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Atypical posterior leaflet motion in echocardiogram in mitral stenosis
DIAGNOSTIC SHELF
Atypical Posterior Leaflet Motion in Echocardiogram
in
Mitral Stenosis
JOHN T. FLAHERTY, SUE LIVENGOOD NICHOLAS Baltimore,
MD*
J. FORTUIN,
MD+
Maryland
The echocardiographic diagnosis of mitral stenosis is based on the finding of a decreased early diastolic slope of the anterior mitral leaflet. This finding is also seen in other conditions in which the rate of left ventricular filling is reduced by decreased compliance of the ventricular myocardium rather than by mitral valve obstruction. Patients with “true” mitral steno& have been differentiated from those with decreased ventricular compliance resulting in “false” mitral stenosis by the direction of movement of the posterior mitral valve leaflet. This report describes a patient with mitral stenosis proved at cardiac catheterization whose echocardiogram showed posterior motion of a thickened posterior mitral leaflet during diastole, a finding previously considered to exclude organic mitral stenosis. This false negative echocardiographic finding in proved mitral stenosis has not previously been reported.
The echocardiographic diagnosis of mitral stenosis is made by finding a reduced rate of anterior mitral leaflet closure after rapid opening in early diasto1e.l Other conditions not associated with mitral stenosis may also produce a reduced diastolic slope of the anterior mitral valve. The term “false” mitral stenosis has been applied in this situation. It has been suggested recently that these patients with false mitral stenosis could be distinguished from those with true mitral stenosis by the direction of movement of the posterior mitral valve leaflet.2 In patients with true mitral stenosis, the posterior leaflet moves in the same direction as the anterior leaflet. In patients with false mitral stenosis the diastolic slope of the anterior mitral leaflet is reduced, but the motion of the posterior leaflet is in a direction opposite to that of the anterior leaflet, as in normal mitral valve motion. This report concerns the echocardiographic findings in a patient with proved mitral stenosis whose posterior mitral valve leaflet motion was opposite to the motion of the anterior leaflet. This finding has not been reported previously in a patient with documented mitral stenosis. Case From the Department of Medicine, Cardiovascular Division, The Johns Hopkins University School of Medicine and The Johns Hopkins Hospital, Baltimore, Md. Manuscript accepted August 28. 1974. * Supported by Special Research Fellowship 5F03HL54033-02 from the National Heart and Lung Institute, National institutes of Health, Bethesda, Md. + Teaching Scholar of the American Heart Association, New York, N. Y Address for reprints: John T. Flaherty, MD, The Johns Hopkins Hospital, 601 N. Broadway, Baltimore, Md. 21205.
Report
An 18 year old youth had a childhood history of frequent respiratory infections (“bronchitis”) without a definite history of acute rheumatic fever. He was otherwise healthy with normal growth and exercise tolerance. At age 7 years a brief episode of aching of the legs was followed 2 weeks later by the acute onset of abdominal pain, for which an appendectomy was performed. A cardiac murmur detected by the surgeon during that hospital admission had not previously been noted in spite of multiple physical examinations by the child’s private physician, including three during the preceding year. At age 7 the boy was referred to The Johns Hopkins Hospital cardiac clinic, where typical auscultatory findings of mitral stenosis were noted. He was seen in consultation by Dr. Milton Markowitz, who believed that the boy had rheumatic heart disease with mild or even absent joint manifestations. He noted that the episode of abdominal pain could have been a manifestation of acute
May 1975
The American Journal of CARDIOLOGY
Volume 35
675
ECHOCARDIOGRAM
IN MITRAL
STENOSIS-FLAHERTY
ET AL.
