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[Left ventricular mechanics in Chagas' disease and primary dilated myocardiopathies. A hemodynamic study]
C Gómez de Pereira1, H A Carrasco, L Guerrero
1Centro Cardiovascular Dr. Abdel M. Fuenmayor, Universidad de los Andes, Mérida, Venezuela.
Insights
Early heart mechanical changes in Chagas disease, like increased afterload and inadequate hypertrophy, are detectable. These changes worsen with disease progression and resemble dilated cardiomyopathy.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Chronic Chagas disease can lead to significant cardiac dysfunction.
- Dilated cardiomyopathy shares some mechanical similarities with advanced Chagasic heart disease.
Purpose of the Study:
- To investigate the evolution of mechanical parameters in left ventricular function.
- To identify early indicators of cardiac abnormalities in Chagas disease.
- To compare mechanical profiles between Chagasic and dilated cardiomyopathy patients.
Main Methods:
- Utilized extensive invasive and non-invasive protocols.
- Derived parameters including preload, afterload, ejection fraction, and hypertrophy indices.
- Analyzed end-diastolic stress, end-systolic stress, mass/index, and mass/volume ratios.
Main Results:
- Increased afterload and inadequate hypertrophy were observed in 25% of early Chagasic patients.
- These abnormalities progressed with disease severity.
- Systolic performance declined progressively, mirroring clinical evolution.
- Dilated cardiomyopathy patients exhibited mechanical profiles similar to advanced Chagasic heart disease.
Conclusions:
- Hemodynamic parameters like mass index and stress/volume ratios are key for detecting early cardiac loading abnormalities in Chagas disease.
- These parameters aid in guiding and evaluating vasodilator therapy for both Chagasic and dilated cardiomyopathy patients.
Abstract:
The evolution of several mechanical parameters of left ventricular function was studied in 32 control subjects, 171 chronic chagasic and 60 primary dilated cardiomyopathy patients, which were submitted to an extensive invasive and non-invasive protocol. Preload and afterload (end-diastolic and end-systolic stress), contractile status (ejection fraction), the magnitude (mass/index) and adequacy of hypertrophy (mass/volume ratio) and afterload (systolic stress/volume ratio) were derived from the invasive explorations. There was an increased afterload in 25% of chronic chagasic patients without other evidence of early myocardial damage, which was accompanied by signs of inadequate hypertrophy. Both findings increased further with the progression of the disease. Systolic performance was initially preserved, but showed a progressive depression paralleling the clinical evolution. Patients with dilated cardiomyopathy showed a mechanical profile similar to chagasic patients with advanced degree of myocardial damage. The hemodynamic determination of mass index, mass/volume ratio, end-systolic and end-diastolic stress seem to be the best parameters for detection of early abnormalities in loading conditions of the heart in chronic Chagas, disease, and for indication and evaluation of the results of vasodilator therapy in both groups of patients.