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