Echocardiography in Valvular Heart Disease Louis Evan Teichholz CHOCARDIOGRAPHY is an important noninvasive technique that allows the study of the dimensions and movements of various cardiac structures, including the valves and chambers. The technical aspects and physical principles as well as the clinical usefulness in various disease settings have been previously reviewed. ~-6 The purpose of this review is to discuss this technique in relation to valvular heart disease. E MITRAL VALVE Normal Mitral Valve In order to fully understand the changes in the mitral valve echocardiogram in patients with valvular heart disease, a brief review of the normal motion pattern of the mitral valve is in order. The mitral valve has two leaflets, a larger anterior leaflet that is easily visualized by echocardiography and a smaller posterior leaflet that is much more difficult to visualize. The normal posterior leaflet shows mirror-image motion as compared to the anterior leaflet. The details of the motion of the mitral valve were originally described by Edler 7,a and further characterized by others. 9-~3 Figure 1 shows the normal pattern of motion of the anterior leaflet of the mitral valve. During systole (C-D), there is smooth anterior motion of both the anterior and posterior leaflets of the valve as the heart and mitral annulus rock anteriorly. In early diastole, the mitral valve opens rapidly (D-E), and then during and after rapid filling the mitral valve floats to midposition (E-F). With long cycle lengths, there may be some low-amplitude oscillatory motion during mid-diastole. With atrial systole, the valve reopens (A) and then closes during the onset of ventricular systole (A-C). The normal amplitude is 20-35 mm/sec, and the normal E-F slope, i.e., diastolic velocity, is 80-150 mm/sec. ~4 From the Cardiovascular Division, Department of Medicine, Peter Bent Brigham Hospital, and the Department of Medicine, Harvard Medical School, Boston, Mass. Supported by USPHS Grant 5 P01 HL 11306 and the Women's A id for Heart Research. Reprint requests should be addressed to Louis Evan Teichholz, M.D., Mt. Sinai Hospital, Fifth Avenue and lOOth Street, New York, N. Y. 10029. 9 1975 by Grune & Stratton, Inc. Figure 2 shows an echocardiogram of a normal mitral valve. Mitral Stenosis The study of the mitral valve in mitral stenosis was one of the earliest uses of diagnostic ultrasound, 7'15'16 since it afforded easy visualization of the anterior leaflet of the mitral valve and the many striking findings present in rheumatic heart disease. The pathophysiologic processes involved in rheumatic mitral stenosis include fusion of the commissures of the anterior and posterior leaflets of the mitral valve, fusion of the Chordae tendineae, leaflet thickening and deposition of calcium, left atrial dilatation, and decreased contractile function of the left atrium. An important finding in mitral stenosis is the decrease in the E-F slope as a manifestation of decreased left ventricular filling in early diastole 9'12'1s-21 (Fig. 3). This finding has its counterpart in the decreased rapid filling wave noted on the apexcardiogram. In the presence of a mobile valve, the E-F slope has been shown to be related to the severity of the mitral s t e n o s i s . 9'15'16'22-24 Severe mitral stenosis with a valve area of <1.0 sq cm has been associated with a velocity of <10 mm/sec. Moderate mitral stenosis with a mitral valve area between 1.0 and 2.5 sq cm has been found to be associated with a diastolic velocity in the range of 10-25 mm/sec, while mild mitral stenosis, i.e., valve area >2.5 sq cm, has usually been associated with diastolic velocities from 25 to 35 mm/sec. If the valve is not mobile and is bound down and thickened because of calcification, fibrosis, or shortening of the chordae tendineae, the excursion of the mitral valve as seen on the echocardiogram will be diminished 4'23'2s (Fig. 4). Normally, the total amplitude of excursion of the mitral valve is greater than 20 mm. In patients with immobile mitral valves, this value is less than 20 mm and usually less than 15 ram. It is important to note that the estimation of the severity of mitral stenosis by the use of the E-F slope is less reliable in the presence of an immobile valve. The determination of the amplitude of the mitral valve has been shown to be useful in predicting whether or not mitral commissurotomy will be successful. In general, those patients with too- Progress in Cardiovascular Diseases, Vol. XVII, No. 4 (January/February), 197,5 283 284 TEICHHOLZ \\ MV DIASTOLtCVEI.OCtTY \~,NL: 80-150 MM/SEC \\ \~E. . . . . . . . . . . . . . . . . . . . . . N\ / J I . ~ 1 ^ ~ / ~ ~.B My AMmTUO~ NL: 20"35 MM L_! .... Fig. 1. Motion pattern of anterior leaflet of mitral valve. C-D, systole, D-E, diastolic opening. E-F, diastolic closing, A-C, systolic closing. Normal valves for amplitude and diastolic velocity are given. Fig. 2. Mitral valve. (A) Normal anterior