Both autonomic nerve activity and electrical remodeling are important in atrial arrhythmogenesis. Therefore, dogs with sympathetic hyperinnervation, myocardial infarction (MI) and completed atrioventricular block (CAVB) may have a high incidence of atrial arrhythmias. We studied 8 dogs (Experimental Group) with MI, CAVB and sympathetic hyperinnervation induced either by nerve growth factor (NGF) infusion (N=4) or subthreshold electrical stimulation (N=4) of the left stellate ganglion (LSG). Cardiac rhythm was continuously monitored by a Data Sciences International (DSI) transmitter for 48±27 days. Three normal control dogs were also monitored. Six additional normal dogs were used for histology control. PAF and PAT were documented in all dogs of experimental group, with an average of 3.8±3 episodes per day including 1.3±1.6 episodes of PAF and 2.5±2.2 episodes of PAT. The duration averaged 298±745 s (range 7 s - 4000 s). There was a circadian pattern of arrhythmia onset (P<0.01). Of 576 episodes of PAF and PAT, 236 (41%) episodes occurred during either sustained or non-sustained ventricular tachycardia. Among these 236 episodes, 53% started before while 47% started after the onset of ventricular tachycardia. Normal dogs did not have either PAF or PAT. The hearts from Experimental Group had a higher density of nerve structures immunopositive (P<0.01) for 3 different nerve specific markers in both right and left atria than that of control dogs. We conclude that induction of nerve sprouting and sympathetic hyperinnervation in dogs with AV block and myocardial infarction creates a high yield model of PAF and PAT.