ECG: Junctional Escape Rhythm

1. ECG OF THE WEEK
Prof Dr.S.TITO’s UNIT M5
Dr.G.Arunkumar

2. 46 year old male a known smoker and diabetic presented
with recurrent episodes of giddiness
O/E General exam- normal
PR- 50/min irregularly irregular
BP-100/70 mm Hg
Systemic examination- no abnormalities

ECG was taken

4. Rhythm strip

5. A standard 12 lead ECG showing
•Heart rate 40/min
•Sinus Arrest
•Junctional rhythm
•Irregularly irregular
•Varying RR interval
•Q waves in II III avf
•QTc interval 352 ms
•QRS axis 60 degree
HEART RATE AFTER ATROPINE ADMINISTRATION WAS 70/MIN

6. Junctional beat without retrograde conduction
Junctional beat with retrograde conduction ( p wave
superimposed on QRS complex)
Prolonged return cycle following retrogradely
conducted junctional beat

7. DIAGNOSIS
Junctional escape rhythm possible sinus
node dysfunction
DIFFERENTIAL DIAGNOSIS
A) SICK SINUS SYNDROME
B) CAD (ACUTE OR CHRONIC)
C) CARDIOMYOPATHY
D) INFLAMMATORY
E) IATROGENIC

9. SICK SINUS SYNDROME
•SSS IS A PAN CONDUCTION DEFECT POSSIBLY INVOLVING THE ENTIRE CONDUCTING SYSTEM
•INCIDENCE EQUAL IN MALE & FEMALE
•MORE THAN 1/2 THE CASES OCCUR>50 YEARS OF AGE
•SSS PRESENTS AS
1.SINUS BRADYCARDIA
2.BRADYCARDIA TACHYCARDIA SYNDROME
3.BRADYCARDIA WITH SA OR AV BLOCK OR ESCAPE
RYTHM, OR HEMIBLOCK OR AF OR INTRA ATRIAL BLOCK
4.SINUS PAUSE/ARREST
5.INADEQUATE SINUS TACHYCARDIA
6.UNCOMPLICATED ESCAPE RHYTHM SEC TO MARKED SA
DEPRESSION
7.PROLONGED RETURN CYCLE FOLLOWING
PREMATURE DISCHARGE OF THE SA PACE MAKER
Eg…ATRIAL, /VENTRICULAR EXTRA SYSTOLE OR
RETROGRADELY CONDUCTED JUNCTIONAL BEAT
SINUS BRADYCARDIA OR SLOW AV JUNCTIONAL RHYTHM
AT THE TIME OF SYMPTOMS IS ENOUGH FOR DIAGNOSIS

10. •STRUCTURAL NODAL DISEASE OCCURS IN 5% OF ALL CASES OF MI
AND MORE THAN 50% OF AIMI (LCA&RCA)
•THE PRESENCE OF STRUCTURAL NODAL DISEASE CAN BE
DIFFERENTIATED FROM EXTRINSIC CAUSES BY VAGOLYTIC AND
SYMPATHOMIMETIC MANOEUVRES AND OVER DRIVE SUPPRESSION
•ATROPINE (1-2mg) ADMINISTRATION SHOULD INCREASE THE SINUS
RATE TO MORE THAN 90
•TREATMENT USUALLY REQUIRES DEMAND
PACE MAKERS

11. APPROACH TO BRADYARRYTHMIAS
BRADYCARDIA
HR<60
MAINTAIN PATENT AIRWAY
ASSIST BREATHING
GIVE O2
MONITOR ECG,BP,OXIMETRY
ESTABLISH IV ACCESS
SIGNS & SYMPTOMS OF POOR PERFUSION
NO YES
OBSERVATION
*PREPARE FOF TRANSCUTANEOUS PACING ,USE WITHOUT
DELAY FOR HIGH DEGREE BLOCK(TYPE 2nd&3
rd
DEGREE
AV BLOCK)
*CONSIDER ATROPINE 0.5 mg WHILE AWAITING PACING
MAY REPEAT TO A TOTAL DOSE OF 3 mg, IF INEFFECTIVE
TRY PACING
*CONSIDER EPINEPHRINE 2-10 mcg/min OR DOPAMINE
2-10mcg/kg/min INFUSION WHILE AWAITING PACER OR
IF PACING IS INEFFECTIVE

12. REFERENCES
1)SCHAMROTH
2)HARRISON
3)HURST
4)WASHINGTON MANUAL