Onset of Apical Hypertrophic Cardiomyopathy in Adulthood
2011; Elsevier BV; Volume: 108; Issue: 12 Linguagem: Inglês
10.1016/j.amjcard.2011.07.048
ISSN1879-1913
AutoresBarry J. Maron, Tammy S. Haas, Carrie Kitner, John R. Lesser,
Tópico(s)Viral Infections and Immunology Research
ResumoThe development of the hypertrophic cardiomyopathy (HC) phenotype with left ventricular (LV) hypertrophy usually occurs in adolescence, and documentation of patients with later onset of wall thickening during adulthood is rare. We report 4 patients with asymptomatic, nonobstructive HC (3 women and 1 man) who were studied with serial cardiovascular magnetic resonance imaging or echocardiography. In these patients, LV wall thickening, confined to the apex and the contiguous distal portions of the ventricular septum and free wall, appeared in midlife and beyond. These patients were >40, >50, or >70 years old when the hypertrophy became evident. The maximum LV wall thickness was 14 to 25 mm (mean 18), with a "spade" deformity of the distal chamber, associated with a nondilated cavity and normal ejection fraction (65% to 80%), in the absence of mitral valve systolic anterior motion. In each patient, similar electrocardiographic patterns with similar diffuse and marked T-wave inversion (with or without increased precordial voltages) preceded the appearance of the HC phenotype on the imaging studies. In conclusion, the recognition that the onset of LV hypertrophy in HC can be delayed well into adulthood (and even to advanced age) has important implications regarding the clinical screening practices for families, and suggests the potential value of extending prospective serial imaging beyond adolescence in some relatives. Electrocardiographic repolarization abnormalities can predict the future development of apical LV hypertrophy in adults with HC. The development of the hypertrophic cardiomyopathy (HC) phenotype with left ventricular (LV) hypertrophy usually occurs in adolescence, and documentation of patients with later onset of wall thickening during adulthood is rare. We report 4 patients with asymptomatic, nonobstructive HC (3 women and 1 man) who were studied with serial cardiovascular magnetic resonance imaging or echocardiography. In these patients, LV wall thickening, confined to the apex and the contiguous distal portions of the ventricular septum and free wall, appeared in midlife and beyond. These patients were >40, >50, or >70 years old when the hypertrophy became evident. The maximum LV wall thickness was 14 to 25 mm (mean 18), with a "spade" deformity of the distal chamber, associated with a nondilated cavity and normal ejection fraction (65% to 80%), in the absence of mitral valve systolic anterior motion. In each patient, similar electrocardiographic patterns with similar diffuse and marked T-wave inversion (with or without increased precordial voltages) preceded the appearance of the HC phenotype on the imaging studies. In conclusion, the recognition that the onset of LV hypertrophy in HC can be delayed well into adulthood (and even to advanced age) has important implications regarding the clinical screening practices for families, and suggests the potential value of extending prospective serial imaging beyond adolescence in some relatives. Electrocardiographic repolarization abnormalities can predict the future development of apical LV hypertrophy in adults with HC. Left ventricular (LV) hypertrophy represents the phenotype of hypertrophic cardiomyopathy (HC) and is the basis for the clinical diagnosis.1Maron B.J. Hypertrophic cardiomyopathy: A systematic review.JAMA. 2002; 287: 1308-1320Crossref PubMed Scopus (0) Google Scholar However, LV hypertrophy is rarely evident at birth or in young children but characteristically develops during adolescence.1Maron B.J. Hypertrophic cardiomyopathy: A systematic review.JAMA. 2002; 287: 1308-1320Crossref PubMed Scopus (0) Google Scholar, 2Maron B.J. Spirito P. Wesley Y.E. Arce J. Development and progression of