Arrhythmia Flashcards
Multifocal atrial tachycardia
Description
Age group
Treatment
Three or more p wave morphologies
Usually infants
RTI commonly
Adenosine doesn’t work
Amiodarone Rx of choice
Atrial flutter
Describe
Most have normal or abnormal heart
Rx
Fast atrial rate- 240-360
Saw tooth
Varying degrees of block
Normal QRS
Most normal
Can be associated with dilated atria, thyrotoxicosis, post Fontan, myocarditis
Adenosine doesn’t revert
Synchronised DC shock after excluding thrombus
Amiodarone prevents recurrence
Atrial fibrillation
Describe
Normal or abnormal heart
Thrombus formation common or uncommon
Rx
Extremely fast atrial rate
350-600beats/min
Irregular ventricular response
Abnormal heart
Thrombus common
Synchronised shock after exclusion of thrombus or warfarin for 3-4 weeks
If cardioversion can’t be delayed: start heparin, wait 5-10d
Junctional rhythm
P wave
QRS
Rate
Rx
Absent, or inverted p wave may follow the QRS
QRS normal
40-60
Is symptomatic Treatment with atropine or over drive pacing
Accelerated junctional rhythm
Pathogenesis
Rate
Treatment
Normal SA node activity and conduction
AV node has enhanced automaticity, captures pacemaker function
60-120bpm
Myocarditis, post cardiac surgery, digitalis toxicity
Treatment not required unless due to digi tox
Junctional ectopic tachycardia
Rate
QRS
Presentation
Rx
120-200bpm
QRS normal or with aberrancy
Post operative or congenital
Post operative- loss of AV synchrony leads to poor CO
Atrial overdrive pacing or amiodarone
Congenital presents in CHF before 6 months
Amiodarone
Ablation if that doesn’t work
Accessory RAVT
Orthodromic
ECG appearance
Antidromic
ECG appearance
Ortho: down normal AV node pathway and back up accessory pathway
Narrow QRS followed by inverted p wave
Antidromic: down accessory pathway and up AV nodal pathway
Inverted p wave followed by broad QRS
Nodal RAVT
Orthodromic
Antidromic
The AV has a re-rentry pathway within it
Orthodromic: down normal pathway (slow) up fast pathway
Narrow QRS, no p wave
Antidromic: down fast pathway, up normal pathway
Inverted p wave followed by Narrow QRS
Jervell and Lange-Nielsen syndrome
Features
Inheritance
AR
Long QT
Congenital deafness
Syncope
Sudden cardiac death
Roman-Ward syndrome
Inheritance
Features
AD
Prolonged QTc, syncope
Familial sudden cardiac death
Anderson - Tawil syndrome
Features
QU interval prolonged
Periodic paralysis
Ventricular arrhythmia
Developmental anomalies
Timothy syndrome
Webbed fingers and toes
Prolonged QTc
Mobitz 1
Causes
Gradual prolonging of PR then dropped QRS
Myocarditis, CM, CHD, cardiac surgery, digitalis toxicity
Vagal tone
Treat underlying cause
Mobitz 2
Block is all or none
May progress to complete heart block
Prophylactic ppm may be required
Congenital heart block
Cause
Difference between AV dissociation and complete HB
60-90% neonatal lupus: placental transfer of anti-Ro, anti-La antibodies
CHD: L-TGA, single ventricle, polysplenia (LA isomerism)
AV dissociation due to slowing of sinus node activity - ventricular rate accelerated, higher. May have some conduction of atrial beats
CHB: atrial rate higher than ventricular- heart running at ventricular rate (slow)
