SYSTOLIC ANTERIOR MOTION OF THE TRICUSPID VALVE IN IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS by Henry Brik, MD; Jose Meller, MD; Alan S. Bahler, MD; Michael V. Herman, MD and Louis E. Teichholz, MD
ABSTRACT A 37 year old man with combined subpulmonic and subaortic idiopathic hypertrophic stenosis proved by cardiac catheterization had typical echocardiographic findings of idiopathic hypertrophic subaortic stenosis (IHSS) and systolic anterior motion of the anterior leaflet of the tricuspid valve. This motion of the tricuspid valve may relate' to the subpulmonic infundibular gradient in the same way that the systolic anterior motion of the anterior mitral leaflet relates to the subaortic left ventricular gradient in patients with IHSS. INTRODUCTION
Idiopathic hypertrophic subaortic stenosis (IHSS), or hypertrophic obstructive cardiomyopathy, may affect the right side as well as the left side of the heart (1,2). Although echocardiographic studies of the interventricular septum and mitral valve motion have been very useful in the study of left-sided hypertrophic subaortic stenosis, to date there have been no studies of echocardiographic abnormalities that might occur on the right side of the heart in the presence of right ventricular outflow obstruction due to IHSS. This report describes echocardiographic evidence of systolic anterior motion of the tricuspid valve in a patient with both leftand right-sided outflow obstruction secondary to hypertrophic cardiomyopathy and its possible physiopathologic mechanism. CASE REPORT
History: A 37 year old man was admitted to the Mount Sinai Hospital because of left-sided seizures with loss of consciousness one day before admission. The patient had had a heart murmur since age 14. Repeated cardiac catheterizations showed a left- and right-ventricular outflow obstruction. A right ventricular angiogram done during one catheterization study showed subpulmonic infundibular stenosis and a normal From the Division of Cardiology, Department of Medicine. Mount Sinai School of Medicine, New York, N Y . Received August 30. 1977; revision accepted January 5 , 1978. For reprints contact: Jose Meller. M.D., Division of Cardiology. The Mount Sinai Hospital, Fifth Avenue and 100th Street, New York. N Y 10029. JCU, Vol. 6. 73-142 (1978),@1978, John Wiley and Sons, Inc., 0091-2751 178/0006-012 1 $01.OO.
pulmonic valve. A 48 mmHg gradient in the left ventricular outflow tract and a 5 t o 10 mmHg right ventricular subpulmonic infundibular gradient were found at rest and without therapy. Because of dyspnea on exertion, he was given digoxin at age 31. He did well until one day before admission, when he had an episode of leftsided seizures and transient loss of consciousness. A review of the family history showed that a first cousin had died at age 39 with IHSS. The positive findings on physical examination were related t o the cardiovascular system. The heart was enlarged, with a prominent left ventricular heave. The rhythm was irregularly irregular. A coarse, grade 3/6 systolic ejection murmur was heard loudest in the second left intercostal space, radiating t o the rest of the precordium, and increasing with the Valsalva maneuver. The rest of the examination was unremarkable. The electrocardiogram revealed atrial fibrillation with a ventricular rate of 80/min, and electrical axis of +150",tall R waves in leads V1 and V2 with equiphasic RS complexes in leads V2 to V5, and nonspecific ST segment and T wave changes. The chest xray showed marked enlargement of the heart without pulmonary congestion. The echocardiogram showed a thick, hypodynamic interventricular septum with an interventricular septum-to-posterior left ventricular wall ratio of 20:12 mm and systolic anterior motion of the mitral valve consistent with IHSS (Fig. 1). The right ventricle was slightly enlarged and the tricuspid valve aisclosed systolic anterior motion of the anterior leaflet of the tricuspid valve (Fig. 2). 121
FIGURE 1. Echocardiogram showing asymmetric septa1 hypertrophy and systolic anterior m o t i o n of the anterior mitral leaflet (arrows). I V S = interventricular septum; M V = mitral valve; LVPW = left ventricular posterior wall.
FIGURE 2 . Echocardtogram showing systolic anterior m o t i o n (arrows) o f the anteri3r leaflet o f the tricuspid valve ( T V ) .
