Describe fourth heart sound in details, Biology

Assignment Help:

Describe Fourth Heart Sound in details?

S4 is generated during the atrial-filling phase. It is a low frequency event. LVS, is best heard over apex. Mechanism of S4 generation: It occurs when augmented atrial contraction occurs against relatively stiff ventricle to generate pre systolic ventricular distension so that it can contract with greater force.

Physiological S4 call is heart, in athletes who have physiological hypertrophy. It is rarely heard in normal subjects hence should be considered pathological unless proved otherwise.

Pathological S, is generated in any condition, which reduces ventricular compliances in LVH, acute MR, HOCM or ischaemic heart disease. Almost all patients with MI will have phonocardiographic S, unless they have MS (in which atria is unable to transmit its pressure freely to LV) or atrial infarction.

S4 is not heard in constrictive pericarditis or tamponade because the ventricle is unable to expand at the end of diastole and also the atria may be tethered by constrictive process and therefore, not contract well. S, is not heard in patients with atrial fibrillation, as atrial booster pump is lost.

 


Related Discussions:- Describe fourth heart sound in details

Explain nutritional management for neuro trauma patients, Define Feeding an...

Define Feeding and Nutritional Management for Neuro trauma? The main objective of nutritional management is to counteract the hypermetabolism associated with inflammation. The

Specific considerations and applied aspects in dentistry, Specific consider...

Specific considerations and applied aspects in dentistry The dental chair and delivery system. The chair should be smooth and seamless. The greatest potential for cross contami

Capital reserves, Capital Reserves 1. This is raised with selling shar...

Capital Reserves 1. This is raised with selling shares at a premium. As the difference among the market price less floatation costs and par value is credited to the capital re

Of which substances is chromatin made, Of which substances is chromatin mad...

Of which substances is chromatin made? Chromatin is made of DNA molecules associated to proteins known as histones. Cell Nucleus Review - Image Diversity: chromatin

Define the osazone test or phenylhydrazine reaction, Define the Osazone Tes...

Define the Osazone Test or Phenylhydrazine Reaction? Compounds with -CO-CHOH group form crystalline osazones with phenyl hydrazine. These osazones have characteristic shapes an

Give choice of catheters for ventriculography, Q. Give Choice of Catheters ...

Q. Give Choice of Catheters for Ventriculography? 1) Pigtail Catheter: This catheter developed by Judkins has end hole and side holes. The end hole permits insertion of the c

Future challenges for scaling from individual to ecosystems, Define Future ...

Define Future challenges for scaling from individual to ecosystems? Scaling of biogeochemical fluxes in terrestrial systems has confirmed much harder. While ecosystem ecologist

Determine the food sources of vitamin a, Determine the Food Sources of Vita...

Determine the Food Sources of Vitamin A? Vitamin A or retinol performed vitamin A), as you may already know, is found only in foods of animal origin, such as milk, cheese, crea

What is phagocytosis and phagosomes?, Protozoans ingest food by phagocytosi...

Protozoans ingest food by phagocytosis, and consequently, the ingested food is surrounded by a plasma membrane creating a food vacuole, or phagosome. Digestion does not start until

Organ that belongs to more than one organ system, What is an organ that bel...

What is an organ that belongs to more than one organ system? One answer is the pancreas. It belongs to both the endocrine and digestive systems. Another one is bone marrow. It

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