leaflet of mitral valve. {B) Mitral valve illustrating normal motion of the anterior leaflet (A) and the mirror image motion of posterior leaflet (P) of mitral valve. bile mitral valves have proved to be much more amenable to mitral valvuoplasty, while those with heavily calcified immobile valves have needed mitral valve replacement. Calcification and thickening of the mitral valve are detected as multiple multilayered echoes on the anterior leaflet of the mitral valve or a thickening in the echo pattern 14'2s (Fig. 4). These echoes may remain promi~ nent as echoes are attenuated, so that echoes from the walls of the heart may disappear while the strong mitral valve echoes remain. However, the hallmark of mitral stenosis is the fusion of commissures of the mitral valve, which has, as its echocardiographic counterpart, the loss of the normal motion of the posterior leaflet of the mitral valve ECH OCAR DI OGRAPHY Fig. 3. Mitral valve echocardiogram from a patient with mitral stenosis. The echo shows (1) decreased E-F slope, (2) normal exclusion, and (3) diminutive A wave. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) 285 o Fig. 4. Mitral stenosis with heavily calcified, immobile valve, The echo shows (11 markedly increased thickness of mitral valve echoes and (2) decreased excursion indicating decreased mobility. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) in the direction opposite to the anterior leaflet. In mitral stenosis, the posterior leaflet of the mitral valve appears to move with the anterior leaflet 26 (Fig. 5). Whether this represents the posterior leaflet being pulled by the larger anterior leaflet, or whether it might represent a posterior leaflet that does not move at all, but that shows the motion of the mitral valve apparatus, is not clear. 3 The finding of a posterior leaflet that definitely moves independently in an opposite direction to the anterior leaflet during diastole appears to exclude the diagnosis of mitral stenosis. Another finding in 286 TEICHHOLZ -A .p Fig. 5. Echocardiogram in mitra| stenosis illustrating the motion of the posterior leaflet of the mitral valve (P), which moves with the anterior leaflet of the mitral valve (A). (From Teichholz LE" Echocardiography slide set, Tampa Tracings; by permission.) mitral stenosis is a diminished A wave when the patient is in normal sinus rhythm that is probably due to dilatation and poor contractile function of the left atrium (Fig. 3). The echocardiographic findings and their physiologic counterparts are summarized in Table 1. A study of the size of the left atrium is also helpful in patients with suspected mitral stenosis. The left atrial dimension is measured from the posterior aortic wall to the anterior portion of the left atrial wall at end-systole. The normal value is less than 2.2 cm/sq m. 27 This dimension has been shown to be correlated with angiographic findings and echocardiography appears to be the most accurate, noninvasive technique for the determination of left atrial size. Using this internal dimension, it has been found that patients with mitral stenosis usually have enlarged left atria (Fig. 6). The left atrium can also be examined by using the suprasternal approach in which the transducer is placed Table 1. Mitral Stenosis Echocardiogram A L M V and PLMV move together Decreased E-F slope Increased thickness of MV Decreased A wave Decreased amplitude of MV Anatomy or Physiology Fusion of commissures Decreased rate of LV filling Fibrosis and calcification Decreased atrial contraction Decreased mobility in a suprasternal notch and angled interiorly and to the left so that the beam passes through the arch of the aorta, the right pulmonary artery, and the left atrium. 28 This gives a left atrial dimension in a different plane and could supplement the information obtained from the standard position. Echocardiography of the mitral valve has been shown to be useful not only in the diagnosis and estimation of the severity of mitral stenosis but also as an adjunctive measure for determining the effects of mitral commissurotomy. The mitral valve velocity will increase significantly after valvuloptasty, and the motion of the mitral valve can be followed by echocardiography in postoperative patients, lo,23,29,34 The decreased E-F slope characteristic of mitral stenosis is presumably secondary to the decreased rate of left ventricular filling, which in turn is due to the fixed stenosis at, the mitral valve orifice. This finding, unfortunately, is not specific for mitral stenosis and is found in other conditions in which there is either (1) a decreased rate of left ventricular filling or (2) decreased flow across the mitral valve. This pattern has been called false or pseudomitral stenosis. 