EKG-Blocks_Pre-Excite Flashcards
What is conduction disturbance btwn Atria and ventricles?
Heart block
This is normal at rest but concerning, can be seen with Meds, stimulants, caffiene?
SVT; TX w/ adenosine or valsalva
What measure time from atria to AV node and if delayed means AV block?
PR interval. Normal is .12-20, 4x. Delayed transient or permanent impaired transmission through AVjx
This rhythm is regual, under a NSR, consitent PRI is >4bx, w/ QRS normal?
1 Degree AV block
2 degree type I AV has what?
Progressively longer PRI 2. Then One QRS drops
What is occureing with second degree blocks?
Gets longer bc retracing. Ventricular Irregular, Atria rythm is regular. QRS normal
What occurs at bundle of his, branches or trifascular?
2nd degree AV block TYPE 2. QRS wide w/ drop 3. PR consitently normal or prolonged 4. Ventricular irregular 5. PAC is Early
3 degree AV block have regular what?
P-P, R-R 2. Wide QRS. NO association btwn atria ad ventricles
Which AV blocks require pacemaker?
2 degree Type 2 and 3rd degree. both symptomatic, palpitations, or syncope
WHat are formed during cardiac development in a variety of locations where impulses can travel?
Pre exciation syndromes. Wolfe Parkinson-White, Lown-Ganong-Levine (james fibers) Mahaim-type fibers
What is the fiber called within a WPW?
Bundle of kent fiber
In a pre excitation syndrome, what affect the appearance of the ECG?
Accessory pathway can conduct impulse MC in both directions. Anterograde towards ventricle, Retrograde- away from
Why are pre excitation syndromes concerning?
Cause PSVT, Vfib, Sudden Death. RECOGNIZE to save a life. SX- dizzy, palpitain, syncompe, sudden death
During WPW Delta way is noted. what does it mean?
Ventricle is activated prematurely, short PRI, impulse delayed at AV node-Widen QRS
What are stats fro WPW?
50-50% symptomatic. Bimodal- 1peak childhood, 2nd peak adult
Which leads will show delta wave, tall R waves, and ST and T wave changes in WPW?
V1-V2
THis is MC, when kent fiber goes to LV?
Type A- WPW patern tall R wave V1-2
THis is LC, when kent fiber goes to RV?
TYPe B-WPW patern NEG RS or QS wave V1-2. V1-V2 close to septum
What is treatment for WPW?
Radiofrequency catheter ablation. DX- electrphysiogram determine pathways
WHat occurs when ventricale contraction must wait for opposite ventricle(cell to cell)?
Slower activation, LONG bizzarie shaped QRS complexes. Bundle branch blocks. Recall QRS .8-.12 2-3bx, SA-AV-HIs-Branches-purkinje
In a normal conduction, but ventricles contract at same time, superimposed, what is indicatvie if L brance is blocked?
Notched, M-shaped, wide QRS. 1st notch is R, 2nd notich Rprime is L. Left stronger, but delayed.
what leads show BBB for L?
LC, V1- DEEP NEG QRS, strong impulse away from RV. V5 OR V6- QRS wide. RSR*, notched
What is lead with LBBB and MI?
V1 deep neg will have tombstone- ST elevation,MI
WHat are the rabbit ears?
RBBB Rl* is R delayed. MC. Leads V1- RSR rabbit ears, V6- slurred S
What should be clinical concern with LBBB and RBBB?
RBBB- benign, monitor HTN, vitals, electrolyets, meds/yr. LBBB-MI
If there is partial block in LBB system then what is suspected?
Fasciular hemiblocks alos likely a Left axis deviation. NOT all LAD and RAD are hemiblocks
What are DDx if QT interval is long >0.45sec?
HYPOK, MG, CA
What are DDx if QRS interval is long >0.12sec?
BBB, fasicular block, PVC, Idioventrciular rhythm
What are DDx if PR interval is long >0.20sec?
AV blocks, 1-3
What are DDx if PR interval is short >0.12sec?
WPW, LGL
