ECG Flashcards
Blood flow through the heart.
Valves of the heart in order.
“Try Pulling My Aorta”
Try - Tricuspid,
Pulling - Pulmonary,
My - Mitral,
Aorta - Aortic.
Electrical conduction of the heart.
Describe
“Sweet Apples Have Big Price”
Sweet - SA Node,
Apples - AV Node,
Have - HIS Bundle,
Big - Bundle branches,
Price - Purkinje fibres.
“Try Pulling My Aorta”
Explain
Blood flow, and valves of the heart.
Try - Tricuspid,
Pulling - Pulmonary,
My - Mitral,
Aorta - Aortic.
What is the defining feature of 1st Deg Heart Block?
How will this present on an ECG?
Slowed AV conduction.
A prolonged PR interval (>0.20 sec) that is constant throughout.
What is the defining feature of 2nd Degree Type I Heart Block?
What will you see on an ECG?
An increasing delay of AV nodal conduction that continues until the atrial impulse fails to conduct.
An increasingly prolonged PR interval until a QRS complex is dropped.
Another name for 2nd Degree Type I Heart Block.
Mobitz Type I,
or Wenckebach.
Another name for 2nd Degree Type II
Heart Block.
Mobitz Type II.
2nd Degree Type II (Mobitz type II)
Heart Block.
Describe the mechanism.
Mobitz II is usually due to failure of conduction at the level of the His-Purkinje system (i.e. below the AV node).
What can be observed on an ECG with 2nd Degree Type II Heart Block.
The PR Interval is constant through out.
It may be normal or prolonged.
Suddenly, a QRS will be dropped.
Second Degree Type II Characteristics:
QRS Complex
Depending on where the interrupted electrical signal occurs, the QRS may be wide or narrow.
1st degree AV block is not technically a block.
Explain.
It is a delay, not a block.
The electrical impulse still reaches your ventricles, but moves more slowly than normal through the AV node. This causes a prolonged PR interval.
This is the most mild type of heart block.
Third degree (Complete) heart block.
Are the atria
(P waves) and ventricles (QRS) working together?
No. They operating independently.
The atrial rhythm is regular and the rate normal.
The ventricular rhythm is regular but the rate is typically much slower (Can be as slow as 40p/m).
- Likely to get variable PR Intervals.
Long QT Syndrome (LQTS)
Where is the QT interval measured from/to?
It is measured from the beginning of the QRS complex to the end of the T wave.
Long QT Syndrome (LQTS)
What does the QT interval represent?
The time it takes for the ventricles to depolarize and repolarize (or, contract and relax).
Long QT Syndrome (LQTS)
Give a brief definition.
LQTS is a condition that affects repolarization (relaxation) of the ventricles.
This leads to an increased likelihood of arrhythmia.
Arrhythmia (most commonly TdP) can lead to fainting, drowning, seizures, cardiac arrest - sudden death.
Long QT Syndrome (LQTS)
Risk factors
- PHX of TdP or other form of cardiac arrest,
- Congenital syndromes or genetic disorders,
- Electrolyte disorders,
- Medications (Medication Induced QT Prolongation).
Long QT Syndrome (LQTS)
“ABCDE” of medication induced QT prolongation
Antiarrhythmics,
antiBiotics,
antipsyChotics,
antiDepressants,
antiEmetics.
