treatment options for PVCs

I have been having PVCs for  3 years, and have been taking 100-200 mgm Amediorone.  A recent 24 holter test showed 9477/637 bigeminy beats/events,  156/42 trigeminy beats/events, and 255 isolated SVEs. In februrary 2008, bigeminy 12/4, trigeminy 2583, and Islated SVE 64.  In October 2007, therte were no bigeminy or trigeminy events. Please comment on clinical significance of this  increase in bigeminy beats/events. Could this be due to toxicity of Amediorone.
Would ablation, pacemaker or another drug be a better option for a 77 year old man? I have been told that PVCs are originating in the left ventricle. Would ignoring them lead to more serious problems like ventricular tachcardia? My heart function is good with ejection fraction 60% to 65%, and normal exercise tolerance. My  heart rate is 55 beat, however, at night it slows to mid forties. Beta-blockers have not been helpful

Thanks so much