ECG abnormalities 2 Flashcards
Inherited Arrhythmia Disorders
- LQTS - Long QT syndrome
- SQTS Short QT Syndrome
- The Brugada syndrome
- ARVC - Arrhythmogennic Right Ventricular Cardiomyopathy
- CPVT - Catecholaminergic Polymorphic Ventricular Tachycardia
LQTS types
- LQT1 -> KCNQ1 gene mutation, potassium channel, early onset broad T wave, usually part of Jervell and Lange-Nielsen syndrome (JLNS) -> with bilateral sensorineural hearing loss
- LQT2 -> KCNH2 gene mutation, potassium channel, bifid, low amplitude T waves
- LQT3 -> SCN5A mutation, sodium channel, long isoelectric ST segments with late-appearing T wave, sudden cardiac death during sleep
LQTS diagnosis
- Suspition -> cQT > 460 ms (usually > 480 ms)
- Rule out secondary causes of LQT
- Schwarz score (LQTS scale) > 3 or mutation of one of the responsible genes
Causes of LQT
- Genetic
- Electrolyte imbalance -> hypokalemia, Hypocalcemia, Hypomagnesemia
- Drugs: antyarrhythmic, Antibotics, Antipsychotics, H1 antagonists, other
- Cardiac conditions: MI, Cardiomyopathy, Myocarditis, bradycardia
- Endocrine: hypothyroidism, hyperparathyroidism, pheochromocytoma, hyperaldosteronism
- Intracranial disorder: SAH, stoke, thalamic hematoma, encephalitis, head injury
- Malnutrition
LQTS treatment and frequency and onset
1/2000, onset usually 5-15
- β-blokers (Nadolol, Propranolol)
- ICD
SQTS
- suspect when QT<360 ms (usually < 300)
- Cause: gain of function mutation of potassium channel or Ca channel -> more rapid repolarization
- Arrhythmias: AF, polymorphic VT, SCD
- treatment: Quinidine or Sotalol or ICD
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
Brugada syndrome causes and diagnosis
- Mutations of sodium channel gene (most common SCN5A) -> predisposition for reentry
- Diagnosis: ECG, can wax and wane -> augmentation: sodium channel blockers: Flecainide, Ajmaline, Procainamide
- Cardiac arrest often in bed, at night, can be provoked by febrile illness
Brugada syndrome treatment
- Quinidine
- ICD
- Avoidance of drugs elevating ST
- Quick management of fever
ARVC
- Genetic fibrofatty replacement of cardiac muscle of RV -> reentry
- Inverted T waves or Epsilon wave in V1-3
- Most common arrhythmias: PVC, VT, VF
- Treatment: avoidance of sports, β-blokers, Amiodarone, ICD, ablation
CPVT
- Mutation of gen codung ryanodine receptore RyR2
- Onset in childhood with syncope due to polymorphic VT
- ECG: PVC, bidirectional VT
- Treatment: avoidance of physical exercise, β-blokers, ICD, left cardiac sympathetic denervation
Subendocardial ischemia typical leads
Typically in:
- leftward: I, aVL, V4, V5, V6
- inferiorly oriented: II, III, aVF
V1-V3 depression -> almost never seen -> can mean either RV subendocardial ischemia (it resolves in the minutes following exercise or stress) or more typical LCX transmural ischemia (lateral wall)
Subendocardial ischemia ECG pattern
- ST depression >0,1 mV -> from J point horizontal or downsloping (upsloping can normal or abnormal when it remains depressed)
- T wave -> juction of ST with T wave depressed but the terminal part of T wave usually remains positive (but T wave can be inverted)
ECG criteria for transmural ischemia
A) significant elevation of ST segment at J point:
- ≥ 0.1 mV in any lead exept V2 and V3
- in leads V2 and V3 -> ≥ 0.25 mV in men < 40 yo, ≥ 0.2mV in men ≥40 yo, ≥ 0.15 in women
B) Depression of ST at J point ≥ 0.1 mV in at least 2 out of 3 leads: V1-V3
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
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
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