New onset of atrial fibrillation pptx.pptx

Discussed physiology, aetiology, management and different doses of drugs

1. New-onset Atrial fibrillation: Overview and Management Irfat Mahjabeen Clinical fellow Worcestershire Acute Hospitals NHS Trust

2. Introduction : Af is a supraventricular cardiac arrythmia resulting from irregular,disorganised electrical activity and ineffective contraction of atria Most common cardiac arrhythmia The prevalence is 2 to 4%, rises with increasing age Men are more commonly affected than women Complication includes strokes, TIA, systemic embolism, LVSD, Cardiomyopathy, HF

3. Pathophysiology : Triggers : Rapidly firing focus in PV micro re-entry circuits in the atria chaotic electrical activity. Substrate : Complex substrate changes , Tissue heterogenecity different electrical properties, alteration in refractory periods. multiple wavelets causes mini contractions instead of single wave of contractions. Sometimes these signals transmit through the AVN & irregularly irregular ventricular rate.

4. Classification : First detected AF The first documentation of AF, regardless of duration/ previous symptoms Paroxysmal AF AF that is intermittent and terminates within < 7 d of onset  spontaneously/ with intervention. Persistent AF AF that is continuous and sustains for >7 d and requires intervention. Long-standing persistent AF AF that has lasted for more than 12 months. Permanent AF A term that is used when the patient and clinician make a joint decision to stop further attempts to restore and/or maintain sinus rhythm

5. Aetiology: Cardiac : Coronary artery disease, hypertension, heart failure, valvular heart disease, Cardiomyopathy Pre-excitation syndromes ( WPW syndrome) Inflammatory conditions (e.g. pericarditis or myocarditis) Non cardiac : Thyrotoxicosis or hypothyroidism COPD and obstructive sleep apnoea, Diabetes mellitus Electrolyte imbalances (e.g. hypokalaemia or hyponatraemia) Sepsis advanced age Genetic heavy alcohol intake

6. Approach to diagnosis : History : Assymptomatic or Palpitatipn Dyspnoea Chest pain Fatigue Dizziness Syncope PMH Social history Family history Sign : irregularly irregular pulse Apical radial pulse deficit Any murmur/ JVP Investigations : ECG findings : irregular RR intervals and absent P-waves. Others : FBC, clotting screen, YFT, LFT, RFT, Echo

7. Management : The mainstay of management of AF : Optimised stroke prevention : consideration of anticoagulation ( CHADS2VAS2 score, HAS-BLED score/ ORBIT score * ) either a rhythm or rate-control strategy based predominantly on symptoms. Treatment of comorbidities

8. CHA2Ds2-VASc : Men & women with a score of ≥2 - Offer anticoagulation Men with a score of ≥1 - Consider anticoagulation

9. ORBIT Bleeding Risk Score for Atrial Fibrillation ORBIT Score : Score 0-2 : low bleed risk Score 3: Medium bleed risk Score 4-7 : High bleed risk

10. Anticoagulation : 1. Vitamin K antagonist : 2. DOAC Apixaban, Edoxaban, Rivaroxaban, dabigatran Act by direct thrombin inhibitor or factor Xa inhibitor fixed dose, No INR monitoring Warfarin Mainly used for prosthetic heart valve or moderate to severe mitral stenosis High bleeding chance Monitoring of INR needed

11. Management of acute with AF AF with haemodynamic instability : Reduced conscious level, SBP < 90mm Hg, Chest pain, Signs of heart failure AF without haemodynamic instability emergency cardioversion (3attempts ) without delaying to achieve anticoagulation +/- Amiodarone if unsuccessful onset >48 hours or uncertain offer anticoagulation rate control ( BB/ CCB / Digoxin ) If cardioversion, anticoagulation should be continued for > 3 weeks pre & post cardioversion onset <48 hours : anticoagulation + rate/ rhythm control Rythm control : DC Cardioversion or pharmacological cardioversion : flecainide, amiodarone Rate control : BB / CCB +/- Digoxin Correct associated Electrolyte imbalance / acute infection

12. Common drugs and dosage: Beta-Blocker IV Oral Maintenance dose Metoprolol tartrate 2.5-5 mg bolus over 2 mins; up to 3 doses 25 – 200 mg twice daily Atenolol N/A 25 – 100 mg daily Bisoprolol N/A 2.5 – 10 mg daily Propranolol 1 mg over 1 min; repeat PRN every 2 mins; up to 3 doses 10-40 mg three to four times daily Non-DHP CCB IV Oral Maintenance dose Diltiazem 0.25 mg/kg IV over 2 mins. May repeat 0.35 mg/kg over 2 mins; then 5-15 mg/hr continuous infusion 120 – 360 mg daily (ER) Verapamil 5 to 10 mg over ≥2 minutes (may repeat twice); then 5 mg/hr continuous infusion (max 20 mg/hr) 180 – 480 mg daily (ER) Agent IV Oral Maintenance dose Amiodarone 150-300 mg IV over 1 hr, then 10-50 mg/h over 24 hrs 100 – 200 mg daily Digoxin* *Increased mortality at plasma concentrations exceeding 1.2 ng/mL 0.25 – 0.5 mg over mins; repeat doses of 0.25 mg every 6 hrs (max 1.5 mg/24 hrs) 0.0625 – 0.25 mg daily

13. Management of chronic AF : rate control ** Anticoagulation ** Rythm control BB / CCB as 1st choice DC Cardioversion Echo to check intracardiac thrombi or pharmacological : flecainide, if no evidence of structural/ ischaemic heart disease amiodarone if evidence of structural heart disease Pharmacological : DOAC/ Warfarin Non pharmacological : left atrial appendage occlusion If fails, add Digoxin, then consider amiodarone. Digoxin as monotherapy only in sedentary patient. Refractory cases : AVN ablation with pacing Pulmonary vein ablation Surgery

14. Rate Vs Rythm control Rate control : AF onset <48 hours or >48 hours No reversible cause Patients who do not have heart failure caused primarily by AF Permanent AF Older patient Pharmacological : BB, rate-limiting CCB (e.g. verapamil or diltiazem), or digoxin. Non pharmacological : AV nodal ablation plus ventricular pacing . Rythm control : AF with a clear reversible cause Heart failure primarily caused by AF New onset or lone AF , Symptomatic paroxysmal AF, Recurrent symptomatic persistent AF Alleviation of symptoms from AF despite adequate ventricular rate control Younger patient DC Cardioversion Pharmacological cardioversion : Class Ia, Ic, III Antiarrhythmic drug . Non pharmacological : Radiofrequency catheter ablation of the left atrium, Pacing, Surgical ablation procedure

15. Reference Oxford handbook of clinical medicine NG196 Algorithms for atrial fibrillation: diagnosis and management : By NICE.CKS UpToDate : Atrial fibrilation BMJ Best practice