Because the therapeutic margin of antiarrhythmic drugs is low in elder
ly patients, the risk/benefit ratio should be carefully evaluated befo
re initiation of treatment. Depressed contractility, arrhythmias, and
depressed conduction are the main cardiac adverse effects of antiarrhy
thmic agents. Cardiac function should be evaluated by echocardiography
before initiation of treatment since adverse effects are more severe
in patients with advanced cardiac dysfunction. A pretreatment Holter r
ecording should also be performed routinely to look for subclinical co
nduction disturbances. Only symptomatic rhythm disorders should be tre
ated. Treatment of identified causes of rhythm disorders is the first
step. A diagnostic and therapeutic strategy for the most common rhythm
disorders in elderly patients (atrial fibrillation, sick sinus syndro
me, and premature ventricular beats) is suggested.