Yes, minerals--including copper, potassium, magnesium, & calcium (generally no one should be taking calcium supplements: elevated calcium levels prove problematic in a number of ways), figure largely in healthy heart function.

For my part, I'd avoid V-8 because of its sodium content. A better solution: Coconut water (not from concentrate; Trader Joe's brand is excellent with good price/value). Coconut water features a good ratio of potassium to magnesium.

Magnesium supplementation (with magnesium taurate or glycinate) must be balanced against other mineral consumption. Too much magnesium supplementation, for example, has been observed to elevate heart rate (even into arrhythmia).

But all of this should be considered...only after blood testing (see what I recommend above)--& then discussed with either a registered dietician or naturopath (someone with pronounced interest/training in diet & other environmental factors in health)...or, I suppose, with your physician--if s/he is knowledgeable about the roles of diet--including supplementation, & other environmental factors in health, including heart health.

Note, however: Blood tests for copper are not generally useful & diagnostic (of anything. Copper shares complex relations with iron & zinc (which are beyond the ken of most physicians).

Most physicians default to prescribing...iron supplementation...even though most Americans consume a standard diet already heavy with iron additives/supplementation (heavy meat diet too), whether for sub-clinical or clinical anemia.

By the way: Both copper deficiency & anemia (including sub-clinical anemia) are associated with heart arrhythmias (e.g., atrial fibrillation).

That's the standard (in legacy clinical practice) recommendation; Take magnesium (either taurate or glycinate) in the evening. That's about as "progressive" as conventional/legacy medicine generally gets.

Instead of sodas or tea & other beverages, try drinking coconut water periodically throughout the day. Probably safe to take a magnesium taurate/glycinate supplement in the evening (500 mg).

For my part, after the blood tests & consultation with a naturopath, I began supplementing with copper (glycinate) & reduced my zinc supplementation (from 40 mg to 15 mg daily). In just 3 days my Atrial Fibrillation Burden (the percentage of time the heart spends in afib over any given measurement period)... decreased by 5% & now a week later is still dropping.

There are published data (from peer-reviewed studies) indicating that an Atrial Fibrillation Burden of 11% or higher is associated with a significant increase in the risk of stroke.

Note: The Apple Watch (I have Apple Watch 8) offers the capability of measuring either Atrial Fribrillation Burden or incident atrial fibrillation, which is very accurate & useful (FDA-approved). I strongly recommend all those interested in & concerned about their health/heart health to purchase an Apple watch 8, which also allows one to take a medical grade EKG--& export the EKG strip/reading to your health-care provider as a digital file. Garmin also offers a smartwatch, the Garmin Venu 2 Plus, that tracks heart function & takes a medical grade ECG (also FDA-approved).

I also have an in-home 24/7 EKG measuring device (Fourth Frontier 2x) that I wear both for continuous measurement (especially useful during sleep) & during fitness workouts (to insure that I do not over-exercise & strain my heart). This device/technology also features A.I./machine-learning software that assesses & learns from prior heart-performance data to provide information & guidance about how much strenuous activity, especially exercise or fitness activities, one should be doing (to ensure good cardiac conditioning & safety).

Afib Burden is increasingly regarded as a significant diagnostic metric (vs. whether or how frequently one experiences paroxysmal afib--let alone persistent or permanent afib). So knowing one's Atrial Fibrillation Burden would be important (for you & for your healthcare provider).

Stay safe & good luck!