left ventricular hypertrophy in children with hypertrophic cardiomyopathy.N Engl J Med. 1986; 315: 610-614Crossref PubMed Scopus (272) Google Scholar Although the de novo appearance of the HC phenotype in adults has been inferred by cross-sectional genotype-phenotype studies,3Niimura H. Bachinski L.L. Sangwatanaroj S. Watkins H. Chudley A.E. McKenna W. Kristinsson A. Roberts R. Sole M. Maron B.J. Seidman J.G. Seidman C.E. Mutations in the gene for human cardiac myosin-binding protein C and late-onset familial hypertrophic cardiomyopathy.N Engl J Med. 1998; 338: 1248-1257Crossref PubMed Scopus (625) Google Scholar the documentation of such events in individual patients with serial imaging studies has been uncommon, particularly in midlife after 40 years of age.4Maron B.J. Niimura H. Casey S.A. Soper M.K. Wright G.B. Seidman J.G. Seidman C.E. Development of left ventricular hypertrophy in adults with hypertrophic cardiomyopathy caused by cardiac myosin-binding protein C mutations.J Am Coll Cardiol. 2001; 38: 315-321Abstract Full Text Full Text PDF PubMed Scopus (200) Google Scholar, 5Obeid A.I. Maron B.J. Apical hypertrophic cardiomyopathy developing at a relatively advanced age.Circulation. 2001; 103: 1605Crossref PubMed Scopus (16) Google Scholar Apical HC is a part of the broad clinical and morphologic spectrum of HC. It is characterized by segmental hypertrophy confined to the distal portion of the LV chamber.6Yamaguchi H. Ishimura T. Nishiyama S. Nagasaki F. Nakanishi S. Takatsu F. Nishijo T. Umeda T. Machii K. Hypertrophic nonobstructive cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients.Am J Cardiol. 1979; 44: 401-412Abstract Full Text PDF PubMed Scopus (431) Google Scholar, 7Maron B.J. Bonow R.O. Seshagiri T.N. Roberts W.C. Epstein S.E. Hypertrophic cardiomyopathy with ventricular septal hypertrophy localized to the apical region of the left ventricle (apical hypertrophic cardiomyopathy).Am J Cardiol. 1982; 49: 1838-1848Abstract Full Text PDF PubMed Scopus (148) Google Scholar, 8Louie E.K. Maron B.J. Apical hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment.Ann Intern Med. 1987; 106: 663-670Crossref PubMed Scopus (105) Google Scholar, 9Kitaoka H. Doi Y. Casey S.A. Hitomi N. Furuno T. Maron B.J. Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States.Am J Cardiol. 2003; 92: 1183-1186Abstract Full Text Full Text PDF PubMed Scopus (154) Google Scholar, 10Sakamoto T. Apical hypertrophic cardiomyopathy (apical hypertrophy): an overview.J Cardiol. 2001; 3: 161-178Google Scholar, 11Eriksson M.J. Sonnenberg B. Woo A. Rakowski P. Parker T.G. Wigle E.D. Rakowski H. Long-term outcome in patients with apical hypertrophic cardiomyopathy.J Am Coll Cardiol. 2002; 39: 638-945Abstract Full Text Full Text PDF PubMed Scopus (340) Google Scholar, 12Arad M. Penas-Lado M. Monserrat L. Maron B.J. Sherrid M. Ho C.H. Barr S. Karim A. Olson T.M. Kamisago M. Seidman J.G. Seidman C.E. Gene mutations in apical hypertrophic cardiomyopathy.Circulation. 2005; 112: 2805-2811Crossref PubMed Scopus (167) Google Scholar Therefore, additional reports of delayed-onset LV hypertrophy, such as those in patients with apical HC, contribute importantly to our understanding of the clinical profile and natural history of this heterogeneous disease. The database of the Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation (Abbott Northwestern Hospital, Minneapolis, Minnesota) was accessed. A search was conducted specifically for adult patients with ≥2 echocardiograms or cardiovascular magnetic resonance (CMR) imaging studies ≥2 years apart and obtained after age 21, for whom the initial study findings were normal but LV hypertrophy was subsequently identified. Paired imaging studies showing the development of LV hypertrophy were obtained with CMR in 3 patients (patients 1, 2, and 4; Table 1) and with 2-dimensional echocardiography in 1 patient (patient 3).Table 1Patients with development of apical hypertrophic cardiomyopathy (HC) in adulthoodPt. No.Initial