Cards/EKGs Flashcards
Causes of LBBB
Aortic stenosis Ischaemic heart disease Hypertension Dilated cardiomyopathy Anterior MI (2/2 LCx or RCA blockage + LAD doesn't supply LPost fascicle) Primary degenerative disease (fibrosis) of the conducting system (Lenegre disease) Hyperkalaemia Digoxin toxicity
Causes of RBBB
Right ventricular hypertrophy / cor pulmonale
Pulmonary embolus
Ischaemic heart disease
Rheumatic heart disease
Myocarditis or cardiomyopathy
Degenerative disease of the conduction system
Congenital heart disease (e.g. atrial septal defect)
2/2 RCA MI or LCx MI
RBBB features
Broad QRS > 120 ms
RSR’ pattern in V1-3 (‘M-shaped’ QRS complex)
Wide, slurred S wave in the lateral leads (I, aVL, V5-6)
Sodium-channel blocking agent — e.g. tricyclic antidepressant ECG features
patient presenting with seizures and hypotension, the combination of…
QRS broadening > 100 ms
R’ wave in aVR > 3 mm
Name the 8 Steps involved in reading an ECG
Rate: fast, slow, normal? Wide QRS or narrow? Reg or irreg? Ps or not? Connected to QRS? Mean QRS axis/other intervals Ischemic/Infarct Hypertrophy Special Situations
300 bpm
Artifact
200 bpm
Likely a bypass tract (WPW)
160+ bpm
AVNRT, AVRT
150 bpm
atrial flutter
140 bpm
Be careful with calling this or anything above this SINUS
100 bpm
Sinus tach
60 bpm
Lower limit of NSR
50 bpm
Bradycardia, but look at the P waves to make sure its actually sinus before you call it sinus brady
AV node rate
40 bpm
Ventricular escape rhythm
Right Axis Deviation
Likely pathology on R side of heart
Left Axis Deviation
Likely path on L side of heart
Isoelectric point on ECGs
TP segment
What causes diffuse ST elevation?
Pericarditis
Benign Early Repolarization
Normal ECG findings in children
Heart rate >100 beats/min
Rightward QRS axis > +90°
T wave inversions in V1-3 (“juvenile T-wave pattern”)
Dominant R wave in V1
RSR’ pattern in V1
Marked sinus arrhythmia
Short PR interval (< 120ms) and QRS duration (<80ms)
Slightly peaked P waves (< 3mm in height is normal if ≤ 6 months)
Slightly long QTc (≤ 490ms in infants ≤ 6 months)
Q waves in the inferior and left precordial leads.
PR Interval
Time from the onset of the P wave to the start of the QRS complex.
It reflects conduction through the AV node.
Normal 120 – 200 ms duration (three to five small squares).
PR segment abnormalities (2)
Pericarditis (PR depression, widespread STE)
Atrial ischaemia