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Thoracic skeletal abnormalities in idiopathic mitral valve prolapse
Thoracic Skeletal Abnormalities in Idiopathic Mitral Valve Prolapse
JOSEPH SALOMON, MD PRAWN M. SHAH, MD, FACC ROBERT A. HEINLE, MD, FACC Rochester. New York
Idiopathic prolapse of the mitral valve Is a common disorder, but many cases are clinically subtle. Thoraclc skeletal abnormalities, reported recently to accompany the syndrome, may serve as an easily ldentlflable clinical indicator. The prevalence of these abnormalities was defined In 24 patients with proved prolapse of the mitral valve. The valvular syndrome was defined cllnlcally, by echocardiography and, in seven cases, by left ventricular anglography. The skeletal deformlties were defined clinically and radlographlcally. Pectus excavatum was present in 62 percent of the patlents, “straight back” In 17 percent and severe scoliosls in 6 percent. Eighteen of the 24 patients (75 percent) had a definite thoracic skeletal deformity. Tfie association of ldiopathic prolapse of the mltral valve wlth these skeletal deformities may represent a forme fruste of fularfan’s syndrome. Patients with “straight back” and pectus excavatum should be examined clinically and perhaps by echocardiography to exclude idlopathlc prolapse of the mitral valve; when murmurs are present, a dlagnosis of “pseudoheart disease” should not be made before mitral valve prolapse has been excluded.
Since the earlier reports of Barlow et a1.Q describing a new syndrome of prolapse of the mitral valve, numerous communications have described its clinical,3-5 pathologic,6s7 echocardiographic8Tg and angiographiFl2 characteristics. The syndrome is now recognized with increasing frequency and is probably a very common disorder. The classic case presenting with nonejection click and late systolic murmur is readily identified. However, many cases are more subtle, and a high level of suspicion and various clinical maneuvers4 are required to detect the click and the murmur, which may be variable13 and evanescent. An easily identifiable clinical indicator is needed to suggest which patients may have mitral valve prolapse so that a more careful and complete examination is conducted. Thoracic skeletal abnormalities, which were reported recently to accompany mitral valve prolapse,14J5 can serve as such an indicator. This report defines the prevalence of these skeletal abnormalities in our patients with prolapse of the mitral valve. Material
From the cardiology unit of the University of Rochester School of Medicine and Dentistry (Strong Memorial Hospital and Rochester General kiospital). Rochester, N. Y. Manuscript accepted December 11, 1974. Address for reprints: Joseph Salomon, MD, Rochester General Hospital, 1425 Portland Ave., Rochester, N. Y. 14621.
32
July 1975
and Methods
The records were reviewed of all patients in the cardiology units of Strong Memorial Hospital and Rochester General Hospital from 1970 through 1972 who were found to have prolapse of the mitral valve. Patients with prolapse of known origin (Marfan’s syndrome, rheumatic heart disease, coronary artery disease and chest trauma) were excluded. Twenty-four patients were found to have idiopathic prolapse of the mitral valve. Fourteen patients were female and 10 were male. The average age was 34 years (range 6 to 72). Clinical evaluation included assessment of the thoracic habitus (pectus excavatum, kyphoscoliosis, loss of the physiologic thoracic kyphosis, shallow chest) and auscultation in the supine and upright positions and during the Valsalva
The American Journal of CARDIOLOGY
Volume 36
#opAlHc
maneuver. Phonocardiograms were recorded in 21 patients. Standard posteroanterior and lateral chest X-ray films were obtained in each case. Anteroposterior diameter of the chest at the level of the eighth thoracic vertebra and transverse diameter at the level of the dome of the diaphragm were measured, and the ratio of the anteroposteri-
MTRAL VALVE PROLAPQE--sMoMoN
ET AL.
or and transverse diameters was calculated. The presence of pectus excavatum was determined from the chest X-ray films and the condition was quantitated as either mild or severe. “Straight back” was defined by the following criteria: (1) loss of the physiologic thoracic kyphosis, and (2) anteroposterior diameter of the chest and anteroposterior
FIGURE 1. Case 16. Left, lateral chest X-ray film demonstrates a short anteroposterior diameter and loss of the physiologic thoracic kyphosis, the characteristic stigmata of “straight back”. Above, phonocardiogram shows a nonejection click followed by a short late systolic murmur.
