ECG quick Flashcards
sinus rhythm
- P wave before every QRS
- P wave with sinus morphology
- Positive in I, II, aVF, negative in aVR
- HR 60-100 bpm
Heart axis
- I + aVF +
- > 0-90 degrees (normal axis)
2. I+ aVF - II + -> 0-(-30) degrees (normal axis) II - -> -30-(-90) degrees (LAD -> left-axis deviation)
- I - aVF +
- > 90-180 degrees (RAD -> right-axis deviation) - I- aVF -
- > -90-(-180) degrees (EAD -> extreme-axis deviation)
P wave duration + amplitude
≤ 0.12 s
amplitude -> normally no more than: 1. 0.25mV in frontal plane leads 2. 0.3 mV in precordial leads 3. V1: positive ≤0.15 mV negative ≤0.1 mV
PR duration
adult: 0.12 to 0.20 s
QRS duration
0.07-0.11 s
Direction of QRS
- Always should be positive in:
1) I, II
2) aVL
3) V4, V5, V6 - Should be negative in
1) aVR
2) V1
3) V2 - In other (III, aVF, V3) can be either
Significant elevation of ST -> norms
1) in V2 and V3
1. Women ≥0.15 mV
2. Men <40 years: ≥0.25 mV
3. Men ≥40: ≥0.2 mV
2) in other leads: ≥0.1 mV
3) Measured in point J
Significant decrease of ST -> norms
- V1, V2, V3 ≥0.05 mV
- Other leads ≥0.1 mV
- Measured in point J
T wave amplitude
1) shouldn’t exceed 0.6 mV in limb leads
2) shouldn’t exceed 1.0 mV in precordial leads
QTc duration
≤ 0.46 s
right atrial enlargement
- peaked proximal part of P wave (A-like appearance)
- > it’s called P PULMONALE - Amplitudes of P wave: >0.25 mV in II or > 0.15 mV in positive phase of V1
left atrial enlargement
Duration of P wave > 0.12s in II or
Increase in duration (>0.04s) and amplitude (0.1 ms) of negative phase of P wave in V1
Left ventricular enlargement suggestion
V1 -> increase in S (QS) wave amplitude
V6 -> increase in R amplitude
I and aVL-> increase in R wave amplitude
Cornell criteria: R wave in aVL + S wave in V3:
⩾ 2.8 mV in males
⩾ 2.0 mV in females
Right ventricular enlargement suggestion
V1 -> increase in R amplitude
V6 -> increase in S amplitude
R>S in V1
S>R in V5 or V6
RBBB
- > all
1. QRS ≥ 0.12 s (incomplete ≥ 0.11 s)
2. V1 or V2: M-shaped QRS (RSR’) and
3. I and V6: S wave wider than R wave or ≥ 0.04 s)
4. Possible changes of ST (oblique decrease) and T (negative) -> V1, V2, V3 - > (if not -> consider myocardial infarction)
5. Late intrinsicoid in V1 R’ peak or late R peak, >0.05 s
LAFB
- Left axis deviation (-45 to -90 degrees)
- Small Q (qR) in aVL and I
- Small R (rS) in III and aVF
- QRS <0.12 s
- Late intrinsicoid deflection in aVL >0.045 s (qR)
LPFB
- Right axis deviation (90 to 180 degrees)
- Small Q (qR) in III and aVF and
- Small R (rS) in I and aVL
- QRS <0.12 s
- Late intrinsicoid deflection in aVF (>0.045 s)
- No evidence of RVH
LBBB
- QRS ≥ 0.12s (incomplete ≥ 0.11 s)
- Mid QRS notching/ slurring in two of the left-leaning leads (I, aVL, V5, V6)
- QS or rS in V1-V3
- V5,V6 -> late (>0.06 s) intrinsicoid
- Possible changes in ST and T opposite to QRS amplitude (if not -> consider myocardial infarction)
- Always look for STEMI criteria with LBBB
Equivalents of STEMI new LBBB criteria
LBBB criteria + 1 of:
- ST elevation ≥ 0.1 mV in a lead with upward QRS complex
- ST depression ≥ 0.1 mV in V1, V2, or V3
- ST elevation ≥ 0.5 mV in a lead with downward (discordant) QRS complex
QS in V1-V4 or Q in V5 or V6 can suggest new or past MI
Ventricular preexcitation ecg criteria
- PR interval duration < 0.12 s
- Delta wave at the beginning of the QRS complex
- QRS > 0.12 s
- Changes in ST segment and T wave -> usually opposite side of the QRS complex
Brugada syndrome ECG
-> in V1-V3
Type I -> ST elevation (usually in J point) ≥0.2 mV with coved ST segment with ST segment decreasing -> to negative T wave
Type II -> High J-point eleviation ≥2mm, saddleback ST first decreasing (but > 1mm above baseline) but T wave positive or biphasic
Type III -> J point eleviation ≥ 2 mm with ST elevation < 1mm (saddleback), positive T wave
Eleviation of ST causes
Electrolites (Hyperkaliemia)
