MUMBAI, Oct 9: Assam Governor JB Patnaik underwent a successful surgery for implantation of a pacemaker at a hospital last week, official sources said on Tuesday. The 85-year-old veteran Congress leader was discharged from Asian Heart Institute (AHI) Monday and is currently recuperating at Raj Bhavan in Mumbai. According to the sources, Patnaik was brought from Guwahati and admitted to AHI, Bandra, last week following complaints of breathing troubles. He underwent an angiography and later a permanent pacemaker implantation procedure was carried out by a cardiology team headed by Dr Tilak Suvarna. He is likely to take rest for some more days before resuming his normal gubernatorial functions in Assam. IANS