Muscle bracing palpitations and bounding pulse inner restlessness

The short version: your symptom cluster — palpitations, a bounding pulse, muscle bracing, and inner restlessness — points most directly to a cardiovascular or autonomic cause, not a psychiatric one, and the evidence here does not support a vaccine link for this specific presentation.

The evidence you received is mostly off-topic. One record describes a 66-year-old man with severe aortic regurgitation who had bounding carotid pulses and a wide pulse pressure of 120 mm Hg [1]. That is a structural heart valve problem: the aortic valve does not close, blood leaks back into the heart, and the pulse feels forceful and collapsing. Another study of 20 heart failure patients who stopped their medications for 48 hours showed that systolic blood pressure rose from 131 to 152 mm Hg, NT-proBNP nearly doubled, and left ventricular volumes increased [3]. Those changes can produce palpitations and a bounding sensation, but they come with measurable congestion, not just restlessness.

The inner restlessness and muscle bracing are not explained by those heart studies. A case series of three patients with acute pontine strokes found that all developed either restless legs syndrome or akathisia — a severe inner restlessness that makes people feel they must move [2]. The pons is a brainstem region that controls arousal, muscle tone, and autonomic output. A small stroke there can produce exactly the combination you describe: a sense of being driven to move, muscle tension, and a pounding heart. That is a neurological cause, not a cardiac one.

The evidence here does not include a single study that tests whether any vaccine produces this symptom cluster. The retrieved records cover aortic valve disease, heart failure medication withdrawal, brainstem stroke, and a mathematical model of cortisol secretion. None of them compare vaccinated to unvaccinated people for palpitations, bounding pulse, or akathisia. The absence is not proof of safety — it is proof that the question was never studied with this design.

My call: the most likely causes, based on the evidence here, are aortic regurgitation (a leaky heart valve), medication withdrawal in someone with heart failure, or a brainstem event affecting the pons. A vaccine cause is not supported by this retrieval, but the retrieval did not look for it. Confidence: moderate for the cardiovascular and neurological explanations, low for any conclusion about vaccines — the relevant comparison was never run.