Arrhythmias Flashcards
What is the term for arrhythmias that are located above the ventricle, which origins of arrhythmia would be there?
Supraventricular arrhythmias (SA node, AV node, atria and His origin.
What is an ectopic beat?
It is a beat that has originated from somewhere other than the SA node.
What is triggered activity?
It is during phase 3 of cardiac myocytes where where there are afterdepolarizations that cause sustained depolarisations.
Factors that cause arrhythmias can lead to an increase in the slope of phase 4 in myocytes leading to an increased heart rate. This is caused by what?
Hyperthermia.
Hypercapnia.
Hypoxia.
Hyperkalemia.
What are some of the symptoms of arrhythmias?
Palpitations. SOB. Presyncope. Syncope. Heart failure. Sudden cardiac death. Angina.
What are some of the investigations you can do into arrhythmias?
ECG. Electrocardiography (ECHO). Exercise ECG. Holors 24hr ECG. CxR
Describe Sinus bradycardia?
HR <60 BPM
Regular rhythm.
Many athletes have.
Treat with atropine.
Describe sinus tachycardia?
HR >100 BPM
Treat underlying causes.
Maybe use beta blockers.
What are the three types of supraventricular tachycardia?
AV nodal reentrant tachycardia (AVNRT)
AV reciprocating tachycardia (AVRT).
Ectopic atrial tachycardia (EAT).
How do you treat an acute supraventricular tachycardia
You are trying to slow the HR and increase vagal tone. II adenosine (potent vasodilator). or verapamil (calcium channel antagonist) if adenosine not good enough.
How do you treat chronic supraventricular tachycardia
Antiarrhythmic drugs - digoxin.
B-blockers - bisoprolol.
RFCA - selective cutting of cardiac tissue to prevent tachycardia.
Describe 1st degree heart block?
It is not really heart block, the PR interval is just increased by >0.2 seconds, every P wave results in a QRS complex
Describe 2nd degree heart block - mobitz type 1?
It is intermittent block at the AV node, PR interval gets increasingly long to the point that a heart beat is missed, happens due to atrial impulses getting weaker and weaker to the point that they fail to stimulate ventricular contraction, cycle then repeats.
Describe 3rd degree heart block?
No action potentials from the SA node get to the AV node.
What are the four types of AF?
Permanent - not treatable.
Persistent - lasts for >48hrs.
Paroxysmal - lasts <48 hrs.
Lone (idiopathic) AF - no identifiable cause.
What rate controlling drugs should you use for AF?
Digoxin.
Verapamil - calcium channel antagonist.
B-blockers.