ECG Tutorial Part 2 - Dr. Johnston Flashcards
1st degree AV block is what
PR segment is longer then 0.2sec
= due to the AV node problem
1st degree AV Block is seen when
- Atherosclerosis, HTN, DM, *
- Fibrosis like in Congenital HD*
- CAD ischemia
- Drugs like CCB, B.B, Anti-arrhymias
- Thyroid problem or adrenal insufficiency
- Inflammation or amyloidosis, hemochromatosis, sarcoidosis
- Valvular calcification
2nd degree AV Block types
- Mobitz type 1 (Wenckbach) : progressive PR prolongation before dropped QRS
= Grouped Beats, there is a pattern - Mobitz type 2
Mobitz type 1 (Wenckbach) is what and associated with
Mobitz type 1 (Wenckbach) : progressive PR prolongation before dropped QRS, “grouped beats” = pattern
= progressive lengthening of PR (since the impulse from SA to AV comes to early during refractory period)
= associated with Inferior wall MI
= transient
Mobitz type 1 (Wenckbach) :causes
- Digitalis toxicity
- Ischemic event (inferior MI)** seen in leads 2,3, AVF
- Myocarditis
- Right coronary artery disease
- Edema around AV node
Mobitz type 1 (Wenckbach) : looks like
Narrow QRS , longer and longer PR before the dropping of QRS
= 40-55bpm
What do you see in MI inferior wall
ST elevation : leads 2, 3, AVF
ST depression : leads 1, AVL
Mobitz type 2 associated with a prognosis
- Ischemic heart disease
- Anterior wall MI
- Conductive system degeneration
- LAD coronary artery disease
= worse prognosis then type 1, progressive and irreversible
Mobitz type 2 looks like and where is the block
PR stays the same in the length
Drops QRS at any point, wide QRS
20-40bpm
= anyplace distal to AV node, bundle of his, bundle branches, fascicularis branches
3rd degree AV Block is what and types (above and below AV node block)
A and V are not communicating at all and work independently
- Above AV block : Junctional rhythm ——> narrow QRS (40-55bpm)
- Below AV Block : Ventricular Pacemaker ——> Wide QRS (20-40bpm)
3rd degree AV Block TX
pacemaker if sustained
3rd degree AV Block causes
- Ischemic HD
- Infiltration disease
- Cardiac surgery : (Bypass, valve, myocarditis, degenerative)
3rd degree AV Block looks like
P and QRS have different HRs and not any pattern to when they show up next to each other
Oder of activation of wall in the ventricles
- Left ventricular septa ——> RIGTH ventricular septa
- To bottom RIGTH ventricular wall ——> upper RIGTH ventricular wall
- Bottom left V wall ——> upper left V wall
BBB ( Bundle Branch Block) looks like
- QRS is wider then 3 small boxes (0.12sec)
2. ST segment and T wave opposite of QRS (seen I premature ventricular contractions)
RBBB which leads should you look at
1, AVL, 6, V1, V2
RBBB what happens
After septum in activated
The left ventricle is activated first and then the right is activated
RBBB looks like what on EKG
QRS is wide and notched (R’)
ST in opposite direction
RIGHT LEAD = R, S, R’
Left side of heart is seen in what leads and what do you see in RBBB
1, V5, V6, AVL = wide R wave with and wide S wave present
RIGTH side of heart in what leads and looks like what in RBBB
V1* and V2* (can have notches), and V3
= R, S, R’
Wide fat QRS
LBBB what happens
Left septum does not activate
Right septum activates first traveling to left septum
Then RIGTH V and last Left ventricle
LBBB what do you see
- No Q wave in V5, V6 (left side heart) + inverted ST
2. DEEP Q and S wave in V1 and V2 (right side heart)
LBBB causes
- HTN
- Ischemia
- Aortic Stenosis
- Cardiomyopathy
- LAD ——> myocardial dysfunction
- RAD ——> Congestive cardiomyopathy
Leads to look at for LBBB
1 (wide R and R’), V6, ALV, V5, = all look the same **
V1/ V2 / V3 (very deep wide or narrow Q and S)**
Hemiblocks are what
Blocks after the bifurcation of the left bundle
Hemiblocks directions it can happen and what does each ekg look like
- Left Anterior (superior fascicle) = more common, upside down QRS, so its R, narrow S at inferior AVF, and normal 1
- Left Posterior (inferior fascicle), normal QRS at AVF and upside down at 1
- NO hemiblock, normal QRS in 1 and AVF
Left anterior Hemiblocks
Left posterior Hemiblocks
Axis
LAH : left axis (+1, -AVF), more then -60degrees
LPH : right axis (-1, +AVF), more ten 120 degrees