1 From the Cardiology Branch, National Heart and Lung Institute, Bethesda, Maryland.
Idiopathic hypertrophic subaortic stenosis (IHSS) is characterized by subaortic obstruction to left ventricular (LV) outflow. However, the obstruction is variable and many patients have no resting gradient and no clinical evidence of IHSS. Although a characteristic systolic movement of the anterior mitral valve leaflet can be demonstrated echocardiographically in many patients with IHSS, this may be absent in patients without obstruction under baseline conditions. Several necropsy studies of patients with IHSS have demonstrated that the ventricular septum characteristically is asymmetrically hypertrophied in relation to the posterior left ventricular wall. Since echocardiography can measure the thickness of the ventricular septum and the posterior LV free wall during life, we have evaluated the sensitivity and specificity of asymmetric septal hypertrophy (ASH) in diagnosing IHSS. The ventricular septum and posterior LV free wall were measured in 15 patients with IHSS documented by catheterization, 11 patients with other forms of fixed LV outflow obstruction, 52 patients with miscellaneous forms of heart disease, and 16 normal subjects. The mean septal-free wall ratio in normal subjects was 1.03, in fixed LV outflow obstruction 1.03, in miscellaneous heart disease 1.03, while in IHSS it was 1.68. The ratio exceeded 1.3 in all 15 patients with IHSS (including seven patients without a gradient under baseline conditions), and it was less than 1.3 in 78 of 79 patients without IHSS. Thus ASH (1) can be diagnosed noninvasively, (2) appears specific for IHSS, and (3) is independent of the degree of obstruction. Moreover, since our findings indicate that the detection of ASH identifies the pathognomonic anatomic abnormality in IHSS and includes a wider spectrum of patients (i.e. those without obstruction as well as clinically normal family members of patients with IHSS), we suggest that a more appropriate term for this disease entity is asymmetric septal hypertrophy or ASH.
Submitted on August 21, 1972
© 1973 American Heart Association, Inc.
Asymmetric Septal Hypertrophy
Echocardiographic Identification of the Pathognomonic Anatomic Abnormality of IHSS
Key Words: Echocardiography • Idiopathic hypertrophic subaortic stenosis • Systolic mitral valve motion • T-scan • Hypertrophic obstructive cardiomyopathy • Septal-free wall ratio
Accepted on September 25, 1972
This article has been cited by other articles:
 |
|
 |
|
  S. R Ommen and R. A Nishimura What causes outflow tract obstruction in hypertrophic cardiomyopathy? Heart, November 1, 2009; 95(21): 1725 - 1726. [Full Text] [PDF]
|
|
|
|
 |
|
 K. Unno, S. Isobe, H. Izawa, X. W. Cheng, M. Kobayashi, A. Hirashiki, T. Yamada, K. Harada, S. Ohshima, A. Noda, et al. Relation of functional and morphological changes in mitochondria to myocardial contractile and relaxation reserves in asymptomatic to mildly symptomatic patients with hypertrophic cardiomyopathy Eur. Heart J., August 1, 2009; 30(15): 1853 - 1862. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. J. Maron, M. S. Maron, E. D. Wigle, and E. Braunwald The 50-year history, controversy, and clinical implications of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy from idiopathic hypertrophic subaortic stenosis to hypertrophic cardiomyopathy: from idiopathic hypertrophic subaortic stenosis to hypertrophic cardiomyopathy. J. Am. Coll. Cardiol., July 14, 2009; 54(3): 191 - 200. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. A. Meyer History of Ultrasound in Cardiology J. Ultrasound Med., January 1, 2004; 23(1): 1 - 11. [Full Text] [PDF]
|
|
|
|
 |
|
