EKGs…The Basics for FP Residents Jess Fogler, MD University of California, San Francisco

Part III Arrhythmias

An Approach… Attempt to diagnose NSR: Start with the rhythm strip Rate Regularity Measure RR interval carefully if rate fast Check for P wave before every QRS

An Approach… Check leads I, II, aVF If P waves upright and consistent morphology: originating from sinus node

An Approach… If not NSR…evaluate: Rate Regularity Width of QRS complex Concentrate on finding P waves V1 most sensitive for P waves Ps are little “noses” that can deform other waves

Atrial Fibrillation The most common sustained arrhythmia Afib: rapid, small amplitude waves that have inconsistent morphology Best seen in V1-2, or inferior leads

Atrial Fibrillation Not all irregular rhythms are afib Irregularly irregular Aflutter with variable conduction Multifocal atrial tachycardia Multiple PAC’s or PVC’s Regularly irregular 2° A-V block (type I or II) Repetitive PVC’s, PJC’s, PAC’s (bigeminy, trigeminy)

Atrial Fibrillation Organized Afib: fibrillatory waves with peak-to-peak amplitude > 2 mm Waves can look similar Examine over several seconds to reveal variations in morphology Differentiate from aflutter (treatment different)

Atrial Flutter Continuous regular atrial activity Re-entrant atrial circuit Atrial rate 250-350/min Flutter waves must have identical morphology subtract for confounding effects of QRS, ST segment, T wave

Atrial Flutter Classical aflutter (seen in 2/3) Atypical flutter Cover R waves and look for negative waves in II, III, F with rate 250-350 Atypical flutter Continuous regular atrial activity at 250-350

Atrial Flutter Conduction of QRS complexes Rhythmicity 1:1 (rare) 2:1 (QRS rate ~140-160) most common 3:1 Rhythmicity Regular rhythm most common Variable conduction possible irregular rhythm Can be irregularly irregular Compare to afib, organized afib

Premature Atrial Complexes PAC’s are the most common rhythm disturbance Incidence increases with age 13% healthy boys 75% adult males More common in patients with cardiac disease Can trigger other arrhythmias Afib, aflutter PSVT

Premature Atrial Complexes PAC’s come in three flavors 1. Premature P wave with normal QRS: Ectopic atrial focus fires before the sinus node Different morphology from sinus P wave Normal QRS when AV node, conduction system repolarized and ready to go.

Premature Atrial Complexes 2. Premature P wave with no QRS: P wave occurs very early between onset of QRS and peak of T wave Check T’s carefully for deformations A-V node and bundles in refractory period (ie asleep)

Premature Atrial Complexes 3. Premature P wave with aberrant ventricular conduction P wave falls after peak of T wave A-V node “awake” Other parts of the conduction system still “asleep” Commonly has RBBB morphology RB asleep, LB awake

Premature Atrial Complexes All PAC’s are followed by a compensatory pause while the sinus node resets With multiple PAC’s rhythm can become irregularly irregular

Multifocal Atrial Tachycardia MAT: an irregularly irregular rhythm P waves with ≥ 3 morphologies per lead Mean atrial rate >100/min Variable PR intervals Non-conducted atrial activity common Associated with pulmonary disease in 60%

Ekg 111 Sinus brady with wenckebach periodicity ?old ant infarct (prob nl)

First Degree A-V Block Prolonged A-V conduction Atrio-ventricular ratio 1:1 P-R interval ≥ 210 msec

Second Degree A-V Block Type I (Wenckebach): PR prolongation Regularly irregular rhythm (group beating) Constant P-P interval Increase in PR interval (but not necessarily progressive) leading to a… Non-conducted P wave Pause < 2 x RR Next PR interval usually shortest

Second Degree A-V Block Type II (Mobitz): sudden failure Constant P-R interval Constant P-P interval Dropped beats Rare Can progress to asystole, 3˚ A-V block, death Permanent pacemaker required

