Innapropriate Sinus Tachycardia

In January of this year I was hospitalized for 5 days with a virus.  I had vomiting, diarrhea, back pain, and fever.  At that time I was running a heart rate of 110- 140 with elevated BP of anywhere between 140/90 to 150/110.  At first this was felt to be secondary to my illiness.  Two weeks after my discharge I continued to have increased pulse rate with hypertension.  I was put on Cardura 2mg bid, Toprol XL 50mg bid and Maxide daily for swelling. I was then admitted again in June for a TAH because of 10 years of female problems.  This problem with my heart rate and BP continued.  Premarin 0.625 mg was then added to my meds. I have for 18 years worked in the medical field as a nurse.  
About 3 months ago the problem with my heart rate got worse more at night and I was wakened frequently so my Toprol XL 50 mg was increased to 3 pills TID. At this time I was placed on 24 hr holter that revealed HR of up to 160 with SVT. It seemed that I could deal with this during the day but it was extremely worse at night. I was then sent to a cardologist who did another holter with tachycardia, had a little MVP on echo, had EP studies and was unable to do ablation because the problem was in the AV node and he said I would have to have a pacemaker.  I have been of Lanoxin, Toprol, Cougard without relief. I am now back of Toprol because it works best-my cardologist is difficult to understand with hime being from another country. At what point should I consider the ablation or continue oral therapy.  Will this cause problems that could lead to cardiomyopathy or maybe even heart failure.  Your opinion in this matter would be greatly appreciated. I have already seen 2 cardoligisy and a PA in this practice but I would be quite grateful for your feedback.

[CCF CARDIO MD JMF]

Dear Denise,

Ablation could be considered in your case if the side effects of the medication or the arrhythmia caused too many symptoms.  
You should make certain that you reduce your caffeine consumption and try to alleviate stress as common causes of an increase in tachycardias.