SRNA Presentations: part 1 Flashcards
Which lead is most useful in detecting arrhythmias since it lies so close to cardiac axis?
Lead II
What makes lead VI unique?
- distinguish between left and right ventricle ectopic
- distinguish right from left BBB
- P waves more easily seen in right sided leads
- differentiate SVT from V tach
What is Einthoven’s triangle?
The 3 lead configuration used in the E.R
What is important about Wilson’s central terminal theory?
- used in 12 lead ECG
- each lead offers unique info that cannot be mathematically derived from other leads
What are indications for a posterior ECG?
Changes in V1-V3 on standard ECG (ST elevation, tall r wave, tall upright T wave)
Where do the coronary arteries originate?
In the aorta, immediately superior to aortic valve
When are coronary arteries perfused?
During diastole
- capillaries have increased resistance during systole, relax during diastole so they fill more easily
Which part of the heart does the left coronary artery supply?
Anterior left ventricle
Left lateral part of left ventricle
What parts of the heart does the right coronary artery supply?
Right atrium
Most of right ventricle
Posterior part of left ventricle (in most people)
The RCA divides into…..
The right marginal and posterior descending artery
The LCA divides into…….
The left circumflex
Left marginal and diagonal
Left anterior descending
How are ST elevation and ischemia defined?
ST elevation: > 1mm in 2 or more contiguous precordial leads
Ischemia: ST elevation or presence of new LBBB
Which leads will show ST elevation in a lateral wall MI?
Which coronary artery supplies this region?
I, aVL
V5, V6
Left circumflex artery
Which leads will show elevation in an inferior wall MI?
Which coronary artery supplies this region?
II, III, aVF
Right coronary artery
Which leads show elevation in a septal wall MI?
What coronary artery supplies this region?
V1, V2
Left anterior descending artery (LAD)
Which leads show elevation in an anterior wall MI?
What coronary artery supplies this region?
V3, V4
Left anterior descending artery (LAD)
In which leads will you see ST elevation and depression during a posterior wall MI?
ST elevation in V7, V8, V9
ST depression in V1, V2