Third Degree A-V Block Complete failure of atrial impulse propagation with independent junctional or ventricular escape rhythm P waves and QRS complexes have no relation to each other Usually will see more P waves than QRS complexes

Paroxysmal Supraventricular Tachycardia (PSVT) Atrial rhythm: narrow QRS (usually) Paroxysmal Rate 140-250 AVRT AVNRT Atrial tachycardia

Paroxysmal Supraventricular Tachycardia (PSVT) Differentiation between types usually not necessary as treatment for all similar Unstable patients: DC cardioversion Stable patients: vagal maneuvers, adenosine, verapamil etc. Adenosine may reveal flutter waves ST-T changes are frequent and a poor predictor of underlying CAD (even with chest pain)

Wide QRS Complex Tachycardia First: is the rhythm regular? Irregularity easily missed at fast rates Use calipers or measure with paper Treatment of irregular WCT different than regular WCT

Ekg 95 Afib with rapid ventricular response with anterior conduction over accessory pathway

Wide QRS Complex Tachycardia Irregular rhythm: Afib with BBB or IVCD (pre-existent or rate related) Afib with anterograde conduction over accessory pathway in WPW Other causes of an irregular rhythm (aflutter with variable conduction, MAT etc) with BBB, WPW, IVCD

ekg97 VT (actually it’s avrt with anterograde conduction over accessory pathway)

Wide QRS Complex Tachycardia Regular rhythm: Ventricular driven rhythm: Vtach - worst case scenario Supraventricular rhythm with aberrant conduction: Sinus tach with BBB (pre-existent or rate related) - most common SVT (atrial tach, PSVT) with BBB Antidromic reciprocating tachycardia in WPW

Wide QRS Complex Tachycardia Basic diagnostic algorithm for WCT with regular rhythm: If QRS complex doesn’t fit the typical pattern of either RBBB or LBBB, the diagnosis defaults to Vtach Remember that sinus tach with BBB is most common so scrutinize for P waves When in doubt treat for Vtach

Ekg 105 Sinus tach (p’s after T waves) LAE LBBB Probable LVH

Ekg 104 VT by quick and brugada

Train your eyes Train your eyes for Rate: Train your eyes for Rhythm: Check the computer Train your eyes for Rhythm: Check the rhythm strip Check I, II, avF Train your eyes for Axis: Check I, II Train your eyes for Intervals: PR: check II QT: check the computer QRS: check I, V1

Train your eyes Train your eyes for LVH: Train your eyes for MI: Look at…in order avL V3 V1 V5,V6 Check your cheat sheet Read the computer Train your eyes for MI: Look at all T waves Look at all ST segments Check for Q waves Check for R waves in V1-2

Practice Makes perfect

Rate: 250 QTC: 410 Ekg 80 AVRT short RP tachycardia

Rate: 42 QTC: 375 Ekg 111 Sinus brady with wenckebach periodicity ?old ant infarct (prob nl)

Rate: 74 QTC: 410 EKG #4: RBBB Lead V1: large R’ Lead I: broad terminal S

Rate: 150 QTC: 410 Ekg 71 A flutter with 2:1 conduction

Rate: 41 QTC: 360 Ekg 114 Sinus brady with 3AVB Lae LVH with repol abnl

Rate: 62 QTC: 390 EKG #70 Organized afib Inverted T’s inferiorly ?dig effect

Rate: 114 QTC: 445 ekg97 VT (actually it’s avrt with anterograde conduction over accessory pathway)

Ekg 113 2AVB mobitz II = dropped beats

Rate: 43 QTC: 440 EKG #5: Sinus brady AVB RBBB LAD LAFB LVH with biphasic T’s

Rate: 73 QTC: 390 EKG #6 LBBB Lead V1: deep wide S wave Lead I: broad, notched R wave (no Q or S)

Rate: 42 QTC: 420 I II EKG #66 Junctional escape rhythm with retrograde Ps III

Rate: 71 QTC: 380 EKG #1 Normal EKG