pearance of a dominantly stenotic valve. The left ventriculogram revealed mild mitral incompetence and slight ventricular enlargement. The patient’s symptoms of easy fatigability and breathlessness, the physical findings and the chest roentgenogram had remained stable from 1966 to the present. Echocardiographic studies were performed for the first time in 1974 utilizing a Smith-Kline 20A ultrasonoscope. Recordings of echocardiograms and phonocardiograms were made on a Cambridge photographic recorder. Standard techniques were employed to record the mitral valve, aortic root and left and right ventricular chamber echoes. A phonocardiogram with simultaneous carotid pulse tracing and apex cardiogram was also recorded. Figure 1 shows the echogram of the anterior and posterior mitral valve leaflets. The anterior leaflet manifests
rheumatic fever, as it had been in several other cases he had previously described.3 Cardiac catheterization was first performed in January 1965 when the boy was 9 years old. Transseptal catheterization of the left atrium was carried out, and a mean mitral valve gradient of 17 mm Hg was measured utilizing simultaneous left atria1 and left ventricular pressure tracings. Injection of contrast medium into the left atrium revealed an enlarged’chamber and a dome-shaped flexible mitral valve. Left ventriculography’revealed no significant mitral regurgitation. A second catheterization in August 1966, again utilizing puncture of the interatrial septum, demonstrated a mean mitral valve gradient of 9 mm Hg and a mitral valve area of 1.3 cm2. In the levophase of a right pulmonary arteriogram, the mitral valve was again visualized and was seen to be mobile and thick with the ap-
FIGURE 1. Echocardiogram demonstrating anterior and posterior mitral valve leaflets (see text). Below, standard lead II electrocardiogram.
FIGURE 2. Echocardiogram, scanning from aortic root to the body of the left ventricular cavity (LV) showing anterior mitral valve leaflet (AML) and posterior mitral valve leaflet (PML).
676
May 1975
The American
Journal of CARDIOLOGY
Volume
35
ECHOCARDIOGRAM
thickening with multiple echoes recorded. The diastolic filling rate is retarded with a slope of 20 mm/set and an excursion of 13 mm. The posterior mitral valve leaflet is clearly visualized and moves in a direction opposite to that of the anterior leaflet. Figure 2 shows a scan from the aortic root to the body of the left ventricular cavity. This demonstrates an enlarged left atrium (4.6 cm), and normal aortic root and aortic valve with normal mitral-aortic continuity. The left ventricular cavity is slightly dilated (end-diastolic dimension, 5.6 cm), but just above this cavity there is normal systolic motion of the anterior mitral leaflet. Whenever it is visualized, the posterior leaflet moves in a direction opposite to that of the anterior leaflet. The right ventricular cavity was normal (end-diastolic dimension 2.1 cm).
IN MITRAL STENOSIS-FLAHERTY
ET AL.
A phonocardiogram (Fig. 3) revealed a loud first heart sound and a normal second heart sound. An opening snap was recorded in all areas with a 0.06 second interval from aortic valve closure to opening snap. A low-pitched middiastolic rumbling murmur with presystolic accentuation was recorded at the apex. An early systolic murmur was recorded at the pulmonary area and at the apex, where it appeared as a continuation of the presystolic murmur, ending well before the second heart sound. The carotid pulse contour was normal.
Discussion The cardinal echocardiographic feature of mitral stenosis is a reduced rate of closure of the anterior
FIGURE 3. Phonocardiogram recorded at the pulmonary area (PA) and the left ventricular apical area (APEX), carotid pulse tracing and standard lead II electrocardiogram. 1 and 2 = first and second heart sounds, respectively; A and P = aortic and pulmonary components, respectively, of second heart sound; MDM = middiastolic murmur; OS = opening snap; PSM = presystolic murmur; SM = systolic murmur.
FIGURE 4. Echocardiogram from another patient with mitral stenosis, scanning from the aortic (AO) root to the mitral valve and showing typical mitral valve motion abnormality (see text).
May 1975
The American Journal of CARDIOLOGY
Volume 35
977
ECHOCARDIOGRAM
IN MITRAL STENOSIS-FLAHERTY
ET AL.
