109
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The diagnosis of hypertrophic cardiomyopathy by cardiovascular magnetic resonance

      review-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease.

          Related collections

          Most cited references88

          • Record: found
          • Abstract: found
          • Article: not found

          Hypertrophic cardiomyopathy: a systematic review.

          Throughout the past 40 years, a vast and sometimes contradictory literature has accumulated regarding hypertrophic cardiomyopathy (HCM), a genetic cardiac disease caused by a variety of mutations in genes encoding sarcomeric proteins and characterized by a broad and expanding clinical spectrum. To clarify and summarize the relevant clinical issues and to profile rapidly evolving concepts regarding HCM. Systematic analysis of the relevant HCM literature, accessed through MEDLINE (1966-2000), bibliographies, and interactions with investigators. Diverse information was assimilated into a rigorous and objective contemporary description of HCM, affording greatest weight to prospective, controlled, and evidence-based studies. Hypertrophic cardiomyopathy is a relatively common genetic cardiac disease (1:500 in the general population) that is heterogeneous with respect to disease-causing mutations, presentation, prognosis, and treatment strategies. Visibility attached to HCM relates largely to its recognition as the most common cause of sudden death in the young (including competitive athletes). Clinical diagnosis is by 2-dimensional echocardiographic identification of otherwise unexplained left ventricular wall thickening in the presence of a nondilated cavity. Overall, HCM confers an annual mortality rate of about 1% and in most patients is compatible with little or no disability and normal life expectancy. Subsets with higher mortality or morbidity are linked to the complications of sudden death, progressive heart failure, and atrial fibrillation with embolic stroke. Treatment strategies depend on appropriate patient selection, including drug treatment for exertional dyspnea (beta-blockers, verapamil, disopyramide) and the septal myotomy-myectomy operation, which is the standard of care for severe refractory symptoms associated with marked outflow obstruction; alcohol septal ablation and pacing are alternatives to surgery for selected patients. High-risk patients may be treated effectively for sudden death prevention with the implantable cardioverter-defibrillator. Substantial understanding has evolved regarding the epidemiology and clinical course of HCM, as well as novel treatment strategies that may alter its natural history. An appreciation that HCM, although an important cause of death and disability at all ages, does not invariably convey ominous prognosis and is compatible with normal longevity should dictate a large measure of reassurance for many patients.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Myocardial fibrosis as an early manifestation of hypertrophic cardiomyopathy.

            Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy and a proposed substrate for arrhythmias and heart failure. In animal models, profibrotic genetic pathways are activated early, before hypertrophic remodeling. Data showing early profibrotic responses to sarcomere-gene mutations in patients with hypertrophic cardiomyopathy are lacking. We used echocardiography, cardiac magnetic resonance imaging (MRI), and serum biomarkers of collagen metabolism, hemodynamic stress, and myocardial injury to evaluate subjects with hypertrophic cardiomyopathy and a confirmed genotype. The study involved 38 subjects with pathogenic sarcomere mutations and overt hypertrophic cardiomyopathy, 39 subjects with mutations but no left ventricular hypertrophy, and 30 controls who did not have mutations. Levels of serum C-terminal propeptide of type I procollagen (PICP) were significantly higher in mutation carriers without left ventricular hypertrophy and in subjects with overt hypertrophic cardiomyopathy than in controls (31% and 69% higher, respectively; P<0.001). The ratio of PICP to C-terminal telopeptide of type I collagen was increased only in subjects with overt hypertrophic cardiomyopathy, suggesting that collagen synthesis exceeds degradation. Cardiac MRI studies showed late gadolinium enhancement, indicating myocardial fibrosis, in 71% of subjects with overt hypertrophic cardiomyopathy but in none of the mutation carriers without left ventricular hypertrophy. Elevated levels of serum PICP indicated increased myocardial collagen synthesis in sarcomere-mutation carriers without overt disease. This profibrotic state preceded the development of left ventricular hypertrophy or fibrosis visible on MRI. (Funded by the National Institutes of Health and others.)
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Evaluation of diffuse myocardial fibrosis in heart failure with cardiac magnetic resonance contrast-enhanced T1 mapping.

              The purpose of this study was to investigate a noninvasive method for quantifying diffuse myocardial fibrosis with cardiac magnetic resonance imaging (CMRI). Diffuse myocardial fibrosis is a fundamental process in pathologic remodeling in cardiomyopathy and is postulated to cause increased cardiac stiffness and poor clinical outcomes. Although regional fibrosis is easily imaged with cardiac magnetic resonance, there is currently no noninvasive method for quantifying diffuse myocardial fibrosis. We performed CMRI on 45 subjects (25 patients with heart failure, 20 control patients), on a clinical 1.5-T CMRI scanner. A prototype T(1) mapping sequence was used to calculate the post-contrast myocardial T(1) time as an index of diffuse fibrosis; regional fibrosis was identified by delayed contrast enhancement. Regional and global systolic function was assessed by cine CMRI in standard short- and long-axis planes, with echocardiography used to evaluate diastology. An additional 9 subjects underwent CMRI and endomyocardial biopsy for histologic correlation. Post-contrast myocardial T(1) times correlated histologically with fibrosis (R = -0.7, p = 0.03) and were shorter in heart failure subjects than controls (383 +/- 17 ms vs. 564 +/- 23 ms, p < 0.0001). The T(1) time of heart failure myocardium was shorter than that in controls even when excluding areas of regional fibrosis (429 +/- 22 ms vs. 564 +/- 23 ms, p < 0.0001). The post-contrast myocardial T(1) time shortened as diastolic function worsened (562 +/- 24 ms in normal diastolic function vs. 423 +/- 33 ms in impaired diastolic function vs. 368 +/- 20 ms in restrictive function, p < 0.001). Contrast-enhanced CMRI T(1) mapping identifies changes in myocardial T(1) times in heart failure, which appear to reflect diffuse fibrosis.
                Bookmark

                Author and article information

                Journal
                J Cardiovasc Magn Reson
                J Cardiovasc Magn Reson
                Journal of Cardiovascular Magnetic Resonance
                BioMed Central
                1097-6647
                1532-429X
                2012
                20 February 2012
                : 14
                : 1
                : 17
                Affiliations
                [1 ]Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, USA
                [2 ]Molecular Biomedical Imaging Laboratory, National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD, USA
                [3 ]Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
                [4 ]Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
                [5 ]Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA
                Article
                1532-429X-14-17
                10.1186/1532-429X-14-17
                3309929
                22348519
                f121d59f-d2b7-47d0-b961-909985b4c9b3
                Copyright ©2012 Noureldin et al; licensee BioMed Central Ltd.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 14 June 2011
                : 20 February 2012
                Categories
                Review

                Cardiovascular Medicine
                Cardiovascular Medicine

                Comments

                Comment on this article