EKG lecture 4 pt 2 Flashcards
What is the main difference between atrial flutter and AFIB as far as rhythm goes?
Atrial flutter is regular (and more affected by carotid massage)
List 4 examples of irregular rhythms
1) Atrial fibrillation (most common)
2) Atrial flutter with variable AV nodal block
3) Multifocal atrial tachycardia
4) Sinus arrhythmia (normal variant)
Multifocal atrial tachycardia (MAT):
1) Is it regular? Explain
2) Can you see the P waves?
3) What is the rate?
4) Who is it common in?
1) Irregular rhythm from random firing of ectopic atrial foci
2) P waves easily identifiable
-At least 3 different P wave morphologies; P waves vary in shape
3) Rate = 100-200/min
-If < 100/min = “wandering atrial pacemaker”
4) Pts w severe lung disease, or in absence of pathology
Paroxysmal atrial tachycardia (PAT); list the:
1) Rhythm (regular or irregular?)
2) Rate
3) Etiology
1) Regular rhythm
2) Rate of 100-200/min
3) Enhanced automaticity of an ectopic atrial focus or reentrant circuit within the atria
Paroxysmal atrial tachycardia (PAT); how do you tell it apart from AFNRT?
1) Warm up or cool down = PAT (atrial origin)
2) If you see abrupt onset/end =AFNRT (AVN origin)
3) Carotid massage has no affect on PAT whereas it will slow down or terminate AVNRT
Premature ventricular contractions (PVC):
1) Are these common or rare?
2) What will the QRS complex look like?
3) Describe the P waves
1) Common
2) Appears wide and bizarre, but may not be wide in all leads
-QRS duration at least 0.12 sec in most leads
3) Often not seen; may be retrograde
1) What usually happens after a PVC?
2) What happens less commonly?
1) A PVC is usually followed by compensatory pause prior to next beat
2) Less commonly a PVC will occur between 2 normal conducted beats without pause
What are the PVC rules of “malignancy”? (i.e. more likely to result in life threatening arrhythmia)
1) Frequent PVCs
2) Runs of 3 or more PVCs (=V-Tach: assess for stable vs. unstable)
3) Multiform PVCs: vary in site of origin/morphology
4) PVCs falling on T wave “R on T” phenomenon, more likely to result in V-tach
5) Any PVC occurring in the setting of acute myocardial infarction
Ventricular tachycardia (V-TACH):
1) What is the rate?
2) What does uniform or monomorphic V-tach indicate?
3) What does polymorphic V-tach indicate?
1) Usually 120-200/min
2) Healed infarctions w. scar tissue allowing ventricular reentrant circuit
2) Assoc. w. ischemia, infarction, electrolyte disturbances, prolonged QT interval (leading to “R on T”)
Ventricular fibrillation (VF/VFIB):
1) Why is it usually just a pre-terminal event seen in dying hearts?
2) What must be done emergently?
1) No cardiac output
2) CPR and Electrical Defibrillation; SHOCKABLE
Accelerated idioventricular rhythm:
1) What is it? When does it occur?
2) What is the rhythm? Why?
3) Describe the sequalae
4) How do you Tx?
1) Benign rhythm; during acute MI or post revascularization
2) Regular rhythm @ 50-100/min (unusually fast for Ventricular pacer)
Ventricular escape focus that has accelerated enough drive the rate
3) Rarely sustained; does not progress to VF
4) Rarely requires treatment
Describe Torsade de Pointes on an EKG
1) QT interval = start of ventricular depole to end of ventricular repole
~ 40% of cardiac cycle if HR < 100
2) Prolonged QT interval usually due to prolonged repole
3) PVC falls on T wave (“R on T”)……….Torsades
What is Torsade de Pointes?
Specific type of V-Tach often seen in patients with prolonged QT interval
