EKG REVIEW Dr. Srikanth Seethala MD,MPH

RBBB: 1.QRS duration more than 120 msec 2.rsr′, rsR′, or rSR′ in leads V1 or V2. The R′ or r′ deflection is usually wider than the initial R wave. 3.S wave of greater duration than R wave or greater than 40 ms in leads I and V6 in adults. 4.Normal R peak time in leads V5 and V6 but greater than 50 ms in lead V1.

LBBB 1.QRS duration more than 120 msec 2.Broad notched or slurred R wave in leads I, aVL, V5, and V6 and an occasional RS pattern in V5 and V6 attributed to displaced transition of QRS complex. 3. Absent q waves in leads I, V5, and V6

1.ST elevation > 1mm in leads with a positive QRS complex in any lead(concordance in ST deviation) (score 5) 2.ST depression > 1 mm in V1-V3 (concordance in ST deviation) (score 3) 3.ST elevation > 5 mm in leads with a negative QRS complex (score 2) 4.A score of more than 3 has a specificity more than 90% 5.Can we apply for the pacing? Sgarbossa criteria

ST segment elevation ≥5 mm in leads with a negative QRS complex Two other criteria are 1.ST elevation ≥1 mm in leads with concordant QRS polarity 2.ST depression ≥1 mm in leads V1, V2, or, V3 GUSTO 1 trial

Other than unable to use V1-3 we can use rest of the leads RBBB and MI

Arrhythmias

Sinus rhythm

Sinus bradycardia with junctional escape

Sinus rhythm with a PAC

Sinus rhythm with 1st degree AVB

Mobitz type 1, Wenckebach : 1.Progressive PR interval prolongation for several beats preceding the non conducted P wave 2.PR interval after the dropped beat is always shorter than that before the non conducted P wave 3.Percentage of PR increase decrease 4.Progressive Shortening of R-R interval 5.R-R interval encompassing the non conducted P wave is less than twice the preceding R-R interval

Mobitz type 2 How to differentiate between Mobitz type 1 and 2 if it is 2:1 conduction 1.Short PR and Wide QRS- type 2 2.Atropine administration: Mobitz type 1 will be 1:1 conduction 3.Carotid sinus massage or adenosine administration: Mobitz type 1 will be 3:2 and paradoxical improvement in type 2

Complete heart block ( AV dissociation)

AV dissociation by default AV dissociation by usurpation Complete Heart block AV dissociation

High degree AV block, 3:1 conduction

Wandering pacemaker

Sinus rhythm with sinus arrest (junctional escapes)

Sinoatrial exit block

Wide complex tachycardia: A rhythm greater than 100/minute and has QRS duration more than 120 msec Ventricular Tachycardia: A WCT originating below the level of bundle his SVT: Tachycardia originating above the level of bundle of his Wide complex tachycardia

Differential Diagnosis 1.Ventricular tachycardia 2.SVT with aberrant conduction Wide complex tachycardia

1. Concordant Pattern 2. Concordance of the limb leads 3. Presence of Q waves 4. AV dissociation (AVD) 5. Fusion beats V tachycardia Vs SVT with aberrancy

6. The “precordial RS absent” criteria 7. V i /V t ratio 8. QRS during VT narrower than in baseline rhythm 9. Contralateral bundle branch block in baseline rhythm and WCT 10. QRS alternans 11. Presence of multiple WCT configurations

LBBB Ventricular Tachycardia SVT with Aberrant conduction V1 Initial R wave > msec Notching of the S wave (Josephson’s sign) R to S wave > msec V6 QS wave qR pattern No Q waves ( there could be minimal Q wave, but should not be pathological) LBBB pattern

RBBB Ventricular Tachycardia SVT with Aberrant conduction V1-2 Smooth monophasic R wave Notched downslope to the R wave — the taller left rabbit ear (= Marriott’s sign) A qR complex (small Q wave, tall R wave) in V1 RSR’ pattern V6 QS complex – a completely negative complex with no R wave (= strongly suggestive of VT) R/S ratio < 1 RBBB

Thank you Sri