EvaluationMost Recent EvaluationAge (yr)/GenderYearNYHA FCMaximum LV Thickness (mm)LV Mass Index⁎Normal LV mass: women, 34–70 g/m2; men, 47–78 g/m2. (g/m2)LVED†Measurements made with echocardiography; all others, measurements made with CMR imaging. (mm)LA†Measurements made with echocardiography; all others, measurements made with CMR imaging. (mm)EF (%)Age (yr)YearNYHA FCMaximum LV Thickness (mm)LV Mass Index⁎Normal LV mass: women, 34–70 g/m2; men, 47–78 g/m2. (g/m2)LVED†Measurements made with echocardiography; all others, measurements made with CMR imaging. (mm)LA†Measurements made with echocardiography; all others, measurements made with CMR imaging. (mm)EF (%)141/Male20041106651356648201111470503266246/Female20041105835317751201111558303981351/Female‡Comparative assessment of LV morphology with echocardiography; other 3 patients studied with CMR imaging.1990110§Investigated by echocardiography with detection of right atrial myxoma (resected surgically).NA463165601998125NA533865474/Female20021767NANANA82201011971424880EF = ejection fraction; FC = functional class; LA = left atrium; LVED = left ventricular end-diastolic dimension; NA = not available; NYHA = New York Heart Association; Pt. No. = patient number. Normal LV mass: women, 34–70 g/m2; men, 47–78 g/m2.† Measurements made with echocardiography; all others, measurements made with CMR imaging.‡ Comparative assessment of LV morphology with echocardiography; other 3 patients studied with CMR imaging.§ Investigated by echocardiography with detection of right atrial myxoma (resected surgically). Open table in a new tab EF = ejection fraction; FC = functional class; LA = left atrium; LVED = left ventricular end-diastolic dimension; NA = not available; NYHA = New York Heart Association; Pt. No. = patient number. The imaging studies were performed with a 1.5 Tesla clinical CMR scanner (Sonata or Avanto, Siemens Medical, Erlangen, Germany). Cine true fast imaging with steady state precession sequences were accessed in the standard horizontal long axis, vertical long axis, and LV outflow tract (echo time/repetition time 1.5/3.0 ms, flip angle 60, contiguous slice thickness 10 mm, in-plane resolution 1.5 × 1.5 mm, temporal resolution 45 ms, and breath hold duration 14 to 17 heartbeats) were performed during breath hold at end-expiration. A short-axis image stack was obtained parallel to the atrioventricular groove (covering the entire left ventricle) with wall thickness measurements made at end-diastole in all segments of the chamber. Late gadolinium enhancement images were acquired 10 to 15 minutes after intravenous administration of 0.2 mmol/kg gadolinium-diethylene triamine pentaacetic acid (Magnevist, Schering, Berlin, Germany), with breath-held segmented inversion-recovery sequences acquired in the same orientations as the cine images. The two-dimensional echocardiographic studies were performed with commercially available instruments. The magnitude and pattern of LV hypertrophy was measured in all cross-sectional planes. The maximum LV wall thickness was defined as the greatest dimension evident at any site within the chamber. The left atrial and LV end-diastolic cavity dimensions were assessed using M-mode echocardiography in a standard fashion. The peak instantaneous outflow gradient was estimated with continuous wave Doppler under basal conditions.1Maron B.J. Hypertrophic cardiomyopathy: A systematic review.JAMA. 2002; 287: 1308-1320Crossref PubMed Scopus (0) Google Scholar In the 4 study patients (3 women and 1 man), the HC phenotype was absent at the initial evaluation (at 41, 46, 51, and 74 years of age, respectively), with normal wall thickness in all segments of the left ventricle. Subsequently, LV wall thickening was first identified at age 48, 51, 60, and 82 years (Figure 1, Figure 2). Therefore, the onset of LV hypertrophy occurred after 40 years of age in each patient, including after 50 years in 1, and after 70 years in 1 patient, as determined by the serial imaging studies.Figure 2Development of apical LV hypertrophy shown with serial 2-dimensional echocardiograms. Patient 3 (with β-myosin heavy chain mutation) at (A) age 51 years with LV apex of normal thickness (10 mm; arrowheads denote endocardial border) and (B) age 60 years, with marked hypertrophy at LV apex, 25 mm thick (asterisk). Arrowheads denote proximal endocardial border.