ECG Flashcards
what does the P wave mean?
atrial depolarisation
what does the PR interval symbolise?
time for electrical activity to move between atria and ventricles
what does the R wave symbolise?
depolarisation of ventricles
what does the ST segment symbolise?
time between depolarisation and repolarisation of ventricles
what does the QT interval symbolise?
time taken for ventricles to depolarise and repolarise
what does the T wave represent?
ventricular repolarisation
what is an electrode?
conductive pad attached to the skin to record electrical activity
what is a lead?
graphical representation of the heart’s electrical activity
where are the chest electrodes?
V1 - 4th intercostal space at right sternal edge
V2 - 4th intercostal space at left sternal edge
V3 - midway between V2 and V4
V4 - 5th intercostal space in midclavicular line
V5 - left anterior axillary line at same horizontal level as V4
V6 - left mid-axillary line at same horizontal level as V4 and V5
how many chest electrodes are there and what are they called?
6
V1-6
what view of the heart do the chest leads provide?
V1&2 - septal
V3&4 - anterior
V5&6 - lateral
what are the limb electrodes?
- red (RA)
- yellow (LA)
- green (LL)
- black (RL)
where do the limb electrodes attach?
red - ulnar styloid process of right arm
yellow - ulnar styloid process of left arm
green - medial/lateral malleolus of left leg
black - medial/lateral malleolus of right leg
what view of the heart do leads I, II and III provide?
I - lateral
II & III - inferior
what view of the heart do the aVR, aVL and aVF leads provide?
aVR & aVL - lateral
aVF - inferior
