Midventricular hypertrophic cardiomyopathy
Citation, DOI, disclosures and article data
At the time the article was created Joachim Feger had no recorded disclosures.View Joachim Feger's current disclosures
At the time the article was last revised Joachim Feger had no recorded disclosures.View Joachim Feger's current disclosures
Midventricular hypertrophic cardiomyopathy is a phenotype or morphological variant of asymmetric hypertrophic cardiomyopathy (HCM) characterized by hypertrophy in the midventricular segment that might result in midventricular obstruction.
On this page:
Midventricular hypertrophic cardiomyopathy is rare 1 accounting for up to 4-10% 2-4.
Midventricular hypertrophic cardiomyopathy in particular with midventricular obstruction is associated with left ventricular apical aneurysms.
Symptoms of midventricular hypertrophic cardiomyopathy and midventricular obstruction do not differ significantly from other types of hypertrophic cardiomyopathy or left ventricular outflow obstruction and include performance deficits, dyspnea, angina, presyncope, syncope on exertion 2.
On auscultation, there might be an apical systolic murmur like or variably a long mitral diastolic murmur 2.
Complications of midventricular hypertrophic cardiomyopathy include 1-4:
- myocardial ischemia or myocardial necrosis
- cardiac thrombus formation
- systemic embolism
- ventricular arrhythmias
- sudden cardiac death
Midventricular hypertrophic cardiomyopathy is characterized by hypertrophy of the midventricular segments not only of the septum but also the free wall, which can result in midventricular obstruction.
Midventricular obstruction is defined by a peak gradient of ≥30 mmHg of the left ventricular mid cavity 1. There are apparently significant variations in the size of the obstructed apical cavity 2.
This phenotype is typically not associated with obstruction of the left ventricular outflow tract or systolic anterior motion (SAM) of the anterior leaflet of the mitral valve 1.
The typical imaging feature of midventricular hypertrophic cardiomyopathy is a dumbell shape or hourglass appearance of the left ventricle, which can be conveniently appreciated on left ventricular long-axis views 1.
Echocardiography can demonstrate the hypertrophied left ventricular segments and can aid in the evaluation of midventricular obstruction defined by a peak mid cavity gradient ≥30 mmHg 1,4-6.
Cardiac MRI can show hypertrophy of the midventricular segments and can aid in the evaluation of cardiac volumes and cardiac function and associated myocardial fibrosis and scarring 1. The following features might be present in midventricular hypertrophic cardiomyopathy 1,3-7:
- confined midventricular wall thickening
- dumbell or hourglass shape of the left ventricle
- left ventricular apical aneurysm
- preserved or increased ejection fraction
cardiac tissue characterization
- T1 mapping: increased native T1 values
- ECV: increased
- late gadolinium enhancement in midventricular and apical segments
- indicating replacement fibrosis or myocardial scarring
- might show complications as apical aneurysms or intracardiac thrombi
The radiological report should include a description of the following 1-6:
- location and extent of hypertrophic wall segments
- cardiac volumes and measurements including left ventricular mass
- cardiac wall motion abnormalities
- signs of myocardial fibrosis, myocardial scarring or replacement fibrosis
- mitral annular plane systolic excursion (MAPSE)
- complications as apical aneurysms or left ventricular thrombus formation
- mid cavity gradient
Conditions that might mimic the clinical presentation or imaging appearance of asymmetric hypertrophic cardiomyopathy include 1,4-6:
- 1. Baxi A, Restrepo C, Vargas D, Marmol-Velez A, Ocazionez D, Murillo H. Hypertrophic Cardiomyopathy from A to Z: Genetics, Pathophysiology, Imaging, and Management. Radiographics. 2016;36(2):335-54. doi:10.1148/rg.2016150137 - Pubmed
- 2. Wigle E. Cardiomyopathy: The Diagnosis of Hypertrophic Cardiomyopathy. Heart. 2001;86(6):709-14. doi:10.1136/heart.86.6.709 - Pubmed
- 3. Fattal J, Henry M, Ou S et al. Magnetic Resonance Imaging of Hypertrophic Cardiomyopathy: Beyond Left Ventricular Wall Thickness. Can Assoc Radiol J. 2015;66(1):71-8. doi:10.1016/j.carj.2014.07.005 - Pubmed
- 4. Minami Y, Kajimoto K, Terajima Y et al. Clinical Implications of Midventricular Obstruction in Patients With Hypertrophic Cardiomyopathy. J Am Coll Cardiol. 2011;57(23):2346-55. doi:10.1016/j.jacc.2011.02.033 - Pubmed
- 5. Syed I, Ommen S, Breen J, Tajik A. Hypertrophic Cardiomyopathy: Identification of Morphological Subtypes by Echocardiography and Cardiac Magnetic Resonance Imaging. JACC Cardiovasc Imaging. 2008;1(3):377-9. doi:10.1016/j.jcmg.2008.02.008 - Pubmed
- 6. Amano Y, Kitamura M, Takano H et al. Cardiac MR Imaging of Hypertrophic Cardiomyopathy: Techniques, Findings, and Clinical Relevance. Magn Reson Med Sci. 2018;17(2):120-31. doi:10.2463/mrms.rev.2017-0145 - Pubmed
- 7. Noureldin R, Liu S, Nacif M et al. The Diagnosis of Hypertrophic Cardiomyopathy by Cardiovascular Magnetic Resonance. J Cardiovasc Magn Reson. 2012;14(1):17. doi:10.1186/1532-429x-14-17 - Pubmed