ECG 2 Flashcards
What 3 abnormalities can be detected by an ECG?
conduction - insulation issue
structural - hypertrophy compromises ability of heart to pump, change in cardiac axis
perfusion abnormalities - coronary artery blockage/narrowing leading to cell death
What is the normal voltage and paper speed of an ECG?
V = 10ml/mV speed = 25ml/s
How does COPD affect the functioning of the heart?
harder to breathe
pulmonary hypertension
RV pumps harder leaving to a RAD
Shortcut for determining HR?
300/number of big squares
What is sinus rhythm?
P wave followed by QRS regular rate (even RR intervals) normal speed (60-100bpm)
What is sinus bradycardia?
rate regular but long slow speed (56bpm)
- could be healthy but with big heart so increased SV and low HR to maintain adequate CO
- medication
- vagal stimulus (activation of PNS)
What is sinus tachycardia?
rate regular (but short) fast (107bpm)
- physiological response (secondary) overactive adrenal gland hyperactive SNS lower SV blood loss (decreased VR)
What is sinus arrhythmia?
irregular rate (variable RR intervals)
normal speed
RR interval changes with breathing cyle
NOT PATHOLOGICAL
What creates a fuzzy trace?
EMR (noise)
What is a trick for determining axis deviation?
Look at LEAD 1 and III
lead 1 positive and 3 negative indicates LAD
lead 1 negative and 3 positive indicated RAD
What is atrial fibrillation?
supraventricular
no visible P wave
oscillating baseline (no isoelectric line) - atria contract asynchronously
irregular rhythm and slow rate
turbulent flow pattern increases clot risk (blood pools)
manage with oral anticoagulants
not so severe as atria are not essential for the cardiac cycle - passive filling maintains CO
What is atrial flutter?
supraventricular
regular, saw tooth pattern in baseline (II, III, avF)
atria to ventricular beats in a 2:1 or 3:1 ratio or more
saw tooth not visible in all leads (has specific vector)
What is first degree heart/AV block?
prolonged PR interval (>200ms)
slower AV conduction
regular ratio
most benign heart block - progressive disease of ageing
What is second degree heart block?
Mobitz 1
gradual prolongation of PR interval until beat skipped
regular P wave and RR interval
regularly irregular
caused by diseased AV node
3:1 ratio of success to failure
What is Mobitz II?
P wave regular - only some followed by QRS
No PR prolongation
regularly irregular
2:1
can rapidly deteriorate to 3rd degree heart block
What is third degree/complete heart block?
non sinus rhythm P and QRS regular but no relationship SAN 70BPM AVM 50BPM ventricular myocardium 30BPM
What is ventricular tachycardia?
ventricle beat faster than can fill –> decrease CO
P wave hidden - dissociated atrial rhythm
regular shape and fast rate (100-200bpm)
at risk of deteriorating into fibrillation (cardiac arrest)
use defibrillator
What is ventricular fibrillation?
asynchronous ventricular contraction
irregular HR (>250bpm)
heart cannot generate output (no filling)
at cardiac arrest
What is ST elevation?
P wave visible, followed by QRS
regular rhythm, normal rate
ST segment elevated more than 2mm above isoelectric line
due to infarction (tissue death by hypoperfusion)
What is ST depression?
P wave visible, followed by QRS
regular rhythm, normal rate
ST segment depressed more than 2mm below isoelectric line
caused by myocardial ischaemia (coronary insufficiency)
