Arrhythmias and Blocks Flashcards
Pneumonic to remember underlying causes of arrhythmias
HIS DEBS H - hypoxia I - Ischemia, Irritability, Infarction S - Sympathetic Stimulation D - Drugs E - Electrolyte Disturbances B - Bradycardia S - Stretch
What are the 4 questions you should ask yourself to assess an arrhythmia?
1) Are the P waves normal?
2) Are the QRS complexes wide or narrow?
3) Is there a P wave for every QRS complex?
4) Is the rhythm regular or irregular?
What are the characteristics of PSVT?
Regular rhythm, P waves are retrograde if even visable, rate:150-250 bpm, carotid massage slows or terminates rhythm
What are the characteristics of A flutter?
Regular rhythm, saw-toothed patter, 2:1 - 4+:1 block, atrial rate:250-350 bpm, ventrivulare rate 1/2-1/4+ atrial rate, carotid massage increases block
What are the characteristics of A fib?
Irregular rhythm, undulating baseline, atrial rate 350-500 bpm, ventricular rate variable, carotid massage may slow ventricular rate
What are the characteristics of MAT?
Irregular rhythm, at least 3 different P wave morphologies, rate 100-200 bpm but can be less, carotid massage has no effect
What are the characteristics of PAT?
Regular rhythm, rate 100-200 bpm, characteristic warm-up period in the automatic form, carotid massage has no effect o only mild slowing
How to you diagnose a 1* AV block?
PR interval is longer than 0.2 sec (5 small squarers or 1 large square)
How do you diagnose a Wenckebach (Mobitz Type I) Block?
the progressive lengthening of each successive PR interval until one P wave doesn’t have a QRS
How do you diagnose a Mobitz Type II block?
every few beats, a P wave doesn’t have a QRS, but there isn’t a progressive lengthening of the PR interval
How do you diagnose a RBBB?
look for wide QRS and rabbit ears in V1 and V2 with ST depressions and T wave inversion with reciprocal changes in V5, V6, I and aVL
How do you diagnose LBBB?
look for wide QRS and broad or noched R wave with prolonged upstroke in V5, V6, I and aVL with ST depression and T wave inversion and reciprocal changes in V1 and V2
How do you diagnose a left anterior hemiblock?
Look for LAD in (+ QRS in lead I, - QRS in lead aVF). If present, look in lead II, if QRS is - then left anterior hemiblock present.
**QRS should be normal in duration with no STT changes and no other cause for LAD present -ie underlying pathological explanation such as ventricular hypertrophy)
How do you diagnose a left posterior hemiblock?
Look for RAD (- QRS in lead I and + QRS in lead aVF)
**QRS should be normal in duration with no STT changes and no other cause for RAD present -ie underlying pathological explanation such as severe lung disease)
What is a bifascicular block?
RBBB with a hemiblock
