12 Lead EKG InterpretationEssentiallyspeaking...

12-lead EKG interpretation has been a lifelong partnerof theEmergency Physicianin patient assessment

Many EPs, though, are not STARS at 12 lead EKG interpretationX

WHY?????

Because most EKG courses are too long, too boring, and teach absolutely unnecessary and unrememberable stuffin ways thatmake students justregurgitate the material

What am INOT talking about? Advanced rhythm assessment Ventricular tachycardia assessment Vtach vs. SVT assessment Block

EinthovenNetherlands ECG 1895

EinthovenString Galvanometer

Einthoven

Fowlers Prime Directiveof Cardiac Emergencies:Some systole is betterthan no systole at all

Pulseless RhythmsCPR, Shock, Intubate with CPR, Epi q 3, Shock, Amio or Lidocaine then ??CPR, Shock, Intubate withCPR, Epi q 3, Shock,Amio or Lidocaine then ??Intubate, IV, Epi q 3,Consider Atropine, Look for cause

Second point:

Much of what we call 12 lead interpretation is in fact actually rhythm strip interpretation.

such as, for example, the evaluation of AV block, which can usually be done in one, or at most, two leads

Third point: AXIS INTERPRETATION IS BORING!!

Hence, I will make it VERY short!

PositiveAs the lead sees the impulse growing (or coming toward it), the machine recordsan upward deflection

PositiveAs the lead sees theimpulse coming then going(or going by the lead), the machine recordsan isoelectric deflection

PositiveAs the lead sees theimpulse coming then going(or going by the lead), the machine recordsan isoelectric deflection

Lead ILead IILead III+++

IIIIII+++The EKG Basic Limb Leads

Lead I is horizontal, and is arbitrarilyestablished at 0 DegreesLead II is 60 degrees down from Lead 1 and is arbitrarilyestablished at Positive 60 DegreesLead III is 120 degreesfrom Lead I, and is arbitrarilyestablished at Positive120 Degrees+++

Lead ILead IILead II+++Augmented Limb LeadsavFavLavRAdded by Goldbergerin 1942

Frontal Plane

V1V2V3V4V5V6Added by AHA and theCardiac Society of Great Britain 1938

The Leads may be movedto the center of the chestIIIIIIIIIIII++++++

IIIIII+++Axis is based on the direction of the hearts depolarization

IIIIII+++IIIIII

IIIIII+++IIIIII

IIIIII+++IIIIII

Rhythm strip interpretation has been a standard for emergency medicinesince the inception ofthe monitor

Basic RhythmStrip InterpretationRateRhythmP WavesPR IntervalQRS ComplexST SegmentT WaveU WaveSummary

Cherchez la P

RateRhythmAxis

Hypertrophy

InfarctionP

PR

QRS

ST

T

U

Assessment

Since serious rhythmdisturbances are the most important issue(like VF, VT, asystole),then if you see a seriousrhythm disturbanceproceed withrhythm strip interpretationFIRST!!!

Normal EKG?

Understanding the Anatomy Is the Key

The coronary circulation

The coronaryarteries supply the three mainwalls of the heart

InferiorAnteriorLateral

ConsideringIschemiaandInjury

The EKG leadsthat are positiveclosest to the site of the infarctionwill showST segment elevation

Concave upwards is probablyearly repolarizationConvex upwards is an injury pattern, meaning infarction

The EKG leadsthat are positiveon the other side of the heart from the infarctionwill show reciprocalST segment depression

The Basic Fundamental of 12 Lead EKG InterpretationYou CANT understand12 leads without understandingthe concept ofGrouped Leads

Grouped LeadsRelate DIRECTLYto Cardiac AnatomySo, if you understand the anatomy,you can quickly look at a 12 lead and understand it immediately!

INFERIORLATERALANTERIOR

INFERIORLATERALANTERIORINFERIORII, III, aVFLATERALI, aVL, V6ANTERIORV1, V2, V3, V4

Inferior wall M.I. = Right Coronary infarction (usually)Elevated ST segmentsin II, III, and avF, withreciprocal depressionin I, avL, and the chest leads

Inferior wall M.I. =

Acute Inferior WallMyocardial Infarction

Lateral wall M.I. = Left Circumflex Coronary infarctionElevated ST segmentin I, L, and V6 with reciprocal depression in II, III, and avF

Acute Lateral WallMyocardial Infarction

Inferior Wall M.I. vs. Lateral Wall M.I.