mitral valve leaflet during diastole.’ Recent studies have shown that this finding is also seen in a variety of other cardiac conditions not associated with mitral valve obstruction including valvular aortic stenosis, idiopathic hypertrophic subaortic stenosis and systemic and pulmonary hypertension.2p4-6 Duchak et a1.2 reported that “true” mitral stenosis can be distinguished from these other causes of a reduced diastolic closure rate by observing the echocardiographic motion of the posterior mitral leaflet. In true mitral stenosis the motion of the posterior leaflet is parallel with that of the anterior leaflet in diastole. In “false” mitral stenosis the anterior and posterior leaflets move in opposite directions, as in the normal situation. Our patient is the first with proved mitral stenosis studied in our laboratory to manifest parallel anterior and posterior mitral leaflet motion in the echocardiogram. The confirmation of significant mitral valve obstruction by cardiac catheterization permits us to conclude that anterior diastolic motion of the posterior mitral valve leaflet is not invariably found in true mitral stenosis and that therefore the latter cannot be excluded if the posterior leaflet moves in a posterior direction. We have not yet seen a case in which parallel motion of both leaflets had a cause other than organic mitral stenosis. The origin of this patient’s valvular lesion remains speculative. We cannot exclude the possibility that this is a form of congenital mitral stenosis. However, a rheumatic origin seems more likely for the following reasons: (1) The patient had been examined by physicians in early childhood and no cardiac murmur had been described; (2) Dr. Milton Markowitz, an authority on manifestations of rheumatic heart disease in children, examined the patient several times between 1963 and 1968 and felt confident that the patient had rheumatic heart disease; (3) the joint aches and episode of abdominal pain may have been manifestations of acute rheumatic fever; (4) the cineangiographic appearance of the valve was typical of rheumatic mitral stenosis; and (5) the development of mitral regurgitation also favors a rheumatic origin. Mechanism of abnormal valve motion in mitral stenosis: The mechanism for the apparent parallel
movement of the two leaflets in mitral stenosis is uncertain. Chakorn et a1.,7 noting the similarity between the motion patterns of the anterior valve leaflet and the valvular ring, suggested that it is the mitral valve ring rather than the posterior leaflet that is seen moving parallel to the anterior leaflet. In chronic rheumatic mitral stenosis, the valvular ring and posterior leaflet are often tightly fused and therefore both would be likely to contribute to the echoes that appear to move parallel to and are posterior to the anterior leaflet. Cineangiographic studies of mitral valve motion in rheumatic mitral stenosis have shown that the entire mitral apparatus moves as a single unit as a result of fibrosis and commissural fusion. The combined motion of anterior and posterior leaflets and mitral valve ring resembles that of a piston descending into the ventricle in an anterior direction during diastole and may account for the parallel anterior motion of these structures observed by the echocardiographic technique. The uniformity of mitral apparatus motion in this condition is illustrated in Figure 4, which is a scan obtained from another patient with mitral stenosis. Here the typical mitral valve motion abnormality is observed in anterior and posterior leaflets that move parallel to each other in diastole. A similar motion pattern can be seen in the anterior mitral ring echo as the ultrasonic beam is directed superiorly, and even is observed to occur in the posterior aortic root. In this patient, as in many with mitral stenosis, a parallel motion pattern of all mitral apparatus structures is observed. In our patient opposite motion of the anterior and posterior leaflets could clearly be demonstrated. It is possible that a mobile mitral valve with incomplete commissural fusion could produce significant valvular obstruction yet still offer some independent posterior motion of the posterior leaflet. In conclusion, (1) The diagnosis of mitral stenosis cannot be excluded if the posterior leaflet moves in a posterior direction during diastole; and (2) “true” and “false” mitral stenosis may still be distinguished echocardiographically by considering other information obtained from the mitral valve echogram, including the thickness of the leaflets and the movement of the valve with atria1 systole.
References 1. Edler I, Gustafson A: Ultrasonic cardiogram in mitral stenosis. Acta Med !&and 159:85-93, 1957 2. Duchak JM Jr, Chang S, Feigenbaum H: The posterior mitral valve echo and echocardiographic diagnosis of mitral stenosis. Am J Cardiol 29:628-632, 1972 3. Markowftz M, Kuttner A: Rheumatic Fever. Diagnosis, Management, and Prevention. WB Saunders, Philadelphia 8 London, 1965, p 94 4. Zaky A, Nasser WK, Feigenbaum H: Study of mitral valve action recorded by reflected ultrasound and its application in the diagno-
678
May 1975
The American Journal of CARDIOLOGY
Volume 35
sis of mitral stenosis. Circulation 37:789-799. 1968 5. Shah PM, Gramiak R, Kramer DH: Ultrasound localization of left ventricular outflow obstruction in hypertrophic obstructive cardiomyopathy. Circulation 40:3-l 1, 1969 6. Goodman DJ, Harrison DC, Popp RL: Echocardiographic features of primary pulmonary hypertension. Am J Cardiol 33:438443, 1974 7. Chakorn SA, Siggers DC, Wharton CFP, et al: Study of normal and abnormal movements of mitral valve ring using reflected ultrasound. Br Heart J 34:480-486, 1972
Atypical Posterior Leaflet Motion in Echocardiogram
in
Mitral Stenosis
JOHN T. FLAHERTY, SUE LIVENGOOD NICHOLAS Baltimore,
MD*
J. FORTUIN,
MD+
Maryland
The echocardiographic diagnosis of mitral stenosis is based on the finding of a decreased early diastolic slope of the anterior mitral leaflet. This finding is also seen in other conditions in which the rate of left ventricular filling is reduced by decreased compliance of the ventricular myocardium rather than by mitral valve obstruction. Patients with “true” mitral steno& have been differentiated from those with decreased ventricular compliance resulting in “false” mitral stenosis by the direction of movement of the posterior mitral valve leaflet. This report describes a patient with mitral stenosis proved at cardiac catheterization whose echocardiogram showed posterior motion of a thickened posterior mitral leaflet during diastole, a finding previously considered to exclude organic mitral stenosis. This false negative echocardiographic finding in proved mitral stenosis has not previously been reported.
