atrial fibrillation abdel karim, m.d. king hussein medical center, amman, jordan jim holliman, m.d.,...

Atrial Fibrillation

Abdel Karim, M.D.King Hussein Medical Center, Amman, Jordan

Jim Holliman, M.D., F.A.C.E.P.Department of Emergency MedicineM. S. Hershey Medical CenterPenn State University

Atrial Fibrillation (AF) Incidence

ƒ Overall prevalence : –2.2 % in men–1.7 % in women

ƒ Age prevalence : –0.2 % at 25 to 34 years–3.0 % at 55 to 64 years

ƒ By age 75, 10 % of population has AF

AF Terminology

ƒ Chronic : present most or all the time

ƒ paroxysmal : short bursts interrupting sinus rhythm

ƒ Lone : in younger people 20 to 30 years with no apparent cause

ƒ Idopathic : in older people 50 years or older with no apparent cause

Causes of AF

ƒ Valvular heart disease –mitral stenosis–mitral regurgitation–aortic stenosis–aortic regurgitation

Causes of AF (cont.)

ƒ Nonvalvular heart disease :ƒPericarditisƒDilated and hypertrophic cardiomyopathyƒIschemic heart diseaseƒSystemic hypertensionƒCongestive heart failureƒSick sinus syndromeƒCongenital heart disease

Causes of AF (cont.)

ƒ Pulmonary diseaseƒPulmonary emboliƒAcute or chronic airway diseaseƒPrimary pulmonary hypertension

Causes of AF (cont.)

ƒ Toxic : alcohol (Acute & Chronic)ƒ Metabolic : hypomagnesemiaƒ Recent thoracotomyƒ Hyperthyroidism (occurs in 24

%)ƒ Lone or idiopathic (8 / 100,000)

Mortality and Morbidity

ƒ doubles mortality risk in patients with other heart disease

ƒ increases risk for stroke by 5 to 7 %

ƒ 45 % of cardiogenic emboli are associated with AF

ƒ risk of pericardioversion emboli increases considerably if AF has been present for more than 2 days

ƒ Are due to : rapid ventricular rate

impaired left ventricular filling

elevated left atrial pressure and decreased cardiac output

DiagnosisSymptoms

Diagnosis (cont.)Symptoms

ƒ palpitations (commonest complaint)ƒ neurological symptoms :

dizziness lightheadedness syncope or near syncope

ƒ shortness of breath

Diagnosis (cont.)Symptoms

ƒ chest pain ƒ reduction in exercise toleranceƒ aggravation of preexisting heart

failure or anginaƒ a few patients may have no

symptoms

Physical Findings

ƒ peripheral pulse : irregular pulse deficit

ƒ fluctuating systolic blood pressure

ƒ absence of "a" wave in jugular venous pulse

ƒ presence of "f" wave in jugular vein

ƒ varying intensity of first heart sound (None of these indicators can be diagnostic)

Diagnosis (cont.)ECG

ƒ fibrillary waves *called f wave *best seen in V1, II, III, and AVF *are fine to coarse *rate 350 to 600 / minute *they are pathognomonic for AF *may not be clearly present & may appear isoelectric

Diagnosis ECG

ƒ presence of missing 'p' wave

ƒ irregularly irregular QRS complexes

ƒ presence of fibrillary waves

AF : Rate

ƒ usual rate is 100 to 160 / minuteƒ if more than 160 / minute :

hyperthyroidism adrenergic

stimulationsƒ fast and wide QRS

.preexcitation syndromes (WPW)

ƒ in AF and WPW, ventricular response may be as rapid as 300 / min. or more and may degenerate to VF

ƒ sometimes it is difficult to differentiate between AF & WPW from VT

ƒ if slow rate :

medications like digitalishigh vagal tone sick sinus syndrome

Rate (cont.)

Investigations

ƒ ECGƒ Echocardiogram :

condition of mitral & aortic valves left atrial enlargement

left ventricular abnormalities pericardial effusion

ƒ thyroid function studiesƒ work up for coronary diseaseƒ work up for pulmonary emboli

Current therapy

ƒ Primary therapeutic goal is control of ventricular rate in new onset as well as chronic Atrial Fibrillation

Cardioversion

ƒ indications :preexcitation syndrome

acute hemodynamic deterioration

ƒ Rx : synchronized cardioversion 100 joules : over 60 % can be

converted 200 joules : over 80 % can be converted

If failure :procainamide IV (18 mg/kg)

and then cardioversion 360 joules

Paroxysmal AF

ƒ No Rx if :episodes are rare

self limited and well tolerated has no associated angina or heart failure nor neurological symptoms

