Diastolic heart failure

Diastolic heart failure

Diuretics if congested
Ca++  channel blockers in some cases
NO ROLE for digoxin.

The rapid relief of acute myocardial ischemia is often effective when diastolic dysfunction is secondary to this condition. The reduction in heart rate caused by beta-blockers has several beneficial on diastolic function, including a prolongation of the filling period and an amelioration of ischemia. calcium channel blockers, especially Verapamil, have been shown to accelerate ventricular relaxation in patients with hypertrophic cardiomyopathy and have been reported to be useful in the treatment of diastolic dysfunction characteristic of this condition. Other beneficial mechanisms are reduction in heart rate, control of hypertension, reduced microvascular ischemia and oxygen demand, amelioration of intracellular calcium overload and regression of left ventricular hypertrophy.

Ventricular filling pressure and secondary venous congestion may be reduced by restriction of sodium intake and the administration of diuretics and venodilators. Even in the absence of ischemia, nitrates, by reducing preload, are useful in managing diastolic dysfunction and in the treatment and prevention of consequent severe pulmonary congestion. Nitroglycerin may be administered intravenously or sublingually in emergency situations, and long acting nitrates, such as isosorbide dinitrate, are often effective in the long term. In the long term, however, excessive preload reduction should be avoided because these patients often require higher-than-normal filling pressures to maintain an adequate stoke volume.

The maintenance of heart rhythm and rate is of critical importance. Tachycardia, whatever the underlying mechanism, must be controlled, thereby increasing the fraction of each cardiac cycle available for ventricular filling. Maintenance of sinus rhythm with synchronized atrioventricular sequential pacing may be crucial in permitting atrial augmentation of ventricular filling. Digoxin and other inotropic agents have no established place in these patients with relatively well preserved ejection fraction, and could, in principle, have an adverse effect in this group. Exercise training induces significant improvement in exercise capacity in patients with dilated cardiomyopathy and a pattern of abnormal left ventricular relaxation. Finally, it has been shown that endogenous nitric oxide released from the coronary microcirculation selectively enhances left ventricular relaxation in the isolated ejecting guinea pig heart. These findings may lead to a new therapeutic approach to diastolic heart failure, with treatments aimed at the coronary microcirculation.

The American College of Cardiology / American Heart Association task force divides pharmacologic treatment into three classifications for the management of diastolic HF : Class I refers to drugs that are always indicated, such as diuretics and nitrates, and drugs suppressing atrioventricular conduction and anticoagulation if atrial fibrillation is present. Class II agents are " acceptable "; however, their efficacy is uncertain. These include calcium channel blockers, beta-blockers, ACE inhibitors and anticoagulation in patients with intracardiac thrombus. Class III drugs are not indicated and include drugs with positive inotropic effects.