The echocardiographic diagnosis of mitral stenosis is made by finding a reduced rate of anterior mitral leaflet closure after rapid opening in early diasto1e.l Other conditions not associated with mitral stenosis may also produce a reduced diastolic slope of the anterior mitral valve. The term “false” mitral stenosis has been applied in this situation. It has been suggested recently that these patients with false mitral stenosis could be distinguished from those with true mitral stenosis by the direction of movement of the posterior mitral valve leaflet.2 In patients with true mitral stenosis, the posterior leaflet moves in the same direction as the anterior leaflet. In patients with false mitral stenosis the diastolic slope of the anterior mitral leaflet is reduced, but the motion of the posterior leaflet is in a direction opposite to that of the anterior leaflet, as in normal mitral valve motion. This report concerns the echocardiographic findings in a patient with proved mitral stenosis whose posterior mitral valve leaflet motion was opposite to the motion of the anterior leaflet. This finding has not been reported previously in a patient with documented mitral stenosis. Case From the Department of Medicine, Cardiovascular Division, The Johns Hopkins University School of Medicine and The Johns Hopkins Hospital, Baltimore, Md. Manuscript accepted August 28. 1974. * Supported by Special Research Fellowship 5F03HL54033-02 from the National Heart and Lung Institute, National institutes of Health, Bethesda, Md. + Teaching Scholar of the American Heart Association, New York, N. Y Address for reprints: John T. Flaherty, MD, The Johns Hopkins Hospital, 601 N. Broadway, Baltimore, Md. 21205.
Report
An 18 year old youth had a childhood history of frequent respiratory infections (“bronchitis”) without a definite history of acute rheumatic fever. He was otherwise healthy with normal growth and exercise tolerance. At age 7 years a brief episode of aching of the legs was followed 2 weeks later by the acute onset of abdominal pain, for which an appendectomy was performed. A cardiac murmur detected by the surgeon during that hospital admission had not previously been noted in spite of multiple physical examinations by the child’s private physician, including three during the preceding year. At age 7 the boy was referred to The Johns Hopkins Hospital cardiac clinic, where typical auscultatory findings of mitral stenosis were noted. He was seen in consultation by Dr. Milton Markowitz, who believed that the boy had rheumatic heart disease with mild or even absent joint manifestations. He noted that the episode of abdominal pain could have been a manifestation of acute
May 1975
The American Journal of CARDIOLOGY
Volume 35
675
ECHOCARDIOGRAM
IN MITRAL
STENOSIS-FLAHERTY
ET AL.
