is a vasodilator, which means it dilates the blood vessels in your body. Evidence suggests that one of its know side effects is irregular heart beats. Since you have already developed this and have seen a doctor, you should immediately stop further use. It is usually seen that the effects of the drug wear out after it is completely metabolized in the body which should have happened by now or will happen soon. Just make sure, you dont use the medicine again. No, there are no chances that there is permanent damage to the heart because of Rogaine
. However, if the symptoms persists after a few days, you must check with the doctor for any other causes which may be causing this.
Hope this helps