Cardiac Rhythm and Recognition Flashcards
What are self-adhesive pads used for?
Monitor rhythm in a collapsed patient as quickly as possible
What are some features of 3 lead monitors?
Display rhythm in real time
One lead on each shoulder and one on the abdomen = red for right, yellow for left, green for abdomen
When is a 12 lead monitor used?
If the rhythm is persisting = gives 3D view of the heart
What does the P wave on the ECG represent?
Atrial depolarisation
What does the QRS complex represent?
Depolarisation of the ventricular myocardium
What does the T wave represent on the ECG?
Ventricular repolarisation
How is a regular heart rate calculated?
300/number of large squares in R-R interval
How is an irregular heart rate calculated?
Multiply the number of cardiac cycles in 30 large squares by 10
What are the six stages of reading the rhythm strip?
Is there electrical activity?
What is the QRS rate?
Is the QRS rate rhythm regular or irregular?
Is the QRS width narrow or broad?
Is atrial activity present?
How is atrial activity related to ventricular activity?
What does the width of the QRS indicate?
Narrow = rhythm comes from SA node Wide = comes from ventricular myocardium
Why is it difficult to tell of atrial activity is present?
Largely obscured by QRS complex on ECG
What are some features of normal sinus rhythm?
Rate 60-100 bpm
Regular P wave to every regular QRS complex
Normal P wave appearance
Normal and constant PR interval
What are some features of atrial flutter?
Atrial rate 250-350 bpm
Usually regular QRS
Classic sawtooth appearance
Most commonly 2:1 conduction = 150bpm ventricular and 300bpm atrial
What are some features of atrial fibrillation?
Irregularly irregular QRS
Fast or slow AV conduction
No P waves = atrial rate > 350 bpm
Irregular baseline
What are some features of ventricular tachycardia?
Rate 100-200 bpm
Regular
Occasional dissociated P waves
Wide bizarre QRS
What are some features of Torsades de pointes?
Twisting of axis May revert to VF or back to sinus rhythm Regular or irregular Associated with electrolyte abnormalities Sinusoidal pattern
What are some features of first degree heart block?
Rate depends on underlying rhythm
Physiologic block in AV node
Regular
Prolonged PR interval > 0.2s
What are some causes of first degree heart block?
Medication, vagal stimulation, disease
What are some features of Mobitz type 1 second degree block?
Dropped beat Regularly irregular Cycle starts over Increasing PR interval Diseased AV node with long refractory period
What are some features of Mobitz type 2 second degree block?
Same PR interval for all conducted beats
P waves usually regular
Some P waves not conducted
May be 2:1, 3:1 or 4:1 etc
What can Mobitz type 2 progress to?
Complete heart block
What are some features of complete heart block?
Atrioventricular dissociation
Regular P waves and QRS complexes but no relationship between the two
What is used to treat complete heart block?
A pacemaker
What leads view the inferior surface of the heart?
Leads II, III and AVF
What leads view the lateral wall of the left ventricle?
Leads I, AVL, V5 and V6
What leads view the septal surface of the heart?
V1 and V2
What leads view the anterior wall of the right and left ventricles?
V3 and V4
How does right bundle branch block appear on the ECG?
Positive R wave in V1
How does left bundle branch block appear on the ECG?
Negative in V1 and positive in V6
What leads view the right coronary artery?
Leads II, III, AVF
Also V3 and V4
What leads view the circumflex artery?
Leads I, AVL, V5 and V6
What leads view the lateral anterior descending artery?
V1 and V2
