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[Left ventricular mechanics in Chagas' disease and dilated cardiomyopathy: echocardiographic study]
Insights
This study reveals early afterload increase and inadequate hypertrophy in Chagas disease patients, identifying those who could benefit from oral vasodilators for improved left ventricular mechanics.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Left ventricular (LV) mechanics are crucial for assessing heart function.
- Chagas disease and primary cardiomyopathy present distinct challenges in LV assessment.
Purpose of the Study:
- To investigate early alterations in left ventricular mechanics in chronic chagasic and primary cardiomyopathy patients.
- To identify parameters indicative of early disease stages and potential therapeutic targets.
Main Methods:
- Utilized extensive invasive and non-invasive protocols in 184 chagasic and 85 primary cardiomyopathy patients.
- Assessed afterload (mean wall stress), contractile status (ejection fraction, circumferential shortening), and hypertrophy (mass index) via M-mode echocardiography.
Main Results:
- Early afterload increase observed in 8% of chagasic patients without evident LV myocardial damage.
- Inadequate hypertrophy accompanied increased afterload in 15% of chagasic patients with early segmental myocardial damage.
- Contractility depression (ejection fraction, shortening) primarily seen in patients with congestive heart failure; dilated primary CM patients showed more pronounced contractility depression without heart failure signs.
Conclusions:
- Mean systolic wall stress and mass index are valuable for identifying patients with early increased afterload and inadequate hypertrophy.
- These parameters can guide the use of oral vasodilators in specific patient groups to improve left ventricular mechanics.
Abstract:
For purposes of studying left ventricular mechanics, 184 chronic chagasic and 85 primary cardiomyopathy patients were submitted to an extensive invasive (LV cine, right and left cardiac catheterization and coronarography) and non-invasive protocol. The afterload, (mean wall stress), the contractile status (ejection fraction and circumpherential shortening) and the degree of hypertrophy (mass index) were assessed by M mode echocardiography. There was a very early increase of afterload in 8% of chagasic patients without evidences of LV myocardial involvement in the left cineventriculogram (group I-A). This increased afterload was accompanied by signs of inadequate hypertrophy in 15% of patients with early segmental myocardial damage (group IB). In contrast, ejection fraction and % circumpherential shortening were depressed only in patients with clinical evidences of congestive heart failure. Dilated primary CM patients showed similar findings, except for a more evident depression of contractility in those cases without signs of congestive heart failure (group II) and more hypertrophy than equivalent group III chagasic patients. Measurements of mean systolic wall stress and mass index are valuable parameters for identification of those patients with early increased after-load and inadequate hypertrophy which could benefit from the administration of oral vasodilators.