Heart rate, was Dry Dose?

[Dr. Joe Rozencwajg, NMD]

This is the kind of situation where I use "focused" remedies, in herbal tinctures or low potency FPP to symptomatically control the activity of an organ or system.

I would use for example, according to the needs, Gemmotherapic Remedies ( a form of herbalism based on bud extracts) like Crataegus, Ficus Carica and Citrus Limonum.

And I would do this kind of exercise:
I list the herbal remedies known for their action on tachycardia:

Passiflora, Crataegus, Lycopus Adonis Vernalis,

Leonorus, Valeriana, Convallaria, Marrubium , Pulsatilla, Sarothamnus Adonis V, Hydrastis Gingko,

Olea Europea.
I eliminate those that would not fit due to associated pathologies, in your case I do not know, so take this as an example only, not a recommendation.
Then I use the repertories, Complete but also Knerr that is very clinical, with as many modalities as possible, and compare the results with the herbal remedies. Sometimes I get very surprising results, other times I need to create a herbal preparation specific to the clinical presentation based only on the herbal energetics, without forgetting the minerals and vitamins....so even while treating only an organ, a "homeopathic" interview is necessary to have a precise and effective treatment.
I realise I have not answered your question precisely, but especially in the realm of severe pathology, I am very wary of "shooting from the hip" as herbs are gentler and easier to use than drugs but if misprescribed, can wreak havoc.
And unfortunately yes, it appears that a slower heart rate is linked to a longer life.
Dr. J. Rozencwajg, NMD. "The greatest enemy of any science is a closed mind". www.naturamedica.webs.com