This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Roberts, R. Articles by Sigwart, U. Search for Related Content PubMed PubMed Citation Articles by Roberts, R. Articles by Sigwart, U. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Cardiomyopathy Heart Surgery Hazardous Substances DB ETHANOL Related Collections Hypertrophy Physiological and pathological control of gene expression Myocardial cardiomyopathy disease Ablation/ICD/surgery Genetics of cardiovascular disease

(Circulation. 2001;104:2249.)
© 2001 American Heart Association, Inc.

Clinical Cardiology: New Frontiers

New Concepts in Hypertrophic Cardiomyopathies, Part II

Robert Roberts, MD; Ulrich Sigwart, MD

From the Section of Cardiology (R.R.), Baylor College of Medicine, Houston, Tex, and The Royal Brompton Hospital (U.S.), London, UK.

Reprint requests to Robert Roberts, MD, Don W. Chapman Professor of Medicine, Professor of Medicine of Cell Biology, Department of Medicine, Section of Cardiology, 6550 Fannin, MS SM677, Baylor College of Medicine, Houston, TX 77030. E-mail rroberts@bcm.tmc.edu

Key Words: cardiomyopathy • hypertrophy • genetics

	Introduction

 
In most patients, the hypertrophy develops initially in the septum and extends to the free walls, often giving a picture of concentric hypertrophy. In 25% of patients with familial hypertrophic cardiomyopathy (FHCM), asymmetrical septal hypertrophy leads to a highly variable pressure gradient between the apical left ventricular chamber and the left ventricular outflow tract (LVOT).¹ LVOT obstruction with a consecutive increase of left ventricular pressure fuels a vicious circle of further hypertrophy and increased LVOT obstruction. Clinical manifestations of LVOT may be present in early childhood or may develop much later in life.² In most patients with LVOT obstruction, the hypertrophy is most pronounced in the high intraventricular septum compared with the rest of the left ventricle.^3,4 Hypertrophic obstructive cardiomyopathy is characterized by a sphincter-like dynamic midventricular obstruction that creates an outflow tract pressure gradient of varying severity.^5–7 The small left ventricular cavity is the main reason for the systolic anterior movement of the mitral valve (SAM), whereby the anterior leaflet may touch the hypertrophied septum.⁸ Mitral incompetence is almost invariably present with LVOT obstruction.⁴ Controversy exists regarding the contribution of the Venturi effect secondary to the increased ejection velocity. Most likely, this Venturi effect is the consequence rather than the origin of the LVOT gradient.⁹ Diastolic left ventricular abnormalities result from loss of myocardial compliance owing to fibrosis and hypertrophy. Whether ischemia is a primary feature or a consequence of the obstruction remains obscure. Because the LVOT obstruction is dynamic, patients in whom the disease is suspected and who . . . [Full Text of this Article]

This article has been cited by other articles:

				W. G. van Dockum, A. M. Beek, F. J. ten Cate, J. M. ten Berg, O. Bondarenko, M. J.W. Gotte, J. W.R. Twisk, M. B.M. Hofman, C. A. Visser, and A. C. van Rossum Early Onset and Progression of Left Ventricular Remodeling After Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy Circulation, May 17, 2005; 111(19): 2503 - 2508. [Abstract] [Full Text] [PDF]

				M. Arad, B. J. Maron, J. M. Gorham, W. H. Johnson Jr., J. P. Saul, A. R. Perez-Atayde, P. Spirito, G. B. Wright, R. J. Kanter, C. E. Seidman, et al. Glycogen Storage Diseases Presenting as Hypertrophic Cardiomyopathy N. Engl. J. Med., January 27, 2005; 352(4): 362 - 372. [Abstract] [Full Text] [PDF]

				J.-A. Mas, E. Garcia-Zaragoza, and M. Cervera Two Functionally Identical Modular Enhancers in Drosophila Troponin T Gene Establish the Correct Protein Levels in Different Muscle Types Mol. Biol. Cell, April 1, 2004; 15(4): 1931 - 1945. [Abstract] [Full Text] [PDF]

				W. G. van Dockum, F. J. ten Cate, J. M. ten Berg, A. M. Beek, J. W. R. Twisk, J. Vos, M. B. M. Hofman, C. A. Visser, and A. C. van Rossum Myocardial infarction after percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: evaluation by contrast-enhanced magnetic resonance imaging J. Am. Coll. Cardiol., January 7, 2004; 43(1): 27 - 34. [Abstract] [Full Text] [PDF]

				F. J. Schoen and R. F. Padera Jr. Cardiac Surgical Pathology Card. Surg. Adult, January 1, 2003; 2(2003): 119 - 185. [Full Text]

				M. Arad, J.G. Seidman, and C. E. Seidman Phenotypic diversity in hypertrophic cardiomyopathy Hum. Mol. Genet., October 1, 2002; 11(20): 2499 - 2506. [Abstract] [Full Text] [PDF]

				F. Cecchi, I. Olivotto, R. Roberts, and U. Sigwart New Concepts in Hypertrophic Cardiomyopathies * Response Circulation, June 11, 2002; 105 (23): e188 - e188. [Full Text] [PDF]

				A. MAASS, J.P. KONHILAS, B.L. STAUFFER, and L.A. LEINWAND From Sarcomeric Mutations to Heart Disease: Understanding Familial Hypertrophic Cardiomyopathy Cold Spring Harb Symp Quant Biol, January 1, 2002; 67(0): 409 - 416. [Abstract] [PDF]