Arrhythmias Flashcards
define an arrhythmia
abnormal heart rhythm
presentation of arrhythmias
- palpitations
- SOB
- syncope and presyncope
- angina
diagnosis of arrhythmias
- ECG
- echocardiogram
- EP study (mechanism of arrhythmia)
define sinus arrhythmia
this is reflex changes in vagal tone during the respiratory cycle e.g. inspiration causes the heart rate to increase
define bradycardia
sinus heart rate of less than 60bpm
management for bradycardia
- atropine
- second line is adrenaline or dobutamine
define sinus tachycardia
sinus heart rate of above 100bpm
management for sinus tachycardia
beta blockers
management for SVT
adenosine
define heart block
abnormally slow heart rate where conduction does not conduct through the AV node
First degree heart block
PR interval of longer than 0.2 seconds
management for first degree heart block
only if symptomatic
- beta blockers
- CCBs
mobitz type I
progressively lengthening PR interval until a beat is dropped
management for mobitz type I
only if symptomatic
- beta blockers
- CCBs
mobitz type II
2:1 or 3:1 ratio
management of mobitz type II
digoxin or
beta blockers or
CCBs or
(ICDs)
third degree heart block
no action potentials conduct through the AV node
management of third degree heart block
digoxin or
beta blockers or
CCBs or
ventricular pacing e.g. ICD
management of VF
defibrillation
ICD
management of haemodynamically unstable VT
synchronised cardioversion
amiodarone (second line is lidocaine)
management for torsades de pointes (polymorphic VT)
magnesium sulfate
management of polymorphic VT
beta blockers
management of VT if pre-existing structural heart disease
adenosine
management of VT after MI
procainamide
define WPW syndrome
this is AV re-entrant tachycardia which has a delta wave on ECG
management of unstable WPW
DC cardioversion
management of stable WPW
first line: carotid massage or valsalva manoeuvre
second line: adenosine
third line: pacemaker
fourth line: DC conversion
management of long QT syndrome (VT)
- lifestyle avoiding strenuous sports e.g. swimming
- beta blockers
- ICD
management of Brugada syndrome
ST elevation in V1-V3
- DC cardioversion
- beta blockers
- catheter ablation
presentation of AF
- irregularly irregular pulse
- palpitations
- syncope
diagnosis of AF
ECG
absent P waves and atrial rate >300bpm
management for haemodynamically unstable AF
DC cardioversion
management for haemodynamically stable AF
- beta blockers (or CCBs if heart failure)
- anticoagulation using CHA2DS2VAS score
CHA2DS2VAS score
congestive heart failure 1 hypertension 1 age 75 and above 2 diabetes 1 stroke 2 vascular disease 1 age 65-74 1 sex (female) 1 max. total = 9
management of persistent or paroxysmal AF
unstable = DCCV stable = beta blockers or CCBs and anticoagulation
ECG of atrial flutter
saw tooth baseline 150bpm
management for unstable atrial flutter
synchronised cardioversion
management for stable atrial flutter
beta blocker or CCB (verapamil) or amiodarone
anticoagulation
how to define a narrow complex tachycardia?
> 100bpm
QRs <120ms
how to treat AVRT and AVNRT?
transiently blocking the AVN without slowing conduction
management of AVRT and AVNRT
vagal manoeuvres= carotid sinus massage, valsalva manoeuvre
IV adenosine
what is the pathway of AVRT?
atria > ventricles > accessory pathway > atria
orthodromic
management of AF + WPW
avoid AV node blockers such as diltiazem, verapamil and digoxin
use flecainide
what are Stokes-Adams attacks?
loss of consciousness caused by AV node block (3rd degree)
what is focal atrial tachycardia?
group of atrial cells acting as pacemaker, outpacing SAN so P wave shape is different
what is the rate in atrial flutter?
300 times a minute, so ventricle contractions are a division (150,100,75)
NEEDS ANTICOAGULATION
what are Stokes-Adams attacks?
loss of consciousness caused by AV node block (3rd degree)
do you need to anticoagulate a patient if AF began 48 hours prior to admission before DC cardioversion?
yes as risks pushing clot to the brain
acute management of AF
DC cardioversion (120-150J) amiodarone if fails
management of stable AF that has been present for <48 hours
flecainide or cardiovert or amiodarone (if structural heart disease)
start heparin in case delayed
management of stable AF that has been present for >48 hours
patient must be anticoagulated for at least 3 weeks (echo for intracardiac thrombi)
management of paroxysmal AF
pill in pocket (sotalol or flecainide PRN)
what is bigeminy?
ectopic every second beat
what is trigeminy?
ectopic every 3rd beat
what is a fusion beat?
normal beat fuses with a VT complex causing an unusual complex
what is a capture beat?
normal QRS amongst a run of VT
indications for a pacemaker
AV block (stoke-Adams, asymptomatic, congenital) mobitz type II persistent AV block after anterior MI symptomatic bradycardia heart failure drug resistance to tachyarrhythmias
what is given prior to insertion of pacemaker?
antibiotics
what drug may reveal underlying atrial flutter?
adenosine
examples of narrow complex tachycardias
AVNRT AVRT atrial tachycardia AF atrial flutter pacemaker
what does AVNRT have?
two input pathways (slow and fast)
ECG findings in AVNRT
P wave visible within T wave
V1 and II best places to look
direction in AVRT (WPW)
retrogradely up the node (antidromic tachycardia) delta wave (slurred upstroke QRS)
how to generate AV block
vagal manoeuvres= carotid massage, valsalva, sudden immersion in cold water
adenosine
caution in use of adenosine when?
asthmatic
feature of ventricular tachycardias
broad QRS
examples of ventricular tachycardias
VPCs
VT
ventricular escape rhythm
VF
ventricular complex bigeminy
1 sinus beat coupled with VPC
ventricular complex trigemeny
1 sinus beat coupled with 2VPC
cardiac arrest rhythms
VT VF complete AV block PEA terminal rhythm sequence
ECG ventricular hypertrophy
R wave V5 orV6 >35mm (less in other criteria’s 20 in women and 28 in men)
