final exam concepts/terms: ECG Flashcards
what is an is not an ECG?
SA node –> AV node –> Bundle of His –> Right and left bundle branches –> Purkinje fibers
Normal time intervals of the ECG
P-R interval: 0.12s-0.20s
QRS complex: under .10s
Q-T interval under 0.38s
Understand how the leads “see” the dipole
Positive Deflection: if the dipole points towards the positive electrode of lead, the ECG will record a positive deflection
Negative Deflection:
If the dipole points away from the positive electrode, the ECG will record a negative deflection.
No Deflection:
If the dipole is perpendicular to the lead axis, there will be no deflection.
knows leads I, II, and III
lead i: left and right arm
lead ii: right arm left leg
lead iii: left arm and left leg
what can an ECG tell you?
can provide valuable information about the heart’s electrical activity, helping diagnose heart conditions
know the normal divisions of the chart paper
each small square represents 1 mm (0.04 seconds horizontally, 0.1mv), each large square is 5 mm 0.2 seconds horizontally, 0.5 mv vertically)
what is the difference and fibrillation? which is more severe? why?
flutter: a rapid but regular rhythym where the atria beat a rapid rate (250-350 bpm), but the rhythym is somewhat organized
fibrillation: a disorganized, chaotic electrical activity often seen in the ventricles or atria. ventricular fibrillation is much more severe because it leads to ineffective pumping of the heart
know the properties of a pvc
wide and abnormal QRS complex, no p-wave preceding the pvc, an irregular rhythm in the heart rate
how can an ECG tell you about myopathes?
Myopathies (muscle diseases) can affect the electrical conduction of the heart, and an ECG can indicate
ECG abnormalities are often suggestive of underlying muscle problems, especially when paired with clinical symptoms
know how to distinguish between 1st, 2nd, and 3rd heart block
1st: increase P-R time interval, conduction occurs but is retarded, PR interval <0.2 sec
2nd: some of the P waves do not result in a QRS depolarization some of the depolarization does not go through the AV node
3rd: P wave does not lead to a QRS complex, there is no conduction through the AV node, complete block
dipole
a vector that represents the difference in charge between different areas of the heart’s muscle, or myocardium
arrythmia
irregular heartbeat, or a problem with a rhythm or rate of your heart’s beat
myopathies
muscle diseases
bradycardia
condition where the heart beats slower than normal, typically less than 60 bpm
tachycardia
when the heart beats faster than normal, usually more than 100 bpm
flutter
A rapid but regular rhythm (e.g., atrial flutter) where the atria beat at a rapid rate (often 250-350 beats per minute), but the rhythm is somewhat organized
fibrillation
A disorganized, chaotic electrical activity, often seen in the ventricles (ventricular fibrillation) or atria (atrial fibrillation).
