PVCs and Aortic Stenosis

Hi, I have a bicuspid aortic valve, noticed first @ 3 yrs, believed congenital.  Monitored annually, including echo doppler U/S.  Taking digoxin 0.25 mg daily about 10 years, successfully controlled occasional atrial tachycardia.   Last  week’s aortic valve measurement was 1.2 cm, down from 1.25 cm about 8 months ago (can they really "see" a .05 cm change with precision?). Normally I am active, able to do step aerobics, vigorous walking, light jogging.  The last 2 to 3 months, my new problem is an arrhythmia.  I wore a PDS monitor & was diagnosed as PVCs (premature ventricular contractions).    When I exercise - which consists only of walking my dog lately, the PVCs start with exertion and will continue unless I slow my pace, or stop to rest.  My doctor says these are not life threatening - but I do find these life altering - I cannot even enjoy a simple walk - I could probably generate a minute or more of continuous PVCs with every beat if I continued the exertion.  The next step is to try a Beta Blocker - metoprolol succinate, see how I do after a couple of weeks, and then schedule a stress test.  My questions: 1) What is the safest way to transition from lanoxin to Toprol XL?  I was told stop the former, start the latter on the same day. 2) Should I be concerned with getting additional tests to determine how these PVCs may interact with my stenotic aortic valve? 3) I am periomenopausal for sure (age 49, F), have night sweats very frequently. My understanding is hormone levels can trigger PVCs - should I pursue something to control hormonal swings rather than a Beta Blocker?  4) I'm concerned about the Beta Blocker particularly side effects and will I ever be able to get off the drug if I start it?  I tend to have low pressure in the morning (90/60 sometimes - and it takes a long time for me to get my engine rev'ved in the a.m. as it is....) Otherwise hhealthy, not overweight, nonsmoker, age 49. Any help/explanation of next steps appreciated.  

[Cleveland Clinic]

1.  It may take about 3 days for the digoxin to wash out, so I would start taking the toprol about 3 days after stopping the digoxin.  

2.  No

3.  No

4.  You will be able to come off it, typically with slow weaning.  

5.  I think you should take the beta blocker and see if it helps with the PVC's.  It is important that you quantify them, as more than a certain number of them per day (>20,000) may increase your risk of developing heart failure.  It is true however that in low numbers these extra beats are quite benign.  Limiting caffeine intake may also help.  With the morning hypotension, you could try taking the toprol at night.  That may help.  

[limoges49]

You wrote " I think you should take the beta blocker and see if it helps with the PVC's.  It is important that you quantify them, as more than a certain number of them per day (>20,000) may increase your risk of developing heart failure.  It is true however that in low numbers these extra beats are quite benign...."

How does one quantify the PVCs?  The type of heart monitor I wore was a PDS - Looping Multi-Event Monitor - push to record only when I felt the PVCs, and then it maxed out after 6 recordings, had to be downloaded by phone, and reset.  It was not a holter monitor.  So I know there are PVCs I skipped when the recorder was full and I didn't have time to dial up and download it.  So, I have no quantification of the number of PVCs, nor does my doctor.     I have just started eliminating caffeine, hydrating more, etc.  and today I had a very good day (only 2 or 3 PVCs runs for short periods that I was aware of).  

[Cleveland Clinic]

From your description your daily PVC burden is very low.  To answer your question, this can only be done by wearing a Holter monitor for 24 hours.