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The patterns of LV hypertrophy were virtually identical in each patient, with wall thickening confined to the most distal portion of the LV chamber (i.e., the apex) and involving contiguous portions of the ventricular septum and free wall, creating the typical "spade" configuration.6Yamaguchi H. Ishimura T. Nishiyama S. Nagasaki F. Nakanishi S. Takatsu F. Nishijo T. Umeda T. Machii K. Hypertrophic nonobstructive cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients.Am J Cardiol. 1979; 44: 401-412Abstract Full Text PDF PubMed Scopus (431) Google Scholar, 7Maron B.J. Bonow R.O. Seshagiri T.N. Roberts W.C. Epstein S.E. Hypertrophic cardiomyopathy with ventricular septal hypertrophy localized to the apical region of the left ventricle (apical hypertrophic cardiomyopathy).Am J Cardiol. 1982; 49: 1838-1848Abstract Full Text PDF PubMed Scopus (148) Google Scholar, 8Louie E.K. Maron B.J. Apical hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment.Ann Intern Med. 1987; 106: 663-670Crossref PubMed Scopus (105) Google Scholar, 9Kitaoka H. Doi Y. Casey S.A. Hitomi N. Furuno T. Maron B.J. Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States.Am J Cardiol. 2003; 92: 1183-1186Abstract Full Text Full Text PDF PubMed Scopus (154) Google Scholar, 10Sakamoto T. Apical hypertrophic cardiomyopathy (apical hypertrophy): an overview.J Cardiol. 2001; 3: 161-178Google Scholar, 11Eriksson M.J. Sonnenberg B. Woo A. Rakowski P. Parker T.G. Wigle E.D. Rakowski H. Long-term outcome in patients with apical hypertrophic cardiomyopathy.J Am Coll Cardiol. 2002; 39: 638-945Abstract Full Text Full Text PDF PubMed Scopus (340) Google Scholar The maximum LV wall thickness in that region ranged from 14 to 25 mm (mean 18). The LV cavity was nondilated (30 to 53 mm in the transverse dimension), and the ejection fraction was preserved (65% to 80%). In each patient, LV outflow gradients were absent at rest, without evidence of systolic anterior motion of the mitral valve. Late gadolinium enhancement was absent in the 3 patients studied with contrast CMR imaging. The 12-lead electrocardiographic patterns at the initial cardiac evaluation were distinctly abnormal and were similar among the 4 study patients ECGs showed diffuse and marked T-wave inversion most prominent in the lateral precordial leads V4 to V6, including 1 patient (patient 4) with tall lateral precordial lead R-wave voltages. At the most recent evaluation, when LV hypertrophy was evident on the imaging studies, the T-wave inversion persisted and was often more marked; increased R-wave voltages in the lateral precordial leads V4 to V6 had appeared in 2 other patients (patients 1 and 2). Genetic testing showed a disease-causing β-myosin heavy chain mutation (MYH7 Glu497Asp) in patient 3,12Arad M. Penas-Lado M. Monserrat L. Maron B.J. Sherrid M. Ho C.H. Barr S. Karim A. Olson T.M. Kamisago M. Seidman J.G. Seidman C.E. Gene mutations in apical hypertrophic cardiomyopathy.Circulation. 2005; 112: 2805-2811Crossref PubMed Scopus (167) Google Scholar who also has a brother with HC and a primary prevention implantable cardioverter-defibrillator. Patient 4 has a LAMP2 Val391Ile mutation, a variant of uncertain significance. The genetic testing findings for patients 1 and 2 were negative. The principle that LV hypertrophy can develop de novo in genetically affected adults with HC well after adolescence represents a paradigm shift in our understanding of the natural history of HC and has important implications with respect to designing family screening strategies.2Maron B.J. Spirito P. Wesley Y.E. Arce J. Development and progression of left ventricular hypertrophy in children with hypertrophic cardiomyopathy.N Engl J Med. 1986; 315: 610-614Crossref PubMed Scopus (272) Google Scholar, 4Maron B.J. Niimura H. Casey S.A. Soper M.K. Wright G.B. Seidman J.G. Seidman C.E. Development of left ventricular hypertrophy in adults with hypertrophic cardiomyopathy caused by cardiac myosin-binding protein C mutations.J Am Coll Cardiol. 