ECG Flashcards
When does a P-wave occur?
Atrial depolariation
Which part of the wave shows ventricular depolarisation?
QRS complex
What does the PR interval show? What is normal?
AV conduction time. 3-5 small squares (120-200ms)
What is a normal QRS complex?
120ms- 3 small squares
what does the T wave show?
Ventricular repolarisation
How to calculate heart rate on ECG?
Regular: 300/no. of boxes between 2 QRS
Irregular: no of peaks in rhythm strip x 6
What conditions will you see a heart rate of 300 bpm?
WPW (where you see supraventricular tachycardia (SVT) and AF, atrial flutter
What is the speed of ECG and amplitude?
25mm/s and 10mm/mV
Where are the chest leads placed?
V1: 4th intercostal right sternal edge
V2: 4th intercostal left sternal edge
V3: between V2 and V3
V4: 5th ICS mid-clavicular line
V5: in line with V4 and V6
V6: 5th ICS mid-axillary line
What are the 4 limb leads and where are they placed?
Ride Your Green Bike
Red- RA
Yellow- LA
Green - LL
Blue- RL
What leads give the anterior, lateral, inferior and septal view of the heart?
Septal: V1, V2
Anterior: V3, V4
Inferior: II, III, AVF
Lateral: I, AVL, V5 V6
In a normal axis, what should lead I, II and AVF look like?
all positive- II more positive than I
In a normal axis, what should lead I, II and AVF look like?
all positive- II more positive than I
If I and AVF are positive what axis is it?
Normal
If I is negative and AVF is positive what axis is it?
Left axis deviation
What will be seen in right axis deviation?
I positive, II negative, AVF negative
What is extreme axis?
AVF and I are both negative
When is right axis deviation normal?
I positive, II positive, AVF negative
What do you see in atrial flutter?
Saw tooth, tachycardia
What is a sinus rhythm
presence of P waves
What is observed in AF?
absence of P waves, irregular rhythm, tachycardia
what is seen in first-degree heart block?
prolonged P wave
what is seen in the different types of second degree block?
Mobitz type 1 (Wendebach): PR interval gets gradually longer until it isn’t followed by a QRS complex
Mobitz type 2: unpredictable- intermittently fail to conduct without prolongation of PR interval
2:1: 2 P waves before QRS wave
what is observed in 3rd degree heart block?
No pattern is observed between P wave and QRS complex
How is MI observed on an ECG?
ST elevation (STEMI)
ST depression (NSTEMI)
T inversion (NSTEMI)
How is LBBB and RBBB observed on an o ECG?
RBBB : MaRoW - 1st lead looks like an M and 6th looks like a W
LBBB: WiLliam - 1st lead looks like a W and 6th looks like a M
both have broad QRS complex
What is a delta wave?
slurred upstroke of QRS complex
with tachycardia, delta illustrates Wolf Parkinson White syndrome (WPW)
What is observed in PE?
S1Q3R3- S depression in I, Q and R depression in III
Sinus tachycardia
