexico, School of Medicine, Albuquerque, N. M. 87131.
October, 1976, Vol. 92, No. 4, pp. 413-415
a n d m u r m u r with p o s t u r a l alterations, a m y l nitrate, vasopressors, Valsalva m a n e u v e r , h a n d grip, etc: 7-9 ~1 M a n y s y m p t o m a t i c p a t i e n t s have inferolateral S T - T changes on the resting E C G s. ~. i,. 14., s u p r a v e n t r i c u l a r and v e n t r i c u l a r a r r h y t h m i a s are frequent, b o t h at rest and after exercise, 9..... ' a n d their presence correlates with a history of palpitations. M a n y n a m e s h a v e been used to describe this s y n d r o m e ( T a b l e I). M o s t e m p h a s i z e either the physical findings or a description of the m i t r a l valve a b n o r m a l i t y . I would like to propose t h a t only t h e t e r m mitral valve p r o l a p s e or mitral valve p r o l a p s e s y n d r o m e ( M V P ) be used by f u t u r e workers in a n effort to clarify the confusion in the literature, and to emphasize this cardinal feature. Angiographic studies h a v e clearly d e m o n s t r a t e d t h a t p r o l a p s e of the m i t r a l valve is the sine qua non of the s y n d r o m e (with or w i t h o u t m i t r a l insufficiency, which is usually mild). :~-~' ~ '~ E c h o c a r d i o g r a p h y h a s provided m u c h additional information. While it is not a l w a y s easy to obtain a high q u a l i t y echo demons t r a t i n g prolapse, 1~, " it a p p e a r s t h a t an echo showing a midsystolic posterior m o t i o n of the m i t r a l valve, with or w i t h o u t a n t e r i o r and posterior leaflet separation, or a h a m m o c k - l i k e deform i t y of the m i t r a l valve, is seen in no other cardiac conditionJ ...... T h a t prolapse can occur w i t h o u t regurgitation is clear; this is seen in individuals with only a midsystolic click, A l t h o u g h m a n y a u t h o r s h a v e stressed isolated posterior leaflet prolapse, ~ 6. s, ~2.1~. is others h a v e d e m o n s t r a t e d a n t e r i o r leaflet prolapse alone, ~6 a n d m o r e often, prolapse of b o t h leaflets2 ~. ~
American Heart Journal
413
Abrams
T a b l e I. P a r t i a l list of proposed n a m e s in the l i t e r a t u r e for M i t r a l Valve Prolapse S y n d r o m e
Click-murmur syndrome Click-late systolic murmur syndrome Systolic click syndrome Mitral click-murmur syndrome Systolic click-late systolic murmur syndrome Mid-systolic click-late systolic murmur syndrome The syndrome of mid-systolic extra sound and late systolic murmur Billowing mitral leaflet syndrome Billowing posterior mitral valve leaflet syndrome Prolapsing mitral valve leaflet syndrome Ballooning posterior leaflet syndrome Prolapsed mitral leaflet myocardiopathy Mitral valve prolapse-click syndrome Mitral valve prolapse syndrome Floppy valve syndrome Bartow's syndrome The syndrome of apical systolic click, late systolic murmur, and abnormal T-waves The syndrome of mid-systolic extra sound and late systolic murmur The auscultatory-electrocardiographic syndrome
Milder degrees of m i t r a l insufficiency are probably correlated with selective posterior leaflet prolapse11. 1~; m o r e severe m i t r a l insufficiency is a l m o s t a l w a y s seen w h e n b o t h the anterior a n d posterior leaflets are prolapsed and incompetent2. 11 E v e n the ability of the e c h o c a r d i o g r a m to identify selective leaflet prolapse has been questioned. 1~ T h u s , the c o m m o n d e n o m i n a t o r of M V P does n o t justify the emphasis on posterior leaflet i n v o l v e m e n t . Use of the t e r m s "billowing" or " b a l l o o n i n g " is p e r h a p s m o r e aesthetic t h a n accurate. S o m e affected individuals also h a v e prolapse of the tricuspid valve. TM 20 T h e etiology of m i t r a l valve prolapse is varied. M o s t cases are idiopathic, with a high incidence of familial involvement2. 