ECG abnormalities 1 Flashcards
Chamber enlargement
- RA -> proximal part of P wave
- LA -> distal part of P wave
- RV -> R wave
- LV -> S wave
Atrial enlargement which leads to look for especially
II
V1
Algorithm of evaluation the right atrial enlargement
-> especially in II and V1
- General contour
1) peaked proximal part of P wave (A-like appearance)
- > it’s called P PULMONALE - P wave duration -> no change
- Amplitudes of P wave -> increased (>0.25 mV in II and > 0.15 in positive phase of V1)
Algorithm of evaluation the left atrial enlargement
-> especially in II and V1
- General contour
1) notch in the middle of P wave followed by 2nd hump (M-like appearance)
- > called P MITRALE - P wave duration -> prolonged >0.12 s
and in V1 negative portion of P wave > 0.04 s - Amplitudes of P wave -> usually doesn’t increase but in V1 -> increased negatively directed portion >0.1 mV
- Axis -> may cause a slight leftward shift in frontal plane (but usually it remains normal)
- > in extreme LAE P wave amplitude May increase and the terminal portion of P wave may become negative in leads II, III and aVF
Algorithm of evaluation the left and right (bilateral) atrial enlargement
- Characteristics of RAE and LAE
Other criteria that may suggest LAE
- Duration of terminal negative P-wave deflection in lead V1 >0.04 s
- Amplitude of terminal negative P-wave deflection in lead V1 >0.1 mV
- Duration between peaks of P-wave notches >0.04 s
- Maximal P-wave duration >0.11 s
- Ratio of P-wave duration to RR segment duration >1:1.6
Ventricular enlargement which leads to look for especially
I
V1
I and V1 QRS amplitude in ventricular enlargement (suggestion, severe)
- LVE
- > V1 -> increase in S wave amplitude
- > V6 -> increase in R amplitude
- > I and aVL-> increase in R wave amplitude - RVE
- > V1 -> increase in R amplitude
- > V6 -> increase in S amplitude - LVE + RVE
- > hybrid of LVE and RVE
Right ventricular enlargement ecg criteria
- Mild no ECG change or axis move rightward (can be S>R in lead I)
- Moderate
- > I - RS (small R),
- > increased R in V1 (RS, R>S)
- > axis may or may not be rightward
- > S wave in V6 - Severe
1) I - rS (small R, R negativity of ST segment and T wave (delayed repolarization, right ventricular strain)
Right ventricular dilation
- QRS axis shifts rightward
- RSR’ appears in V1 and V2
- QRS duration can be prolonged
- Occurs during compensation or volume overload or after it’s hypertrophy fails to compensate for pressure overload
Left ventricular dilation
- Increase of the leftward and posteriorly directed QRS waveforms
- S wave amplitudes are increased in V1-V3
- R wave amplitudes are increased in left-leaning (I, aVL, V5-6)
- T waves amplitudes can be increased in the same leads and direction as amplitude of QRS complex
- > it can be also directed away from QRS complex -> indicating left-ventricular strain - Occurs during compensation or volume overload or after it’s hypertrophy fails to compensate for pressure overload
Left ventricular hypertrophy
- Prolonged intrinsicoid deflection
- Negative ST and T segment (delayed repolarization, reverse repolarization-> from endocardium to epicardium) in leftward-oriented leads (i.e. V5, V6)
- > left-ventricular strain - Increase of the leftward and posteriorly directed QRS waveforms
- S wave amplitudes are increased in V1-V3
- R wave amplitudes are increased in left-leaning (I, aVL, V5-6)
Ventricular hypertrophy algorithm
- General contour
1) prolongation of the intrinsicoid deflection-> can be mid-QRS notches
2) ST segment slope in the direction of the T wave-> when in rightward precordial leads -> called right-ventricular strain, in LV analogously - Duration of QRS complex
1) LVH -> May cause prolongation (progressive, usually slower than in LBBB)
2) RVH -> usually normal duration (but in dilation can be slight increase) - Amplitudes
1) see criteria - Axis
A) frontal
1) RVH -> rightward or vertical
2) LVH -> leftward
Ventricular hypertrophy criteria
- RVH
1) Butler-Leggett formula
2) Sokolow-Lyon criteria - LVH
1) Romhilt-Estes scoring system
2) Sokolow-Lyon criteria
3) Cornell Voltage criteria
Butler-Leggett formula for RVH
A+R-PL ≥ 0.70 mV in RVH
A (anterior) -> tallest R or R’ amplitude in V1 or V2
R (rightward) -> deepest S amplitude in I or V6
PL (posterior lateral) -> S amplitude in V1
Sokolow-Lyon criteria for RVH
R-> R wave amplitude in V1
S -> S wave amplitude in V5 or V6 (bigger)
In RVH
R+S ≥ 1.10 mV