2001; 38: 315-321Abstract Full Text Full Text PDF PubMed Scopus (200) Google Scholar, 13Maron B.J. Seidman J.G. Seidman C.E. Proposal for contemporary screening strategies in families with hypertrophic cardiomyopathy.J Am Coll Cardiol. 2004; 44: 2125-2132Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar The advanced age of onset of apical LV hypertrophy evident in our patients after 40, 50, or 70 years of age is striking and suggests that such a remodeling process can develop at virtually any age in life. Furthermore, increasing recognition of delayed-onset LV hypertrophy underscores the principle that it may be inadvisable to terminate routine echocardiographic screening in family members when LV hypertrophy is absent after physical maturity has been achieved (e.g., 17 to 21 years of age).4Maron B.J. Niimura H. Casey S.A. Soper M.K. Wright G.B. Seidman J.G. Seidman C.E. Development of left ventricular hypertrophy in adults with hypertrophic cardiomyopathy caused by cardiac myosin-binding protein C mutations.J Am Coll Cardiol. 2001; 38: 315-321Abstract Full Text Full Text PDF PubMed Scopus (200) Google Scholar, 13Maron B.J. Seidman J.G. Seidman C.E. Proposal for contemporary screening strategies in families with hypertrophic cardiomyopathy.J Am Coll Cardiol. 2004; 44: 2125-2132Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar A reasonable inference of our data is the prudence of extending screening with echocardiography (and probably CMR imaging) beyond adolescence, continuing at about 5-year intervals well into midlife, or even later, assuming a disease-causing sarcomere mutation has not been identified.13Maron B.J. Seidman J.G. Seidman C.E. Proposal for contemporary screening strategies in families with hypertrophic cardiomyopathy.J Am Coll Cardiol. 2004; 44: 2125-2132Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar However, whether routinely extending almost indefinitely the period of surveillance is a practical, feasible, or, even, obligatory recommendation for most relatives of patients with HC is not entirely clear at this juncture. This is because of the relatively advanced ages at which morphologic conversion occurred in our patients and the burden of continued testing and required compliance and motivation of those at risk for considerable periods of time. Furthermore, it would be expected that the vast majority of those relatives with normal imaging and electrocardiographic findings at 18 years of age will be, in fact, genetically unaffected. Extended morphologic surveillance (i.e., with echocardiographic and/or CMR imaging studies) could imply to families significant indecision regarding the risk of developing HC, with the potential of eliciting the psychological perception and stigma of cardiac disease in many young, healthy subjects free of heart disease. If the causative HC gene is identified in a family member, molecular testing can exclude genetically affected status, probably eliminating the need for future clinical studies, and also diffusing unnecessary anxiety.14Ho C.Y. Genetics and clinical destiny: improving care in hypertrophic cardiomyopathy.Circulation. 2010; 122: 2430-2440Crossref PubMed Scopus (72) Google Scholar, 15Landstrom A.P. Ackerman M.J. Mutation type is not clinically useful in predicting prognosis in hypertrophic cardiomyopathy.Circulation. 