26 The decreased E-F slope has been found in varied groups of patients including those with aortic stenosis, coronary artery disease, idiopathic hypertrophic subaortic stenosis (IHSS), hypertensive cardiomyopathy with left ventricular hypertrophy, and pulmonary hypertension. All these conditions can be characterized by either a decreased volume of blood flow across the mitral ECH OCAR DI OG R APHY 287 i11 i~ Enlarged left atrium in a patient with severe mitral stenosis. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) 9 il I i ~: ....... - Fig. 6. valve, as in pulmonary hypertension, or as a decreased rate of flow across the mitral valve usually secondary to decreased left ventricular compliance. 3s The differentiation of these conditions from mitral stenosis requires a careful examination of the mitral valve echocardiographic pattern. The finding of a posterior leaflet that moves normally, i.e., independently of the anterior leaflet, supports the etiology as being other than mitral stenosis. Unfortunately, it is not possible in all cases to definitely record the posterior leaflet of the mitral valve. Other criteria that tend to support the diagnosis of a condition other than mitral stenosis is the finding of a normal A wave when the patient is in normal sinus rhythm and the finding of the mitral valve diastolic velocity greater than 50 mm/sec. Mixed Mitral Stenosis and Mitral Insufficiency In mixed lesions of mitral stenosis and mitral insufficiency, one may or may not see evidence of mitral insufficiency. 36 In some cases, even with the clinical findings of mitral insufficiency, one sees the echocardiographic pattern of pure mitral stenosis. 37 In many cases, the stenotic component will dominate; however, occasionally one can see the diastolic slope more rapid initially, then becoming slow 14'38 (Fig. 7). When this pattern is found, mixed mitral stenosis and insufficiency is suggested. -;: ,,J-! iJ i Isolated Mitral Insufficiency The pattern of mitral valve motion in mitral msufficiency can be varied depending on the etiology. 39 It was originally thought that in patients with mitral insufficiency, the anterior leaflet echoes showed increased excursion and increased diastolic velocity. 9'3~176 However, in our experience and the experience of others, this pattern has not been specific for mitral insufficiency but can be seen in any condition in which there is a hyperkinetic circulation with increased flow across the mitral valve, i.e., ventricular septal defect or a normal young person with a catecholamine drive. On occasion, we have seen such a finding in mitral insufficiency, but it is distinctly uncommon, and in the vast majority of patients with mitral insufficiency neither the excursion nor the velocity is increased. Recently, Millward et al. 42 discussed the finding of multiple systolic echoes in patients with cardiomyopathy.and mitral insufficiency and concluded that the finding of these multiple echoes during systole is indicative of mitral insufficiency. This has not been our experience. Frequently, these multiple echoes are seen in a patient with a dilated heart but without mitral insufficiency as determined by left ventricutar angiography. There are multiple echoes, but by moving the transducer, one can see, at a given position, systolic apposition of both the anterior and the posterior leaflet of the mitral valve. Such 288 TEICHHOLZ .= . . . . ~ , - ' ~ . . "' . ,: '- , ~ . . .-.. ,~, ;, ~ ,, ; ~ ~ a finding probably represents a dilated left ventricle with a greater opportunity for seeing larger portions of the leaflets of the mitral valve. The multiple echoes may be due to the fact that larger portions of the mitral valve can be seen by the relatively wide echo beam. Adjunctive measurements in the detection of mitral insufficiency consist of the finding of increased left atrial size or exaggerated left atrial motion. In many cases of acute mitral insufficiency where there has not been dilatation of the left atrium, a marked exaggera- .y - -,. ..:-~. -- " -,-. . - =.. . . . . . '~-..- Fig. 7. Combined mitral stenosis-mitral insufficiency with slow diastolic velocity and initially more rapid diastolic velocity due to the mitral insufficiency. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) tion of the motion of the posterior wall of the left atrium is seen 3 (Fig. 8). This tends to disappear as the left atrium dilates. In addition, as in aortic insufficiency, there tends to be a hyperdynamic left ventricular motion pattern seen especially in the interventficular septum with an increased ejection fraction. 43 There are, however, certain abnormalities of the mitral valve that may be associated with mitral insufficiency in which the echocardiogram is much more helpful. These will be discussed in subsequent sections. -7-- Fig. 8. Two examples of hyperdynamic motion of the left atrial wall (moving posteriorly in systole) behind the mitral valve secondary to acute severe mitral insufficiency. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) ECH OCAR DI OG RAPH Y 289 /A Fig. 9. Two echocardiograms showing Barlow's syndrome with systolic separation of anterior and posterior leaflets of mitra| valve. (A) Late systolic prolapse. (B) Holosystolic prolapse. