EKG/ECG

What is the P wave

depolarization (contracting) of the atria

QRS Complex

depolarization (contracting) of the ventricles 

T wave

repolarization of the ventricles

What are the normal responses to exercise?

• P wave increases in height

• R wave decreases in height

• QRS is shortened d/t increased HR

• ST segment has a rapid upsloping pattern

• T wave decreases in height

imagine everything gets “smushed” together bc heart is beathing faster

ST elevation is good/bad

BAD

• can mean myocardial infarction

• STEMI = ST elevated MI

Inverted T wave

T wave is pointed downwards indicating:

• left ventricular hypertrophy = CHF

• myocardial ischemia 

depolarization means…

contracting state

repolarization means…

relaxing state 

QT Interval

total time for ventricular contraction and relaxation

ST Segment

• Period when ventricles are fully contracted

• Occurs between contraction and relaxation

• Changes (elevation/depression) can indicate ischemia or MI

ST Segment depression

= ischemia

• any depression of the ST segment is BAD

• depression greater than 1.0 mm

ST segment elevation

= myocardial infarction / heart attack

• ST wave is above baseline

SA Node of the Heart

• pacemaker of the heart

  • sets the pace of the heart

• sends signals to the R and L atrium

AV Node

• “middle man”

• receives signals from the SA node and sends them to the R and L atrium

P wave during exercise (normal response)

increases in height

R wave during exercise (Normal EKG response)

decreases

ST segment during exercise (Normal EKG response)

• normally flat, may slightly upslope with exercise

• no significant change from baseline

Q-t interval during exercise (Normal EKG response)

shortens slightly with increased HR