Pain In Ribs After Laying Down To Sleep After An Angioplasty. Reasons ?

My dad underwent an angioplasty recently. The course in the hospital was as follows: 68 yr male patient admitted in CIU with above complaint for required managment and close monitoring, lab investigation done. 2d echo done s/o IHD, RWMA, Grade I diastotic dysfunction, Mild LV systolic dysfunction. Patient underwent Emergency Coronary Angiography on 4/2/13 s/o IHD- double Vessel CAD. Recommendation : Primary PTCA to RCA, PTCA stenting to OM at a later stage. On 4/2/13 Coronary angioplasty done PTCA to RCA (stent: Xience V 3.0 x 15 mm, Xience Prime 3.0 x 33 mm) Stood procedure well. yesterday night my dad could not sleep. He is experiencing pain in ribs after laying down to sleep.