Corona exits trial without permission. After reading his lengthy opening statement, Chief Justice Renato Corona leaves the witness stand at 5:07 pm without the permission of Senate President Juan Ponce Enrile during his impeachment trial on Tuesday. Manny Marcelo/Pool

Impeached Chief Justice Renato Corona will remain under observation for 48 hours and will not be cleared to return to the Senate for his trial Wednesday afternoon, according to doctors at The Medical City in Pasig City, where Corona was confined after he abruptly left the Senate session hall after his testimony Tuesday.

Dr. Eugenio Ramos, SVP for medical services, cited the possibility of an acute coronary syndrome or heart attack and pushed for further observation, radio dzBB's Glen Juego reported.

However, Ramos said Corona's vital signs appeared stable as of Wednesday morning. Corona was brought to the hospital's intensive care unit at 1 a.m. Wednesday.

Senate President Juan Ponce Enrile had warned Corona's defense team at Tuesday's session that their client must return for cross examination on Wednesday, otherwise his testimony will be stricken off the record and the senator-judges will vote based on previous evidence. 

The senators will decide today on whether to accept Corona's medical reason for his absence and ppostpone the cross-examination. 

Diabetic

Dr. Ramos said Corona has been diabetic for the last 20 years, and had heart bypasses in 2005 and 2008.

"We have to consider him a very high-risk patient," he said.

Ramos also said Corona has been diabetic for past years and this may cause "complications involving both the kidneys and heart."

GMA News' Lia Mañalac del Castillo tweeted that doctors want Corona monitored in the ICU for 48 hours, and cannot appear at his impeachment trial on Wednesday.

Corona was brought to the Medical City past 7 p.m. Tuesday, after he appeared before the Senate impeachment court and delivered a lengthy opening statement. — LBG/HS, GMA News