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[Left ventricular diastolic dysfunction in cardiomyopathies]
Insights
Diastolic dysfunction, a key factor in cardiac disease, significantly impacts heart function. Recognizing its role in conditions like cardiomyopathy improves patient symptom understanding and management.
Area of Science:
- Cardiology and cardiovascular physiology.
- Understanding cardiac mechanics and disease pathology.
Context:
- Historically, clinical focus has been on systolic function.
- Recent decades highlight the critical role of diastolic function in cardiac health.
- Diastolic dysfunction is increasingly recognized as central to various heart conditions.
Purpose:
- To underscore the clinical significance of diastolic function in cardiovascular disease.
- To elucidate the mechanisms and consequences of diastolic dysfunction.
- To emphasize the prevalence of diastolic dysfunction across different cardiomyopathies.
Summary:
- Left ventricular diastolic dysfunction, stemming from impaired relaxation or altered myocardial properties, reduces ventricular distensibility and elevates filling pressures.
- This dysfunction is a primary driver of symptoms in many cardiomyopathy patients.
- Specific examples include hypertrophic cardiomyopathy (due to hypertrophy, disorganization, fibrosis), restrictive cardiomyopathy (mimicking constrictive pericarditis), and dilated cardiomyopathy (associated with reduced compliance).
Impact:
- Elevates the understanding of cardiac disease pathophysiology.
- Provides a framework for improved diagnosis and management of heart failure patients.
- Highlights the importance of assessing diastolic function for comprehensive cardiac evaluation.
Abstract:
Although physiologists have recognised for many years that cardiac performance is based on two functions, systolic and diastolic, it has only been in the last 15 years that clinicians have acknowledged the essentiel role of diastole in the physiopathology of cardiac disease. Many studies have shown that left ventricular diastolic dysfunction resulting from abnormal active relaxation or changes in passive visco-elastic properties of the myocardium modulating its rigidity were responsible for decreased distensibility of the ventricle and an increase in its filling pressures. Therefore, the symptoms of the majority of patients with cardiomyopathy are due, more or less, to diastolic dysfunction. This is particularly the case in hypertrophic cardiomyopathy, most case of which have diastolic dysfunction secondary to an often asymetric distribution of the hypertrophy, to the disorganisation of the myocardiofibres and to interstitial fibrosis. With respect to advanced forms of restrictive cardiomyopathy, as their clinical and haemodynamic characteristics resembling constrictive pericarditis show, they demonstrate caricatural diastolic dysfunction. Finally, although the main abnormality in dilated cardiomyopathies is poor contractility, a decrease in ventricular compliance is constantly observed.