Persistent Juvenile T Wave Pattern
- normal for kids to have t wave inversions in right precordial leads (V1-V3) which can often persist in people < 40 yo (especially women)
- Should be asymmetric and shallow NOT symmetric and deep
How do you determine if in sinus rhythm?
p waves should be upright in I, II, III and aVF
if inverted then suggests ectopic origin of atrial beats
Benign Early Repolarization
- ST elevations in multiple leads (but not aVR or V1),
- precordial»_space; limb
- Notched or irregular J point
- No reciprocal changes
- Concave shaped J point elevation
- ST elevation is <25% of the T wave height in V6
- May have prominent T waves
- Can be hard to distinguish from pericarditis, go by symptoms, also diffuse PR depressions point to pericarditis
AV Junctional Rhythm
- Narrow complex, rate b/n 40-60 w/ p waves either hidden, before QRS with short PR or after QRS
- If rate is 60-100 then called “accelerated junctional rhythm”
- If rate > 100 then called “AV Junctional Tachycardia”
Accelerated Idioventricular Rhythm
- Often seen w/ re-perfusion following MI
- A/V dissociation with ventricular escape rhythm that is > 40
RBBB
- rSR’ or qR in lead V1
- Slurred/wide s wave in lateral leads
- QRS > 120 ms
- ANY ASSOCIATED ST ELEVATIONS SHOULD PROMPT STEMI EVALUATION
LBBB
- rS in V1 (small r with very deep and broad S wave)
- R in I or V6 (broad monophasic R wave)
- LAD
- Discordance between QRS and ST segments in all leads (“appropriate discordance”)
- Consider Sgarbossa Criteria
Left Anterior Fasicular Block
- LAD
- qR or R in I and aVL
- rS in III
- No other causes of LAD identified
Left Posterior Fasicular Block
- Usually occurs with RBBB
- RAD
- qR in lead III
- No other causes of RAD identified
- Commonly see t wave inversions in inferior leads
Differential for LAD (7)
LBBB LAFB inferior wall MI LVH WPW ventricular ectopy paced beats
Differential for RAD (8)
LFPB lateral wall MI RVH acute and chronic lung disease (PE, COPD) normal young adults with horizontal slanted heart ventricular ectopy hyperkalemia Na channel blocker OD
LVH Criteria
- R amp > 11 mm in aVL
- R amp in V5 or V6 + S amp in V1 > 35 mm
RVH Criteria
- R:S > 1 in V1
- R:S < 1 in V6
- R amp > 7 mm in V1 (if RBBB exists then R amp must be > 15 mm instead)
- RAD
LAE Criteria
- Notched p waves and duration > 110 ms in ANY lead
- Downward p wave deflection > 1 mm and duration > 40 ms in lead V1
RAE Criteria
p amp > 2.5 mm in ANY inferior lead
Differential for NARROW Complex Tachycardia
Regular
- Sinus tachycardia, SVT, atrial flutter
Irregular
- A fib, atrial flutter with variable conduction ratio, multifocal atrial tachycardia
Hypothermia ECG Changes
J Waves/Osborne Waves - positive deflections at the end of the QRS complex
- prolonged QRS and QT intervals
2 Major Pacemaker ECG Findings
1 - should see pacer spikes followed by QRS complex (“capture”)
2 - should also see appropriate discordance between QRS and ST segments
How do you detect a posterior wall STEMI?
- If ST elevations in inferior leads (inferior wall MI), look to see if ST elevations in lead III are more prominent than in lead II
- If inferior STEMI expect reciprocal changes in I, aVL and V5/6 but may be posterior extension if also see horizontal ST depressions in V1-V3
- Enlargement of R waves in right-sided leads
- Tall, broad (> 30 ms) R waves in V2-V3
- R:S > 1 in V2
- Can obtain R-sided precordial leads - RV MI if ST elevations in V4, V5 or V6 (PRELOAD DEP)
Wellen’s Syndrome
biphasic t waves in anterior leads, represent large proximal LAD occlusion
Poor R Wave Progression (definition + meaning)
R amp < or = 3 in V3
indicative of prior anterolateral MI
Hyperkalemia
Hypokalemia
Hyperkalemia
- Peaked t waves - Flattening of p waves - PR and QRS prolongation - Bradycardia, bundle branch blocks, sinusoidal
Hypokalemia
- U waves - waves after t wave, typically smaller amp than t wave, causes camel hump shape, may make it look like QT is prolonged
ECG Findings in Massive PE (6)
- Tachycardia
- RAD
- Incomplete RBBB
- S1Q3T3 - large S wave in lead I, q wave in lead III, inverted t wave in lead III)
- Simultaneous t wave inversions in inferior and anteroseptal leads
- Pointy p waves in V1
Low Voltage Criteria and Differential
- Criteria:
- Amp of QRS in all limb leads < 5 mm
- OR amp of QRS in all precordial leads < 10 mm
- Diff:
- Myxedema, large pericardial effusion, large pleural effusion, end stage cardiomyopathy, severe COPD, infiltrative myocardial diseases, constrictive pericarditis, prior massive MI
