12 lead Flashcards
What is a 12 Lead ECG?
Ten electrodes are placed on the chest and extremities.
Provides 12 different perspectives of electrical activity in the heart
What is a 12 Lead ECG?
Ten electrodes are placed on the chest and extremities.
Provides 12 different perspectives of electrical activity in the heart
What’s it look for?
What doesn’t an EKG show or calculate?
Conduction problems
Arrhythmias
Ischemia, infarction
Hypertrophy
Pacer activity
Effectiveness of drug therapy
Ejection fraction
Percentage of blockage
The standard EKG has 12 leads:
The ___ of a particular lead represents the viewpoint
from which it looks at the heart
Standard Limb Leads (I, II, III)
Augmented Limb Leads (aVL, aVR, aVF)
Precordial Leads (V1-V6)
axis
positive electrode is eye looking back at heart
Electrodeplacement
Electrodes create an imaginary line, a “____” which serves as a reference point from which the electrical activity is viewed.
The “lead” is like the eye of the camera: narrow peripheral field of vision looking only at the electrical activity directly in front of it. (from negative to positive, positive looks back on that side of the heart.
Sometimes providers will order a right-sided 12 lead EKG. So V1-V6 will be placed in a mirror-image position on the right side of the chest. This is more sensitive in detecting right ventricular MIs.
lead
Configuration will differ from each lead
the configuration of a normal rhythm tracing from lead I will differ from the configuration of a normal rhythm tracing from lead II, lead II will differ from lead III, and so on.
To make an accurate assessment of the heart’s electrical activity or to identify where, when, and what abnormalities occur, the ECG needs to be evaluated from every lead, not just from lead II.
If your patient is on telemetry, which two leads do they typically choose to display on the monitor and why?
Leads I and II
-nice upright P wave
-looks at inferior heart looking up
-Shows right coronary artery
Coronary artery anatomy
SEE slide
Left main coronary artery - the worst the be affected
Right coronary artery
Left anterior descending coronary artery
Circumflex coronary artery
Heart is rotated and tilts to left. PMI, where left ventricle is closest to chest wall
In general, RCA supplies right side of heart. LCA supplies left side of heart.
12 lead determines:
treatment
cath lab? stress test? go home?
when are coronary arteries perfuses?
diastole
Tachycardia effects the filling time
