ECG diagnoses Flashcards
P wave duration, amplitude & Characteristics
P duration < 0.12 sec = 3 small squares
P amplitude < 2.5 mm
Notched P waves “P mitrale” = Left atrial enlargement. Normal amplitude but increased duration (> 3 small squares )
If the P is not seen in LII, look for it in V1
FREQUENCY CALCULATION
Vertical bar every 15 big squares
30 bigs squares = 6 sec
Number of Rs x 10 in 6 sec = Heart frequency
300, 150, 100, 75, 60, 50, 40
PR interval duration
0.12 - 0.20 sec
3 - 5 small squares
1 big square = 0.20 seg = 200 ms
Prolong PR interval cause
> 1 big square or > 220 ms
1st degree AV Block
Short PR interval cause
< 0.12 sec or < 3 small squares
Presence of an accessory pathway
Asocc with delta wave = WPW
ECG Normal Axis
Lead I: QRS (+)
AVF: QRS (+)
(0 to +90)
ECG Left deviated Axis
Lead I: QRS (+)
AVF: QRS (-)
(0 to +90)
CAUSES OF LEFT AXIS DEVIATION
Left ventricular hypertrophy
Left bundle branch block
Wolff-Parkinson-White Syndrome
Horizontally orientated heart: Short patient, pregnant or ascites
ECG Rigth deviated Axis
Lead I: QRS (-)
AVF: QRS (+)
(+90 to +180)
CAUSES OF RIGHT AXIS DEVIATION
Right ventricular hypertrophy
Pulmonary embolism
Lateral/posterior wall STEMI
Chronic lung disease: COPD
Sodium-channel blockade: TCA poisoning
Wolff-Parkinson-White syndrome
Dextrocardia
Normal paediatric ECG <2yo
Left Ventricle Hypertrophy (LVH) in the ECG
Left deviated Axis
V6: QRS (+) & T (-)
V1: QRS (-) & T (+)
Left Ventricle Hypertrophy (LVH) CAUSES
- Essential hypertension
- Hypertrophic Obstructive Myocardiopathy (HCOM)
- Subaortic and Aortic stenosis
- Aortic regurgitation
- Mitral regurgitation
- Coarctation of the aorta
- Ventricular septal defect (VSD)
- Infiltrative cardiac processes: Amyloidosis, Fabry disease, Danon disease
HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HCOM) in the ECG
Classic dagger Q waves on the left precordial leads
Right Ventricle Hypertrophy (LVH) in the ECG
Right deviated Axis:
V6: QRS (-) & T (+)
V1: QRS (+) & T (-)
Normal QRS duration
Right Ventricle Hypertrophy (LVH) causes
- Acyanotic Congenital Heart Diseases: ASD & VSD
- Pulmonary valve stenosis (Amiodarone)
- Tricuspid valve regurgitation
- Tetralogy of Fallot
- Lung diseases: Pulmonary fibrosis, chronic obstructive pulmonary disease, and sleep apnoea.
Lead II Isoelectric meanings
- Right Ventricle Hypertrophy (RVH)
- Mechanical: Right deviated Axis
- Electrical Conduction impaired: Normal Axis
- Left Branch Bundle Block (LBBB)
Left Branch Bundle Block (LBBB) in the ECG
Lead II : P wave wide & prolong PR interval
Axis will be normal or Left deviated
V6: QRS (+) usually notched & T (-) with ST depression
V1: QRS (-)
Rigth Branch Bundle Block (RBBB) in the ECG
V1: QRS (+) Wide-notched and T (-) with ST depression
V6: Prominent S
- RsR’ on V1 –V2
Axis will be normal or Right deviated
QRS Duration
0.06 - 0.10 sec
1.5 - 2.5 small squares
> 2.5 small squares = Wide QRS
Wide QRS causes
- Hyperkalemia.
- Hyper- or hypo-magnesemia.
- Supraventricular tachycardia (SVT) + bundle branch block (BBB)
- SVT with aberrant conduction.
- Atrial fibrillation (Afib) + Wolff-Parkinson-White syndrome (WPWS)
- Mono-morphic ventricular tachycardia (VT)
- Sodium Channel Blockers: Phenytoin, Lidocaine, Triamterene, Lamotrigine, Oxcarbazepine, and Amiloride
- Drug overdose and toxicities: TCA’s, digoxin, cocaine, lithium, diphenhydramine
Q wave present indicates
- Post STEMI
- Pulmonary Embolism: S1Q3T3
- HCOM: Dagger Q waves in left leads
S waves meaning
Final DEPOLARIZATION of the ventricles (Purkinje fibers)
Mirror effect, shows the opposite side
U waves meaning
Represent REPOLARIZATION of the ventricles (Purkinje fibers).
Best seen in the right precordial leads. Usually not seen.
Amplitude is usually < 1/3 T wave amplitude in the same lead.
