Pacemakers -Indications for pacemakers and ICD. Modes - VVI and DDD. Pacemaker Troubleshooting. Failure to Pace, Sense, Capture. Twiddlers syndrome. Pacemaker malfunction and causes. Heart Failure. HFrEF & HFpEF. LV Dysfunction POCUS. AVR Elevation & LMCA CAD. Polymorphic VT