FIGURE 2. Case 2. Above, lateral chest X-ray film shows prominent pectus excavatum. Right, echocardiiram of mitral valve shows a posterior “step” in late systole, characteristic of mitral valve prolapse. The arrow marks the onset of the posterior displacement.
July 1975
The American Journal of CARDIDLDGY
Volume 36
33
TABLE I Cfinlcal,
Radiographic and Laboratory Data
Case no.
Age W & Sex
1 2
Click
Murmur
3 4 5 6 7 8 9 10 11 12 13 14 15
44F 35F 40F 46F 45F 35F 18F 18F 40F 26F 35F 27F 6F 27F 24M
+ + + + + + + + + +
f + -t +
+ +
-I+ -I+ + f
16 17 18 19 20 21 22 23 24
19M 17M 17M 45M 43M 54M 51M 32M 72M
+ f i+ + + +
+ + + + + + “I-t -I-
“I-t + f -
Echo MVP MVP MVP MVP MVP MVP MVP MVP MVP MVP
... MVP MVP MVP MVP MVP MVP MVP ...
. *. MVP MVP MVP MVP
Angio ... ... .,. MVP MVP MVP .._ ... ... ... MVP ... ... ... MVP MVP ,., ... ... MVP ... ._. ... ,..
Pectus
St. Back
+s
-
-4-M -t-M +M +M -
+ + -t -
+M +M +M -t-S -
-i -
+s -
--t
4-S -
+
+s +s 4-S
ss -
+ -
AP/Trans.* cm
%
Comments
42
fl.5/27 13.5/29 8.5/32 10/25.5 12.3/26.8 6.8/22.8 10.5/25.5 12.5j27.7 15.1/26 U/27.5 8/24.6 11.6/25.6 ... U/29.2 13.6/32.6
46 26 39 46 30 41 45 58 40 32 45 ... 38 42
9132 14.7133.5 7124 14.5,‘32.5 16/29 15132.5 12/29.5 U/31 .*.
28 44 29 45 55 46 41 39 ...
Loss of thoracic
Severe
kyphosis
scoliosis
Anterior flaring of lower thoracic cage
Severe scoliosis
*Not determined in Cases 13 and 24 because of severe scoliosis. t These patients had clinical features of “straight back,” but their condition did not fulfill the strict radiographic criteria. - = absent; + = present; +M = marked; fS = slight. Angio = angiocardiography; AP/Trans. = ratio of anteroposterior to transverse diameter of the chest as measured on chest X-ray film; Echo = echocardiography; MVP = mitral valve prolapse; Pectus = pectus excavatum; St. Back = “straight back.”
transverse diameter ratio smaller than 2 standard deviations from the normal mean as reported by Twigg et al.‘” Echocardiograms, recorded in 21 patients, were reviewed for mitral valve prolapse, utilizing previously published criteria.* Left ventricular angiography was performed in the right anterior oblique projection in seven patients, and the description of prolapse of the mitral valve as discussed by Jeresaty” and Ranganathan et al.” was used to define this abnormality.
Results All 24 patients had the characteristic auscultatory features of mitral valve prolapse-mid-late systolic click or late systolic apical murmur, or both-and the findings were confirmed by phonocardiography in 21 (Fig. 1). ~chocardiographic confirmation was obtained in all 21 patients studied by this technique (Fig. 2). Prolapse of the mitral valve with mild to moderate mitral regurgitation was demonstrated by left ventricular angiography in all seven patients who underwent cardiac catheterization (Table I, Fig. 3). Pectus excavatum (Fig. 2 and 3) was observed radiographically in 15 of 24 patients (62 percent). “Straight back” (Fig. 1) was present in four patients (17 percent). Two additional patients (8 percent) had
34
July 1975
The American Journal of CARDIOLOGY
Volume 36
severe scoliosis. Three patients had a combination of two abnormalities. Six patients (25 percent) had no definite chest deformity; two of these and a third patient with pectus excavatum had clinical features of “straight back,” but their condition did not meet the strict radiographic criteria. Therefore, 18 of the 24 patients (75 percent) manifested a definite thoracic skeletal deformity and 2 had a probable deformity (Table II). The mean anteroposterior diameter of the chest and the mean anteroposterior transverse diameter ratio of these 24 patients were decreased as compared with normal standards (Table III), but the differences were not statistically significant.