2010; 122: 2441-2449Crossref PubMed Scopus (1) Google Scholar To date, the number of adult patients reported with delayed-onset LV hypertrophy has been relatively small. That circumstance appears to result largely from a lack of opportunity, given that it is uncommon for multiple echocardiographic or CMR imaging studies to be performed over long periods in adult HC family members, without LV hypertrophy after adolescence. In the present analysis, we encountered lengthy intervals of up to almost 10 years (average 7) between the initial normal CMR imaging or echocardiographic study and the subsequent imaging study that documented LV hypertrophy for the first time. The recognition of adult-onset LV hypertrophy in HC is often by chance or fortuitous circumstances such as evident in patient 2 (with a disease-causing MYH7 mutation) in whom the initial echocardiographic study identified right atrial myxoma when the LV wall thickness was normal. Unexpectedly, apical hypertrophy was later recognized for the first time during routine follow-up imaging after the tumor had been resected. It is unlikely that a particularly large series of such patients can be assembled either retrospectively or prospectively. Thus, the precise prevalence with which delayed penetrance and late-appearing LV hypertrophy occurs in a HC population will be difficult to ascertain. Consequently, the documentation of late (adult) onset of the HC phenotype, even in a relatively small number of cases, enriches our understanding of this complex disorder and opens a window to this novel aspect of its natural history largely invisible in routine clinical practice. It is also possible that the increasing availability of serial high-resolution tomographic CMR imaging studies, providing more precise LV wall thickness measurements (particularly in the anterolateral free wall or apex)16Moon J.C. Fisher N.G. McKenna W.J. Pennell D.J. Detection of apical hypertrophic cardiomyopathy by cardiovascular magnetic resonance in patients with non-diagnostic echocardiography.Heart. 2004; 90: 645-649Crossref PubMed Scopus (319) Google Scholar, 17Maron M.S. Finley J.J. Bos J.M. Hauser R.H. Manning W.J. Haas T.S. Lesser J.R. Udelson J.E. Ackerman M.J. Maron B.J. Prevalence, clinical significance and natural history of left ventricular apical aneurysms in hypertrophic cardiomyopathy.Circulation. 2008; 118: 1541-1549Crossref PubMed Scopus (407) Google Scholar, 18Maron M.S. Maron B.J. Harrigan C. Buros J. Gibson C.M. Olivotto I. Biller L. Lesser J.R. Udelson J.E. Manning W.J. Appelbaum E. Hypertrophic cardiomyopathy phenotype revisited after 50 years with cardiovascular magnetic resonance.J Am Coll Cardiol. 2009; 54: 220-228Abstract Full Text Full Text PDF PubMed Scopus (353) Google Scholar, 19Rickers C. Wilke N.M. Jerosch-Herold M. Casey S.A. Panse P. Panse N. Weil J. Zenovich A.G. Maron B.J. Utility of cardiac magnetic resonance imaging in the diagnosis of hypertrophic cardiomyopathy.Circulation. 2005; 112: 855-861Crossref PubMed Scopus (449) Google Scholar, 20Fattori R. Biagini E. Lorenzini M. Buttazzi K. Lovato L. Rapezzi C. Significance of magnetic resonance imaging in apical hypertrophic cardiomyopathy.Am J Cardiol. 2010; 105: 1592-1596Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar will ultimately enhance the future detection of late-onset hypertrophy, as CMR penetrates further into family screening for HC. In each of the 4 study patients, a distinctive 12-lead electrocardiographic pattern showing repolarization abnormalities with marked T-wave inversion preceded the appearance of the HC phenotype. Therefore, in these patients, the electrocardiogram can be regarded as a diagnostic marker that predicted LV remodeling, similar to that reported in Italian competitive athletes with repolarization abnormalities prior to development of the HC phenotype,21Pelliccia A. Di Paolo F.M. Quattrini F.M. Basso C. Culasso F. Popoli G. De Luca R. Spataro A. Biffi A. Thiene G. Maron B.J. Outcomes in athletes with marked ECG repolarization abnormalities.N Engl J Med. 2008; 358: 152-161Crossref PubMed Scopus (247) Google Scholar and young HC family members.22Panza J.A. Maron B.J. Relation of electrocardiographic abnormalities to evolving left ventricular hypertrophy in hypertrophic cardiomyopathy during childhood.Am J Cardiol. 