| Background With the aging of human body, the cardiovascular system also changes in strcuture and physiological function, which leads to the appearance of arrhythmia characterized by decreased pace action, conductive dysfunction and ectopic activation. And the hepatic and renal function of the senile decrease, the half life of medicine is prolonged, which affects the senile's endurance .So it is of great significance to search safe and effective antiarrhythmic agents for the incidence and mortality decrease of senile arrhythmia. Amiodarone has been generally classified as a Vaughan-Williams class III agent, it also has class I , class II and class IV activity. It can be used to manage virtually all forms of supraventricular and ventricular tachycadia with clinical significance, it becomes the focus of studies published, and also the most-often-prescribed antiarrythmic agent. But there are few studies about its clinical effect and safety on the elderly population.Objective 1. To explore the efficacy of amiodarone on the senile patients suffering from frequent premature ventricular contractions and atrial fibrillation; 2. To explore the adverse effects of amiodarone on cardiovascular system and extra-cardiovascular system when used in senile patients.Material and methods 1. patient: We selected 88 patients(age≥60y), among them there were 24 patients with frequent premature ventricular contractions(PVCs, mean PVCs>30 beats/hour), 30 patients with paroxysmal atrial fibrillation(AF) and 34 patients with persistent AF. We divided the patients with frequent PVCs andpersistent AF into Am group(8 cases with PVCs,13cases with AF), Pr group (8 cases with PVCs,l leases with AF) and Mo group(8 cases with PVCs,10cases with AF), and patients with paroxysmal AF into Am group(15 cases) and Pr group(15 cases). At the same time we selected 34 patients younger than 60y(Young group) , among them there were 12 patients with frequent PVCs ,12 patients with paroxysmal AF and 10 patients with persistent AF, and all of them were treated with amiodarone. 2. Treatment method: All of the patients began to accept treatment after stopping other antiarrhythmia drugs for 5 half-lives and systematic examitation including physical exam,a full laboratory examination, chest X-ray, ECG, echocardiography etc. Method: ( i) Patients with frequent PVCs: Am group: After receiving a standardised loading dose of amiodarone 600 mg/day (divided into three times) for 5-7 days, followed by 400 mg/day for 5-7 days, with a subsequent maintenance dose of 200 mg/day; Pr group: propafenone 150mg thrice daily; Mo group moricizine 150 thrice daily. (ii) Patients with AF: ?for paroxysmal AF: Am group and Young group— amiodarone 150mg was used intravenously(i.v.) as a bolus within 10 minutes and it could be used repeatedly one time after 10-15 minutes ,followed by continuous i.v. infusion with the dose l-1.5mg/min for 6 hours , on the same day patients should be given amiodarone 200mg orally thrice daily for 5-7days, then 200mg twice daily for 5-7days and 200mg once daily thereafter; Pr group- the dose of i.v. bolus was propafenone l-2mg/kg at the speed of lOmg/min, the maximal amount of one time is 140mg ,and stop it quickly when converting into sinus rhythm, 30-60minutes later it could be used repeatedly one time if failed , after convertion patients began to take orally propafenone 150mg thrice daily; (2) for persistent AF: Am group~8 patients received medicine both intraveneously and orally(iv+po subgroup), the other 5 patients only received medicine orally(po subgroup); Pr group- propafenone 150mg tid thrice daily orally; Mo group-moricizine 150 thrice daily; Young group~5 patients received medicine both intraveneously and orally(iv+po subgroup), the other 5 patients only received medicine orally(po subgroup) 3. Follow: Follow up 6-12 months to observe the effect and adverse effect. 4. syatistical method: the data are presented as mean ± standarddeviation. Data were tested by /test,and ^examination,, P<0.05 was accepted as the limit of significance.Result 1. For frequent PVCs: there were no significant differences among Am group > Pr group and Mo group (Z^O.05) ,and the same result was gained between Am group and Young group (P >0.05) ; 2. For persistent AF: amiodarone was more effective than propafenone and moricizine in the conversion of persistent AF(P <0.05), but there were no significant differences among three groups in the maintenance of sinus rhythm (P >0.05) ; there was no significant difference between Am group and Young group (P >0.05) ; the iv+po subgroup was faster than po subgroup in convertion of AF (P O.001) ,but their convertion rates had no statistical difference (P >0.05 ); 3. For paroxysmal AF: there was no significant difference between Am group and Young group in the convertion rate, convertion time and maintenance of sinus rhythm (P >0.05);also no difference between Am group and Pr group in the convertion rate, but the onset of Pr group was more rapid than that of Am group (P <0.05) ,the maintenance rate of Am was higher than that of Pr group (P <0.05) .4. After 2 weeks QTc> P-R interval significantly prolonged in Am group (P <0.05), but LVEF value did not change significantly (P >0.05) . 5. The number of patients in Am group suffering from adverse effects was more than those in Pr group, and patients necessitating withdrawal in Am group was more than those in Pr group and Young group.Conclusion (1) Amiodrone is effective for frequent PVCs and AF in the senile patients,especially is more effective than propafenone and moricizine in the conversion of persistent AF ,also in the maintenance of sinus rhythm; (2) The combination of intrvenous and oral amiodarone has a rapider onset than only oral amiodarone in convertion of AF, but their convertion rates have no statistical difference.(3) Amiodarone does not affect LVEF value,so patients with heart dysfunction can use it. It can significantly prolong QTc, but it decreases the dispersion of repolarization,and inhibits early afterdepolarizations(EAD),so it has low proarrhythmic potential; (4) Its adverse effects mainly are extracadiac toxicity. Pulmonary toxicity is the most severe,;long-term treament with amiodarone can lead to hypothyroidism in the senile;hepatic toxicity also can be found; cardiac toxicity including sinusbradycardia ,sinus-atrial and atrium-ventricular block often appear in the eldly patients with structural heart disease, so must be carefully monitored,such as periodic measurement of thyroid,hepatic function and chest X-ray.
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