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 sugars - chemistry and functionality, Define Sugars - Chemistry and ...

Define Sugars - Chemistry and Functionality? In this section we will learn about the simple carbohydrates called sugars. As you may already know, those carbohydrates that canno

What are some of the possible treatments, My friend was injured several yea...

My friend was injured several years ago in a car accident and she was diagnosed with a herniated disc. Can you please explain using the correct anatomical terminology what herniati

Freshwater biomes, Low levels of dissolved salts characterise the freshwate...

Low levels of dissolved salts characterise the freshwater biomes. The salt content of fresh water is about 0.005 percent. The freshwater biomes consist of inland bodies of standing

How much milk require by patient in a day, How many protein require patien...

How many protein require patient in a day Patients who require high protein diets are encouraged to drink 600-800 mL of milk a day. Now, you must be wondering how one can consu

What are the main parts of the human ear, What are the main parts of the hu...

What are the main parts of the human ear? The human ear is separated into three mains parts: the external ear, the middle ear and the internal ear. Hearing Review - Image D

Aschelminthes, General characters of aschelminthes

General characters of aschelminthes

Agro industrial-reproductive tract infections, Reproductive tract infection...

Reproductive tract infections The major cause of reproductive tract infections are, improper dry cow nutrition, contamination at calving due to unsanitary calving area; virule

Mechanism of circulatory system, MECHANISM - 1 .      AURICULAR SYSTO...

MECHANISM - 1 .      AURICULAR SYSTOLE - First of all from complete body impure blood comes in R.A. by superior and inferior vena cava or pre and post cavals. Pure blo

Define estimation of nitrogen and protein content, Estimation of Nitrogen a...

Estimation of Nitrogen and Protein Content Using Micro Kjeldahl's Method? Standardization of H 2 SO 4 Prepare a solution of 0.1 N H 2 SO 4  by diluting 2.8 ml of the con

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