1989; 63: 1258-1265Abstract Full Text PDF PubMed Scopus (96) Google Scholar The present patients remained asymptomatic and clinically unaffected by HC despite the LV remodeling occurring in adulthood, consistent with the generally benign natural history associated with relatively mild segmental LV hypertrophy in this disease.23Spirito P. Bellone P. Harris K.M. Bernabo P. Bruzzi P. Maron B.J. Magnitude of left ventricular hypertrophy and risk of sudden death in hypertrophic cardiomyopathy.N Engl J Med. 2000; 342: 1778-1785Crossref PubMed Scopus (883) Google Scholar The absence of late gadolinium enhancement in our 3 patients studied with contrast CMR imaging is also in concert with the benign nature of late-onset apical HC. However, at this juncture, we are uncertain whether all patients incurring such late phenotypic remodeling will remain free of symptoms. Nevertheless, the findings from our patients with apical HC are consistent with the principle that this morphologic variant is a part of the overall clinical spectrum of HC (rather than a separate disease entity),5Obeid A.I. Maron B.J. Apical hypertrophic cardiomyopathy developing at a relatively advanced age.Circulation. 2001; 103: 1605Crossref PubMed Scopus (16) Google Scholar, 6Yamaguchi H. Ishimura T. Nishiyama S. Nagasaki F. Nakanishi S. Takatsu F. Nishijo T. Umeda T. Machii K. Hypertrophic nonobstructive cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients.Am J Cardiol. 1979; 44: 401-412Abstract Full Text PDF PubMed Scopus (431) Google Scholar, 7Maron B.J. Bonow R.O. Seshagiri T.N. Roberts W.C. Epstein S.E. Hypertrophic cardiomyopathy with ventricular septal hypertrophy localized to the apical region of the left ventricle (apical hypertrophic cardiomyopathy).Am J Cardiol. 1982; 49: 1838-1848Abstract Full Text PDF PubMed Scopus (148) Google Scholar, 8Louie E.K. Maron B.J. Apical hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment.Ann Intern Med. 1987; 106: 663-670Crossref PubMed Scopus (105) Google Scholar, 9Kitaoka H. Doi Y. Casey S.A. Hitomi N. Furuno T. Maron B.J. Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States.Am J Cardiol. 2003; 92: 1183-1186Abstract Full Text Full Text PDF PubMed Scopus (154) Google Scholar, 10Sakamoto T. Apical hypertrophic cardiomyopathy (apical hypertrophy): an overview.J Cardiol. 2001; 3: 161-178Google Scholar, 11Eriksson M.J. Sonnenberg B. Woo A. Rakowski P. Parker T.G. Wigle E.D. Rakowski H. Long-term outcome in patients with apical hypertrophic cardiomyopathy.J Am Coll Cardiol. 2002; 39: 638-945Abstract Full Text Full Text PDF PubMed Scopus (340) Google Scholar, 12Arad M. Penas-Lado M. Monserrat L. Maron B.J. Sherrid M. Ho C.H. Barr S. Karim A. Olson T.M. Kamisago M. Seidman J.G. Seidman C.E. Gene mutations in apical hypertrophic cardiomyopathy.Circulation. 2005; 112: 2805-2811Crossref PubMed Scopus (167) Google Scholar and caused by sarcomere mutations similar to those identified in patients with other morphologic forms of HC.12Arad M. Penas-Lado M. Monserrat L. Maron B.J. Sherrid M. Ho C.H. Barr S. Karim A. Olson T.M. Kamisago M. Seidman J.G. Seidman C.E. Gene mutations in apical hypertrophic cardiomyopathy.Circulation. 2005; 112: 2805-2811Crossref PubMed Scopus (167) Google Scholar The Need to Continue Screening for Hypertrophic Cardiomyopathy After AdolescenceAmerican Journal of CardiologyVol. 115Issue 7PreviewIn a report, Maron et al.1 tell us that the number of adult patients reported with delayed-onset left ventricular hypertrophy (LVH) has been relatively small and that it would be expected that most relatives of patients with hypertrophic cardiomyopathy (HC) with normal imaging and electrocardiographic findings at 18 years of age will be genetically unaffected. This opinion is not supported by data from a recently published cohort of Dutch HC mutation carriers.2 Full-Text PDF
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