DISCUSSION
Although right-sided hypertrophic subpulmonic stenosis has been reported in patients with IHSS, its pathology or pathophysiology has not been well characterized. The finding of systolic anterior motion of the anterior leaflet of the tricuspid valve in this patient with rightsided ventricular outflow obstruction and leftsided ventricular outflow obstruction suggests that hemodynamic and hydrodynamic principles similar to those that determine systolic anterior motion in the left side of the heart may also be possible on the right side of the heart, despite the marked difference in anatomy. The reason for the systolic anterior motion of the anterior mitral leaflet in IHSS may be a Venturi effect during rapid ventricular ejection which 122
F I G U R E 3. Schematic drawing o f the normal relationship between tricuspid leaflets and right ventricular o u t f l o w tract, and between mitral leaflets and left ventricular o u t f l o w tract ( A ) . In IHSS, (61, functional obstruction o f the right ventricular o u t f l o w tract i s produced b y systolic anterior m o t t o n ( S A M ) of the anterior tricuspid leaflet ( A L T V ) toward the anterior wall of the right ventricle ( A W R V ) . The left ventricular o u t f l o w obstruction is caused b y systolic anterior m o t i o n o f t h e anterior mitral leaflet ( A L M V ) toward t h e septum ( I V S ) .
will suck a portion of the mitral valve into the outflow tract of the left ventricle in patients who have abnormal displacement of the mitral valve ( 4 ) . Support for this postulate has recently been reported using B scan ultrasonography (5) and real time scanning (6). The subpulmonic J O U R N A L O F CLINICAL ULTRASOUND
functional obstruction in patients with rightsided hypertrophic subpulmonic stenosis would be caused by the suction of the anterior leaflet of the tricuspid valve toward the right ventricular anterior wall during right ventricular ejection, as seen in the diagram in Figure 3. The reason for the systolic anterior motion of the anterior tricuspid leaflet toward the anterior right ventricular wall, while the anterior mitral leaflet moves anteriorly toward the septum in systole, seems to be the different pathway for the blood flow from ventricular inflow to outflow in each ventricle (Fig. 3). Systolic anterior motion of the mitral valve in the absence of IHSS has been described (7,8). It can occur in the absence of obstruction, probably related t o a small left ventricle or left ventricular outflow with apposition of the anterior leaflet of the mitral valve t o the septum. It can also occur with a hypercontractile ventricle with rapid blood flow. It is possible that these conditions may occur in IHSS, involving the right ventricle and pulling the anterior leaflet of the tricuspid valve toward the free wall of the right ventricle. The sensitivity or specificity of the systolic anterior motion of the tricuspid valve in “right-sided IHSS” is unclear a t this time. Larger series of echocardiographic studies in patients with right-sided ventricular obstruction will be required t o prove the utility of this observed phenomenon and to determine whether it can aid in the diagnosis of this syndrome.
VOLUME 6 . NUMBER 2,1978
REFERENCES 1. Braunwald E, Morrow AG, Cornell WD, et al: Idiopathic hypertrophic subaortic stenosis: Clinical, hemodynamic and angiographic manifestations. Am J Med 29:924,1960. 2. Braunwald E, Brockenbrough EC, Morrow AG: Hypertrophic subaortic stenosis-A broadened concept. Circulation 26:161,1962. 3. Braunwald E, Lambrew CT, Rockoff et al: Idiopathic hypertrophic subaortic stenosis. A description of the disease based upon an analysis of 64 patients. Circulation 30 (Suppl 4): 3,1964.
4. Wigle ED, Adelman AG, Silver MD: Pathophysiological considerations in muscular subaortic stenosis. In Ciba Foundation Symposium: Hypertrophic obstructive cardiomyopathy, p. 63, 1971. Ed. by GEW Wolstenholme, M O’Conner, J and A Churchill, London. 5. Cohen MV, Teichholz LE, Gorlin R: B scan ultrasonography in idiopathic hypertrophic subaortic stenosis. Br Heart J 38:595,1976. 6. Henry WL, Clark CE, Griffith JM, e t al: Mechanism of left ventricular outflow obstruction in patients with obstructive asymmetric septal hypertrophy (idiopathic hypertrophic subaortic stenosis). Am J Cardiol 35:337.1975. 7. Bulkley BH, Fortuin NJ: Systolic anterior motion of the mitral valve without asymmetric septal hypertrophy. Chest 69:694, 1976.
