OUP user menu

Significance of left ventricular apical–basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

Christiane Gruner, Raymond H. Chan, Andrew Crean, Harry Rakowski, Ethan J. Rowin, Melanie Care, Djeven Deva, Lynne Williams, Evan Appelbaum, C. Michael Gibson, John R. Lesser, Tammy S. Haas, James E. Udelson, Warren J. Manning, Katherine Siminovitch, Anthony C. Ralph-Edwards, Hassan Rastegar, Barry J. Maron, Martin S. Maron
DOI: http://dx.doi.org/10.1093/eurheartj/ehu154 2706-2713 First published online: 8 May 2014


Aims Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical–basal).

Methods and results CMR was performed in 230 genotyped HCM patients (48 ± 15 years, 69% male), 30 genotype-positive/phenotype-negative (G+/P−) family members (32 ± 15 years, 30% male), and 126 controls. Left ventricular apical–basal muscle bundle was identified in 145 of 230 (63%) HCM patients, 18 of 30 (60%) G+/P− family members, and 12 of 126 (10%) controls (G+/P− vs. controls; P < 0.01). In HCM patients, the prevalence of an apical–basal muscle bundle was similar among those with disease-causing sarcomere mutations compared with patients without mutation (64 vs. 62%; P = 0.88). The presence of an LV apical–basal muscle bundle was not associated with LV outflow tract obstruction (P = 0.61). In follow-up, 33 patients underwent surgical myectomy of whom 22 (67%) were identified to have an accessory LV apical–basal muscle bundle, which was resected in all patients.

Conclusion Apical–basal muscle bundles are a unique myocardial structure commonly present in HCM patients as well as in G+/P− family members and may represent an additional morphologic marker for HCM diagnosis in genotype-positive status.

  • Hypertrophic cardiomyopathy
  • Cardiovascular magnetic resonance
  • Muscle bundle
  • Genotype
View Full Text

Sign In

ESC members if your subscription is provided via the European Society of Cardiology, either as a member or an ESC Congress delegate, select the 'ESC Member and Congress Delegate Sign In' link in the list below. Discover if you are an ESC member here. Note: after sign in you will be redirected to the journal's home page. 'ESC member' will display at the top of the page to indicate you have full access rights for this session.

Otherwise, if your subscription is via OUP, enter your OUP username and password, or select an alternative sign in option below.

List of OpenAthens registered sites, including contact details.