A 65-year-old lady presented with breathlessness and was found to have an irregularly irregular pulse. Her ECG showed atrial fibrillation with a slow ventricular response of 60 beats per minute and no P waves. She was diagnosed with new onset atrial fibrillation. As it appeared to be ongoing for more than 48 hours, she would be anticoagulated. An echocardiogram and further testing were planned to evaluate for underlying structural heart disease or clots that may have increased her risk of stroke.

1. ECG OF THE WEEK Prof.Dr.P.Vijayaraghavan’s unit Dr.C.R.Rajkumar M6 unit

2. 65 year old lady presented with breathlessness to the OPD. No significant past history. On Examination: Pulse was irregularly irregular, varying in volume. Rate – 50/min, Pulse deficit 11/min. BP – 110/70 CVS – S1 varying in intensity. No murmurs. ECG was taken.

4. ECG SHOWS Ventricular Rate of 60/min Varying RR interval QRS Axis 35 QRS Duration 100ms QRS morphology normal, occasional artifacts No ST segment T wave changes Absent P waves Undulating baseline .

5. DIAGNOSIS New onset Atrial Fibrillation with slow ventricular response

6. DD FOR AF WITH SLOW VENTRICULAR RESPONSE: High vagal tone AF with associated AV heart block Digoxin effect Beta blocker and other drugs

7. ATRIAL FIBRILLATION The most common sustained cardiac rhythm disturbance Def: Supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function.

8. MECHANISM Atrial factors: Enhanced automaticity in 1 or several rapidly depolarizing foci and reentry involving 1 or more circuits. The multiple-wavelet hypothesis: that fractionation of the wave fronts as they propagate through the atria results in self-perpetuating “daughter wavelets

9. CLASSIFICATION: First onset AF: whether or not it is symptomatic or self-limited, recognizing that there can be uncertainty about the duration of the episode and about previous undetected episodes Recurrent AF : (1) Paroxysmal AF (self terminating, episodes <7 days) (2) Persistent AF (not self terminating usually greater than 7 days) (3) Permanent AF (cardio version failed or not attempted)

10. MYOCARDIAL AND HEMODYNAMIC CONSEQUENCES 3 factors affect hemodynamic function: loss of synchronous atrial mechanical activity. Irregularity of ventricular response. Inappropriately rapid heart rate

11. MYOCARDIAL AND HEMODYNAMIC CONSEQUENCES A persistently rapid atrial rate can adversely affect atrial mechanical function (tachycardia-induced atrial cardiomyopathy) A persistently elevated ventricular rate during AF can produce dilated ventricular cardiomyopathy. HF can be the initial manifestation of AF

12. COMMON CAUSES 10% elderly, more than 75 yrs Lone AF less than 65 yrs Valvular heart disease Hypertension Myocarditis and cardiomyopathy Cardiac surgery Hyperthyroidism Alcohol poisoning Autonomic dysfunction SVT Sick sinus syndrome

13. CLINICAL MANIFESTATIONS Symptoms vary with the ventricular rate, underlying functional status, duration of AF and individual patient perceptions. Most patients with AF complain of palpitations, chest pain, dyspnea, fatigue, or light headedness, polyuria, syncope.

14. IF UNSTABLE Cardioversion

15. IF STABLE Rate control Minimize thrombo-embolic risk . Establish etiology Restore sinus rhythm Maintain sinus rhythm

16. PLAN FOR THIS PATIENT: In this patient since clinically it appears to be new onset fibrillation of more than 48 hrs duration, patient can be anti-coagulated. Since clinically stable, rate and rhythm control are of secondary importance. Echo to rule out structural heart disease. TEE (Trans-Esophageal Echo) for LA clot.