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) Barlow's Syndrome It is becoming evident that Barlow's syndrome is a very common disorder. 44 This is a syndrome consisting of a mid-systolic click with or without late systolic murmur. The pathophysiology is that of a redundant mitral valve with ballooning of the leaflets, usually during mid-systole. Pathologically, these valves show myxomatous degeneration. Echocardiography has proved to be a sensitive and specific technique for the detection of this abnormality. 4s'46 There is abnormal motion of the mitral valve in early or mid-diastole with separation of leaflets at some point during systole accounting for the mitral insufficiency. Usually, this abnormality affects both leaflets. The echocardiographic finding of posterior leaflet prolapse is much more dramatic than that of the anterior leaflet but unfortunately harder to find. The echocardiographic abnormality is characterized by an abnormal systolic posterior motion of the anterior and posterior leaflets. The anterior leaflet usually shows discrete posterior motion, flat motion, or a hammockshaped deformity. The posterior leaflet shows either a late systolic prolapse, or, on occasion, holosystolic prolapse. 47 Since there is redundancy in the mitral valve itself, there are usually multi- 290 - Z ~ Z _ ~ - - - - - ~ - Z - _ Z - - - - - TEICHHOLZ . . . . . . - . . . . i . . . . •--z- i ;lli!ltliil!iill iiiillf!! i Fig. 10. Echocardiogram from a patient with ruptured chordae to anterior leaflet of mitral valve. Multiple systolic echoes and increased excursion a r e demonstrated. (From ~ Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) ple diastolic and systolic echoes recorded. Examples of Bartow's syndrome are seen in Figs. 9A and B. This abnormality of the mitral valve has been found to be frequent in patients with Marfan's syndrome, pectus excavatum without Marfan's syndrome, and recently patients with secundum atrial septal defects. With lesser degrees of abnormality, the detection may be more difficult. In our own experience, the abnormality may not be detected on all portions of the valve. The abnormal motion tends to be most prominent when the beam is po!nting in the area of the AV groove. Therefore, if one suspects this abnormality, one must explore the valve very carefully to pick up the abnormal motion pattern. Sometimes, it is necessary to change the position of the patient, i.e., record in the left lateral decubitus position or with the patient sitting up. On occasion, amyl nitrite will bring out a latent abnormality in the valve. Ruptured Chordae-Flail Valve The pattern seen in ruptured chordae of the mitral valve is dependent on which leaflet is involved. In rupture of the anterior leaflet, 48'49 two findings can usually be noted: (1) coarse erratic motion of the mitral valve during diastole, and (2) multiple echoes in systole occurring over a wide portion of the leaflet (Fig. 10). In a few cases, a notch has been reported on the echo immediately after the E point. 3 Posterior ruptured chordae 48-s~ has been associated with marked exaggerated motion of the posterior leaflet in systole and during diastole. The posterior leaflet moves anteriorly, may display fluttering, and stays in midposition until the onset of systole. Occasionally, if there is only a small portion of flail valve, certain areas of the valve may look relatively normal, while others will show an abnormal pattern of motion. In some cases, the flail leaflet has been shown to be in the left atrial cavity in the position where one records the aortic root and the left atrium. In many cases, the rupture of chordae is of recent origin, and, therefore, the left atrium has not dilated but, rather, shows a hyperdynamic motion pattern. In our experience, there is an increased incidence of ruptured chordae in patients in whom the underlying echocardiographic motion pattern of the mitral valve is consistent with that of Barlow's syndrome. Papillary Muscle Dysfunction Talburg et al. 41 have discussed the echocardiographic findings of papillary muscle dysfunction and have commented on an increased excursion and an increased diastolic velocity in this disorder 9 We have been unable to confirm these findings in our laboratory, s2 Although one may occasionally see an increased excursion and velocity in papillary muscle dysfunction, other findings include a low-amplitude systolic bulge seen on the anterior leaflet of the mitral valve in association with a normally sized left ventricular outflow tract. However, in our opinion, none of these findings is specific, and, in the majority of cases, no abnormality ECHOCARDIOGRAPHY 291 AAO AV Fig. 11. Normal aortic root and valve cusps. (AAO) Anterior aortic wall. (AV) Aortic valve cusps. (PAO) Posterior aortic wall. (From Teichholz LE: Echocardiography Tampa Tracings; by permission.) slide set, 9 , .' . , . . . . . J . - . seen. 14 The anterior cusp is the right coronary cusp, the posterior, the noncoronary cusp. The left coronary cusp is not in the plane of the transducer and thus is not visualized. 