pearance of a dominantly stenotic valve. The left ventriculogram revealed mild mitral incompetence and slight ventricular enlargement. The patient’s symptoms of easy fatigability and breathlessness, the physical findings and the chest roentgenogram had remained stable from 1966 to the present. Echocardiographic studies were performed for the first time in 1974 utilizing a Smith-Kline 20A ultrasonoscope. Recordings of echocardiograms and phonocardiograms were made on a Cambridge photographic recorder. Standard techniques were employed to record the mitral valve, aortic root and left and right ventricular chamber echoes. A phonocardiogram with simultaneous carotid pulse tracing and apex cardiogram was also recorded. Figure 1 shows the echogram of the anterior and posterior mitral valve leaflets. The anterior leaflet manifests
rheumatic fever, as it had been in several other cases he had previously described.3 Cardiac catheterization was first performed in January 1965 when the boy was 9 years old. Transseptal catheterization of the left atrium was carried out, and a mean mitral valve gradient of 17 mm Hg was measured utilizing simultaneous left atria1 and left ventricular pressure tracings. Injection of contrast medium into the left atrium revealed an enlarged’chamber and a dome-shaped flexible mitral valve. Left ventriculography’revealed no significant mitral regurgitation. A second catheterization in August 1966, again utilizing puncture of the interatrial septum, demonstrated a mean mitral valve gradient of 9 mm Hg and a mitral valve area of 1.3 cm2. In the levophase of a right pulmonary arteriogram, the mitral valve was again visualized and was seen to be mobile and thick with the ap-
FIGURE 1. Echocardiogram demonstrating anterior and posterior mitral valve leaflets (see text). Below, standard lead II electrocardiogram.
FIGURE 2. Echocardiogram, scanning from aortic root to the body of the left ventricular cavity (LV) showing anterior mitral valve leaflet (AML) and posterior mitral valve leaflet (PML).
676
May 1975
The American
Journal of CARDIOLOGY
Volume
35
ECHOCARDIOGRAM
thickening with multiple echoes recorded. The diastolic filling rate is retarded with a slope of 20 mm/set and an excursion of 13 mm. The posterior mitral valve leaflet is clearly visualized and moves in a direction opposite to that of the anterior leaflet. Figure 2 shows a scan from the aortic root to the body of the left ventricular cavity. This demonstrates an enlarged left atrium (4.6 cm), and normal aortic root and aortic valve with normal mitral-aortic continuity. The left ventricular cavity is slightly dilated (end-diastolic dimension, 5.6 cm), but just above this cavity there is normal systolic motion of the anterior mitral leaflet. Whenever it is visualized, the posterior leaflet moves in a direction opposite to that of the anterior leaflet. The right ventricular cavity was normal (end-diastolic dimension 2.1 cm).
IN MITRAL STENOSIS-FLAHERTY
ET AL.
A phonocardiogram (Fig. 3) revealed a loud first heart sound and a normal second heart sound. An opening snap was recorded in all areas with a 0.06 second interval from aortic valve closure to opening snap. A low-pitched middiastolic rumbling murmur with presystolic accentuation was recorded at the apex. An early systolic murmur was recorded at the pulmonary area and at the apex, where it appeared as a continuation of the presystolic murmur, ending well before the second heart sound. The carotid pulse contour was normal.
Discussion The cardinal echocardiographic feature of mitral stenosis is a reduced rate of closure of the anterior
FIGURE 3. Phonocardiogram recorded at the pulmonary area (PA) and the left ventricular apical area (APEX), carotid pulse tracing and standard lead II electrocardiogram. 1 and 2 = first and second heart sounds, respectively; A and P = aortic and pulmonary components, respectively, of second heart sound; MDM = middiastolic murmur; OS = opening snap; PSM = presystolic murmur; SM = systolic murmur.
FIGURE 4. Echocardiogram from another patient with mitral stenosis, scanning from the aortic (AO) root to the mitral valve and showing typical mitral valve motion abnormality (see text).
May 1975
The American Journal of CARDIOLOGY
Volume 35
977
ECHOCARDIOGRAM
IN MITRAL STENOSIS-FLAHERTY
ET AL.
