Diastolic Dysfunction

Diastolic dysfunction is a common cause of heart failure and is manifested by a poorly compliant and preserved systolic function. Although it can be seen alone, it frequently accompanies severe systolic heart failure. The common cause of diastolic dysfunction is hypertensive heart disease. The drug treatment of diastolic dysfunction includes diuretics to lower filling pressure, beta blockers to decrease heart rate and, thus, increase diastolic filling may be particularly useful. Aggressive management of hypertension with ACE inhibitors, ARBs and calcium channel blockers is also helpful.

The term heart failure with preserved ejection fraction defines a clinical syndrome wherein typical signs and symptoms of congestive heart failure occur in the clinical setting of primarily abnormal diastolic function with normal or near normal systolic function. Thus, heart failure with preserved ejection fraction is often used as a synonym for diastolic heart failure, even though the term heart failure with preserved ejection fraction typically refers to patients whose heart failure is due to intrinsic myocardial diastolic dysfunction. There are some patients with heart failure and preserved ejection fraction with extrinsic non-myocardial diastolic dysfunction, such as pericardial constriction or tamponade and mitral stenosis. In addition, some patients have heart failure with preserved ejection fraction without diastolic dysfunction, for example, acute mitral regurgitation and high output states.

In patients with dilated cardiomyopathy the most common clinical presentation is congestive heart failure. It is mainly due to systolic dysfunction, although nearly all patients also have diastolic dysfunction. Additional important clinical presentations include arrhythmias and thomboemboli that must be addressed when planning their treatment.

Arrhythmias are common in patients with dilated cardiomyopathy. Atrial fibrillation can significantly reduce cardiac output due to both the loss of atrial contraction and rapid heart rate. The immediate goal is control of the ventricular response, usually with beta blockers. Digitalis and/or amiodarone may be useful adjuncts. Restoration of sinus rhythm with drugs such as amiodarone or electrocardioversion is often critically important in cardiomyopathy patients. Ventricular arrhythmias are common and these patients may be at significant risk of sudden death. However, antiarrhythmic drug treatment carries a significant risk of pro arrhythmia. Implantable cardioverter-defibrillators reduce arrhythmic mortality in patients with ejection fractions less than thirty-five percent even in the absence of documented ventricular arrhythmias and should be strongly considered.

Conditions that predispose patients to thromboembolic events include the presence of left ventricular or atrial mural thrombi and atrial fibrillation. Unless there is a contraindication, anticoagulation therapy, typically with warfarin, is recommended in patients with dilated cardiomyopathy who have left ventricular or atrial mural thrombi or atrial fibrillation.