systolic pressure may varies up to 20 mm Hg in normal case.
hypertension may occur in acromegaly,not hypotension.
it seems to be that your chest discomfort
is not related to your low blood pressure.
gallop rhythm usually occurs in heart failure
& valvular heart disease
but you have no any symptoms or history of these disease.
your chest discomfort probably due to peptic ulcer disease
or non ulcer dyspepsia.
you may take antiulcerant,if not responding then consult your doctor.