6. Arrhythmias Flashcards
What is the definition of an arrhythmia?
A disturbance of cardiac rhythm
They are typically common, benign, intermittent and may be severe
What are the cardiac causes of arrhythmias?
Ischaemic heart disease Cardiomyopathy Pericarditis Myocarditis Aberrant conduction pathways
What are some non-cardiac causes of arrhythmias?
Caffeine Smoking Alcohol Pneumonia Drugs (B agonists, digoxin, l-dopaminergic tricyclics, doxorubicin) Metabolic imbalance Phaeochromocytoma
How may arrthymias present?
Palpitations Chest pain Presyncope/syncope Hypotension Pulmonary oedema Incidentally
What are the main tests for arrhythmia’s?
FBC, U&E’s, glucose, TSH
ECG
24 hour ECG monitoring
ECHO
What are the general classes of arrhythmia’s?
Narrow complex tachycardias
Atrial fibrillation and flutter
Broad complex tachycardia
Bradycardia
How do you manage pacemaker?
Remove triggers
Medical mangement- regular tablets or pill in pocket
Interventional management- pacemakers, ablation, implantable defibrillators
What is sick sinus syndrome?
Commonly found in elderly, the sinus node fibroses ending to bradycardia, tachyarrhythmias or sinus pauses
Treated with pacemakers and thromboembolism
What is meant by narrow complex tachycardia?
HR>100bpm
QRS<120ms (normal <120)
The QRS is normal however something is causing the heart to be tachycardiac
How do you treat narrow complex tachycardias?
Identify and treat the underlying rhythm
Transiently blocking the atrioventricular node will help in supra ventricular tachycardias (valsalva manoeuvres, carotid sinus massage, IV adenosine)
May require more serious treatment e.g. ablation
What is meant by broad complex tachycardia?
ECG shows a rate of >100 and QRS of greater than 120ms
If there are no clear QRS complexes then it is VF or asystole (or the machine isn’t working)
How do you manage broad complex tachycardia
Patient may be periarrest so get help
If in doubt treat as VT
If suspected wolf Parkinson white then avoid drugs that slow AV conduction
How can ectopic beats be classed as broad complex tachycardias?
When an ectopic beat happens it will have a broad QRS complex
Bigeminy-ectopic every other beat
Trigeminy - every third beat is an ectopic
Couplet- two ectopic together
Triplet - three ectopic together
Are ectopic concerning or not?
Frequent ectopic in otherwise healthy people are common and rarely significant
However if they occur >60 beats per hour then they’re frequent and cardiac disease should be looked for
What is af?
A chaotic irregular atrial rhythm at 300-600bpm.
The AV node reposnds intermittently hence an irregular ventricular rhythm
What are the causes of AF?
Heart failure Hypertension Ishchaemic heart disease Pulmonary embolism Mitral valve disease Pneumonia Hyperthyroidism Caffeine Alcohol
What are the symptoms of AF?
An irregularly irregular pulse. May be asymptomatic
May also cause chest pain, palpitations, breathlessness or faintness
What are the tests that should be carried out when someone has AF?
ECG
bloods: U&E’s, cardiac enzymes, TFT’s
ECHO
How do you manage acute AF?
Look for adverse signs, ABCDE and get senior input
Correct electrolyte imbalance
< 48 hours- rate or rhythm control (DC cardioversion) and heparin
>48 hours- rate control (bisoprolol)
What is DC cardioversion
A procedure used to convert an abnormal heart rhythm into a normal one
What are the goals of treat,ent of chronic AF?
Rate control and anticoagulation
How do you treat chronic AF?
Rate control- beta blocker or calcium channel blocker
Rhythm control- elective D.C. cardioversion
Paroxysmal AF- pill in the pocket
What are some temporary pacemaker indications
Symptomatic bradycardia, unresponsive to atropine
After acute anterior MI
After inferior MI
Suppression of drug resistant tachyarrythmias.
What are some permenant pacemaker indications?
Complete AV block
Mobitz type II AV block
Symptomatic bradycardia
HF
