COMPONENTS OF THE NORMAL ELECTROCARDIOGRAM Flashcards
atrial depolarization wave
P wave
ventricular depolarization wave
QRS complex
ventricular repolarization wave
T wave
EKG Leads
Leads are electrodes which measure the difference in electrical potential between either bipolar or unipolar
HR = 300 ÷ # heavy lines between 2 QRS’s
Calculation for HR on EKG
ex:
(300/6 boxes)= 50 BMP
Depolarization moving toward a positive electrode produces a ______ deflection
positive
and vice versa
QRS will be upright (+) in \_\_\_\_\_\_ leads And downward (-) in right-sided leads
left and lateral
Leads: Two different points on the body
bipolar leads
std limb leads I, II, III
Leads: One point on the body and a virtual reference point with zero electrical potential, located in the center of the heart
unipolar leads
V1-V6
aVR
aVL
aVF
QRS will be upright (+) in left and lateral leads And downward (-) in \_\_\_\_\_\_\_\_
right-sided leads
Ischemia occurs when blood supply is insufficient to meet:
oxygen demand in the ventricles
Ischemia due to sudden high oxygen demand (under stress) in the presence of fixed coronary obstruction causes:
depression of the ST segment
Ischemia due to acute coronary artery obstruction (at rest) during low oxygen demand causes:
T wave inversion
ST elevation is a sign of
TRANSMURAL CURRENT OF INJURY
Can be Tissue damage MI
Is reversible
1- PEAKED T-WAVE 2- T-WAVE INVERSION 3- ST ELEVATION or Q-WAVE ST-ELEVATION T-INVERSION
Caused by?
EVOLVING TRANSMURAL MYOCARDIAL INFARCT