Discussion At least 75 percent of the patients in our series had skeletal thoracic deformities, thereby confirming the initial observations of DeLeon and Ronan,14 who reported a similar prevalence rate of 78 percent. A more recent communication mentioned a tower though still significant prevalence rate of 47 percent.15 We found pectus excavatum to be the most common deformity (62 percent) followed by “straight back” (17 percent) and scoliosis (8 percent). There
lDlWATHlC MITRAL VALVE PROLAPSE-SALOMON ET AL.
FIGURE 3. Case 4. Left, lateral chest X-ray film demonstrates marked pectus excavatum. Right, frame from the left ventricular angiogram shows the ventricle in late systole in the right anterior oblique view. The scalloped appearance of the mitral valve prolapsing into the left atrium is readily seen.
TABLE
TABLE
II
Prevalence
of Thoracic
Skeletal
III
Radiographic Diameters standard deviation)
Abnormalities
of the Thorax (mean f
1
Patients Females
Males
AP/Trans
All Patients
(%)
Total patients Pectus excavatum “Straight back” Scoliosis Any deformity
no.
%
no.
%
no.
%
14 10 2 1 12
100 71 14 7 86
10 5 2 1 6
100 50 20 10 60
24 15 4* 2 18
100 62 17 8 75
Female subjects Present series Normal* Male subjects Present series Normal*
* Three additional patients had clinical features of “straight back,” but their condition did not meet the radiographic criteria.
significant difference between the female and male patients. Even though mitral valve prolapse occurs in patients with normal body build, it seems to be more frequently associated with asthenic habitus, pectus “straight back” and, occasionally, kyexcavatum, phoscoliosis. These skeletal deformities may provide the easily identifiable clinical indicator that is necessary to arouse suspicion of mitral valve deformity and lead to more accurate definition of the disease. These abnormalities are reminiscent of Marfan’s syndrome, in which there is frequently prolapse of the mitral valve17J8 as well as pectus excavatum and kyphoscoliosis. lg Moreover, the mucoid degenerative changes described in patients with mitral valve prolapse and Marfan’s syndrome are very similar.6~7~20 One is tempted to postulate that the same mesenchyma1 heredity that determines the skeletal habitus also affects the mitral valve, resulting in weakening and stretching of the chordae tendineae, loss of leaflet support and eventual development of prolapse of the valve leaflets. Patients with pectus excavatum or “straight back”
was no
10.94+ 2.26 11.961- 1.62 NS
40.61 f 8.22 45.7 h6.67 NS
12.64zt 2.98 14.20 f 1.69 NS
41.OOz!c 8.39 47.0 * 5.15 NS
* Normal standards as reported by Twigg et aLI AP = mean anteroposterior diameter of the chest; AP/Trans = mean ratio of anteroposterior to transverse diameter of the chest; NS = no significant difference between data in present series and normal standards.
occasionally manifest right ventricular hemodynamic restrictive phenomena,21t22 probably as a result of “pancaking” of the heart within the shallow chest. Mechanical pressure on the heart could account for mitral valve distortion in only a small number of patients with an extremely shallow chest and is probably not a significant factor in the etiology of mitral valve prolapse. Both “straight back” and pectus excavatum have been shown to be associated with “pseudoheart disease.” The murmurs of the “straight back” syndrome are of basal and pulmonary location,22 whereas in pectus excavatum murmurs can also be heard at the apex21 and could be confused with those of mitral valve prolapse. Since these rather rare skeletal abnormalities are very prevalent in patients with prolapse of the mitral valve, patients should not be diagnosed as having “pseudoheart disease” until valve prolapse has been excluded.
