AF Flashcards
Definition?
Atrial Fibrillation is a supraventricular tachyarrhythmia, characterised by uncoordinated atrial electrical activity.
Types?
Paroxysmal <7 days
Persistent/permanent-> 7 days-remodelling constant
Risk factors?
- Older
- DM
- HT
- CHF
- Valvular heart disease
- Coronary artery disease
- Other arrhythmias
- Cardiac/thoracic surgery
- Hyperthyroidism
For Acute? PARASITE
Pulmonary disease Anaemia Rheumatic heart disease Atrial myxoma Sepsis Ischaemia Thyroid disease Ethanol
Differentials and features?
- Atrial flutter-sawtooth ECG
- Wolff-Parkinson-White Syndrome-younger-Delta wave and shortened PR interval
- Atrial tachycardia-abnormal P waves-usually in COPD pts
Epidemiology?
Age: older
Sex: male
Ethnicity:
Prevalence:
Clinical Presentation?
- Asymptomatic
- Palpitations, Dizziness, syncope, fatigue, SOB
- Murmurs
- Tachycardia and irregularly irregular pulse
- Apex-pulse deficit
- Pulmonary oedema
- TE events
- Ventricular tachycardia
Pathophysiology?
• Supra ventricular tachycardia-atria don’t contract in a synchronised way and quiver
• LA-stasis-clotting-embolization-stroke
• Trigger-ectopic foci-impulse generated from pacemaker cells in place other than -SAN-usually pulmonary veins on left-fire rapidly
• AVN picks up impulses irregularly-and relays them to the ventricles irregularly
R-entry circuit-IHD, age HT-change atrial shape-diff conductivities/excitability-shorter refractory periods- shorter re-excitement and re-entry circuit-unsynchronised rhythms relayed through AVN
Investigations-first line?
Cardio/resp exam-Signs of arrhythmias
Investigations-second line?
- ECG-absent P waves; presence of fibrillatory waves that vary in size, shape, and timing; irregularly irregular QRS complexes
- Serum electrolytes-high or low potassium or low magnesium
- Cardiac biomarkers-elevated creatine kinase-MB or troponin with myocardial ischaemia
- Thyroid function test-suppressed TSH in thyrotoxicosis
- CXR-may show cardiomegaly, in particular left atrial enlargement; signs of heart failure; other precipitating pathology, such as pneumonia
- Transthoracic echo-may show dilated left atrium; valvular disease; low LVEF; diastolic dysfunction
- Transoesophageal echo-atrial thrombus
- Electrophysiological-Shows abnormal impulse conduction
- Exercise stress-CAD
Management-first line?
Stroke prevention-anticoagulation-unless LAA occlusion
NV-NOAD’s
V-warfarin
Management second line? 1 and 2 step drugs
Controlling rate-
1-CCB and beta blocker/digoxin
2-BB, diltiazem and digoxin
Management third line? 1 and 2 step
Controlling rhythm-
1-Cardioversion-pharm/electrical
2-dromodarone and bb
Management 4th line?
Ablation-surgical or catheter
Management acute?
anticoagulation-heparin or pharm
Management after surgery?
anticoagulants and rhythm control
Second line if acute?
Felcainide-Class I AA-stops Na influx in AVPs
or amiodarone if no heart disease
Amiodarone if structural heart disease
Prognosis?
Depends on underlying disorders
Poor if linked to MI
Complications?
Acute stroke MI CHF Airway disease Ablation-surgical/catheter Death Bradycardia Pro-arrhythmic drugs Amiodarone linked pulmonary toxicity and thyroid dysfunction