ECG OF THE WEEKProf.Dr.P.Vijayaraghavan’s unit

Dr.C.R.Rajkumar

M6 unit

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.

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

.

DIAGNOSIS

New onset Atrial Fibrillation with slow ventricular response

DD FOR AF WITH SLOW VENTRICULAR RESPONSE:

1) High vagal tone2) AF with associated AV heart block3) Digoxin effect4) Beta blocker and other drugs

ATRIAL FIBRILLATION The most common sustained cardiac rhythm

disturbance

Def: Supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function.

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

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)

MYOCARDIAL AND HEMODYNAMIC CONSEQUENCES 3 factors affect hemodynamic function: loss of synchronous atrial mechanical

activity. Irregularity of ventricular response. Inappropriately rapid heart rate

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

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

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.

IF UNSTABLECardioversion

IF STABLE1. Rate control 2. Minimize thrombo-embolic risk.3. Establish etiology4. Restore sinus rhythm5. Maintain sinus rhythm

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.