July 1975
The American Journal of CARDIOLOGY
Volume 36
35
KMOPATMCMTRAL VALVE PROLAPSE-SALOMW
ET AL.
Clinical implications: It is apparent that many patients (‘75 percent in our series) with mitral valve prolapse have easily recognizable khest wall and thoracic spine abnormalities that should alert the physician to consider mitral valve disease. Careful auscultation of the heart will almost invariably reveal the
correct diagnosis, which can be substantiated by phonocardiography, echocardiography and, in selected cases, angiocardiography. The identification of these patients is extremely important since they tend to have potentially fatal ventricular arrhythmias23-25 and are predisposed to bacterial endocarditis.26127
References 1. Barlow JB, Pocock WA, Marchand P, et al: The significance of late systolic murmurs. Am Heart J 66:443-452, 1963 2. Barlow JB, Boeman CK: Aneurysmal protrusion of the posterior leaflet of the mitral valve. Am Heart J 71:166-176. 1966 3. Hancock EW, Cohn K: The syndrome associated with mid-systolic click and late systolic murmur. Am J Med 41: 183-196, 1966 4. Barlow JB, Boeman CK, Pocock WA, et al: Late systolic murmurs and non-ejection (“mid-late”) clicks. Br Heart J 30:203218, 1968 5. Pocock WA, Barlow JB: Etiology and electrocardiographic features of the billowing posterior mitral leaflet syndrome. Am J Med 51:731-739, 1971 6. Read RC, TheI AP, Vernon EW: Symptomatic valvular myxomatous transformation (the floppy valve syndrome); a possible forme fruste of the Marfan syndrome. Circulation 32:897-910, 1965 7. Sherman EB, Char F, Dungan WT, et al: Myxomatous transformation of the mitral valve producing mitral insufficiency. Am J Dis Child 119:171-175, 1970 8. Shah PM, Gramlak R: Echocardiographic recognition of mitral valve prolapse. Circulation 47: Suppl lll:1ll-45. 1970 9. DeMarla AN, King JF, Bogren HG, et al: The variable spectrum of echocardiographic manifestations of the mitral valve prolapse syndrome. Circulation 50:33-41, 1974 10. Crlley JM, Lewis KB, Humphrles JO, et al: Prolapse of the mitral valve: clinical and cine-angiocardiographic findings. Br Heart J 28:488-496, 1966 11. Jeresaty RM: Ballooning of the mitral valve leaflets. Radiology 100:45-52, 1971 12. Ranganathan N, Sliver MD, Roblnson T, et al: Angiographicmorphologic correlation in patients with severe mitral regurgitation due to prolapse of the posterior mitral valve leaflet. Circulation 48514-518, 1973 13. Fontana ME, Pence HL, Leighton RF, et al: The varying clinical spectrum of the systolic click-late systolic murmur syndrome. Circulation 41:807-816. 1970
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July 1975
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Volume 36
14. DeLeon AC, Ronan JA: Thoracic bony abnormalities with the click and late systolic murmur syndrome (abstr). Circulation 43: Suppl ll:ll-157, 1971 15. Scampardonls G, Yang SS, Maranhao V, et al: Left ventricular abnormaltties in prolapsed mitral leaflet syndrome. Circulation 48:287-297, 1973 16. Twlgg HL, DeLeon AC, Perloff JK, et al: The straight back syndrome: radiologic manifestations. Radiology 88:274-277. 1967 17. Anderaon RE, Grondln C, Amplatt K: The mitral valve in Marfan’s syndrome. Radiology 91:9 10-914, 1968 18. Edwards JE: Mitral insufficiency resulting from “overshooting” of leaflets. Circulation 43:606-812, 197 1 19. McKuslck V: The cardiovascular aspects of Marfan’s syndrome: a heritable disorder of connective tissue. Circulation 11: 321-342. 