14 of mitral valve motion may be detected; in fact, some patients may show a decreased E-F slope secondary to decreased left ventricular compliance. AORTIC VALVE Normal Aortic Valve and Root Aortic Stenosis The anatomy of the normal aortic root and valve has been described, s3-s7 The normal aortic root shows two parallel-moving echos with a dimension measured in systole of less than 2.2 cm/sq m. With proper angulation of the transducer, one can visualize inside the root the fine, boxlike structures of the aortic valve cusps-opening at the beginning of systole and closing at the end of systole (Fig. 11). Occasionally, a fine fluttering motion can be The detection of aortic valve disease by diagnostic ultrasound is much more difficult technically and the data somewhat less reliable than in the study of mitral valve disease. Dilatation of the aortic root is detected by an increased width of aortic root echoes (aortic root >2.2 cm/sq m). Calcification shows up as thick multiple echoes within the root s3,s4,58 (Fig. 12). In a heavily calcified valve, it may be impossible to obtain a 9 . , . . . . . . i . Fig. 12. Calcification in aortic valve and root. Echo shows multiple echoes within the root that persist on the echoes are progressively attenuated. The normal aortic cusp motion is not seen. 2.92 ,v , TEICHHOLZ 9 Fig. 13. Mild aortic stenosis. The aortic valve cusps are visualized and show decreased excursion. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) good picture of the valve leaflets, and the normal boxlike motion may be obscured. If two fine, mobile cusps are visualized in adults with acquired aortic stenosis, aortic stenosis with a significant gradient can be excluded. 3 The average separation o f the cusps during systole in normals was 1.9 cm with a range of 1.6-2.6 cm. Recently, it has been shown that if this orifice diameter is less than 0.6 cm, this would be associated with a gradient greater Fig. 14. Aortic root and valve from a patient with bicuspid aortic valve. The upper and lower arrows point to the walls of the aortic root. The middle arrow points to the diastolic echo of the aortic valve, which is eccentrically placed. than 55 mm Hg. If the measurement, however, were between 1.3 and 2.0 cm, this would be associated with a gradient less than 35 mm Hg. s9 Figure 13 shows a patient with mild aortic stenosis with decreased aortic valve excursion. However, it ,should b e noted that decreased excursion of the aortic valve may also be seen in conditions other than aortic stenosis, most notably those with low cardiac output states, s9 In congenital aortic ste- ECHOCAR DIOG R APHY nosis, there can be a significant gradient with (1) a lack of calcium in the aortic valve or root and (2) relatively normal aortic valve motion. Echocardiography, therefore, has not been found to be useful in this condition. However, bicuspid aortic valve has recently been diagnosed by the use of ultrasound using the criteria of a large asymmetrically placed cusp with marked eccentricity of the aortic valve cusp echoes in diastole with multilayered diastolic echoes 6~ (Fig. 14). Echocardiography has also been helpful in evaluating the effects of systolic overload on the left ventricle as related to the development of increased thickness of the walls of the left ventricle. The determination of left ventricular wall thickness is accurate and can be correlated with direct measurements of wall thickness of postmortem specimens. 61'6s Aortic Insufficiency The diagnosis of aortic insufficiency rests not with the examination of the aortic valve but rather with examination of the mitral valve, since generally there are no characteristic findings of aortic valve motion that suggest a diagnosis of aortic insufficiency. The useful finding in aortic insufficiency is a rapid, high-frequency fluttering of the mitral valve 66-68 (Fig. 15). The mechanism for this fluttering is presumably the same as that offered to explain the Austin-Flint murmur in this condition. 69'7~ The leak through the aortic valve causes blood to strike the anterior leaflet of the mitral valve and set it in motion. In some cases, fluttering of the posterior leaflet of the mitral Fig. 15. Mitra| valve echocardiogram from a patient with aortic insufficiency. There is marked high frequency "fluttering" of the anterior leaflet of the mitral valve during diastole. 