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

Are sex-linked diseases associated to genes of x chromosome, Are sex-linked...

Are sex-linked diseases associated only to genes of the X chromosome? There are so many X-linked diseases such like, hemophilia B, hemophilia A and adrenoleukodystrophy, but re

Management of hypertension, Q. Management of hypertension? the manageme...

Q. Management of hypertension? the management of hypertension, angina pectoris and myocardial infarction. It must be clear to you that some aspects of dietary management may di

What are the maintenance sequences of implant, Maintenance sequences of imp...

Maintenance sequences of implant Achieving a successful result with the treatment is only half the battle won. The main challenge is maintain that result over a long period of

Define trace elements for school children and adolescents, Define Trace ele...

Define Trace elements for school children and adolescents? Iodine requirements peak in adolescence. Consumption of iodized salt should be ensured. Adequacy of zinc for growth i

Define the agarose gel electrophoresis (age), Define the Agarose gel electr...

Define the Agarose gel electrophoresis (AGE)? This technique is used to analyze serum proteins, haemoglobin variants, lactate dehydrogenase isoenzymes, lipoprotein fractions an

What are gene chips, Question  Write a short note on the following 1 St...

Question  Write a short note on the following 1 Stem cells 2 Edible vaccines 3 Biologic Materials 4 Liposomes 5 What are gene chips? Explain any 4 applications of g

Proximity between amino and ribosomes acids, Q. Why is the proximity betwee...

Q. Why is the proximity between amino and ribosomes acids important for the protein formation? What is the enzyme that catalyzes that reaction? The proximity between amino and

Study of embryology, Embryology This is the study of growth, fertilizatio...

Embryology This is the study of growth, fertilization, division or differential of the zygote into embryo of early development of living beings before the attainment of structure

Protozoa, what are the disadvantages of protozoa

what are the disadvantages of protozoa

Kreb cycle, where does kreb cycle takes place

where does kreb cycle takes place

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