Possibly, but I would more likely interpret it as she is worried about heart palpitations. When your blood pressure starts to sink the body responds by increasing the heart rate. The way the woman to her left holds her arm, one wonders if she is checking HRC's pulse.
As other have asked - why did they take her to Chelsea's apartment and not to a hospital for a check-up?
Faintness, palpitations, nausea in a 68-year old woman with prior health issues like deep vein thromboses and you decide not to have looked at at the ER. One may definitely question the quality of care....
The staff probably wanted to take her to the hospital but my guess is she told them, in the best way she knows how, to forget the hospital because that would cost her the campaign and everyone would be out on their ear. She probably ordered everyone to take her to St. Chelsea’s and have specialists brought over.
Note though she dies this in her speeches too
Er “does” not “dies”