This method is more successful in finding certain types of heart arrhythmias. The success of a second ablation depends on a number of things and your doctor can give you a better estimate on the success rate. I don't know of any alternatives to medication and ablation therapy. Here is some general information on inappropriate sinus tachycardia. Sinus tachycardia is defined as a heart rate of greater than 100 beats per minute originating from the sinus node.
Sinus tachycardia is classified as either appropriate or inappropriate.
There are many causes of appropriate sinus tachycardia such as exercise, anxiety, panic attacks, dehydration, deconditioning, volume loss due to bleeding or other loss of body fluids, hyperthyroidism, electrolyte abnormalities and many other conditions. Inappropriate sinus tachycardia can only be diagnosed when all causes of appropriate sinus tachycardia have been ruled out. It is not clear what causes inappropriate sinus tachycardia but possible etiologies are an increase in the rate at which the sinus node depolarizes and an increased sensitivity to adrenaline. Once the diagnosis has been made by ruling out all of the potential causes of appropriate sinus tachycardia there are several treatment options. If the symptoms are not overly concerning no treatment needs to be done.