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[Diuretics in the treatment of heart failure: current pathophysiological aspects]
L Mandinov1, C Matter, P Kaufmann
1Kardiologie, Inselspital Bern.
Insights
Heart failure involves systolic or diastolic dysfunction, impacting ejection fraction or filling pressures. Treatment focuses on symptom relief using medications like ACE-inhibitors, digitalis, and diuretics, with some drugs also improving long-term outcomes.
Area of Science:
- Cardiology and Pathophysiology
- Pharmacology and Therapeutics
Context:
- Heart failure is pathophysiologically classified into systolic and diastolic dysfunction.
- Systolic dysfunction involves reduced ejection fraction, common in younger patients with cardiomyopathy.
- Diastolic dysfunction presents with preserved systolic function but elevated filling pressures, typical in elderly patients with hypertrophy.
Purpose:
- To outline the pathophysiologic basis of heart failure.
- To detail current treatment strategies for congestive heart failure.
- To discuss the primary goals and secondary considerations in medical therapy.
Summary:
- Treatment strategies encompass preload and afterload reduction, regression of hypertrophy, maintaining atrial contraction, decreasing heart rate, improving left ventricular (LV) relaxation, and preventing myocardial ischemia.
- Primary therapeutic goals focus on symptomatic improvement, with secondary aims of reducing morbidity and mortality.
- Medications include ACE-inhibitors, beta-blockers, digitalis, vasodilators, diuretics, and aldosterone antagonists, each with specific roles in managing heart failure symptoms and progression.
Impact:
- ACE-inhibitors and certain beta-blockers are key for achieving therapeutic goals.
- Digitalis and vasodilators enhance quality of life, particularly in atrial fibrillation.
- Aldosterone antagonists show promise in LV remodeling and mortality reduction, while the roles of endothelin antagonists and atriopeptidase inhibitors require further investigation.
Abstract:
From a pathophysiologic point of view heart failure can be divided into systolic and diastolic dysfunction. Systolic dysfunction is characterized by a decreased ejection fraction and increased chamber volume which can be typically found in young people with congestive cardiomyopathy. Diastolic dysfunction is associated with an enhanced filling pressure but with a normal systolic pump function. This disorder can be typically found in elderly patients with myocardial hypertrophy. Treatment of congestive heart failure includes. 1.) reduction of central blood volume (preload reduction) 2.) decrease of peripheral resistance afterload reduction) 3.) regression of myocardial hypertrophy (improving myocardial stiffness) 4.) maintenance of atrial contraction (atrial kick) 5.) decrease of heart rate (prolongation of diastolic filling time and increase in contractility) 6.) improvement of LV relaxation (positive lusitropic effect) and 7.) prevention of myocardial ischemia (improvement in contractility and relaxation). The primary goal of medical therapy is symptomatic improvement. Reduction in morbidity and mortality is only a secondary consideration. To achieve this goal ACE-inhibitors and in certain cases betablockers (cave: neg. inotropic action) are suited best. Additionally, digitalis-especially in the presence of atrial fibrillation- and vasodilators can be used to further improve quality of life. In the case of severe heart failure with or without atrial fibrillation oral anticoagulation is indicated to prevent systemic embolication. Diuretics are often used for symptomatic improvement but have no effect on long-term survival. Aldosterone antagonists (e.g, spironolactone) have a beneficial effect on LV remodeling and probably also on mortality. The role of endothelin antagonists and atriopeptidase inhibitors in the treatment of heart failure are not yet clear.