L 56 & 57 Pathology of HF/Dysarrythmia Flashcards
Patients may describe AF as…
- Heart thumping out of chest
- Lightheaded and anxious feeling that resolves shortly after the heart symptoms
Is AF a vascular disease?
No, as no vessels are involved!
The action potential movement across the heart starts with the … and the…, and then the …. This short pause between … and … allows the … to fill as much as possible before contraction, optimising how much blood is going around the body
The action potential movement across the heart starts with the right atrium and the left atrium, and then the ventricles. This short pause between atria and ventricles allows the ventricles to fill as much as possible before contraction, optimising how much blood is going around the body
DVT occurs in a … and PE is in an …
DVT occurs in a vein and PE is in an artery
Median heart rate in adults is …
75 bpm
What are the 4 general steps of the hearts conduction system?
- Pacemaker cells generate action potentials (APs)
- APs travel along the conduction system resulting in depolarisation and contraction of cells
- APs travel to LA via Bachmann’s bundle and to the ventricles via the AV node.
- Cardiac cells repolarise and depolarise over 60 times per minute
Do the ventricles or atria depolarize first?
Atria!
Think of A coming first in the alphabet
m
m
What is dysrhythmia?
A disturbance in the rhythm or rate of cardiac muscle contractions
How are dysrhythmia’s defined/classified? x4
- By their site of origin (e.g supraventricular, ventricular, atrial)
- Mechanism of disturbance (e.g fibrillation)
- Rate of disturbance (e.g tachycardia, bradycardia)
- Electrocardiogram appearance (e.g long QT syndrome)
Are dysrhythmias acute or chronic?
Both acute and chronic
What is an example of a life threatening type of dysrhythmia?
Ventricular fibrillation (VFib)
What does ECG/EKG stand for?
What does it mean?
Electrocardiogram: a measure of the electrical activity of the heart rate and rhythm
What are the following:
P wave:
QRS:
T wave:
P wave: atrial depolarisation
QRS: ventricular depolarisation and atrial repolarisation
T wave: ventricular repolarisation
How long are the following:
PR interval:
QRS:
QT interval:
PR interval: <0.2 sec
QRS: <0.1 sec
QT interval: <0.4 sec
What % of people over 65 in NZ have AF?
5%
AF gives a 4-5 fold increase in … stroke risk
Ishcaemic stroke risk (ischaemic embolic stroke)
What is the mechanism of dysrhythmia?
An abnormal impulse formation with increased automaticity and triggered activity.
There is also abnormal conduction