Increment in U wave amplitude = Premature ventricular complexes (PVC)
QT segment Duration
- Normal = 0.4 to 0.44 sec
(2 big squares) - Short QT < 0.35 sec
- Prolong QT > 0.44 sec Predecessor of Torsade pointes(PVT) then VF
Prolong QT Causes
- HYPOS:
- Hypokalaemia
- Hypomagnesaemia
- Hypocalcaemia
- Hypothermia - Raised intracranial pressure
- Drugs
- Congenital:
- Romano Ward syndrome (AD)
- Jervell and Lange Nielsen syndrome (AR) - bilateral sensorineural hearing loss -
Prolong QT Causes: Drugs
- Antipsychotics
- TCAs
- SSRIs: Citalopram, Escitalopram
- SNRIs: Venlafaxine
- Apitypical Antidep: Bupropion
- MAOIs: Moclobemide
- Antihistamines
- Antiarrhythmics: Quinidine, procainamide, flecainide, sotalol,
and Amiodarone. - Antimalarial: Chloroquine, Hydroxychloroquine, and quinine
- Macrolides: Erythromycin, and Clarithromycin
Digoxin
TCA Intoxication ECG
Prolong QT Symptom
Syncope
Prolong QT Management
- Correct underline causes
- B-Blockers
- Implantable cardioverter-defibrillator (ICD)
UNSTABLE: Torsade de Pointes Treatment
Raised Intracranial Pressure ECG changes
Widespread giant T-wave inversions (“cerebral T waves”)
QT prolongation
Bradycardia
Short QT Causes
HYPERS:
Hypercalcemia
Hyperkalemia
Hyperthermia
Digoxin: Salvador Dali Sign
PULMONARY EMBOLISM IN ECG
S1 Q3 T3 : Cor Pulmonale
- Deep S in Lead I
- Q in Lead III
- T inverted In Lead III
✓ SINUSAL TACHICARDIA
✓ RBBB can be associated
Causes of ST-Segment Elevation
- Being an MI until proven otherwise
- Pericarditis
- Ventricular aneurysm
Causes Of ST-segment Depression
- Myocardium Ischaemia – Non-Stemi
- Unstable Angina
ACUTE PERICARDITIS ECG CHANGES
ST-segment elevation with reciprocal PR-segment depression in all leads except V1 and AVR
Aneurism ECG changes
V1 - V3 ST elevation with concave morphology
Deep Q waves
Brugada syndrome ECG changes
ST-segment elevation V1-V3 followed by a negative T wave.
Association with clinical criteria:
- Family history of sudden cardiac death at <45 years old .
- Young, Male, Southeast Asian patient
- Syncope
Takotsubo Cardiomyopathy (Broken Heart) ECG changes
Same ECG that STEMI: T wave inversion leads II, III, aVF, V3-6
In the context of:
- Pregnancy with CHF
- Sepsis with CHF
- Alcohol Cardiomyopathy
ECG MI: Anterior wall
Leads Affected: V2 to V4
Vessel Involved: Left Anterior Descending artery (LAD) – Diagonal branch
ECG MI: Septal wall
Leads Affected: V1 and V2
Vessel Involved: Left Anterior Descending artery (LAD) – Septal branch
ECG MI: Lateral wall
Leads Affected: I, aVL, V5, V6
Vessel Involved: Left Coronary Artery (LCA) – Circumflex branch
ECG MI: Inferior wall
Leads Affected: II, III, aVF
Vessel Involved: Right Coronary Artery (RCA) – Posterior descending branch
ECG MI: Posterior wall
Leads Affected:
V1 to V4 Mirror image ST depression
V7-V9
Vessel Involved:
*Left Coronary Artery (LCA) – Circumflex branch
*Right Coronary Artery (RCA) – Posterior descending branch
Hyperkalemia ECG changes
5.5 - 6.5 *Peaked T waves
6.5 - 7 *P waves widening,
flattening or absent
*Prolong PR interval
7 - 9 *Bradyarrhythmias
*Prolonged QRS
> 9 *Asystole
*Ventricular fibrillation
*PEA
Hypokalemia ECG changes
K < 2.7 mmol/L
- Increased P wave amplitude (>2,5 mm)
- Prolongation of PR interval (> 1 big square)
- Widespread ST depression and T wave flattening/inversion
- Prominent U waves - PVC (best seen in V2-V3)
- Apparent long QT interval due to fusion of T and U waves (= long QU interval)
Digitalis toxicity in ECG
- ST depression and T wave inversion in V5-6 in a reversed tick pattern.
- Bradycardia
- Prolonged PR
- Shortened QT
- Arrhythmias, especially heart block or bigeminy
Amiodarone overdose ECG Changes
Widening of QRS complex
Prolongation of the PR and QT intervals
Ventricular tachycardia and ventricular fibrillation