Related Experiment Video
Updated: Jan 17, 2026
Comprehensive Echocardiographic Assessment of Right Ventricle Function in a Rat Model of Pulmonary Arterial Hypertension
Published on: January 20, 2023
Inclusion of the Right Ventricular Muscle Bundle During Interventricular Septal Measurement Improves Diagnostic
Daniel M Spevack1,2, Pragya Ranjan1,2, Yeraz Khachatoorian1,2
1Department of Cardiology, Westchester Medical Center, Valhalla, New York, USA.
Insights
Including right ventricular muscle bundles (RVMB) in interventricular septum (IVS) measurements improves hypertrophic cardiomyopathy (HCM) diagnosis. This approach enhances accuracy, particularly for septal hypertrophy, aiding in better patient classification.
Area of Science:
- Cardiology
- Medical Imaging
- Diagnostic Accuracy
Background:
- Interventricular septum (IVS) measurement is crucial for diagnosing hypertrophic cardiomyopathy (HCM).
- Right ventricular muscle bundles (RVMB) can obscure IVS measurements in echocardiography and MRI.
- Current HCM diagnostic criteria rely on left ventricular wall thickness (≥15 mm) but lack data on RVMB inclusion.
Purpose of the Study:
- To evaluate the impact of including RVMB in IVS measurements on HCM diagnostic accuracy.
- To assess whether RVMB thickness differs between HCM patients and controls.
Main Methods:
- Echocardiography was used to measure IVS and RVMB thickness in 97 subjects undergoing evaluation for HCM.
- Subjects were categorized as having HCM or not, with HCM patients further classified into septal (HCM-Sep) or apical (HCM-Ap) hypertrophy.
- Diagnostic accuracy was assessed using receiver operating characteristic (ROC) curves with and without RVMB inclusion.
Main Results:
- Subjects with HCM-Sep showed significantly increased IVS and RVMB thickness compared to controls.
- Including RVMB in IVS measurements improved the area under the ROC curve for HCM detection (0.83 vs. 0.75).
- Excluding HCM-Ap cases, RVMB inclusion further enhanced ROC curve performance (0.94 vs. 0.82), improving correct classification from 78% to 94%.
Conclusions:
- Incorporating RVMB into IVS measurements on echocardiography can improve diagnostic accuracy for HCM.
- Increased RVMB thickness is observed in HCM patients, suggesting it's part of the pathology, especially in HCM-Sep.
- Findings support standardizing IVS measurement protocols in echocardiography and MRI for HCM reporting.
Introduction:
Measurement of the interventricular septum (IVS) is a key diagnostic and prognostic parameter in the evaluation of hypertrophic cardiomyopathy (HCM). Right ventricular muscle bundles (RVMB) that parallel the IVS complicate septal measurement on both echocardiography and magnetic resonance imaging. Current guideline statements reference left ventricular wall thickness measurements greater than or equal to 15 mm as part of the diagnostic criteria for HCM. The medical literature lacks published data on the impact of including RVMB as part of the IVS measurement and its influence on diagnostic accuracy for HCM.
Methods:
We measured the IVS and RVMB separately on echocardiography in 97 consecutive subjects referred for both echocardiography and magnetic resonance imaging (MRI) as part of the initial evaluation for HCM. Subjects were categorized as having or not having HCM based on current practice guidelines. Patients with HCM were sub-categorized as having septal involvement (HCM-Sep) or primarily apical hypertrophy (HCM-Ap). This was done because subjects with obvious HCM-Ap could be diagnosed with HCM irrespective of IVS thickness.
Results:
Compared to subjects who did not have HCM, those with HCM-Sep had both increased IVS (15.4 ± 2.7 vs. 9.8 ± 1.9 mm, p < 0.001) and RVMB thickness (5.2 ± 3.1 vs. 1.9 ± 1.9 mm, p < 0.001). In the whole study group, the area under the receiver operating characteristic (ROC) curve for HCM was higher (0.83 [95% confidence interval (CI): 0.75, 0.91]) when the RVMB was included in the IVS measurement compared to when it was excluded (0.75 [95% CI: 0.68, 0.81]). When the subjects with HCM-Ap were excluded, the area under the ROC curve for HCM was higher (0.94 [95% CI: 0.89, 0.99]) when the RVMB was included in the IVS measurement compared to when it was excluded (0.82 [95% CI: 0.75, 0.89]). The number of subjects classified correctly for HCM improved from 78% to 94% when the RVMB was included.
Conclusions:
Inclusion of the RVMB in the measurement of IVS thickness on echocardiography may improve overall diagnostic accuracy for HCM. In addition, RVMB thickness is increased and is more often visible on parasternal long-axis imaging in subjects with HCM, consistent with being part of the HCM pathology. This is particularly true in those with HCM-Sep. These data have implications for the standardization of echocardiographic and MRI reporting in HCM.
More Related Videos
07:11Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography
Published on: October 28, 2020
10:33Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography
Published on: February 3, 2014
Related Concept Videos
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:23Mitral Stenosis II: Clinical features and Diagnostic Tests