293 valve, in addition to the anterior leaflet, may be noted. This finding can occasionally be found in patients in whom the murmur of aortic insufficiency is not appreciated. If the mitral valve is thickened and not sufficiently pliable to vibrate, as in mitral stenosis, the finding may be absent; however, we have seen this fluttering pattern in patients with mild stenosis. This rapid fluttering should be distinguished from the slower frequency of fluttering in atrial fibrillation 71 (Fig. 16) and the chaotic fluttering of a flail anterior leaflet of the mitral valve. Fluttering similar to that seen in aortic insufficiency has been seen in patients with ventricular septal defects and right-to-left shunts. In some cases of aortic insufficiency, the E-F slope is decreased. The explanation for the decreased slope is probably related to a decrease in left ventricular compliance. In many patients, there is a question of combined valvular disease; i.e., aortic insufficiency in association with mitral stenosis. The murmur of aortic insufficiency may be heard, as well as a diastolic rumble that could represent mitral stenosis or the Austin-Flint murmur. The echocardiogram may be very helpful in the differentiation of these two conditions by the use of the following criteria: (1) In aortic insufficiency without mitral stenosis, the A wave of the anterior leaflet of the mitral valve tends to be preserved in contrast to the findings observed in mitral stenosis. (2) The mitral valve diastolic velocity (E-F slope) is usually greater than 50 mm/sec in aortic insufficiency, while in mitral slenosis values of less than 50 mm/sec, usually less than 35 mm/sec, are seen. 294 TEICHHOLZ Fig. 16. L o w frequency oscillation o f mitral valve secondary to fibrillatory waves from a patient with atrial fibrillation w i t h o u t intrinsic mitral valve disease. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) If there is an increase in the left ventricular enddiastolic pressure, one may also see a notch on the A-C slope 72 (Fig. 17). This has been reported in various conditions, and we have frequently seen this finding in patients with aortic insufficiency. A helpful adjunct to the diagnosis of aortic insufficiency is the finding of a dilated hyperdynamic left ventricle secondary to the left ventricular volume overload. ~3 In acute, severe aortic insufficiency, occasionally there is premature closure of the mitral valve that can be detected on the echocardiogram. In this case, the mitral valve becomes fully closed before the onset of the QRS complex. 68 Fig. 17. Mitral valve echo from a patient with increased left ventricular end diastolic pressure. The "notch" on the A - C slope is indicated in the last complex by the' arrow 9 (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) TRICUSPID VALVE The normal tricuspid valve has a motion pattern similar to that of the mitral valve 29 (Fig. 18). The posterior septal cusp is difficult to visualize. It is very difficult to record the entire motion of the tricuspid valve in normal subjects, and if one easily records a tricuspid valve, this usually indicates right ventricular enlargement. Tricuspid stenosis can sometimes be diagnosed by the finding of a decrease in the E-F slope of the tricuspid valve. 9'29"74 However, just as in the case ofmitral valve disease, this is not specific for tricuspid stenosis and can also be seen in other processes that cause a decreased filling rate of the right yen- ECHOCAR DI OGRAPH Y 295 liiiiilil,,tliiidli,,ii lidlilii !!, , Cl llllllll!ll!tll.llll,,lll!ll!llllill - Fig. 18. Normal tricuspid valve. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.} " - - - . . . . . . " ~---ZCZ-=-- ii tricle) 4 Fluttering of the tricuspid valve has been reported in pulmonic insufficiency, 14'75 and rapid diastolic slopes have been recorded in tricuspid insufficiency. ~4 In addition, with right ventricular diastolic overload, one will see an increased right ventricular internal dimension measured from the anterior wall of the right ventricle to the right ventricular side of the interventricular septum and a paradoxical septal motion in which the septum during systole moves anteriorly toward the right ventricle rather than posteriorly towards the posterior wall of the left ventricle. This finding is seen in tricuspid ino sufficiency. ~6 In patients with valvular or other cardiac disease and an increased RVEDP, an echocardiogram showing a notch on the A-C slope of the tricuspid valve may be recorded. In addition, patterns with an A wave greater than the E point and with decreased C-D slope may be recorded in patients with an elevated initial diastolic pressure. No discussion of the tricuspid valve would be complete without some comments on Ebstein's anomaly] 7-8~ In the presence of Ebste~,n's anomaly, the tricuspid valve is usually found further to the left of the sternum, and the beam must, therefore, be oriented in that direction. Significant echocardiographic findings in Ebstein's anomaly of the tricuspid valve are: (I) large excursion of the tricuspid valve; (2) decreased E-F slope; (3) delayed closure of the tricuspid valve; and (4) abnormal paradoxical septal motion. It should be noted that the delayed closure of the tricuspid valve has been seen in patients with