Related Experiment Videos
[Dilated cardiomyopathy: recent advances and current treatment]
1Profesor Titular de Medicina. Centro Médico. Caracas. Venezuela. hacquetalla@true.net
Insights
Dilated cardiomyopathy (DC) causes heart muscle weakening and affects millions. New therapies, including beta-blockers, significantly reduce mortality in congestive heart failure (CHF) patients.
Area of Science:
- Cardiology
- Genetics
- Pathophysiology
Context:
- Dilated cardiomyopathy (DC) is characterized by ventricular dilatation and systolic dysfunction.
- It is a significant cause of cardiac morbidity, leading to congestive heart failure (CHF) and arrhythmias.
- Prevalence estimates indicate left ventricular systolic dysfunction in 2-3% and CHF in 1.5% of the general population.
Purpose:
- To review the current understanding of dilated cardiomyopathy's pathogenesis, treatment, and prognosis.
- To highlight the impact of recent therapeutic advancements on mortality rates.
- To discuss future directions in research, particularly in genetic mechanisms.
Summary:
- DC pathogenesis involves genetic factors, viral infections, immune responses, and myocardial apoptosis.
- Mortality in severe CHF, previously high (50% at 2 years), has been reduced by "triple" therapy (diuretics, digoxin, ACE inhibitors).
- Additional mortality reduction (35%) is achieved with beta-blockers and spironolactone, with beta-blockers also decreasing sudden death.
Impact:
- Improved management strategies have significantly decreased mortality associated with severe CHF.
- Beta-blockers are now a near-mandatory treatment for stable chronic CHF due to their survival benefits.
- Cardiac transplantation and defibrillator implantation offer improved survival for specific patient groups.
- Advances in understanding genetic mechanisms hold promise for future treatment innovations.
Abstract:
The combination of dilatation and systolic dysfunction of the left or both ventricles from idiopathic or specific origin define dilated cardiomyopathy (DC). It is an important cause of cardiac morbidity through congestive heart failure (CHF) or arrhythmias. Prevalence studies estimate a rate of left ventricular systolic dysfunction of 2% to 3% or more, and of 1.5% of CHF among the general population. Genetic studies on familial DC have identified at least 5 genetic locus. In addition, the role of virus, genetic abnormalities, immunologic responses and increased myocardial apoptosis are factors recognized factors that play a significant role in the pathogenesis of idiopathic DC. Mortality in severe CHF may reach 50% at 2 years after diagnosis. The introduction of "triple" therapy combining diuretics, digoxin and angiotensin converting enzyme inhibitors (ACEI) has significantly decreased this high mortality. Recent large, multicentric clinical trials on drugs aimed to diminish the neuroendocrine hyperactivity of patients in stable chronic CHF (betablockers and spirolactone) have resulted in an additional reduction in total mortality of about 35% in relation with control groups. Betablockers, compared to ACEI, also diminish the rate of sudden death prompting their almost mandatory indication in the absence of contraindications. Cardiac transplantation presently offers a survival rate of 66% at 5 years but donor scarcity has stabilized the number of procedures. In patients resuscitated from malignant arrhytmias the implantation of defibrillators offers a better survival than drugs. Future advances in the knowledge of the pathogenesis and especially of genetic mechanisms, may substantially change the understanding and treatment of these disorders.