Rhythms Flashcards
Cardiac Conduction
Leads
- Anterior - V1 - V4
- Lateral - I / aVL / V5 / V6
- Inferior - II / III / aVF
Normal Sinus Rhythm
Must meet these criteria:
- Regular
- Rate 60-100 bpm
- PR interval is normal & constant
- A P wave precedes each QRS complex
- QRS width <120msecs
Inferior MI
- ST elevation eq/gr 1mm Lead II / III / aVF
- Progressive development of Q waves in leads II / III / aVF
- Reciprocal ST depression in aVL (+/- lead I)
Inferior MI - Right Ventricular (RVMI)
- If elevation in II / III / aVF then check V4R - look for elevation >0.5mm
- If elevated in V4R and hypotensive give fluid bolus (250ml) to improve preload/improve cardiac output
- If RVMI confirmed then avoid repeat GTN
Left Main (Widow Maker)
- ST depression eq/gr 1mm in 6 or more leads
- coupled with ST elevation in aVR and/or V1
- Suggestive of multi-vessel ischaemia or LMS insufficiency
ST depression / T wave inversion in aVL
- Can be reciprocal changes to an impending inferior MI
- Get serial ECG’s
Sinus Bradycardia
- Regular
- Rate <60 bpm
- Popping P waves
- Each P followed by a QRS
- PR normal & constant
Sinus Tachycardia
- Regular
- Rate >100 bpm <150 bpm
- Popping P waves
- Each P followed by QRS
- PR normal & constant
Atrial Fibrilation
- Irregularly irregular
- No POPPING P waves
- Rate may be slow, normal or fast
- QRS usually normal
High Risk of Stroke, anticoagulation therapy is commonly used.
Atrial Flutter
SA node signal blocked, so fired around atria:
- Usually regular
- No POPPING P waves
- FLutter (F) waves - saw tooth appearance
- Atrial rate around 300 bpm
- Relationship between atrial & ventricles is expressed as a ratio
- If the block is constant - rhythm regular
- Varying block - Rhythm irregular
Atrial Ectopics
- Originates from a focus in the atria
- Usually P wave is abnormal in shape - NOT POPPING!
- Usually normal QRS
- Followed by compensatory pause
Ventricular Ectopic Origin Points
Sinus Rhythm with Multifocal Ventricular Ectopics
Sinus Rhythm with Multifocal Ventricular Ectopics
- Rhythm irregular
- PR interval normal
- QRS normal
- Excitable myocardium - increased risk of ventricular arrythmias
Sinus Rhythm with Unifocal Ventricular Ectopics
Sinus Rhythm with Unifocal Ventricular Ectopics
- Rhythm regular
- PR interval normal
- QRS normal
- If associated with an MI - increases mortality
- Usually benign
Sinus Rhythm with R on T Ectopics
Sinus Rhythm with R on T Ectopics
- Regular rhythm
- PR interval normal
- QRS normal
- May precipitate a fatal arrythmia (usually VF)
- If >10 per minute concern should be greater
Ventricular Tachycardia
Narrow Complex Tachycardia
Narrow Complex Tachycardia
- Rate >100 (usually >150 bpm)
- Regular
- QRS normal - narrow (<120msecs)
- Absence of P waves
Left Axis Deviation
Left Axis Deviation
- Leads I & aVL are +
- Leads II, III & aVF are -
Right Axis Deviation
Right Axis Deviation
- Leads I & aVL are -
- Leads II, III & aVF are +
Brugada
Brugada
RBBB
+
V1/2 has cone shaped elevation extending into inverted T wave
Wolf Parkinson White (WPW)
Wolf Parkinson White (WPW)
- Slurred upstroke of QRS (delta wave)
- Short PR interval
Hypertrophic Cardiomyopathy
Hypertrophic Cardiomyopathy
- Deep Q waves in lateral (V5/6,I,aVL) & inferior (II,III,aVF)
- Tall QRS
- Inverted T waves
High Risk ACS
T wave inversion
or
ST depression
(any 2 leads)
+
PT looks unwell AND has ACS pain
Sudden Cardiac Death
Sudden Cardiac Death
Long QT
- Male >440
- Female > 460
Polarisation abnormality leads to VT
(Worry when QTc exceeds >500msecs)
Posterior MI
Posterior MI
- ST depression & tall, broad R waves in V1-V3
- Dominant R wave in V2
- Upright T waves
- Remove leads V5 & V6 and re-site below left scapula
- This is now posterior ECG - V5 & V6 have now become V7 & V8
- >1mm ST elevation in both V7 & V8 + pain & symptoms is confirmation to treat as STEMI
