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Updated: May 7, 2026
Evaluation of Left Ventricular Structure and Function using 3D Echocardiography
Published on: October 28, 2020
[Exercise echocardiography in the evaluation of obstructive types of hypertrophic cardiomyopathy]
Chun-li Shao1, Fu-jian Duan, Shu-bin Qiao
1Chinese Academy of Medical Science of Medical Sciences and Peking Union Medical College, Fuwai Hospital, Beijing 100037, China.
Insights
Many hypertrophic cardiomyopathy patients with no resting obstruction develop latent left ventricular outflow tract obstruction during exercise. Systolic anterior motion of the mitral valve and septal hypertrophy patterns help identify these patients.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Heart Diseases
Background:
- Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease.
- Left ventricular outflow tract obstruction (LVOTO) is a common complication in HCM.
- The dynamic nature of LVOTO, particularly during exercise, requires further investigation.
Purpose of the Study:
- To evaluate the prevalence and characteristics of latent left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM) patients.
- To identify predictors of latent LVOTO under physiological exercise conditions.
- To differentiate morphological features between obstructive and non-obstructive HCM phenotypes.
Main Methods:
- Sixty HCM patients with resting left ventricular outflow tract gradient (LVOTG) <50 mm Hg were enrolled.
- Echocardiography was used to measure LVOTG at rest and during exercise.
- Morphological characteristics, including systolic anterior motion (SAM) and septal hypertrophy distribution, were analyzed.
Main Results:
- Approximately 50% of patients with non-obstructive HCM at rest developed latent LVOTO during exercise (peak LVOTG ≥ 30 mm Hg).
- Latent LVOTO was significantly associated with the presence of SAM (73.1%), narrow LVOT (46.2%), and mitral regurgitation at rest.
- Multivariate analysis identified SAM (OR 6.431) and septal hypertrophy distribution (OR 0.011) as independent predictors of latent LVOTO.
Conclusions:
- Latent LVOTO is a significant finding in a substantial proportion of HCM patients initially classified as non-obstructive.
- Systolic anterior motion (SAM) of the mitral valve and specific patterns of septal hypertrophy are valuable indicators for identifying patients at risk of developing latent obstruction.
- These findings emphasize the importance of exercise echocardiography in the comprehensive assessment of HCM patients.
Objective:
To assess the condition of left ventricular outflow tract obstruction (LVOTO) under resting conditions and physiological exercise in hypertrophic cardiomyopathy (HCM) patients.
Methods:
A total of 60 patients with HCM and left ventricular outflow tract gradient (LVOTG) <50 mm Hg (1 mm Hg = 0.133 kPa) at rest were enrolled consecutively, and LVOTG at rest and exercise were measured by echocardiography. Of 51 patients with gradients <30 mm Hg at rest, 26 were latent LVOTO with exercise peak value LVOTG ≥ 30 mm Hg, 25 were non LVOTO with exercise peak value LVOTG < 30 mm Hg, and 9 were resting obstruction with LVOTG 30-49 mm Hg. The morphological characteristics of different types of obstruction were analyzed.
Results:
Patients with latent LVOTO were more likely to have SAM (73.1% vs 8.0%) , narrow of LVOT (46.2% vs 4.0%) , higher resting gradients [(16.9 ± 7.2) mm Hg vs (7.1 ± 4.3) mm Hg] and mitral regurgitation grade at rest than patients with non-obstructive (all P values <0.05). The distribution of septal hypertrophy were different in the two groups (P < 0.05). Multivariate logistic regression analysis showed independent predictors of latent LVOTO were SAM (OR 6.431, 95%CI 2.323-291.112, P = 0.002) at rest and distribution of septal hypertrophy(OR 0.011, 95% CI 0.001-0.179, P = 0.008).
Conclusions:
Approximately half of patients with non-obstructive HCM at rest have latent LVOTO. SAM and distribution of septal hypertrophy may be useful to identify patients with latent obstruction.
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