LBBB
Early repolarization (benign)
Ventricular hypertrophy
A3 -> Arrhyrhmia (VT, Brugada), Aneurysm of LV, Aortic dissection
T -> TBA - Traumatic brain injury or Takotsubo disease
Infarction
Osborn waves (hypothermia)
Non-artherosclerotic vasospasm (Prinzmetal angina)
Equivalents of STEMI (signs allowing to diagnose STEMI without additional criteria)
- new LBBB with addition criteria
- Posterior MI
- LMCA Occlusion
- Wellen’s Syndrome
- De Winter’s T Waves
Posterior MI
- RCA (90%), LCX (10%)
- V2, V3 -> ST depression ≥ 0.05 mV
- Usually broad, prominent and tall R waves in V1-V2 (R≥S, R ≥ 40ms)
- V7-V9 ST elevation ≥ 0.05 mV
LMCA Occlusion
- ST elevation in aVR with diffuse (at least 8) ST depressions
Wellen’s Syndrome
- Deeply-inverted or biphasic T waves in V2-3 (V1-V4) with or without ST elevation
- Suggests critical LAD occlusion
De Winter’s T Waves
- Precordial ST-segment depression at the J-point
- Tall, peaked, symmetric T waves in the precordial leads
- Suggest LAD occlusion
ECG localization of STEMI
- Anterior (LAD): V1-V4
- > Anteroseptal (LAD, diagonal) -> V1-V2
- > Anteroapical (distal LAD) -> V3-V4 - Lateral (LCX) -> I, aVL, V5-V6
- Inferior (PDA) -> II, III, aVF -> + in 1/3 RV ischemia
- Posterior (PDA) -> ST depressions in V1-V3 with tall R waves, V7-V9 ST elevation
- RV (RCA, acute/right marginal artery) -> VR3-VR4, suggested by eleviation of ST in V1
Progression of STEMI ECG waves and segements with time
- Increase in T wave amplitude, tombstoning
- ST elevation -> Pardee waves
- Q waves (takes several hours to days to develop) and decreasing R wave amplitude
- Invertion of T waves (negative), ST return to isoelectric
Acute pericarditis ECG
STAGE 1 -> because inflammation involves epicardial myocardium
- Widespread ST elevations, often horizontal or upward
- Upright T waves
- PR depression (50%)
STAGE 2
- ST return to normal
- T waves become inverted
Pericardial effusion and chronic constriction ECG
- Low voltage
- Widespread ST-elevation
- Total electrical alternans -> alternating high and low voltages of all ECG waveforms between cardiac cycles within a given lead
- T-wave inversion
- AF in 1/3
PE ECG
- Tachycardia
- Nonspecific ST and T changes
- Negative T waves in V2-V4
- QR in V1
- SIQIIITIII -> rarely
- Acute Cor Pulmonale, RV overload -> rarely, in massive PE
Cor Pulmonale (Pulmonary hypertension, RV overload features) ECG
- RV dilation/ hypertrophy
- RBBB
- Rightward axis devation
- P pulmonale
Hypothermia in ECG
- Osborn waves -> deflections at the J point at the same direction as QRS complex -> height roughly proportional to the degree of hypothermia
- PR and QT prolongation
- Widening of QRS
Hypokaliemia in ECG
LUFTP -> Low K - U waves, Flattened T, Prolongation of QTc
- Flattening or invertion of T wave
- ↑ prominence of U waves
- ↑ of QTc (and sometimes PR interval)
- Slight depression of ST segment
-> hyperpolarization
+ often premature beats and sustained tachyarrhythmias, tordases de pointes
ALKALOSIS
Hyperkaliemia in ECG
- Tall, peaked T waves (from 5.5 mM)
- Loss or flattening of P waves (from 6.5 mM)
- Widened QRS (from 7 mM)
- ↓ of QTc
- ↑ of PR
- Sine wave appearance (K levels 7-8 mM)
-> decrease of potential, AV blocks, VF, Asystolia
ACIDOSIS
Hypocalcemia and hypercalcemia in ECG
Hypocalcemia -> ↑ QTc
Hypercalcemia -> ↓ QTc
Digitalis effect on ECG
- Coved ST-segement depression -> “Salvador Dali sagging” appearance
- Flattened T wave
- ↓ QTc interval
Tricyclic Antidepressant (TGA) ECG
- Wide QRS complex
2. ↑ of QTc
Class 1 Antiarrhythmics on ECG
1A -> ↑ of QTc, ↓ T wave and ↑ U wave amplitude toxicity -> prolongation of QRS
1B -> usually no effect on ECG
1C -> broadening of QRS, without affecting interval between J point and T wave
Class 2, 3, 4 Antiarrhythmics on ECG
2 and 4 -> sinus bradycardia, ↑ PR 3 -> ↑QTc (Amiodaron has class 1, 2, 3 effect)
