Patrick Trueman (Rudolph Walker) is to collapse in pain following an argument with Cora Cross (Ann Mitchell) and Stan Carter (Timothy West) during next week's episodes of EastEnders.
The shock scene - to be broadcast on Monday 7 July - will see a home alone Patrick clutch his arm and fall to the floor after rowing with Cora and Stan, who have defaced a picture of son Anthony in a medical journal.
A bewildered Patrick will then be seen struggling to comprehend what is happening and deciding not to tell anybody. The Walford stalwart tries to put on a brave face and attempts to carry on as normal, even going so far as to perform karaoke at the Vic the next day.
But the problem is only set to get worse when - in the coming weeks - Patrick has a major stroke. The storyline is set to explore the topic of care for the elderly, with the effect of the stroke on both Patrick and those closest to him charted throughout the rest of 2014.
Actor Rudolph Walker, who has played Patrick since 2001, said recently: "This is a truly important storyline as strokes affect so many different people, in so many different ways. We are all working very hard on this and I really hope Patrick’s story can help raise awareness.”
Dominic Treadwell-Collins, executive producer at EastEnders, added: "This is an important storyline in so many ways. Not only does it give the wonderful Rudolph Walker a chance to shine, but we also hope it will raise awareness of the warning signs that come before a stroke and the difficulties of caring for the elderly in 21st century Britain."