My Husband Has Exercise Induced Pvc's And Extreme Vt And

My husband has exercise induced pvc's and extreme vt and cardiomyelgy and suffers with an umbilical hernia that needs to be operated on....he is scheduled for a est from his electrocardio physiologist who recommends he stay on his heart meds...( metropolol, fleucenide, losartan, simvastatin ...maybe more ..not sure) during stress test.. His first est he was immediately told to stop within 3 minutes...hence the aforementioned diagnoses. Im assuming he will need clearance from his cardiologist for this type of surgery....what are some suggestions you may offer regarding next steps...also how long is the clearance good for?