Arrythmias Flashcards
What are the potential causes of sinus tachycardia?
Physiological
Pathological - hyperthyroidism, cocaine, amphetamines
Compensatory - MI, PE, sepsis, heart failure
What are the four adverse features to assess for in the management of arrhythmia?
Shock
Heart failure
Syncope
Myocardial ischaemia
How is a tachycardia managed when there is the presence of 1 or more adverse feature?
DC cardio version up to three times
Then, if there is no resolution 300mg IV amiodarone over 20m minutes followed by 900mg IV amiodarone over 24 hours
Describe the ECG appearance of paroxysmal SVT?
Tachycardia 150-200 bpm
Narrow QRS
Absent or retrograde P waves
Describe the initial management of narrow complex tachycardia without adverse features?
1st line - vagal manoeuvers
2nd line - IV adenosine 6mg, then 12mg, then 12mg
3rd line - specialist referral and further rate control
What underlying factors may result in paroxysmal SVT?
Psychological stress
Caffeine
Nicotine
Wolff Parkinson White syndrome
Describe the ECG appearance of Wolff Parkinson White syndrome?
Elongated QRS
Shortened PR interval
Presence of delta wave
What accessory pathway is present in Wolff Parkinson White syndrome?
Bundle of Kent
Describe the management of Wolff Parkinson White syndrome?
Pharmacotherapy - amiodarone or procainomide
If unstable - DC cardio version
Definitive management - catheter ablation
What is the definitive management for long-standing atrial flutter or AF?
Catheter ablation
What are the risk factors for atrial flutter?
Increasing age Valvular disease Atrial septal defect Cardiac / thoracic procedure Anti-arrythmics Hyperthyroidism COPD Asthma Pneumonia
What is the definition of paroxysmal, persistent, long-standing and permanent AF?
Paroxysmal - more than 1 episode lasting more than 30 seconds which resolves (spontaneously or with intervention_ within seven days
Persistent - AF episode which persists >7 days
Long-standing - AF episode which persists >1 year
Permanent - AF which is refractory to treatment
Describe the management of acute AF?
If unstable or present <48hours - DC cardio version or rhythm control and anticoagulation
If stable and >48 hours - rare control (beta blockers, non-dihydropyridamole calcium channel blockers, 2nd line - digoxin)
If rate control fails - rhythm control with amiodarone
If CHASVAS score >1 in men or >2 in women the long-term anticoagulation with DOAC
Arrythmias are often asymptomatic, however what are the potential symptoms of arrhythmia?
Palpitations Chest pain Dizziness Syncope Altered mental status
What is the management of torsades de pointes?
IV magnesium sulphate
2nd line - isoprenaline
What is the management of VT?
DC cardio version if unstable / adverse features present
Otherwise, IV amiodarone 300mg over 20 mins then 900mg IV amiodarone over 24 hours
What are the potential causes of VT?
Drugs - macrolides, antipsychotics Ischaemic heart disease - inferior MI Congenital heart disease Hypertrophic or idiopathic dilated cardiomyopathy Chagas disease
If a patient survives VF, what intervention should be considered?
Placement of implantable cardiodefibrillator device
What are the causes of sinus bradycardia?
Physiological - in athletes Hypothyroidism Hypothermia Valvular disease Drugs - calcium channel blockers, beta blockers, Iatrogenic Ischaemic heart disease (inferior MI) Hypokalaemia TB Thyphoid fever Rheumatic fever Viral myocarditis
What are the causes of heart block?
Ischaemic heart disease / ACS Cardiomyopathy Valvular disease Drugs - beta blockers, calcium channel blockers, digitalis Electrolyte disturbances / acidosis Myocarditis Cardiac TB Infective endocarditis Lyme disease Erbs dystrophy Myotonic dystrophy
Describe the management of bradycardia?
If adverse features (shock, MI, HF, syncope) or type 2 Mobitz or complete heart block:
Give atropine 500 micrograms IV up to six times
Then external transcutaneous pacing if not resolved
If none of the above criteria:
Observe and treat underlying cause
What are the potential causes of right bundle branch block?
Can be physiological Right ventricular hypertrophy Atrial septal defect Ischaemic heart disease Brugada syndrome PE Rheumatic heart disease Myocarditis Cardiomyopathy Hypertension
What are the potential causes of left bundle branch block?
Acute MI Aortic stenosis Dilated cardiomyopathy Extensive coronary artery disease Hypertension -> aortic regurgitation Lyme disease
