ECG Flashcards
Describe the components of a normal ECG and how they correlate to the cardiac cycle?
P wave = atrial depolarisation
QRS complex = ventricular depolarisation
T wave = ventricular repolarisation
Atrial repolarisation is lost in the QRS complex
What is happening in the following ECG?
Anterior STEMI
There is progressive ST elevation and Q wave formation in V2-5
ST elevation is now also present in I and aVL.
There is some reciprocal ST depression in lead III.
What is happening in the following ECG?
Atrial Fibrilation
No P waves
Irregular rhythm
What is happening in the following ECG?
Mobitz Type 1 (Wenchebachs)
QRS complexes cluster in groups, separated by non-conducted P waves.
Progressively lengthened PR intervals followed by a droppped beat.
The P:QRS conduction ratio varies from 5:4 to 6:5.
What is happening in the following ECG?
Sinus tachycardia
HR 150bpm
P waves slightly hidden in preceding T waves
Sinus rhythm
What is happening in the following ECG?
Pericarditis
Widespread ST elevation throughout
What is happening in the following ECG?
Supra ventricular tachycardia
AV nodal rentry tachycardia (slow-fast)
Narrow complex tachycardia 150bpm
Regular
P waves are hidden in the QRS complex.
Can see the p wave as a pseudo R’ wave in V1 and V2.
What is happening in the following ECG?
RBBB
Wide QRS complexes.
MarroW formation.
If you turn the page 90 degrees complexes point to the right.
What is happening in the following ECG?
Anterolateral STEMI
ST elevation is present in the anterior (V2-4) and lateral leads (I, aVL, V5-6).
There is reciprocal ST depression in the inferior leads (III and aVF).
What is happening in the following ECG?
Ventricular Fibriliation
What is happening in the following ECG?
1st degree heart block.
PR interval greater than 200m/s aka 5 small squares.
1:1 conduction for P waves to QRS complexes
What is happening in the following ECG?
NST ACS
Changes in Non ST ACS are:
ST depression, T wave invesrion and T wave flattening
In this ECG you can see inverted T waves in V2, V3 and V4.
Note: ST depression which is localise usually represents a reciporocal change from a STEMI so look for one.
What is happening in the following ECG?
Lateral STEMI
?anterolateral
ST depression can be seen in III and AVF.
ST depression from a NSTEMI does not usually localise so look for a STEMI.
Can see ST elevation in AVL.
What is happening in the following ECG?
Atrial flutter with AV block.
Saw tooth p waves.
Normally flutter is regular and tachycardic.
What is happening in the following ECG?
Slow Fast AVNRT + ST depression
Regular tachycardia 220bpm
P waves are hidden.
ST depression throughout can be normal in SVT’s however should repeat ECG after patinets SVT resolves to rule out any ACS.
What is happening in the following ECG?
Lateral MI
ST elevation in I, AVL, V5 and V6
Reciporocal changes in III and AVF.
ST depression in V1-3 may be reciporocal or indicated further underlying ischaemia.
What is happening in the following ECG?
LBBB
Wide QRS complexes.
Rotate page 90 degrees predominant R waves pointing to the left.
Left axis deviation.
What is happening in the following ECG?
Ventricular Tachycardia
What is happening in the following ECG?
Massive PE
RBBB
Extreme right axis deviation
S1 Q3 T3 (s wave in lead I, Q wave in lead III and T wave inversion in III)
What is happening in the following ECG?
Complete/3rd degree Heart Block
AV dissociation aka the p waves and QRS complexes are not related.
Broad spectrum QRS complexes as they are generated from the ventricles (ventricular escape rhythm).
What is happening in the following ECG?
WPW
Short PR interval less than 3 small squares (120ms)
Broad QRS with an upward slant (delta wave)
Either T wave inversion in with prominent R waves in
V1-V3 (right sided accessory pathway)
V4-V6 (left sided accessory pathway)
In this ECG it is a right sided accessory pathway.
What is happening in the following ECG?
Mobitz Type II Heart block
3 conducted p waves with one dropped beat.
No PR interval lengthening.
What is happening in the following ECG?
Inferior STEMI
ST elevation in II, III and aVF.
Reciprocal ST depression and T wave inversion in aVL
