ECG Interpretation Flashcards
What does the ST segment represent?
The period between ventricular depolarisation (QRS) and ventricular repolarisation (T)
ST elevation represents?
Myocardial Infarction
ST depression represents?
Ischemia
What is the process of ST depression during an ECG exercise test?
Upsloping ST > Horizontal ST > Downsloping ST
What is the J point and what does it mean if it is 1mm below or above the Q wave?
Start of ST segment, below means ST depression, above means ST elevation
True or False, ST elevation means a partial block
False! It’s a complete blockage and indicates MI
What are some causes of ST elevation?
LV hypertrophy, pericarditis, ventricular fibrosis
What substance is released and can be found in blood tests after a myocardial infarction?
Troponin
True or False, STEMI is more severe than NSTEMI
True! NSTEMI is still a myocardial infarction, however it may only indicate a partial block
List the STEMI evolution
First few minutes = complete block, ST elevation (or NSTEMI)
Hours to days = Q wave becomes deeper, T wave inverted, ST elevation
1 week = Slight ST elevation, T wave slightly inverted
Months = ST slightly higher than Q wave, rest of ECG normal
What leads are Bipolar?
Lead I, II, III
What leads are Unipolar?
Lead avR, avL, avF
What leads are Precordial?
V1-V6
What is Sinus Bradycardia?
Regular rhythm, <60bpm, normal P wave, normal QRS
What is Sinus Tachycardia?
Regular rhythm, 100-160bpm, normal P wave, normal QRS
What is sinus Arrhythmia?
Irregular rhythm, >60bpm, normal P wave, normal QRS
What does it mean if there is no P wave?
Not a sinus rhythm and the contraction is not coming from the SA node
What is the difference between Atrial flutter and Atrial fibrillation?
Atrial flutter is 3 depolarisations of the atria before QRS, Atrial fibrillation is rapidly depolarisation of the atria before QRS.
What is Premature Ventricular Contraction?
Irregular rhythm, >60bpm, normal P wave, normal QRS - random ventricular depolarisation
What is Atrial Fibrillation?
Irregular rhythm, rate may be fast or slow, p wave is absent, QRS is normal
What is a Sinus Block?
Rhythm in atria and ventricle is regular when present, there is a pause between P wave
What is a unifocal PVC?
PVC that look the same
What is a multifocal PVC?
PVC that have different shapes
What is R on T syndrome?
Very premature ventricular depolarisation
What is Ventricular Tachycardia?
No p wave, regular rhythm, >100bpm, QRS is wide and bizzare, anything more than ventricular triplet
-Electrical current gets stuck in necrotic tissue
What is Ventricular Fibrillation?
Ventricles are vibrating and firing from all over the place, rhythm is chaotic, rate is undeterminable, QRS is unidentifiable