8. Mintz GS, Kotler MN, Segal BL, et al: Systolic anterior motion of the mitral valve in the absence of asymmetric septal hypertrophy. Circulation 53-54 (Suppl 11): 191,1976.
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ABSTRACT A 37 year old man with combined subpulmonic and subaortic idiopathic hypertrophic stenosis proved by cardiac catheterization had typical echocardiographic findings of idiopathic hypertrophic subaortic stenosis (IHSS) and systolic anterior motion of the anterior leaflet of the tricuspid valve. This motion of the tricuspid valve may relate' to the subpulmonic infundibular gradient in the same way that the systolic anterior motion of the anterior mitral leaflet relates to the subaortic left ventricular gradient in patients with IHSS. INTRODUCTION
Idiopathic hypertrophic subaortic stenosis (IHSS), or hypertrophic obstructive cardiomyopathy, may affect the right side as well as the left side of the heart (1,2). Although echocardiographic studies of the interventricular septum and mitral valve motion have been very useful in the study of left-sided hypertrophic subaortic stenosis, to date there have been no studies of echocardiographic abnormalities that might occur on the right side of the heart in the presence of right ventricular outflow obstruction due to IHSS. This report describes echocardiographic evidence of systolic anterior motion of the tricuspid valve in a patient with both leftand right-sided outflow obstruction secondary to hypertrophic cardiomyopathy and its possible physiopathologic mechanism. CASE REPORT
History: A 37 year old man was admitted to the Mount Sinai Hospital because of left-sided seizures with loss of consciousness one day before admission. The patient had had a heart murmur since age 14. Repeated cardiac catheterizations showed a left- and right-ventricular outflow obstruction. A right ventricular angiogram done during one catheterization study showed subpulmonic infundibular stenosis and a normal From the Division of Cardiology, Department of Medicine. Mount Sinai School of Medicine, New York, N Y . Received August 30. 1977; revision accepted January 5 , 1978. For reprints contact: Jose Meller. M.D., Division of Cardiology. The Mount Sinai Hospital, Fifth Avenue and 100th Street, New York. N Y 10029. JCU, Vol. 6. 73-142 (1978),@1978, John Wiley and Sons, Inc., 0091-2751 178/0006-012 1 $01.OO.
pulmonic valve. A 48 mmHg gradient in the left ventricular outflow tract and a 5 t o 10 mmHg right ventricular subpulmonic infundibular gradient were found at rest and without therapy. Because of dyspnea on exertion, he was given digoxin at age 31. He did well until one day before admission, when he had an episode of leftsided seizures and transient loss of consciousness. A review of the family history showed that a first cousin had died at age 39 with IHSS. The positive findings on physical examination were related t o the cardiovascular system. The heart was enlarged, with a prominent left ventricular heave. The rhythm was irregularly irregular. A coarse, grade 3/6 systolic ejection murmur was heard loudest in the second left intercostal space, radiating t o the rest of the precordium, and increasing with the Valsalva maneuver. The rest of the examination was unremarkable. The electrocardiogram revealed atrial fibrillation with a ventricular rate of 80/min, and electrical axis of +150",tall R waves in leads V1 and V2 with equiphasic RS complexes in leads V2 to V5, and nonspecific ST segment and T wave changes. The chest xray showed marked enlargement of the heart without pulmonary congestion. The echocardiogram showed a thick, hypodynamic interventricular septum with an interventricular septum-to-posterior left ventricular wall ratio of 20:12 mm and systolic anterior motion of the mitral valve consistent with IHSS (Fig. 1). The right ventricle was slightly enlarged and the tricuspid valve aisclosed systolic anterior motion of the anterior leaflet of the tricuspid valve (Fig. 2). 121
FIGURE 1. Echocardiogram showing asymmetric septa1 hypertrophy and systolic anterior m o t i o n of the anterior mitral leaflet (arrows). I V S = interventricular septum; M V = mitral valve; LVPW = left ventricular posterior wall.
FIGURE 2 . Echocardtogram showing systolic anterior m o t i o n (arrows) o f the anteri3r leaflet o f the tricuspid valve ( T V ) .
