Tamil Nadu Chief Minister J Jayalalithaa remains very critical after last evening's cardiac arrest, Chennai's Apollo hospital said in a statement not long after her party the AIADMK said that the leader had a heart surgery this morning and that she "is improving." The hospital has denied that Ms Jayalalithaa had an angio procedure and said she continues to be on an extracorporeal membrane heart assist device or ECMO, a life support system that aids heart and lung functioning.