My father has alcohol-induced cirrhosis with portal hypertension, ascites, and hepatic encephalopathy; no esophageal varices but has gastropathy. He has been diagnosed with a stone in each kidney 1 cm on the right, 8 mm on the left per CT scan. His urologist would like to perform a lithotripsy and cystoscopy to remove the stones. What are the risks involved? He has a history of heart disease/bypass surgery and past surgeries for kidney stone removal. He is 57 years old with a normal ECG but has a slightly elevated QTc of 454 ms.