INTERPRETATION of ELECTROCARDIOGRAMS BRIAN D. LE, MD Presbyterian Hospital CIVA

Outline I. Approach to interpretation of ECGs II. Cases illustrating approach principles III. Unusual Cases

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

INTERVALS PR < 200 ms QRS < 120 ms QTc: Men < 440 ms, Women < 460 ms

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

Left Ventricular Hypertrophy Left Ventricular Hypertrophy Cornell +R (aVL)+Sw(V3)>24mm (male) >20mm (female) Cornell +R (aVL)+Sw(V3)>24mm (male) >20mm (female) Sokolow S(V1) + R(V5)=32mm Sokolow S(V1) + R(V5)=32mm Rw (aVL)>11mm Rw (aVL)>11mm Rw (I)>14mm Rw (I)>14mm

Right Ventricular Hypertrophy Right Ventricular Hypertrophy 1. RAD>100* 1. RAD>100* 2. IRBBB 2. IRBBB 3. R>S V1 3. R>S V1 4. R<S V6 4. R<S V6 5. R in V1>=7mm 5. R in V1>=7mm 6. R V1 + S V5 or V6 >=10mm 6. R V1 + S V5 or V6 >=10mm 7. RAE 7. RAE 8. strain pattern in rt precordial leads 8. strain pattern in rt precordial leads

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

ANATOMICAL LOCALIZATION ANTERIOR: V1-V4, SEPTAL V1-V2 LATERAL: V5-V6, I, Avl INFERIOR: II, III, aVF

Seven Step Approach Rate Rate Rhythm Rhythm Axis Axis Intervals Intervals Hypertrophy Hypertrophy ST/Tw changes, Q waves ST/Tw changes, Q waves Conduction system Conduction system

LBBB LBBB QRS > 0.12 sec QRS > 0.12 sec wide monophasic R in I, V5 and V6 wide monophasic R in I, V5 and V6 (usually notched or slurred) (usually notched or slurred) no Q in I, V5 and V6 no Q in I, V5 and V6 Left Anterior Fascicular Block Left Anterior Fascicular Block LAD > -30', + I, aVR, -II/III/aVF LAD > -30', + I, aVR, -II/III/aVF qR in I and L qR in I and L rS in II, III and aVF rS in II, III and aVF Left Posterior Fascicular Block Left Posterior Fascicular Block RAD > 100' RAD > 100' small R in I and aVL, Q in II, III, aVF small R in I and aVL, Q in II, III, aVF S1 Q3 pattern S1 Q3 pattern RBBB RBBB QRS>0.12 sec QRS>0.12 sec R' > r in right precordium R' > r in right precordium wide S in I, V5 and V6 wide S in I, V5 and V6

Normal Variants- Juvenile Tw inversions

Nuts and Bolts

Electrode Misplacement

Amplitude Artifact

Parkinson’s Tremor

CASES

Case 1: 21 yo presents for routine physical exam

DEXTROCARDIA

Case 2: 38 yo with one week of URI presents with chest pain

Acute Pericarditis Stage I--ST elevation, Tw upright, Stage I--ST elevation, Tw upright, PR depression PR depression Stage II--ST baseline, flattened Tw Stage II--ST baseline, flattened Tw Stage III--inv Tw Stage III--inv Tw Stage IV--Tw baseline, days to wks Stage IV--Tw baseline, days to wks

Case 3: 48 yo homeless man found unresponsive

Hypothermia

Case 4: 34 yo ESRD missed three days of dialysis

Hyperkalemia

Case 5: 28 yo woman s/p neck surgery

Hypocalcemia

Case 6: 32 yo female on antidepressants had syncope

Acquired Long QT Syndrome

Case 7: 60 yo man with chest pain

Inferior MI with RV infarction and 2:1 and complete heart block

2:1 Heart block with ventriculophasic effect

Case 8 : 80 yo man with syncope

Aflutter with complete heart block Aflutter with normal conduction Aflutter with complete heart block

Aflutter with 1:1 conduction

Aflutter with carotid sinus massage

Counter-clockwise Aflutter

Clockwise Aflutter

Case 9: 50 yo man with DCM

Biventricular pacing

Case 10 : 25 yo man with palpitations

Pre-excited Atrial Fibrillation- right sided postero-septal pathway

Wolf-Parkinson-White: Left anterolateral pathway

Postero-septal pathway pre-ablation

Post-ablation with repolarization abn due to memory effect

Case 11: 25 yo female with lightheadedness

AV Node Re-entrant Tachycardia (AVNRT)

Case 12: 75 yo man with ischemic DCM and syncope

Ventricular Tachycardia BRUGADA'S CRITERIA- Circulation '91 BRUGADA'S CRITERIA- Circulation '91 1. Absence of all RS complex in all precordial leads S 21%, SP 100% 1. Absence of all RS complex in all precordial leads S 21%, SP 100% 2. R to S interval > 100ms in one precordial lead S 65%, SP 98% 2. R to S interval > 100ms in one precordial lead S 65%, SP 98% 3 A-V Dissociation, fusion, capture beats S 82%, SP 98% 3 A-V Dissociation, fusion, capture beats S 82%, SP 98% 4. Morphologic criteria in V1+2, 6 4. Morphologic criteria in V1+2, 6

Ventricular Tachycardia

Ventricular Tachycardia: AV dissociation, RS >100ms

Case 13: 18 yo Asian man with family history of SCD presents with syncope

Brugada Syndrome Genetic mutation in SCNA5 Genetic mutation in SCNA5 Predominantly in Asian males Predominantly in Asian males Syncope and sudden cardiac death Syncope and sudden cardiac death Three types Three types

Brugada’s Type II- Saddle back

Case 14: 28 yo man with syncope

Arrythmogenic Right Ventricular Dysplasia (ARVD)

Case 15: 28 yo man with syncope

Short-coupled Torsades

Case 16 : 34 yo woman with fatigue, weight gain, and abn menstrual period

Myxedema

Case 17: 84 yo man with skipped beats

Sino-atrial exit block Type I

Case 18 : 64 yo woman presents for routine exam

Retrograde concealed conduction into the AV node