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 the over nutrition obesity of infant, Define the Over nutrition obes...

Define the Over nutrition obesity of Infant? An infant is never put on a reducing diet. The chances of obesity are least if an infant is exclusively breast-fed till 6 months. I

Birth control - permanent methods, PERMANEN T METHOD - 1. Vasectomy in...

PERMANEN T METHOD - 1. Vasectomy in male. 2. Tubectomy in female. 3. Leproscopy is used in tubal ligation , to ligate fallopian tubes.

What is working of mouth in human body, What is Working of Mouth in human b...

What is Working of Mouth in human body? Food enters the digestive system through the mouth, where it is processed by the teeth and mixed with saliva, prior to being swallowed.

What is polymorphisum?, According to the chemistry concept the existence of...

According to the chemistry concept the existence of different kinds of crystal of the same chemical compound is known as polymorphism

Digestive system, Digestive system is one of eleven major body organ syste...

Digestive system is one of eleven major body organ systems in animals; it converts food from the external environment into the nutrient molecules which can be used and stored by t

Trypanosomiasis, Trypanosomiasis The trypanosomiasis, also known as Af...

Trypanosomiasis The trypanosomiasis, also known as African sleeping sickness or Chaga’s disease, is caused by Trypanosoma cruzi, T. gambiense and T. rhodesience. T. evansi cau

Define regulation of water balance, Define Regulation of Water Balance? ...

Define Regulation of Water Balance? The input of water, as well as, its loss can be highly variable due to individual habits and environmental factors; in spite of this, the to

Autoregulation of coronary blood flow, The ability to maintain myocardial p...

The ability to maintain myocardial perfusion at constant levels in the face of changing driving presence is termed autoregulation. In normal cases, autoregulation is maintained at

What are the part of the musculoskeletal system, Which are the organs that ...

Which are the organs that are part of the musculoskeletal system? The main organs and tissues that are part of the musculoskeletal system in humans are the cartilages, the bone

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