1955 20. Shankar KR, Hultgren MK, Lauer RM, et al: Lethal tricuspid and mitral regurgitation in Marfan’s syndrome. Am J Cardiil 20: 122-128, 1987 21. Vega Dlaz F, Pelous AN, Valdes FG, et al: Pectus excavatum. Hemodynamic and electrocardiographic considerations. Am J Cardiol 10: 272-277, 1962 22. DeLeon AC, Perloff JK, Twlgg H, et al: The straight back syndrome. Clinical cardiovascular manifestations. Circulation 32: 193-203, 1965 23. Pocock WA, Barlow JB: Postexercise arrhythmias in the billowing posterior mitral leaflet syndrome. Am Heart J 80:740-745. 1970 24. Krelsman K, Kletger R, Bchad N, et al: Arrhythmia in prolapse of the mitral valve (abstr). Circulation 43: Suppl ll:ll-44, 1971 25. Gooch AS, Vlcencte F, Maranhao V, et al: Arrhythmias and left ventricular asynergy in the prolapsing mltral leaflet syndrome. Am J Cardiol29:6 1 l-820, 1972 26. LeBauer JE, Perloff JK, Kellher TF: The isolated systolic click with bacterial endocarditis. Am Heart J 73:534-537, 1967 27. Lachman AS, Bramwell-Jones DM, Lakler JB, et al: Infective endocarditis in the billowing posterior mitral leaflet syndrome (abstr). Circulation 45: Suppl ll:ll-179, 1972
JOSEPH SALOMON, MD PRAWN M. SHAH, MD, FACC ROBERT A. HEINLE, MD, FACC Rochester. New York
Idiopathic prolapse of the mitral valve Is a common disorder, but many cases are clinically subtle. Thoraclc skeletal abnormalities, reported recently to accompany the syndrome, may serve as an easily ldentlflable clinical indicator. The prevalence of these abnormalities was defined In 24 patients with proved prolapse of the mitral valve. The valvular syndrome was defined cllnlcally, by echocardiography and, in seven cases, by left ventricular anglography. The skeletal deformlties were defined clinically and radlographlcally. Pectus excavatum was present in 62 percent of the patlents, “straight back” In 17 percent and severe scoliosls in 6 percent. Eighteen of the 24 patients (75 percent) had a definite thoracic skeletal deformity. Tfie association of ldiopathic prolapse of the mltral valve wlth these skeletal deformities may represent a forme fruste of fularfan’s syndrome. Patients with “straight back” and pectus excavatum should be examined clinically and perhaps by echocardiography to exclude idlopathlc prolapse of the mitral valve; when murmurs are present, a dlagnosis of “pseudoheart disease” should not be made before mitral valve prolapse has been excluded.
Since the earlier reports of Barlow et a1.Q describing a new syndrome of prolapse of the mitral valve, numerous communications have described its clinical,3-5 pathologic,6s7 echocardiographic8Tg and angiographiFl2 characteristics. The syndrome is now recognized with increasing frequency and is probably a very common disorder. The classic case presenting with nonejection click and late systolic murmur is readily identified. However, many cases are more subtle, and a high level of suspicion and various clinical maneuvers4 are required to detect the click and the murmur, which may be variable13 and evanescent. An easily identifiable clinical indicator is needed to suggest which patients may have mitral valve prolapse so that a more careful and complete examination is conducted. Thoracic skeletal abnormalities, which were reported recently to accompany mitral valve prolapse,14J5 can serve as such an indicator. This report defines the prevalence of these skeletal abnormalities in our patients with prolapse of the mitral valve. Material
From the cardiology unit of the University of Rochester School of Medicine and Dentistry (Strong Memorial Hospital and Rochester General kiospital). Rochester, N. Y. Manuscript accepted December 11, 1974. Address for reprints: Joseph Salomon, MD, Rochester General Hospital, 1425 Portland Ave., Rochester, N. Y. 14621.