ƒ Rx if : the patient has symptomatic episodes

AF : RxSustained AF

ƒ AF less than 2 daysƒ AF more than 2 days but TEE shows

no left atrial emboli Rx :control ventricular response

immediate cardioversion

AF : Rx

ƒ every patient deserves a chance at cardioversion

ƒ the probability of successful long-term cardioversion may be low if :

–AF has lasted for more than one year –left atrium is greater than 4.5 cm by echo

AF : Rx

ƒ acute AF more than 2 daysƒ long standing AF

Rx :.control ventricular response .anticoagulate.have patient return back in 3 to 4 weeks for cardioversion

AF : Rx

ƒ rapid ventricular rate should be treated initially with IV medication to avoid emboli, and then oral medication

ƒ anticoagulation : –warfarin for 4 weeks –maintain INR 2 to 3 times control–continue giving warfarin for 2 to 3 weeks following cardioversion

AF : Rx

ƒ control ventricular response only without restoring sinus rhythm if :–long standing well-tolerated sustained AF–patient refractory to cardioversion–patient who declines cardioversion–recurrent AF

AF : Rx

ƒ in the absence of contraindications, anticogualation is recommended even without cardioversion

AF : Rxƒ DO NOT USE –digoxin–beta blockers–calcium channel blockers

in patients with preexitation syndromes

AF : Rxƒ irregular slow

ventricular response to AF may signal the presence of AV node disease

AF : Rxƒ regular slow

ventricular response to AF may signal the presence of complete heart block often caused by digitalis toxicity

AF : RxDigoxin

ƒ used for over 200 yearsƒ commonest drug for control of AFƒ IV onset of action is 30 minutesƒ maximal response occur in 1 to 4

hoursƒ loading dose 0.1 to 0.6 mgƒ additional doses as needed 0.1 to

0.25 mg every 4 to 6 hoursƒ total dose in 24 hours is 1 mg

AF : RxDigoxin

ƒ for patients already on digoxin additional dose is 0.25 mg every 6 to 12 hours

ƒ Beta blockers or calcium channel blocker can be added if necessary

ƒ contraindications to digoxin :

*hypertrophic cardiomyopathy *WPW syndrome

AF : RxBeta Blockers

ƒ ordinarily used –Esmolol–Propranolol

ƒ particularily used in –thyrotoxicosis

ƒ adverse effects–hypotension –cardiac depression & bradyarrhythmias–bronchospasm

AF : RxBeta blockers (cont.)

ƒ Esmolol–rapid acting : half-life a few minutes–loading dose 500 mcg / kg over 1 min.– maintenance infusion 50 mcg / kg / min.–loading dose can be repeated after 5 min.–maintenance dose can be increased to 100 mcg /kg / min. as needed–effects dissipate within minutes of discontinuation of infusion

AF : RxBeta blockers (cont.)

ƒ Propranolol–can be taken orally as well as IV–dose : 1 to 3 mg boluses every 2 min. until control achieved–usual total dosage is 10 to 20 mg–effective for 4 to 10 hours–*Adverse effects : ƒ hypotension ƒ cardiac depresion

AF : RxCalcium channel blockers

ƒ verapamilƒ diltiazem

–Particularly useful in patients with pulmonary disease who cannot take beta blockers–Adverse effects :

*hypotension

*bradyarrhythmias

*cardiac depression

AF : RxCalcium channel blockers (cont.)

ƒ Verapamil–dose 5 to 10 mg given over 2 min.–if no response : additional dose after 5 to 10 min.–is usually effective for 4 to 6 hours

ƒ Diltiazem–20 mg (0.25 mg / kg) bolus over 2 min.–second bolus of 25 mg can be given 15 min. later ( if necessary)–infusion of 5 to 15 mg / hour will control the response for 24 hours

AF : RxAnticoagulation

ƒ long term Warfarin is recommended for :–mitral valve disease–previous embolic events–congestive heart failure

ƒ Aspirin 325 mg daily may be considerd in patients with nonvalvular AF

AF : RxAnticoagulation (cont.)

ƒ contraindications : –active peptic ulcer –alcoholism–gait disorders –uncontrolled hypertension–previous major bleeding–previous intracranial bleeding

ƒ incidenceƒ terminologyƒ causesƒ mortality and morbidityƒ symptomsƒ signsƒ ECG findingsƒ investigationsƒ current therapy

AF : Summary