14. 21. ~2 T h e s y n d r o m e has been definitely f o u n d following d o c u m e n t e d rheum a t i c m i t r a l insufficiency. 14. ~3 While the association of midsystolic clicks and late systolic m u r m u r s in c o r o n a r y disease h a s been held to be coincidental b y some, ~ there is little d o u b t t h a t M V P h a s been f r e q u e n t l y d o c u m e n t e d in severe c o r o n a r y atherosclerotic h e a r t disease. TM 2~ M a r f a n ' s s y n d r o m e , either full-blown or forme fruste, has been suspected in some instances2 . . . . . . C e r t a i n l y the u n i f o r m finding of m y x o m a t o u s d e g e n e r a t i o n a n d increase in the a c i d - m u c o p o l y saccharide c o n t e n t of the m i t r a l valve leaflets,3. ,0. 11. 26 along with thin elongated chordae
414
tendineae, suggests an underlying connective tissue defect. T h e r e a p p e a r s to be an increased incidence of m i n o r skeletal a b n o r m a l i t i e s in m a n y affected individuals. 12. 57. 28 M V P h a s also been associated with s e c u n d u m A S D ' s a n d I H S S . 7. 1.... M a n y groups h a v e d o c u m e n t e d left v e n t r i c u l a r c o n t r a c t i o n a b n o r m a l i t i e s in p a t i e n t s with MVP, suggesting t h a t a focal or generalized cardiomyo p a t h y is a possible c o m m o n link ~2. 59-3,; others t a k e exception to this view22. 33 In all of the above conditions, the final common pathway is mitral
valve prolapse. One of the m o s t vexing aspects of M V P is the presence of chest pain a n d E C G abnormalities. T h e r e h a s been m u c h speculation a b o u t the causes of these p h e n o m e n a , a n d the m o s t p r e v a l e n t concept p o s t u l a t e s an i m b a l a n c e b e t w e e n m y o c a r d i a l oxygen supply a n d d e m a n d involving the p a p i l l a r y muscles and s u r r o u n d i n g myocardium.7. ~1.34 T h e reason for this, and its d o c u m e n t a t i o n , is obscure. A recent s t u d y d e m o n s t r a t e d congenital absence of the A-V groove b r a n c h of t h e left circumflex a r t e r y in a high p e r c e n t a g e of these p a t i e n t s 2 ~ In a n y case, M V P is clearly present in all such cases, and some suggest t h a t the prolapse itself c o n t r i b u t e s to the relative " i s c h e m i a " b y increasing tension in the p a p i l l a r y muscle. 32 M u c h is still u n k n o w n a b o u t various aspects of M V P . T h e c o m m o n utilization of the t e r m " m i t r a l valve prolapse" should result in decreased confusion in the l i t e r a t u r e and at the s a m e time e m p h a s i z e t h a t diverse etiologies can result in prolapse. I t is the prolapse of either or b o t h m i t r a l leaflets into the left a t r i u m , with or w i t h o u t valve i n c o m p e t e n c e , which results in the varied clinical sequelae. F u t u r e research hopefully will b e t t e r c h a r a c t e r i z e the m e c h a n i s m s resulting in prolapse, a n d the effects of prolapse itself. REFERENCES
1. Reid, J. V.: Mid-systolic clicks, S. Afr. Med. J. 35:353, 1961. 2. Barlow, J. B., Pocock, W. A., Marchand, P., and Denny, M.: The significance of late systolic murmurs, AM. HEARTJ. 66:443, 1963. 3. Bittar, N., and Sosa, J. A.: The billowing mitral valve leaflet, Circulation 38:763, 1968. 4. Jeresaty, R. M.: Ballooning of the mitral valve leaflets. Angiographic study of 24 patients, Radiology 100:45, 1971. 5. Criley, J. M., Louis, K. B., Humphries, J. 0., and Ross, R. S.: Prolapse of the mitral valve: Clinical and cineangiographic findings, Br. Heart J. 28:488, 1966. 6. Shappell, S. D., Orr, W., and Gunn, C. G.: The ballooning
October, 1976, Vol. 92, No. 4
Mitral valve prolapse
7.
8.
9. 10.
11. 12.
13. 14.
15. 16.
17. 18. 19.
20.