32
July 1975
and Methods
The records were reviewed of all patients in the cardiology units of Strong Memorial Hospital and Rochester General Hospital from 1970 through 1972 who were found to have prolapse of the mitral valve. Patients with prolapse of known origin (Marfan’s syndrome, rheumatic heart disease, coronary artery disease and chest trauma) were excluded. Twenty-four patients were found to have idiopathic prolapse of the mitral valve. Fourteen patients were female and 10 were male. The average age was 34 years (range 6 to 72). Clinical evaluation included assessment of the thoracic habitus (pectus excavatum, kyphoscoliosis, loss of the physiologic thoracic kyphosis, shallow chest) and auscultation in the supine and upright positions and during the Valsalva
The American Journal of CARDIOLOGY
Volume 36
#opAlHc
maneuver. Phonocardiograms were recorded in 21 patients. Standard posteroanterior and lateral chest X-ray films were obtained in each case. Anteroposterior diameter of the chest at the level of the eighth thoracic vertebra and transverse diameter at the level of the dome of the diaphragm were measured, and the ratio of the anteroposteri-
MTRAL VALVE PROLAPQE--sMoMoN
ET AL.
or and transverse diameters was calculated. The presence of pectus excavatum was determined from the chest X-ray films and the condition was quantitated as either mild or severe. “Straight back” was defined by the following criteria: (1) loss of the physiologic thoracic kyphosis, and (2) anteroposterior diameter of the chest and anteroposterior
FIGURE 1. Case 16. Left, lateral chest X-ray film demonstrates a short anteroposterior diameter and loss of the physiologic thoracic kyphosis, the characteristic stigmata of “straight back”. Above, phonocardiogram shows a nonejection click followed by a short late systolic murmur.
FIGURE 2. Case 2. Above, lateral chest X-ray film shows prominent pectus excavatum. Right, echocardiiram of mitral valve shows a posterior “step” in late systole, characteristic of mitral valve prolapse. The arrow marks the onset of the posterior displacement.
July 1975
The American Journal of CARDIDLDGY
Volume 36
33
TABLE I Cfinlcal,
Radiographic and Laboratory Data
Case no.
Age W & Sex
1 2
Click
Murmur
3 4 5 6 7 8 9 10 11 12 13 14 15
44F 35F 40F 46F 45F 35F 18F 18F 40F 26F 35F 27F 6F 27F 24M
+ + + + + + + + + +
f + -t +
+ +
-I+ -I+ + f
16 17 18 19 20 21 22 23 24
19M 17M 17M 45M 43M 54M 51M 32M 72M
+ f i+ + + +
+ + + + + + “I-t -I-
“I-t + f -
Echo MVP MVP MVP MVP MVP MVP MVP MVP MVP MVP
... MVP MVP MVP MVP MVP MVP MVP ...
. *. MVP MVP MVP MVP
Angio ... ... .,. MVP MVP MVP .._ ... ... ... MVP ... ... ... MVP MVP ,., ... ... MVP ... ._. ... ,..
Pectus
St. Back
+s
-
-4-M -t-M +M +M -
+ + -t -
+M +M +M -t-S -
-i -
+s -
--t
4-S -
+
+s +s 4-S
ss -
+ -
AP/Trans.* cm
%
Comments
42
fl.5/27 13.5/29 8.5/32 10/25.5 12.3/26.8 6.8/22.8 10.5/25.5 12.5j27.7 15.1/26 U/27.5 8/24.6 11.6/25.6 ... U/29.2 13.6/32.6
46 26 39 46 30 41 45 58 40 32 45 ... 38 42
9132 14.7133.5 7124 14.5,‘32.5 16/29 15132.5 12/29.5 U/31 .*.
28 44 29 45 55 46 41 39 ...
Loss of thoracic
Severe
kyphosis
scoliosis
Anterior flaring of lower thoracic cage
Severe scoliosis
*Not determined in Cases 13 and 24 because of severe scoliosis. t These patients had clinical features of “straight back,” but their condition did not fulfill the strict radiographic criteria. - = absent; + = present; +M = marked; fS = slight. Angio = angiocardiography; AP/Trans. = ratio of anteroposterior to transverse diameter of the chest as measured on chest X-ray film; Echo = echocardiography; MVP = mitral valve prolapse; Pectus = pectus excavatum; St. Back = “straight back.”
transverse diameter ratio smaller than 2 standard deviations from the normal mean as reported by Twigg et al.‘” Echocardiograms, recorded in 21 patients, were reviewed for mitral valve prolapse, utilizing previously published criteria.* Left ventricular angiography was performed in the right anterior oblique projection in seven patients, and the description of prolapse of the mitral valve as discussed by Jeresaty” and Ranganathan et al.” was used to define this abnormality.
