What are changes in st-segment, Biology

Assignment Help:

Q. What are changes in ST-Segment?

Normal Exercise Electrocardiogram ST and J Point

As the heart rate increases with exercise, a number of predictable changes occur in a normal ECG tracing. The PR-interval is shortened after 1 minute of exercise. The P-wave becomes taller and the Ta wave (wave of atrial repolarisation) increases, resulting in downward displacement of the PQ junction. This is particularly important because the so called baseline, for terms of evaluating ST-segment change, is below that usually considered to be isoelectric tracing. With exercise, the Ta wave tends to extend through the QRS and may influence that junction between the ST-segment and the T-wave.

Prognostic Significance

Asymptomatic patient-Abnormal test prevalence 5 to 12 per cent. Risk of event-9 times greater in abnormal test. 2 per cent event rate (angina) over 4 year follow up. BLS study - with risk factors- elderly patient - event rate varies 3.5 per cent to19 per cent in 9 years follow up. Females- 15 per cent to 20 per cent prevalence-less prognostic value.

Symptomatic Patient: Case Study

First stage positive: 5 per cent annual mortality, Low risk group: < 1 per cent annual mortality. It has become standard practice to use the line of PQ or PR junction as a marker for the baseline when the ST-segment is measured at one fourth the distance between the QRS and peak T in left to right leads, considerable depression is normally seen. The anterior posterior lead changes (V1 to V2) are less prominent than those in the lateral and vertical leads. The absence of significant ST-segment depression in young, vigorous boys and in athletic, middle aged men, suggests that the effect of the Ta wave, can usually be recognized because of the short duration (usually 0.045) of the J point depression.


Related Discussions:- What are changes in st-segment

Invertebrate zoology, give an example invertebrate phylum/phyla for protopl...

give an example invertebrate phylum/phyla for protoplasmic grade organization

How are fishes characterized, Q. Fish identity card. How are fishes charact...

Q. Fish identity card. How are fishes characterized according to examples of representing beings, skin, basic morphology, circulation, nitrogen waste, respiration, thermal control

Poultry and duck diseases-avian adenovirus infections, Avian adenovirus inf...

Avian adenovirus infections EDS-76, an adenovirus, has been etiologically associated with drop in egg production. Other adenoviruses affecting chicken and other birds include

Marine biomes, The marine biomes consist of the earth's oceans and its asso...

The marine biomes consist of the earth's oceans and its associated areas like the shorelines, islands, reefs and estuaries. The marine waters contain about 3.5 percent salt, mostly

Consider the evolution of metabolic pathways, Consider the evolution of met...

Consider the evolution of metabolic pathways. Some biologists believe that these pathways evolved from?

What is gestational diabetes, Q. What is Gestational Diabetes? When a p...

Q. What is Gestational Diabetes? When a pregnant woman develops diabetes, it is known as gestational diabetes. It occurs in only 1% of the pregnant women. Pregnant women who ha

Explain alkaline butt -carbohydrate utilization pattern test, Explain Alkal...

Explain Alkaline Butt -carbohydrate utilization pattern test? Alkaline slant (red) and alkaline butt (red) or no change (orange-red) butt- Instead of carbohydrates, peptone in

Explain main reason for the anomalous behaviour of lithium, How does chemic...

How does chemical adsorption of a gas on a solid vary with temperature? a) Mention the main reason for the anomalous behaviour of lithium in Group of the periodic table.

Genetics, how to determine that the phenotype of a wild type is due to the ...

how to determine that the phenotype of a wild type is due to the action of one or two genes?

Prevention of malaria, Prevention of malaria No drug for malaria preven...

Prevention of malaria No drug for malaria prevention is 100% effective. Travelers to countries that have malaria should seek prompt medical attention for febrile illness wherea

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