posterior leaflet syndrome: Minnesota multiphasic personality inventory profiles in symptomatic and asymptomatic groups, Chest 66:6, 1974. O'Rourke, R. A., Crawford, M. H., Johnson, A. D., et al.: Prolapsing mitral valve leaflet syndrome-University of California, San Diego (Specialty conference), West J. Med. 122:217, 1975. Barlow, J. B.,~ Bossman, C. K., Pocock, W. A., and Marchand, P.: Late systolic murmurs and non-ejection ("mid-late") systolic clicks. An analysis of 90 patients, Br. Heart J. 30:203, 1968. Hancock, E. W., and Cohn, K.: The syndrome associated with mid-systolic click and late systolic murmur, Am. J. Med. 41:183, 1966. Marshall, C. E., and Shappell, S. D.: Sudden death and ballooning posterior leaflet syndrome. Detailed anatomic and histochemical investigation, Arch. Pathol. 98:134, 1974. Jeresaty, R. M.: Mitral valve prolapse-click syndrome, Progr. Cardiovasc. Dis. 1 5:623, 1973. Gooch, A. S., Vicencio, F , Maranhao, V., and Goldberg, H.: Arrhythmias and left ventricular asynergy in the prolapsing mitral leaflet syndrome, Am. J. Cardiol. 29:611, 1972. Sloman, G., Wong, M., and Walker, J.: Arrhythmias on exercise in patients with abnormalities of the posterior leaflet of the mitral valve, AM. HEART g. 83:312, 1972. Pocock, W. A., and Barlow, J. B.: Etiology and electrocardiographic features of the billowing posterior mitral leaflet syndrome. Analysis of a further 130 patients with a late systolic m u r m u r or non-ejection systolic click, Am. J. Med. 51:731, 1971. Popp, R. L., Brown, O. R., Silverman, J. F., and Harrison, D. C.: Echocardiographic abnormalities in the mitral valve prolapse syndrome, Circulation 49:428, 1974. Kerber, R. E., Isaess, D. M., and Hancock, E. W.: Echocardiographic patterns in patients with the syndrome of systolic click and late systolic murmur, N. Engl. J. Med. 284:691, 1971. Dillon, J. C., Haine, C. L., Chang, S., and Feigenbaum, H.: Use of echocardiography in patients with prolapsed mitral valve, Circulation 43:503, 1971. King, J. F., and Dunn, M.: Mitral-valve leaflets and systolic clicks. (Letter to Ed.) N. Engl. J. Med. 284:1329, 1971. Gooch, A. S., Maranhao, V., Scampardonis, G., Cha, S. D., and Yang, S. S.: Prolapse of both mitral and tricuspid leaflets in systolic murmur-click syndrome, N. Engl. J. Med. 287:1218, 1972. Ainsworth, R. P., Hartmann, A. S., Aker, U., and Schad, N.: Tricuspid valve prolapse with late systolic tricuspid insufficiency, Radiology 107:309, 1973.
American Heart Journal
21. 22.
23. 24.
25.
26.
27.
28. 29.
30.
31.
32. 33. 34.
Rizzon, P., Biasco, G., Brindicci, G., and Mauro, F.: Familial syndrome of mid-systolic click and late systolic murmur, Br. Heart J. 35:245, 1973. Shell, W. E., Walton, J. A., Clifford, M. E., and Willis, P. W.: The familial occurrence of the syndrome of midlate systolic click and late systolic murmur, Circulation 39:327, 1969. Steinfeld, L., Dimich, I., Rappaport, H., and Baron, M.: Late systolic m u r m u r of rheumatic mitral insufficiency, Am. J. CardioL 35:397, 1975. Steelman, R, B., White, R. S., Hill, J. C., et al: Midsystolic clicks in arteriosclerotic heart disease. A new facet in the clinical syndrome of papillary muscle dysfunction, Circulation 44:503, 1971. Aranda, J. M., Befeler, B., Lazzara, R., Embi, A., and Machado, H.: Mitral valve prolapse in coronary artery disease. Clinical, hemodynamic, and angiographic correlations, Circulation 52:245, 1975. Roberts, W. C., Dangel, J. C., and Bulkley, B. H.: Nonrheumatic valvular cardiac disease: A clinical pathologic survey of 27 different conditions causing valvular dysfunction, in Likoff, W., Editor: Cardiovasc. Clin. 5:379, 1973. Bon Tempo, C. P., Ronan, J. A., de Leon, A. C., and Twigg, H. L.: Radiographic appearance of the thorax in systolic click-late systolic m u r m u r syndrome, Am. J. Cardiol. 36:27, 1975. Salomon, J., Shah, P., and Heinle, R. A.: Thoracic skeletal abnormalities in idiopathic mitral valve prolapse, Am. J. Cardiol. 36:32, 1975. Ehlers, K. H., Engle, M. A., Levin, A. R., Grossman, H., and Fleming, R. J.: Left ventricular abnormality with late mitral insufficiency and abnormal electrocardiogram, Am J. Cardiol. 26:333, 1970. Liedtke, A. J., Gault, J. H., Leaman, D. M., and Blumenthal, M. S.: Geometry of left ventricular contraction in the systolic click syndrome. Characterization of a segmental myocardial abnormality, Circulation 47:27, 1973. Gentzler, R. D., Gault, J. H., Liedtke, A. J., McCann, W. D., Maun, R. H., and Hunter, A. S.: Congenital absence of the left circumflex artery in the systolic click syndrome, Circulation 52:490, 1975. Jeresaty, R. M.: Etiology of the mitral valve prolapse-click syndrome, Am. J. Cardiol. 36:110, 1975. Nutter, D. O., Wickliffe, C., Gilbert, C. A., Moody, C., and King, S. B., III: The pathophysiology of idiopathic mitral valve prolapse, Circulation 52:297, 1975. LeWinter, M. M., Hoffman, J. R., Shell, W. E., Karliner, J. S., and O'Rourke, R. A.: Phenylepherine-induced atypical chest pain in patients with prolapsing mitral valve leaflets, Am. J. Cardiol. 34:12, 1974.
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