Results All 24 patients had the characteristic auscultatory features of mitral valve prolapse-mid-late systolic click or late systolic apical murmur, or both-and the findings were confirmed by phonocardiography in 21 (Fig. 1). ~chocardiographic confirmation was obtained in all 21 patients studied by this technique (Fig. 2). Prolapse of the mitral valve with mild to moderate mitral regurgitation was demonstrated by left ventricular angiography in all seven patients who underwent cardiac catheterization (Table I, Fig. 3). Pectus excavatum (Fig. 2 and 3) was observed radiographically in 15 of 24 patients (62 percent). “Straight back” (Fig. 1) was present in four patients (17 percent). Two additional patients (8 percent) had
34
July 1975
The American Journal of CARDIOLOGY
Volume 36
severe scoliosis. Three patients had a combination of two abnormalities. Six patients (25 percent) had no definite chest deformity; two of these and a third patient with pectus excavatum had clinical features of “straight back,” but their condition did not meet the strict radiographic criteria. Therefore, 18 of the 24 patients (75 percent) manifested a definite thoracic skeletal deformity and 2 had a probable deformity (Table II). The mean anteroposterior diameter of the chest and the mean anteroposterior transverse diameter ratio of these 24 patients were decreased as compared with normal standards (Table III), but the differences were not statistically significant.
Discussion At least 75 percent of the patients in our series had skeletal thoracic deformities, thereby confirming the initial observations of DeLeon and Ronan,14 who reported a similar prevalence rate of 78 percent. A more recent communication mentioned a tower though still significant prevalence rate of 47 percent.15 We found pectus excavatum to be the most common deformity (62 percent) followed by “straight back” (17 percent) and scoliosis (8 percent). There
lDlWATHlC MITRAL VALVE PROLAPSE-SALOMON ET AL.
FIGURE 3. Case 4. Left, lateral chest X-ray film demonstrates marked pectus excavatum. Right, frame from the left ventricular angiogram shows the ventricle in late systole in the right anterior oblique view. The scalloped appearance of the mitral valve prolapsing into the left atrium is readily seen.
TABLE
TABLE
II
Prevalence
of Thoracic
Skeletal
III
Radiographic Diameters standard deviation)
Abnormalities
of the Thorax (mean f
1
Patients Females
Males
AP/Trans
All Patients
(%)
Total patients Pectus excavatum “Straight back” Scoliosis Any deformity
no.
%
no.
%
no.
%
14 10 2 1 12
100 71 14 7 86
10 5 2 1 6
100 50 20 10 60
24 15 4* 2 18
100 62 17 8 75
Female subjects Present series Normal* Male subjects Present series Normal*
* Three additional patients had clinical features of “straight back,” but their condition did not meet the radiographic criteria.
significant difference between the female and male patients. Even though mitral valve prolapse occurs in patients with normal body build, it seems to be more frequently associated with asthenic habitus, pectus “straight back” and, occasionally, kyexcavatum, phoscoliosis. These skeletal deformities may provide the easily identifiable clinical indicator that is necessary to arouse suspicion of mitral valve deformity and lead to more accurate definition of the disease. These abnormalities are reminiscent of Marfan’s syndrome, in which there is frequently prolapse of the mitral valve17J8 as well as pectus excavatum and kyphoscoliosis. lg Moreover, the mucoid degenerative changes described in patients with mitral valve prolapse and Marfan’s syndrome are very similar.6~7~20 One is tempted to postulate that the same mesenchyma1 heredity that determines the skeletal habitus also affects the mitral valve, resulting in weakening and stretching of the chordae tendineae, loss of leaflet support and eventual development of prolapse of the valve leaflets. Patients with pectus excavatum or “straight back”
was no
10.94+ 2.26 11.961- 1.62 NS
40.61 f 8.22 45.7 h6.67 NS
12.64zt 2.98 14.20 f 1.69 NS
41.OOz!c 8.39 47.0 * 5.15 NS
* Normal standards as reported by Twigg et aLI AP = mean anteroposterior diameter of the chest; AP/Trans = mean ratio of anteroposterior to transverse diameter of the chest; NS = no significant difference between data in present series and normal standards.
