Beta - blockers, Biology

Assignment Help:

Beta-blockers have traditionally been considered contraindicated in patients with heart failure because they may block the compensatory actions of the sympathetic nervous system with potential to worsening of symptoms. However, chronically failing heart is adrenergically activated and persistent elevations of catecholamines and sympathetic nervous system activity cause progressive myocardial damage, leading to worsening left ventricular function and dilation. Several large clinical trials have demonstrated that beta-blockers decrease mortality in patients who are already receiving standard heart failure therapy (i.e., angiotensin-converting enzyme [ACE] inhibitors and diuretics with or without digoxin). Hence the role of beta blockade in heart failure management.

Beneficial effects of beta-blockers in heart failure include improvement in LV ejection fraction over a period of 3-6 months decrease in LV end-systolic and end-diastolic volumes and mass in 4 to 12 months ('reversed remodeling').

Large randomized trials have shown mortality reduction to the tune of 35 per cent with beta-blocker therapy.

Current guidelines recommend that beta-blockers be used in patients with systolic dysfunction, ejection fraction less than 40 per cent, and mild to moderate heart failure as judged by New York Heart Association (NYHA) (10) class II or III symptoms. Beta-blockers should be started at low doses and gradually increased to the target goals. Effective beta blockade can be reached progressively by increasing doses of beta-blocker agents every 2 to 3 weeks.

Agents found useful in heart failure are second generation selective B 1 agents or third generation agents with vasodilatory action. There is evidence for the usefulness of metoprolol, bisoprolol, and cardvedilol in heart failure.


Related Discussions:- Beta - blockers

Define principle for estimation of cholesterol - lipids, Define Principle f...

Define Principle for Estimation of cholesterol - Lipids? Zlatkis and associates have evolved a method of quantitative determination of cholesterol based on a reagent containing

Treatment of angina pectoris, Q. Treatment of angina pectoris? Proper a...

Q. Treatment of angina pectoris? Proper and careful treatment of the underlying cause (usually dyslipidemia, advanced atherosclerosis or sever chronic hypertension) is imperati

In which strcture sperm cells go after passing epididymides, Q. After passi...

Q. After passing the epididymides through which structures do sperm cells go until exteriorization? After leaving the epididymis in the testicle sperm cells enters the vas defe

Pregnancy - fungal infections, Pregnancy - Fungal Infections Amphoteric...

Pregnancy - Fungal Infections Amphotericin B is the preferred treatment for deep fungal infections during pregnancy. Fluconazole is teratogenic in animals and a same pattern of

Digestion, Adsk question #Minimum 100 words accepted#saliva enzyme

Adsk question #Minimum 100 words accepted#saliva enzyme

Locomotion, Locomotory apparatus in protozoa

Locomotory apparatus in protozoa

How many different genotypes can the individual present, Considering a pair...

Considering a pair of homologous chromosomes containing a gene having two different alleles how many different genotypes can the individual present? If a gene of the diploid sp

What is cytokinesis in cell reproduction, what is Cytokinesis in cell repro...

what is Cytokinesis in cell reproduction? Cytokinesis: Mitosis is usually followed by cytokinesis, the division of the cytoplasm and cell membrane. Cellular organelles are no

Depleted (vulnerable) species, Depleted (Vulnerable) Species These are...

Depleted (Vulnerable) Species These are the species whose numbers are greatly reduced from those of the recent past, and they are continuing to decrease. It is the continued d

Describe the working of ploidy reduction, Q. During which meiosis division ...

Q. During which meiosis division does ploidy reduction take place? And Does it ploidy reduction occur in mitosis? In the cell division by meiosis ploidy reduction occurs in mei

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd