Cardiac inotropes in management of decompensate heart failure : current agents and future directions

Abstract

Heart failure is a clinical syndrome that can result from any disorder that impairs the ability of the ventricle to fill with or eject blood, thus rendering the heart unable to pump blood at a rate sufficient to meet the metabolic demands of the body. (Hunt et al, 2001) Decompensated heart failure encompasses a group of related clinical syndromes broadly defined as new or worsening symptoms or signs of heart failure leading to hospitalization (Felker et al, 2003). The severity of decompensated heart failure may range from mild volume overload in the setting of nonadherence to diet or pharmacotherapy to life-threatening cardiogenic shock and multiorgan failure (Petersen and Michael, 2008). Impaired cardiac contractility plays a central role in heart failure ,activating a series of maladaptive hemodynamic,structural and neurohormonal responses which contribute to heart failure progression. (Tamagro et al, 2011). Inotrope administration can greatly help to stabilise the patient and provides considerable symptomatic and haemodynamic benefit in the short term. (Greenberg et al, 2003). Treatment with conventional inotropes improves symptoms and haemodynamics as it increases stoke volume and left ventricular ejection fraction and reduces left ventricular filling pressures of decompensated heart failure patients ,However their benefits can be counteracted by serious adverse effects including neurohumoral activation, maladaptative remodeling ,intracellular Introduction 2 calcium overload and hypotension which decreases coronary perfusion. (Tamargo et al 2010). These findings may be related to the fact that these agents increase myocardial concentrations of cAMP, producing an increase in intracellular calcium that possibly leads to myocardial cell death and/or increases lethal arrhythmias