 T. Nakamura, H. Sugihara, N. Kinoshita, S. Yoneyama, A. Azuma, and M. Nakagawa Can Serum Carnitine Levels Distinguish Hypertrophic Cardiomyopathy From Hypertensive Hearts? Hypertension, August 1, 2000; 36(2): 215 - 219. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R. Gottshall, J. J. Hunter, N. Tanaka, N. Dalton, K. D. Becker, J. Ross Jr., and K. R. Chien Ras-dependent pathways induce obstructive hypertrophy in echo-selected transgenic mice PNAS, April 29, 1997; 94(9): 4710 - 4715. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Nakao, T. Takenaka, M. Maeda, C. Kodama, A. Tanaka, M. Tahara, A. Yoshida, M. Kuriyama, H. Hayashibe, H. Sakuraba, et al. An Atypical Variant of Fabry's Disease in Men with Left Ventricular Hypertrophy N. Engl. J. Med., August 3, 1995; 333(5): 288 - 293. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. J. MARON and J. J. MULVIHILL The Genetics of Hypertrophic Cardiomyopathy Ann Intern Med, October 1, 1986; 105(4): 610 - 613. [Abstract] [PDF]
|
|
|
|
 |
|
 M. M. Shenoy, A. Khanna, M. Nejat, E. Greif, and S. A. Friedman Hypertrophic Cardiomyopathy in the Elderly: A Frequently Misdiagnosed Disease Arch Intern Med, April 1, 1986; 146(4): 658 - 661. [Abstract] [PDF]
|
|
|
|
 |
|
 H. Rowell, H. Racker, and R. C. Bansal Spectrum of Hyperirophic Cardiomyopathy Viewed by M-Mode, 2D, and Doppler Echocardiography: A Review Journal of Diagnostic Medical Sonography, January 1, 1986; 2(1): 24 - 30. [Abstract] [PDF]
|
|
|
|
 |
|
 G. M. Folger The Spectrum of Left Ventricular Outflow Tract Obstruction: an Overview Angiology, November 1, 1980; 31(11): 779 - 799. [PDF]
|
|
|
|
|
|
J. M. Isner, R. J. Hawley, A. M. Weintraub, and W. K. Engel Cardiac Findings in Charcot-Marie-Tooth Disease: A Prospective Study of 68 Patients Arch Intern Med, October 1, 1979; 139(10): 1161 - 1165. [Abstract] [PDF]
|
|
|
|
|
|
M. G. Pandian, J. G. Greenwald, A. Lichtman, and H. Truax Pulmonary Hypertension Associated With Echocardiographic Pseudoid-Iopathic Hypertrophic Subaortic Stenosis Angiology, January 1, 1977; 28(1): 36 - 39. [Abstract] [PDF]
|
|
|
|
 |
|
 A. L. Riba and J. Morganroth Unsuspected Substantial Pericardial Effusions Detected by Echocardiography JAMA, December 6, 1976; 236(23): 2623 - 2625. [Abstract] [PDF]
|
|
|
|
|
|
E. R. SMITH, L. P. HEFFERNAN, V. E. SANGALANG, L. M. VAUGHAN, and C. S. FLEMINGTON Voluntary Muscle Involvement in Hypertrophic Cardiomyopathy: A Study of Eleven Patients Ann Intern Med, November 1, 1976; 85(5): 566 - 572. [Abstract] [PDF]
|
|
|
|
|
|
Cardiovascular Disease: An Annotated Bibliography of Recent Literature: References to Journal Articles and Other Papers Ann Intern Med, October 1, 1976; 85(4): 544 - 548. [Abstract] [PDF]
|
|
|
|
 |
|
 J. J. Nora, R. H. Lortscher, and R. D. Spangler Echocardiographic Studies of Left Ventricular Disease in Ullrich-Noonan Syndrome Arch Pediatr Adolesc Med, December 1, 1975; 129(12): 1417 - 1420. [Abstract] [PDF]
|
|
|
|
|
|
A. J. KOLIBASH, D. E. RUIZ, and R. P. LEWIS Idiopathic Hypertrophic Subaortic Stenosis in Pregnancy Ann Intern Med, June 1, 1975; 82(6): 791 - 794. [Abstract] [PDF]
|
|
|
|
|
|
J. MORGANROTH, B. J. MARON, W. L. HENRY, and S. E. EPSTEIN Comparative Left Ventricular Dimensions in Trained Athletes Ann Intern Med, April 1, 1975; 82(4): 521 - 524. [Abstract] [PDF]
|
|
|
|
|
|
S. E. EPSTEIN, W. L. HENRY, C. E. CLARK, W. C. ROBERTS, B. J. MARON, V. J. FERRANS, D. R. REDWOOD, and A. G. MORROW Asymmetric Septal Hypertrophy Ann Intern Med, November 1, 1974; 81(5): 650 - 680. [Abstract] [PDF]
|
|
|
|
|
|
H. D. ALLEN, W. E. LARTER, and S. J. GOLDBERG The Ullrich-Noonan Syndrome Arch Pediatr Adolesc Med, July 1, 1974; 128(1): 115 - 115. [Abstract] [PDF]
|
|