Related Experiment Videos
Echocardiographic analysis of regional and global left ventricular shape in Chagas' cardiomyopathy
1Cardiovascular Imaging and Hemodynamic Laboratory, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA.
Insights
Chagas' heart disease alters left ventricular (LV) shape, causing apical deformation and a more spherical ventricle. These geometric changes occur even with preserved LV volumes, impacting cardiac function.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Chagas' heart disease is a leading cause of cardiomyopathy in Latin America.
- Left ventricular (LV) dysfunction and apical aneurysm are common in Chagas' cardiomyopathy.
- Cardiac geometry significantly influences LV function.
Purpose of the Study:
- To characterize regional and global changes in LV geometry in patients with Chagas' heart disease.
- To correlate LV shape alterations with LV function and volume.
- To compare LV shape in Chagas' patients with healthy controls.
Main Methods:
- Quantitative shape analysis of 2D echocardiograms from 43 Chagas' patients and 22 controls.
- Measurement of endocardial curvature for regional shape assessment.
- Fourier shape analysis of the endocardial contour for global shape evaluation.
Main Results:
- Patients with Chagas' disease showed decreased apical curvature and a more spherical LV shape compared to controls.
- Fourier shape power index was significantly reduced in Chagas' patients.
- LV shape disruption was evident even in patients with preserved LV volumes.
Conclusions:
- Chagas' cardiomyopathy is characterized by significant LV apical deformation and altered global geometry.
- These shape changes disrupt the optimal prolate-ellipsoid LV form.
- LV geometric alterations are a key feature of Chagas' heart disease, irrespective of LV volume.
Abstract:
Chagas' heart disease is a common form of cardiomyopathy in Latin America and an important cause of cardiac morbidity and mortality there. Left ventricular (LV) apical aneurysm and LV dysfunction are frequent findings in Chagas' cardiomyopathy. Because cardiac shape has important implications for LV function, we sought to characterize regional and global changes in LV geometry in Chagas' heart disease. Quantitative shape analysis was performed on 2-dimensional echocardiograms from 43 patients with Chagas' cardiomyopathy. Regional shape was quantitated by measuring endocardial curvature and global shape was evaluated by Fourier shape analysis of the endocardial contour. Data from 22 age- and sex-matched normal test subjects were used for comparison. Regional shape analysis demonstrated decreased apical curvature (consistent with blunting of normal apical shape) in the group with Chagas' disease compared with controls (apical 2-chamber view: 19 +/- 1 vs 24 +/- 1 [p = 0.0039] at end-diastole and 20 +/- 2 vs 29 +/- 3 [p = 0.0019] at end-systole). Fourier shape power index was decreased in the Chagas' group, consistent with a more spherical ventricle (apical 2-chamber view: 9 +/- 1 vs 17 +/- 2 [p <0.0001] at end-diastole and 12 +/- 1 vs 35 +/- 3 [p <0.0001] at end-systole). Shape changes among the population with Chagas' disease were further evaluated in those with end-diastolic volumes equal to or greater than the median for the group (104 ml) and those < 104 ml. Global shape did not differ between patients with dilated ventricles and those with relatively nondilated ventricles. Diastolic Fourier shape power index = 8 +/- 2 in dilated ventricles compared with 9 +/- 5 in nondilated ventricles (p = 0.53); systolic Fourier shape power index = 10 +/- 2 in dilated versus 14 +/- 2 in nondilated ventricles (p = 0.15) (apical 2-chamber view). In Chagas' cardiomyopathy, LV apical deformation results in disruption of the optimal global prolate-ellipsoid shape, even in patients with relatively preserved LV volumes.