DISCUSSION
Although right-sided hypertrophic subpulmonic stenosis has been reported in patients with IHSS, its pathology or pathophysiology has not been well characterized. The finding of systolic anterior motion of the anterior leaflet of the tricuspid valve in this patient with rightsided ventricular outflow obstruction and leftsided ventricular outflow obstruction suggests that hemodynamic and hydrodynamic principles similar to those that determine systolic anterior motion in the left side of the heart may also be possible on the right side of the heart, despite the marked difference in anatomy. The reason for the systolic anterior motion of the anterior mitral leaflet in IHSS may be a Venturi effect during rapid ventricular ejection which 122
F I G U R E 3. Schematic drawing o f the normal relationship between tricuspid leaflets and right ventricular o u t f l o w tract, and between mitral leaflets and left ventricular o u t f l o w tract ( A ) . In IHSS, (61, functional obstruction o f the right ventricular o u t f l o w tract i s produced b y systolic anterior m o t t o n ( S A M ) of the anterior tricuspid leaflet ( A L T V ) toward the anterior wall of the right ventricle ( A W R V ) . The left ventricular o u t f l o w obstruction is caused b y systolic anterior m o t i o n o f t h e anterior mitral leaflet ( A L M V ) toward t h e septum ( I V S ) .
will suck a portion of the mitral valve into the outflow tract of the left ventricle in patients who have abnormal displacement of the mitral valve ( 4 ) . Support for this postulate has recently been reported using B scan ultrasonography (5) and real time scanning (6). The subpulmonic J O U R N A L O F CLINICAL ULTRASOUND
functional obstruction in patients with rightsided hypertrophic subpulmonic stenosis would be caused by the suction of the anterior leaflet of the tricuspid valve toward the right ventricular anterior wall during right ventricular ejection, as seen in the diagram in Figure 3. The reason for the systolic anterior motion of the anterior tricuspid leaflet toward the anterior right ventricular wall, while the anterior mitral leaflet moves anteriorly toward the septum in systole, seems to be the different pathway for the blood flow from ventricular inflow to outflow in each ventricle (Fig. 3). Systolic anterior motion of the mitral valve in the absence of IHSS has been described (7,8). It can occur in the absence of obstruction, probably related t o a small left ventricle or left ventricular outflow with apposition of the anterior leaflet of the mitral valve t o the septum. It can also occur with a hypercontractile ventricle with rapid blood flow. It is possible that these conditions may occur in IHSS, involving the right ventricle and pulling the anterior leaflet of the tricuspid valve toward the free wall of the right ventricle. The sensitivity or specificity of the systolic anterior motion of the tricuspid valve in “right-sided IHSS” is unclear a t this time. Larger series of echocardiographic studies in patients with right-sided ventricular obstruction will be required t o prove the utility of this observed phenomenon and to determine whether it can aid in the diagnosis of this syndrome.
VOLUME 6 . NUMBER 2,1978
REFERENCES 1. Braunwald E, Morrow AG, Cornell WD, et al: Idiopathic hypertrophic subaortic stenosis: Clinical, hemodynamic and angiographic manifestations. Am J Med 29:924,1960. 2. Braunwald E, Brockenbrough EC, Morrow AG: Hypertrophic subaortic stenosis-A broadened concept. Circulation 26:161,1962. 3. Braunwald E, Lambrew CT, Rockoff et al: Idiopathic hypertrophic subaortic stenosis. A description of the disease based upon an analysis of 64 patients. Circulation 30 (Suppl 4): 3,1964.
4. Wigle ED, Adelman AG, Silver MD: Pathophysiological considerations in muscular subaortic stenosis. In Ciba Foundation Symposium: Hypertrophic obstructive cardiomyopathy, p. 63, 1971. Ed. by GEW Wolstenholme, M O’Conner, J and A Churchill, London. 5. Cohen MV, Teichholz LE, Gorlin R: B scan ultrasonography in idiopathic hypertrophic subaortic stenosis. Br Heart J 38:595,1976. 6. Henry WL, Clark CE, Griffith JM, e t al: Mechanism of left ventricular outflow obstruction in patients with obstructive asymmetric septal hypertrophy (idiopathic hypertrophic subaortic stenosis). Am J Cardiol 35:337.1975. 7. Bulkley BH, Fortuin NJ: Systolic anterior motion of the mitral valve without asymmetric septal hypertrophy. Chest 69:694, 1976.
8. Mintz GS, Kotler MN, Segal BL, et al: Systolic anterior motion of the mitral valve in the absence of asymmetric septal hypertrophy. Circulation 53-54 (Suppl 11): 191,1976.
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