Practice ECG (KWH AED examples) Flashcards
Bradycardia
Atrial rate: 76
Ventricular rate: 38
2nd degree of heart block
2:1 heart block
What should patient receive?
Rate: 48 bpm
ST elevation in II, III, aVF, reciprocal changes in lead I, aVL, V1-V6
Inferior STEMI
Need to r/o aortic dissection before giving nitrates
AD dissecting to RCA can lead to this picture
For general STEMI
Very short: PCI
Very long: still PCI, but delayed
3rd degree heart block (look at lead II) = right coronary artery is blocked, proximal to take-off of AV nodal branch (no blood going to AV node)
V1 has alternating QRS complex: RBBB = RSR’
What treatment?
Wenkebach heart block = Mobitz I
PR interval gets gradually longer until a beat is dropped
Bradycardia
Wenkebach is usually benign = does not need pacemaker
What treatment?
Complete heart block (complete AV dissociation)
Atrial rate:
Ventricular rate:
Mobitz II and type 3 heart block NEED pacemaker
In complete heart block
1. QRS complex should be regular (If it is irregular, some PR waves may be conducted to the ventricles)
Is narrow or wide QRS safer?
Narrow: Junctional (MORE STABLE, safer)
- Usually escape is coming from site of blockage
-
Wide: Ventricular
May need pacing: place wire into ventricles
If patient has junctional escape: permanent pacemaker
If there is wide QRS, put in temporary wire pacing ASAP = fatal
Patient above develops this
Tachycardia = Torsade de Pointes (quite organised, V fib is disorganised)
QT interval is refractory period. There is a window inside the refractory period that is prone to attack. = Long QT syndrome
In patients with bradycardia, the refractory period is prolonged.
RCA has AV nodal branch.
If blockage is proximal to AV nodal branch, RCA occlusion can cause complexe heart block
Inferior MI: aspirin, clopidogrel, LMWH, thrombolytics
If patient has aortic dissection, patient will die
Be careful of inferior MI pattern
1st degree HB
c
Look at V1: You can see the P waves
PR relationship
Sometimes WRS comes shorter
Bigeminy: once every 2 beats = extra heartbeat between every normal one
Supraventricular/atrial: QRS morphology is narrow = frequent premature atrial ectopics
Benign = only treat is patient is symptomatic, or very frequent
All the PR complex looks weird, but they’re weird in unison (they all look the same)
Atrial flutter, 5:1 block
Negative saw tooth pattern
Postitive over aVF
R-sided
Usually involve R atrium only, in counter-clockwise pattern
Shortest distance that flutter wave should pass. Put line across CS = Tachycardia will stop
Go into heart via IVC, then go into right atrium, to the tricuspid valve.
Put line across tricuspid valve to IVC = isthmus is the most narrow part, ablate across the isthmus. Put some heat energy and damage the muscle = does not allow electrical activity to pass through
150 bpm for ventricular rate
Rhythm is regular
QRS = 160 m/s
Wide complex tachycardia
Give adenosine:
1. Terminate the tachycardia (once you block the node, tachycardia either stops, or something is unmasked)
First column: tachycardia
Second column: effect of ATP
Increased frequency of P wave
After giving ATP, there is some P flutter wave abnormality (morphology is different but mechanism is simmilar)
Something above AV node
Atrium itself has tachycardia. Even if you block AV node, it won’t affect tachycardia.
AV node–indepent tachycardia
AVRT and AVNRT = AV node dependent tachycardia
Delta wave
PR interval shortened
Wide QRS (due to prsence of delta wave)
Wolff-Parkinson-White
Delta = pre-excitation, excitation of ventricles via accessory pathway
