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

Determine the deamination during rna editing, Which of the following is not...

Which of the following is not needed for C to U deamination during RNA editing? A. Formation of localized segments of double stranded RNA. B. The 5' and 3' efficiency elemen

Changes in animal life during xerosere, Changes in Animal Life during Xeros...

Changes in Animal Life during Xerosere Just like the hydrosere, there occur successive changes in animal life during the xerosere. A few mites are usually found associated wi

Pelagic zone - organisation of the marine ecosystem, Pelagic Zone - Organis...

Pelagic Zone - Organisation of the Marine Ecosystem The waters contained in the sea basin, constitute the pelagic zone which is divided into The neritic zone situ

What is the host factors of implants, What is the Host Factors of implants ...

What is the Host Factors of implants These factors are very important and it is essential for the clinician to keep these in mind during the diagnosis and treatment planning st

How does sexual reproduction take place in bacteria, Q. How does sexual rep...

Q. How does sexual reproduction take place in bacteria? How dissimilar are the modalities of bacterial sexual reproduction? Sexual reproduction occurs when bacteria incorporate

What is the kind of digestive system of echinoderms, Q What is the kind of ...

Q What is the kind of digestive system of echinoderms? Echinoderms present a complete digestive system with anus and mouth. Q. Do sea urchins have teeth? Sea urchins ha

Observing root hairs, Observing root hairs Study the root hairs with a ...

Observing root hairs Study the root hairs with a hand lens and view how they are constructed.

Skin, what is the advantage of being dark skinned?

what is the advantage of being dark skinned?

Which is an isotope of pgisphorous, The most abundant from of phosphorous h...

The most abundant from of phosphorous has 15 protos, 16 neutrons and 15 electrons. Which of the following is an isotope of pgisphorous? (make all correct choices) A. an atom wit

Excretion, what is the excretory organ of agama lizard

what is the excretory organ of agama lizard

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