Ebstein's anomaly with or without type B Wolff-Parkinson-White syndrome and thus appears to be associated with the delayed component of the first heart sound rather than the conduction abnormality. PULMONIC VALVE Gramiak et al. 81 have discussed the normal anatomy and physiology of the pulmonic valve and the normal echocardiographic patterns. This valve is particularly difficult to study in adults. Although there have been some preliminary findings of valvular abnormalities in pulmonic stenosis and in pulmonary hypertension, 3 the number of instances in which this valve can be appreciated in adults is small enough to make it less useful diagnostically. PROSTHETIC VALVES Characteristic echocardiographic patterns have been reported from various types of cardiac prostheses. 82-9s In general, parallel echoes from the cage and sewing ring are seen with superimposed motion of the poppet when the transducer is positioned along the axis of motion. When there is a silastic ball as the poppet, it may appear to be larger than the actual valve itself because the speed of sound is slower by a factor of 0.64 in silastic. 96 The prosthetic aortic valve has been found to be much more difficult to record than the prosthetic mitral valve, due in part to the orientation of the valve in the chest wall. Malfunction of prosthetic valves have been reported as characterized by a 296 TEICHHOLZ ." ..,~, 7" . t . . . . . \ 9 .,,~ . " '~, 9 ,~ ' ," " ~ Fig. 19. Porcine (heterograft) valve prosthesis in the mitral position. The transducer was swept from the aortic root (on the left} to the prosthesis (on the right}. The motion of one of the valve cusps can be seen within the sewing ring of the prosthesis. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) limitation of excursion, reduction in the velocity of the poppet motion, or inconsistent motion pattern of the poppet. 97'9a Fungal vegetations have been identified 99 as well as decreased motion secondary to clot a~176 and excessive rocking motion due to loss of support of the suture line. ~~ Recently, stented fascia lala grafts have been studied, x~ and we have looked at porcine mitral valves; the patterns seen in these patients represent a structure similar to a double aortic root and motion o f the porcine valve cusps can sometimes be visualized (Fig. 19). Of interest is the finding of abnormal septal motion in a large proportion of patients with either an aortic or a mitral valve prosthesis. ~~ The nature o f this abnormal motion is not clear at this time. This does not appear to be related to tricuspid insufficiency and may disappear with time after surgery. Combined use o f echocardiography and phonocardiography should allow one to follow serially individual patients with prosthetic valves and hopefully allow one to diagnose at an early stage manifestations of prosthetic valvular dysfunction. MISCELLANEOUS CONDITIONS Idiopathic Hypertrophic Subaortic Stenosis (IHSS} Echocardiography has proved to be a sensitive method for the diagnosis of idiopathic hypertrophic subaortic stenosis (IHSS). 1~176 The earliest description of the echocardiographic ab- normalities in IHSS was that of abnormal motion of the anterior leaflet of the mitral valve (ALMV). l~176 The ALMV forms one side of the outflow tract of the left ventricle with the interventricular septum (IVS) forming the other boundary. In IHSS, there is a decrease in the outflow tract size, i.e., the distance between the ALMV and IVS. In addition, in IHSS with obstruction there is an abrupt systolic anterior motion of this leaflet (SAM) (Figs. 20A and B). The duration and extent of abnormality appears to be related to the severity of obstruction, m'112 This abnormality is lacking in patients without obstruction, but can be induced by maneuvers that increase the gradient such as the Valsalva maneuver, isoproterenol infusion, or inhalation of amyl nitrite.~~ ms,l~o The effect of propanolol therapy on SAM has been inconstantvarious groups reporting correction of this abnormality, 6'1~ while others have found no effect despite abolition or reduction of the gradient. ~~ Ventriculotomy has been shown to abolish both the gradient and the SAM in the majority of patients, mS'1~~ although this has not been seen by other observers. 112 Although the SAM is an important diagnostic finding in IHSS, care must be exercised to examine the tip of the ALMV because a form of systolic anterior movement can be seen in normals if one examines the ALMV in a position close to the mitral annulus. 6'11~ This is especially common in patients with hyperdynamic left ventricular motion with increased excursion of posterior wall and mitral annulus. This "systolic ECHOCARDIOGRAPHY 297 A Fig. 20. Two examples of abnormal mitral valve motion in IHSS. Both show the systolic anterior motion (SAM) of the anterior leaflet of the mitral valve and decreased E-F slope. B also shows a notch on the A-C slope secondary to increased left ventricular enddiastolic pressure. