Will a 10mg dose of aventyl (nortriptyline) have the cardiac side effects that come as a warning? If so will a reduced dose help?

In some people YES. In my experience an extremely small percentage of people with adversely react to 10 mg. of Aventyl (Nortriptyline). In fact, that is precisely why I titrate nortriptyline starting at 10mg. and escalate SLOWLY by only 10mg. weekly when treating my headache patients just to be able and gauge potentially intolerable side effects. Only handful in over 25 years who have major disaster at lowest dose.