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

Explain etiology and clinical feature of parkinson''s disease, Explain the ...

Explain the Etiology and Clinical Features of Parkinson's disease? The cause of Parkinson's is unknown. Genetic predisposition (in most cases the reason for the death of these

Clotting disorder - haemophilia, Clotting Disorder - Haemophilia Haemo...

Clotting Disorder - Haemophilia Haemophilia  is a congenital  blood clotting  disorder caused by the genetic lack/ deficiency of  coagulation factor VIII or antihaemophiliac

Active transport, Active transport is the transport of the molecules again...

Active transport is the transport of the molecules against the concentration gradient (from area of low concentration to area of high concentration) with the help of proteins in t

Find the effective spring constant of the molecule, A Molecule of DNA is 2....

A Molecule of DNA is 2.17 um long. The ends of the molecule become strongly ionixed: negative on one end, positive on the other. The helical molecule acts like a spring and compres

Electron microscopy, ELECTRON MICROSCOPY (EM) In EM, the object is view...

ELECTRON MICROSCOPY (EM) In EM, the object is viewed by a beam of electrons instead of visible light. An electron beam has a shorter wadelength (h = 0.004 nm) compared with vis

How many biochemicals would be detected, How many biochemicals would be det...

How many biochemicals would be detected in the stomach contents of an omnivorous dinosaur?

Sex-limited traits, can u show the different activities on the topic

can u show the different activities on the topic

What is osseointegration, What is Osseointegration Osseointegration was...

What is Osseointegration Osseointegration was the hallmark of success in implant dentistry in the 1980s. It was believed that an implant was successfully integrated when there

Definition of osseointegration in microscopic biophysical, Q. Definition of...

Q. Definition of Osseointegration in microscopic biophysical? Osseointegration implies that at light microscopic and electron microscopic levels, the identifiable components of

Explain the several terms atp, Explain the several terms ATP, NAD, and FAD ...

Explain the several terms ATP, NAD, and FAD ? Adenosine Triphosphate (ATP) is an ester, an organic compound formed from a reaction between carboxylic acid and an alcohol. ATP i

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