Betablockers in right bundle branch block (RBBB)
Q: Iam 65 years old and have been suffering from hypertension for the last 15 years. I was on Tenormin OD for several years and then Betatrop OD. About 2 years ago, I was found to have RBBB. The cardiologist treating me advised to stop Beta-blockers as they have adverse effect on RBBB and put me on Depin Retard 20 mg OD. Another cardiologist has recently advised to take Betaloc 25 mg OD (as it has positive effect on conduction) along with Nicardia Retard 10 mg. A third doctor has advised Amlopress AT OD. After a lteral medullary infarct which I suffered about 10 months ago, I have also developed postural hypotension which quite often results in drop of 30 to 40 degree in systolic from lying to standing position. This is another problem as I am required to have adequate blood flow to the brain because of medullary infarct. I am presently on Coversyl 4mgOD, Amloz 5mgOD and ASA 50 OD. My BP is generally in the range of 150/90, though sometime it rises in the evenings. Please advice on the following: 1. Is it a fact that Beta-blockers should not be taken in case of RBBB? 2. What should be the combination of drugs in my case so as to check hypertension as well as postural hypotension? 3. What would be the ideal ranges of lying/sitting/standing BP in my case?
A:Beta-blockers do worsen conduction in the heart like RBBB, but a selective blocker like bisoprolol may do less harm. Considering the potentially beneficial effect that these group of drugs have specially in a situation like yours, it may be worthwhile to give low dose betablockers a try. Coversyl is an excellent drug. Personally I do not prefer calcium channel blockers like Nifedipine as short-acting nifedipine have been shown to increase mortality in certain studies. Cause of postural hypotension needs aggressive search. Doses of antihypertensives specially like those of Coversyl and amlodipine needs to be re-evaluated. There should be less than 10 mm Hg fall of systolic blood pressure between the standing and lying position; the diastolic blood pressure should remain almost same.