mitral valve leaflet during diastole.’ Recent studies have shown that this finding is also seen in a variety of other cardiac conditions not associated with mitral valve obstruction including valvular aortic stenosis, idiopathic hypertrophic subaortic stenosis and systemic and pulmonary hypertension.2p4-6 Duchak et a1.2 reported that “true” mitral stenosis can be distinguished from these other causes of a reduced diastolic closure rate by observing the echocardiographic motion of the posterior mitral leaflet. In true mitral stenosis the motion of the posterior leaflet is parallel with that of the anterior leaflet in diastole. In “false” mitral stenosis the anterior and posterior leaflets move in opposite directions, as in the normal situation. Our patient is the first with proved mitral stenosis studied in our laboratory to manifest parallel anterior and posterior mitral leaflet motion in the echocardiogram. The confirmation of significant mitral valve obstruction by cardiac catheterization permits us to conclude that anterior diastolic motion of the posterior mitral valve leaflet is not invariably found in true mitral stenosis and that therefore the latter cannot be excluded if the posterior leaflet moves in a posterior direction. We have not yet seen a case in which parallel motion of both leaflets had a cause other than organic mitral stenosis. The origin of this patient’s valvular lesion remains speculative. We cannot exclude the possibility that this is a form of congenital mitral stenosis. However, a rheumatic origin seems more likely for the following reasons: (1) The patient had been examined by physicians in early childhood and no cardiac murmur had been described; (2) Dr. Milton Markowitz, an authority on manifestations of rheumatic heart disease in children, examined the patient several times between 1963 and 1968 and felt confident that the patient had rheumatic heart disease; (3) the joint aches and episode of abdominal pain may have been manifestations of acute rheumatic fever; (4) the cineangiographic appearance of the valve was typical of rheumatic mitral stenosis; and (5) the development of mitral regurgitation also favors a rheumatic origin. Mechanism of abnormal valve motion in mitral stenosis: The mechanism for the apparent parallel
movement of the two leaflets in mitral stenosis is uncertain. Chakorn et a1.,7 noting the similarity between the motion patterns of the anterior valve leaflet and the valvular ring, suggested that it is the mitral valve ring rather than the posterior leaflet that is seen moving parallel to the anterior leaflet. In chronic rheumatic mitral stenosis, the valvular ring and posterior leaflet are often tightly fused and therefore both would be likely to contribute to the echoes that appear to move parallel to and are posterior to the anterior leaflet. Cineangiographic studies of mitral valve motion in rheumatic mitral stenosis have shown that the entire mitral apparatus moves as a single unit as a result of fibrosis and commissural fusion. The combined motion of anterior and posterior leaflets and mitral valve ring resembles that of a piston descending into the ventricle in an anterior direction during diastole and may account for the parallel anterior motion of these structures observed by the echocardiographic technique. The uniformity of mitral apparatus motion in this condition is illustrated in Figure 4, which is a scan obtained from another patient with mitral stenosis. Here the typical mitral valve motion abnormality is observed in anterior and posterior leaflets that move parallel to each other in diastole. A similar motion pattern can be seen in the anterior mitral ring echo as the ultrasonic beam is directed superiorly, and even is observed to occur in the posterior aortic root. In this patient, as in many with mitral stenosis, a parallel motion pattern of all mitral apparatus structures is observed. In our patient opposite motion of the anterior and posterior leaflets could clearly be demonstrated. It is possible that a mobile mitral valve with incomplete commissural fusion could produce significant valvular obstruction yet still offer some independent posterior motion of the posterior leaflet. In conclusion, (1) The diagnosis of mitral stenosis cannot be excluded if the posterior leaflet moves in a posterior direction during diastole; and (2) “true” and “false” mitral stenosis may still be distinguished echocardiographically by considering other information obtained from the mitral valve echogram, including the thickness of the leaflets and the movement of the valve with atria1 systole.
References 1. Edler I, Gustafson A: Ultrasonic cardiogram in mitral stenosis. Acta Med !&and 159:85-93, 1957 2. Duchak JM Jr, Chang S, Feigenbaum H: The posterior mitral valve echo and echocardiographic diagnosis of mitral stenosis. Am J Cardiol 29:628-632, 1972 3. Markowftz M, Kuttner A: Rheumatic Fever. Diagnosis, Management, and Prevention. WB Saunders, Philadelphia 8 London, 1965, p 94 4. Zaky A, Nasser WK, Feigenbaum H: Study of mitral valve action recorded by reflected ultrasound and its application in the diagno-
678
May 1975
The American Journal of CARDIOLOGY
Volume 35
sis of mitral stenosis. Circulation 37:789-799. 1968 5. Shah PM, Gramiak R, Kramer DH: Ultrasound localization of left ventricular outflow obstruction in hypertrophic obstructive cardiomyopathy. Circulation 40:3-l 1, 1969 6. Goodman DJ, Harrison DC, Popp RL: Echocardiographic features of primary pulmonary hypertension. Am J Cardiol 33:438443, 1974 7. Chakorn SA, Siggers DC, Wharton CFP, et al: Study of normal and abnormal movements of mitral valve ring using reflected ultrasound. Br Heart J 34:480-486, 1972