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) J, * B hump" can be distinguished from the SAM of IHSS by taking care to examine the tip of the ALMV, which is usually at a position where the posterior leaflet is also visualized. Secondly, in IHSS there is abrupt posterior motion of the ALMV prior to diastole, while the annular motion blends into the diastolic opening motion of the ALMV. Other abnormalities of the mitral valve seen in IHSS are a decrease in the E-F slope secondary to decreased left ventricular compliance 1~176176 (Figs. 20A and B) and, occasionally, a notch on the A-C slope in the presence of an increased left ventricular end-diastolic pressure. In most cases, ? ~ N '; " ~* "' ~ '* "" the ALMV appears to touch the IVS in early diastole, but this finding is not specific for IHSS and is seen in some patients with small or hyperdynamic left ventricles. Examination of the aortic root and valve cusps in patients with significant left ventricular outflow obstruction shows an abnormal pattern of motion of the aortic valve cusps, s'11~ There is normal initial opening followed by mid-systolic reopening. This finding has as its counterparts the mid-systolic dip in the carotid pulse tracing and the double apical systolic impulse. However, the echocardiographic finding that is 298 TEICHHOLZ ... :. t .'.. ,, i" . "., i , i;. ,.;' 9 9 Fig. 21. Asymmetric septal hypertrophy (ASH) in a patient with I HSS. The ratio of the thickness of the interventricular septum (IVS) to the posterior wall (PWLV) is approximately 13:1. (From Teichholz LE: Echocardiography slide set, Tampa Tracings; by permission.) the most sensitive indicator of this disease is asymmetric septal hypertrophy 114-117 (Fig. 21), i.e., hypertrophy of the IVS so that the ratio of IVS thickness/posterior wall thickness is greater than 1.2/1. This finding may be found in patients without left ventricular outflow obstruction and in asymptomatic relatives of patients with IHSS] Is To avoid artifacts care must be taken to record and make measurements of the thickness of the IVS and posterior wall in the position just below the mitral valve. Recently, it has been suggested that ASH is not absolutely specific for IHSS but may be found in patients with right ventricular systolic overload as wellJ 19 The study of IHSS by echocardiography has not only been of aid in the diagnosis but has also aided in the study of the pathophysiology of this disorder. Recently, study of the IVS and ALMV in IHSS by B-scan ultrasonography lz~ has clearly demonstrated the displacement of the mitral valve anteriorly toward the IVS, probably as a result of abnormal orientation of the papillary muscles secondary to the left ventricular distortion caused by the marked septal hypertrophy. Subacute Bacterial Endocarditis Echocardiography has recently been used to detect involvement of specific valves with vegetations secondary to subacute bacterial endocarditis.12~' 122 In these studies, vegetations were felt to be detected on valves if these vegetations were greater than 2 mm in diameter. Further work is necessary to confirm and extend these observations. A trial M y x o ma Left atrial myxomas are usually pedunculated tumors arising from the interatrial septum, which may prolapse and obstruct the mitral valve orifice. Echocardiography has proved to be a very useful tool in the diagnosis of this disorderJ 23-~a7 Since each tumor is different in size, shape, location, and mobility, it is not surprising that the echocardiographic manifestations may be markedly varied. Usually, one sees multilayered, usually parallel echoes behind the mitral valve in diastole as the tumor prolapses into the mitral orifice. In some cases, the multiple echoes may also be seen in systole. Because of the obstruction to left atrial emptying and left ventricular filling caused by the tumor, there is also a decrease in the E-F slope. Although the use of echocardiography in the detection of left atrial myxoma has proved to be extremely useful, care must be taken to adjust the sensitivity or gain setting carefully in order to obtain adequate echocardiograms. The sensitivity should not be so high as to introduce artifacts. In addition to examining the echoes of the mitral valve, the left atrial cavity behind the aortic root ECH OCAR DI OG RAPHY 299 should be examined carefully so as to visualize the echoes behind the mitral valve, and the absence of abnormal echoes in the left atrium behind the aortic root make the diagnosis of left atrial myxoma doubtful. Right atrial myxomas have also been studied using ultrasound. 138-14~ SUMMARY Echocardiography is a useful new technique that allows for the diagnosis and assessment of the severity of various forms of valvular heart disease. It is a safe and noninvasive procedure that can readily be used on the critically ill as well as the ambulatory patient. 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