Imam performed prayers until the end of his life.

A memoir by Mrs Farishteh I'rabi

ID: 74166 | Date: 2022/05/22
A day before Imam passed away, he prayed his Zohr and Asr prayers having done wudhu.  As of one hour before the time of Zohr, he would ask anyone who passed by as to how much time remained before Zohr.  His aim was to make sure he said his prayers on time.
 
At 3.30 in the afternoon, Imam became unconscious.  The doctors tried to revive him.  At around Magrib time, the doctors knowing that Imam had a deep attachment with prayers, called to him and said, "Agha, it is the time for prayers."  Imam, who was still unconscious at the time, responded to this call with a movement.  Then, with the motion of his hands and eyebrows, he proceeded to pray the Magrib prayers.
 
(A memoir by Mrs Farishteh I'rabi)