Three short lines, and nearly all of the drama is in one act of listening. A speaker lies in bed at night and becomes aware of their own heartbeat. They don't find it reassuring, as a steady pulse might be. They find it sad. The central idea is that the body, which usually works unnoticed, grows audible in the quiet, and what we hear in it depends on how we feel. The poem never says why the speaker is sad, and it doesn't need to. The heartbeat has already taken on the mood.
The word that does the most work is "heave." A pulse is normally imagined as a tidy tick or thump. A heave is something else: a swell of the sea, a sob, a retch, the effort of lifting something too heavy. By choosing it, the poem turns each beat into a labour, a small struggle the heart has to repeat. "Every" adds to this. It makes the beats feel counted and inescapable, one after another, with no skipping any of them. The word "heart" also carries a double meaning. It is the muscle that is being heard, and it is the traditional seat of grief, so the sadness lives in the same place as the sound.
The sound of the lines supports this. "Heart's," "heave" and "hear" all begin with a breathy h, so the first two lines seem to exhale, and the word that names the organ is linked to the act of hearing it. The syllable count is five, five and four, which recalls the compression of haiku without following the 5-7-5 pattern. The stresses are worth listening to as well. In "my heart's every heave," the strong beats fall close together on "heart's," "ev-" and "heave," so the line lurches rather than glides. "A sad noise to hear" puts "sad" and "noise" side by side, two heavy syllables that land like consecutive beats. Then the last line, "at night in bed," settles into a gentler alternation and ends on "bed," a short word closed by a hard d. It works like a final soft thud, and it leaves the silence the heart has been working against. There is no rhyme to round things off. "Hear" and "bed" don't match, and the lack of a chime keeps the poem from sounding finished or consoled.
The grammar is just as bare. There is no main verb. "My heart's every heave" is a noun phrase, and "a sad noise to hear" simply sits beside it with no "is" to join them. The poem is lowercase and has no punctuation, so it never reaches a full stop. That suits its subject, since a heartbeat never stops of its own accord and the sentence is left hanging in the same way. The choice of "noise" is telling too. A beat could have been a rhythm, a drum or a sound, but "noise" suggests something unwanted and unmusical, something the speaker would silence if they could. Then there is "to hear." The speaker is both the source of the sound and the only audience for it, so the self is split into a body that produces and a mind that listens. Whether the "sad" belongs to the heart or to the listener is deliberately unclear, and the poem is stronger for that blur.
The title, "Pulse," is the most clinical word in the piece. It points to something a nurse would measure, which sets the neutral fact against the emotional response in the lines below it. We are given the measurable thing first and then shown what it feels like to live inside it.
The final line delays the setting until the end, and that placement matters. Only after the heartbeat has been established do we learn that this is night, and bed. These are the conditions that make such a sound audible, when there is no daytime noise to cover it, and they also leave a person alone with their thoughts. The poem gives no sign of anyone else in the room, though that is an inference from its single, inward voice. Bed can suggest rest, but here it seems closer to a place of exposure. A reader might think of insomnia, grief or worry, or of the plain, unsettling awareness that the heart is a finite machine. The poem leaves all of these open.
What makes it significant is how much it holds in so little space. It takes a fact everyone has and turns it into a feeling most people will recognise. It shows, in a few words, how attention can change the way we experience our own bodies.