Slide 1

Atrial fibrillationIntroductionAtrial-two upper chambers of heartFibrillate-contract very fast and irregularlyACC/AHA/ESC classify AF into:

*not related to reversible cause of AFCan be more than one form in a patientAtria beat rapidly, chaotically and ineffectively-ventricles responds at irregular interval-irregularly irregular pulse

Paroxysmal1 yeareither because cardioversion has failed or has not been attemptedGoal: rate control and anticoagulation

*Lone AF-younger pt without structural heart disease, lower risk of thromboembolismPathophysiology Interaction btwn initiating factors and abnormal tissue substrate that capable of maintaining the arrhythmia.Focal initiators of AFRapidly firing ectopic fociTissue substrate capable of maintaining AFMultiple wavelets of excitationElectrophysiological remodellingSubstantial refractory period shortening which facilitate perpetuation of the arrhythmia

Common causesrisk factors -age, male sex, valvular heart disease, systolic/diastolic dysfunction, hypertension, and diabetesAtrial pressure elevation (causing dilatation)Valvular dz, systolic/diastolic dysfx, hypertrophic cardiomyopathy, pulmonary embolism, intracardiac thrombi or tumourInflammatory and infiltrative processPericarditis/myocarditis, amyloidosis, sarcoidosis, age induced atrial fibrosisInfectionEndocrineHyperthyroidism, phaechromocytoma NeurogenicStroke, subarachnoid haemorrhageAtrial ischemia MIDrugsAlcohol, caffeineIdiopathic (lone afib if less than 60 years old)FamilialClinical features90% asymptomaticPalpitations, dyspnoea, fatigue, dizziness, angina (chest pain), presyncope or syncope

Physical examIrregularly irregular pulse, tachycardic Head and neck: exophthalmos, thyromegaly, elevated JVP, cyanosis, carotid artery bruitsLungs: rales, pleural effusion, wheeze, diminished breath soundsHeart: displaced apex beat, S3, prominent P2Abdomen: ascites, hepatomegalyLower limb: edemaNeurology: sign of TIA or CVAPrior stroke and hyperreflex suggest hyperthyroid6Differential diagnosisAtrial FlutterAtrial TachycardiaAtrioventricular Nodal Reentry Tachycardia (AVNRT)Multifocal Atrial TachycardiaParoxysmal Supraventricular TachycardiaWolff-Parkinson-White SyndromeInvestigation 12 lead electrocardiogramHolter and Event monitorStress testEchocardiography (TEE, TTE)CXRBlood testCBC count- anemia, infectionSerum electrolytes and BUN/creatinine - electrolyte disturbances or renal failureCardiac enzymes - CK and/or troponin level primary or seconday MIBNP CHFTFTToxicology testing or ethanol level

Management Treat the primary disorder Goal: Rate controlRhythm controlMinimise risk of thromboembolismTreat underlying disease

Rate controlbeta-blockers (metoprolol, atenolol, propanolol) calcium channel blockers (diltiazem, verapamil), sodium-potasium ATPase inhibitors (digoxin), and class III antiarrhythmic agents such as amiodarone.Rhythm controlPharmaco: refer imageNon pharmaco: direct current cardioversion, ablationPrevent thromboembolismAspirin or warfarinBased on CHADS2 score

Complications

Stroke

Heart failureheart can't pump enough blood to meet the body's needs, because the ventricles are beating very fast and can't completely fill with blood.