Minutus

These are some rubrics that (insufficiently, partially) describe your case.
Generally, and in this case, the only homeopathic "protocol" that I can
recommend is to take a full & complete case.

GENERALS - TREMBLING - Externally - vertigo with
GENERALS - WEAKNESS - vertigo, with
MIND - PROSTRATION of mind - heart failure, with
MIND - PROSTRATION of mind - trembling, with
MIND - PROSTRATION of mind
CHEST - ANXIETY in - Heart, region of - moving about - amel.
CHEST - ANXIETY in - Heart, region of
CHEST - HEART; complaints of the - accompanied by - respiration; difficult
CHEST - HEART; complaints of the - chronic - accompanied by - weakness;
general
CHEST - HEART; complaints of the
GENERALS - MOTION - slow motion - amel.

Some small remedies to consider:
Crat., Glon., Dig., Aur-i (& all the Aurums), Camph., Am-c.
Polychrests:
Puls, Bell, Ars, Nat-m., -also consider Gels.

For reading material..
There is a book - Diseases of the Heart
By Alexander Leslie BLACKWOOD, MD
www.minimum.com/p7/engine2/tocpage.asp?n=322