occasionally manifest right ventricular hemodynamic restrictive phenomena,21t22 probably as a result of “pancaking” of the heart within the shallow chest. Mechanical pressure on the heart could account for mitral valve distortion in only a small number of patients with an extremely shallow chest and is probably not a significant factor in the etiology of mitral valve prolapse. Both “straight back” and pectus excavatum have been shown to be associated with “pseudoheart disease.” The murmurs of the “straight back” syndrome are of basal and pulmonary location,22 whereas in pectus excavatum murmurs can also be heard at the apex21 and could be confused with those of mitral valve prolapse. Since these rather rare skeletal abnormalities are very prevalent in patients with prolapse of the mitral valve, patients should not be diagnosed as having “pseudoheart disease” until valve prolapse has been excluded.
July 1975
The American Journal of CARDIOLOGY
Volume 36
35
KMOPATMCMTRAL VALVE PROLAPSE-SALOMW
ET AL.
Clinical implications: It is apparent that many patients (‘75 percent in our series) with mitral valve prolapse have easily recognizable khest wall and thoracic spine abnormalities that should alert the physician to consider mitral valve disease. Careful auscultation of the heart will almost invariably reveal the
correct diagnosis, which can be substantiated by phonocardiography, echocardiography and, in selected cases, angiocardiography. The identification of these patients is extremely important since they tend to have potentially fatal ventricular arrhythmias23-25 and are predisposed to bacterial endocarditis.26127
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14. DeLeon AC, Ronan JA: Thoracic bony abnormalities with the click and late systolic murmur syndrome (abstr). Circulation 43: Suppl ll:ll-157, 1971 15. Scampardonls G, Yang SS, Maranhao V, et al: Left ventricular abnormaltties in prolapsed mitral leaflet syndrome. Circulation 48:287-297, 1973 16. Twlgg HL, DeLeon AC, Perloff JK, et al: The straight back syndrome: radiologic manifestations. Radiology 88:274-277. 1967 17. Anderaon RE, Grondln C, Amplatt K: The mitral valve in Marfan’s syndrome. Radiology 91:9 10-914, 1968 18. Edwards JE: Mitral insufficiency resulting from “overshooting” of leaflets. Circulation 43:606-812, 197 1 19. McKuslck V: The cardiovascular aspects of Marfan’s syndrome: a heritable disorder of connective tissue. Circulation 11: 321-342. 1955 20. Shankar KR, Hultgren MK, Lauer RM, et al: Lethal tricuspid and mitral regurgitation in Marfan’s syndrome. Am J Cardiil 20: 122-128, 1987 21. Vega Dlaz F, Pelous AN, Valdes FG, et al: Pectus excavatum. Hemodynamic and electrocardiographic considerations. Am J Cardiol 10: 272-277, 1962 22. DeLeon AC, Perloff JK, Twlgg H, et al: The straight back syndrome. Clinical cardiovascular manifestations. Circulation 32: 193-203, 1965 23. Pocock WA, Barlow JB: Postexercise arrhythmias in the billowing posterior mitral leaflet syndrome. Am Heart J 80:740-745. 1970 24. Krelsman K, Kletger R, Bchad N, et al: Arrhythmia in prolapse of the mitral valve (abstr). Circulation 43: Suppl ll:ll-44, 1971 25. Gooch AS, Vlcencte F, Maranhao V, et al: Arrhythmias and left ventricular asynergy in the prolapsing mltral leaflet syndrome. Am J Cardiol29:6 1 l-820, 1972 26. LeBauer JE, Perloff JK, Kellher TF: The isolated systolic click with bacterial endocarditis. Am Heart J 73:534-537, 1967 27. Lachman AS, Bramwell-Jones DM, Lakler JB, et al: Infective endocarditis in the billowing posterior mitral leaflet syndrome (abstr). Circulation 45: Suppl ll:ll-179, 1972