What scenes or statements would make his heart condition, the situation and setting of Krapp's Last Tape seem believable?
Krapp's Last Tapes is a clear representative of realism. The minimalist approach used by Beckett effectively convey the focal topics, to include shattered dreams, idealized existence, health and aging, disillusion, and death.
The first part of the play clearly depicts Krapp as a man who is both sick and aging. The manner in which Becket subtlety suggests his heart condition is by depicting Krapp's typical dynamics in a strained manner:
White face. Purple nose. Disordered grey hair. Unshaven...Cracked voice... Laborious walk
The laborious walk, the purple nose, the cracked voice and the unshaven look suggest the image of a sick man, perhaps even an alcoholic. These are, furthermore, suggestions of a man who does not take care of himself physically and, perhaps, health-wise.
Becket further describes the setting taking into consideration the manner in which everything seems to follow a disorderly and chaotic pattern; this is an allegory of Krapp's own life.
He turns, advances to edge of stage, halts, strokes banana, peels it, drops skin at his feet, puts end of banana in his mouth and remains motionless, staring vacuously before him.
Krapp's movements are automated, repetitive, unimportant. Typical dynamics of a man whose daily life has a purpose and goal that only he can figure out, for its original purpose is devoid of meaning altogether. Yet, from the combination of actions and setting the audience can certainly get a whole picture: the setting is meant to be as messy and chaotic as Krapp himself.
Moreover, the background tapes serve as a backdrop that strengthens the atmosphere of gloom, nostalgia, and desolation that affects the play. The bouts of silence from, both, the younger and older Krapp leave time for the audience to realize the void that has become Krapp's life. It also serves as background "dust" noise that is effectively combined with Krapp's fits of coughing.
Now the day is over,
Night is drawing nigh-igh,
Shadows--Fit of coughing. He comes back into light, sits down, wipes his mouth, switches on..
This denotes how the setting is not only meant to look physically forsaken, but that the atmosphere that surrounds it, filled with the past ghosts of dreams misbegotten, seem to fill the air with the dust of passing time. The final image of Krapp that the audience gets shows a man staring blankly at something, listening to the voice of his past on tape which, ironically, had hoped for a productive future.
Here I end this reel... Perhaps my best years are gone... But I wouldn't want them back. Not with the fire in me now. No, I wouldn't want them back.Krapp motionless staring before him.The tape runs on in silence.
This scene greatly ends and yet accentuates the setting further, for Krapp's look adds to the helplessness of his condition, and atones perfectly with his surroundings.
All these elements effectively convey realism and the possibility that a situation such as Krapp's could actually happen to anyone else, provided that they have also let life slip through their fingers in the quest of impossible or fantastic dreams.