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Updated: Nov 4, 2025
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Restricted left atrial dilatation can visually differentiate cardiac amyloidosis from hypertrophic cardiomyopathy
Haruhiko Higashi1, Katsuji Inoue1, Shinji Inaba1
1Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Toon, Japan.
Insights
Visual assessment of left atrial (LA) dilatation can help differentiate cardiac amyloidosis (CA) from hypertrophic cardiomyopathy (HCM). Restricted LA dilatation is a key indicator for CA diagnosis, aiding in early detection and risk stratification.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Cardiac Electrophysiology
Background:
- Cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) are distinct infiltrative and genetic myocardial diseases, respectively.
- CA can present with clinical and echocardiographic features that mimic HCM, complicating diagnosis.
- Accurate differentiation is crucial for appropriate patient management and prognosis.
Purpose of the Study:
- To evaluate the diagnostic capability of visual assessment of left atrial (LA) function, specifically LA dilatation, in differentiating CA from HCM using echocardiography.
- To compare the discriminatory power of visual LA dilatation grading with quantitative LA function parameters.
Main Methods:
- Retrospective analysis of 127 patients (93 with HCM, 34 with CA) with cardiac magnetic resonance imaging or biopsy confirmation.
- Echocardiographic assessment of LA dilatation grade (preserved=1, abnormal=2, restricted=3) based on reservoir phase expansion.
- Reproducibility of visual LA dilatation grading assessed using kappa statistics.
- Quantitative evaluation of LA emptying fraction and reservoir strain.
- Kaplan-Meier analysis to assess cardiac event rates based on LA dilatation grade.
Main Results:
- Visual LA dilatation grading demonstrated good intra- and inter-observer reproducibility (kappa=0.82 and 0.70).
- Restricted LA dilatation (Grade 3) was more prevalent in CA (71%) compared to HCM.
- Patients with CA showed significantly higher LA dilatation grades than those with HCM (P<0.01).
- The area under the curve for differentiating CA and HCM was highest for LA dilatation grade (0.88) and LA emptying fraction (0.88).
- Restricted LA dilatation was associated with a higher incidence of cardiac events (P<0.01).
Conclusions:
- Visual assessment of LA dilatation, particularly restricted LA dilatation, is a valuable tool for diagnosing CA.
- Echocardiographic evaluation of LA function can aid in differentiating CA from HCM.
- This method may help identify high-risk patients with HCM and those with CA requiring further investigation.
Aims:
Cardiac amyloidosis (CA) is an infiltrative myocardial disease that occasionally mimics hypertrophic cardiomyopathy (HCM). The aim of this study is to investigate the discriminatory ability of visual assessment of left atrial (LA) function between CA and HCM on echocardiography.
Methods And Results:
In total, 93 patients with cardiac magnetic resonance imaging (CMR)-confirmed HCM and 34 with cardiac biopsy-confirmed CA were retrospectively assessed. LA dilatation was assessed via echocardiography in an apical four-chamber view. Visual assessment was performed to identify LA dilatation grade (preserved = 1, abnormal = 2, and restricted = 3) based on the extent of outward expansion in the LA reservoir phase. Regarding the reproducibility of visually assessing LA dilatation grade, the kappa values between intra- and inter-observer measurements were 0.82 and 0.70, respectively. Of 127 participants, 57 (45%), 42 (33%), and 28 (22%) presented with LA dilatation Grades 1, 2, and 3, respectively. All 57 patients with preserved LA dilatation (Grade 1) had HCM, and 20 of 28 patients (71%) with restricted LA dilatation (Grade 3) presented with CA. Patients with CA had a higher LA dilatation grade than those with HCM (P < 0.01). LA emptying fraction and reservoir strain were also quantitatively evaluated. The area under the curves of LA dilatation grade (0.88) and LA emptying fraction (0.88) for differentiation of these two diseases were higher than that of LA reservoir strain (0.73) (P < 0.01, respectively). During follow-up, nine patients with HCM and 16 with CA experienced cardiac event (cardiac death or hospitalization due to heart failure). In Kaplan-Meier analysis including both groups of HCM and CA, the incidence of cardiac events was higher in patients with restricted LA dilatation than in those with preserved or abnormal LA dilatation (log-rank test, P < 0.01).
Conclusions:
Restricted LA dilatation is an indicator for the diagnosis of CA. Further, visual assessment of abnormal LA motion may facilitate diagnosis in patients with CA and high-risk patients with HCM.
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