Cardiology Flashcards
ECG squares
Small square = 1mm = 0.04sec
Big square = 5mm = 0.2sec
ECG axis
Look at lead I + aVF
Lead I + aVF positive = normal axis
Lead I positive + aVF negative = left axis deviation (always abnormal)
Lead I negative + aVF positive = right axis deviation
Lead I negative + aVF negative = north west axis deviation (always abnormal)
P waves
3mm tall + 2mm wide
Tall P wave = right atrial hypertrophy
Wide P wave = left atrial hypertrophy
PR interval
3-4/4-5mm
Short = Wolf Parkinson White Long = first degree heart block, myocarditis, high potassium Variable = second degree heart block Mobitz 1, second degree heart block Wencheback 2, third degree heart block
QRS
Low amplitude = pericarditis, myocarditis
High amplitude = ventricular hypertrophy
Narrow <2mm = SVT
Broad >3mm = bundle branch block, Wolf Parkinson White
ECG - Right ventricular hypertrophy
RAD
Tall R aVR, V1
Deep S V5, V6
Upright T V1, V3, V4R
8do-8yo: TOF, VSD, PVS, CoA - newborn
ECG - Left ventricular hypertrophy
LAD
S V1 > 2x R V5, R V5 + V6 (taller)
S V1 > V6
AS, CoA, HOCM, AR, MR
ECG - LBBB
AS
High K
WPW
Dilated cardiomyopathy
ECG - RBBB
RVH
Myocarditis
CHD
TOF repair
QT
Short: hypercalcaemia
Long: congenital, hypocalcaemia, myocarditis, drugs
T waves
Upright V1-3: <8d >8y (if upright in between = RVH)
Peaked: hyperkalaemia, LVH
Flat: normal, hypokalaemia, pericarditis, myocarditis
Alternating: long QT
ECG - Pericarditis
ST elevation
PR depression
Flat T waves
ECG - Myocarditis
Long PR
Low amplitude QRS
Low amplitude T waves
ECG - Hypokalaemia
Flat T waves
Long QT
U waves
ECG - Hyperkalaemia
Peaked T waves
ECG - Wolf Parkinson White
Short PR
Qide QRS
Slurred upstroke QRS (Delta waves)
ECG - ALCAPA
ST elevation
Inverted T waves aVL, V5, V6
ECG - APVD
RAD
RVH
RAH
ECG - Aortic stenosis
LVH
ECG - ASD
Primum: superior axis
Secudum: RBBB, RAD, first degree heart block 50%
ECG - VSD
Small: normal
Moderate: LVH
Severe: RVH
ECG - CoA
<6m: RBBB/RVH
>6m: LVH or RBBB
ECG - Ebstein
RAH
RBBB
RVH disappears when exercising
ECG - HLHS
RVH
ECG - MS
RAD
RVH
RAH
ECG - PDA
Moderate: LVH
Large: LAH
Severe: RVH
ECG - TOF
RAD
RVH
ECG - Tricuspid atresia
Superior QRS
LVH
ECG - TGA
RAD
RVs + LVH
Complete heart block
SVT
Retrograde bundle of Kent
Treatment:
Vagal stimulation
Adenosine, DC shock
Long term - beta blocker, digoxin
Atrial fibrillation
Amiodarone
Cardioversion
Ablation
Ventricular tachycardia
Amiodarone
DC shock
Ventricular fibrillation
In long QT, Brugada, cardiomyopathy - defibrillation
Brugada
Coned ST elevation
LBBB
Death in sleep
Fever = emergency
Males, Asian
Wolf Parkinson White
Anterograde conduction accessory AV pathway before conduction through AV node Re-entrant Pre-excitation Sotalol, flecainide Avoid digoxin + calcium channel blockers
Long QT syndrome
AD
Deafness
Seizures/syncope
Treatment: Beta blockers No competitive sports Screen Family Avoid macrolides, TCA, antipsychotics, antifungals
Think of DiGeorge if neonate
Long QT type 1
KVLQT1
Low K efflux
Exercise triggered
Long QT type 2
HERG/KCHN2
K channel gene
Stress
Long QT type 3
SCN5A
High Na/defect Na channel gene
Triggered by rest or sleep
Mobitz type 1/Wenkebach
Progressive prolonging of PR until one drops
Mobitz type 2
Constant PR but periodic drops 2:1 3:1