Normal EKG, right?

Normal vs. abnormalLeft Coronary Artery

The EKG leadsthat are positiveclosest to the site of the infarctionwill showST segment elevation

Acute Anterior WallMyocardial Infarction

Acute Anterior WallMyocardial Infarction

Early RepolarizationPattern

Okay, smarty pants:What exactlywould leads I, II, and IIIshow in the case of an anterior (LAD) infarction?HMMMMM????

Reciprocal depressionin all three leads!!All three leads are on theother side of the heart from the infarction!

Having a 12 lead machine around to keep an eye on the tracings is a good idea sometimes...

Monitoring For Ectopyon a 12 Lead EKG

Sometimes the tracings can bequite hard to interpret

and sometimesalmost worthless...

sometimes VERY interesting...

Acute Hyperkalemia

Acute Hypokalemia

The problemwithletting themachineread the tracing???

but sometimesthe machine canbe RIGHT!!!

Dont forget that 12 leadscan let us forgetto analyze the rhythm!!!

VentricularHypertrophy

Left VentricularHypertrophyLeft Axis DeviationDeep S wave in V1Large R wave in V5V1 plus V5 adds upto more than 35 millimetersAnd/Or aVL 11 mm or greater

Right VentricularHypertrophyLook to the RIGHT sideof the heart to find it,namely V1

Finding VentricularHypertrophyAlways look at V1

Finding VentricularHypertrophyLarge R wave in V1 = RVHDeep S wave in V1 = LVHCorollary: If the complex iswider than 0.12 seconds,this is probably a bundle branch blockand not ventricular hypertrophy

Bundle Branch Block

Normal Conduction

V6Left Bundle Branch Block

V1Right Bundle Branch Block

Bundle Branch BlockPositive Deflection Rabbit Ears in V1with wide complex

RightBundleBranchBlockPositive Deflectionin V6with wide complex

LeftBundleBranchBlock

Right Bundle Branch Block

Left Bundle Branch Block

Left Anterior Hemiblock

Brugada Syndrome

Brugada SyndromeBrugada syndrome is a disorder characterized by coved or saddle-shaped ST-segment elevation in leads V1 through V3 on ECG

Brugada SyndromeBrugada syndrome is most common in people from Asia. The reason for this observation is not yet fully understood but may be due to an Asian-specific sequence in the promoter region of SCN5A (Bezzina, 2005).In Asia (eg, the Philippines, Thailand, Japan), Brugada syndrome seems to be the most common cause of natural death in men younger than 50 years. Brugada syndrome is 8-10 times more prevalent in men than in women,

Brugada Syndrome

Brugada Syndrome

Brugada Syndrome

Brugada Syndrome

Wellens Syndrome

Wellens' syndrome is a pattern of electrocardiographic T-wave changes associated with critical, proximal left anterior descending (LAD) artery stenosis.

The syndrome is also referred to as LAD coronary T-wave syndrome. Syndrome criteria include T-wave changes plus a history of anginal chest pain without serum marker abnormalities; patients lack Q waves and significant ST-segment elevation; such patients show normal precordial R-wave progression.

Wellens Syndrome is an easy to identify cardiac syndrome which indicates a critical high grade occulsion of the proximal LAD. If not identified and properly treated the mean time from onset of symptoms to extensive anterior wall MI is 8.5 days

Wellens Syndrome

Now, kiddiesITS EXAMTIME!!

Crushing Chest Pain with Diaphoresis 58 y/o

Acute Chest Pain in 118 Year Old Patient

Diffuse ST Segment Elevation in Chest Painin a middle-aged lady who has recently had a cold

Check the axis and the PR Interval

Older guy, feeling crummy

Older guy having palpitations and lightheadedness

Middle-aged guy found semi-consciouswith weak radial pulse

What is this patients blood pressure?

Synthesis

Prompt and accurate analysisof the ECG requiresanatomical understandingand continual practice

About the time you thinkyoure getting real good atECG analysis, youve realizedthat you may have forgottennearly as much as youever learned: Remember Wellens and Brugada!

Promise yourself(and your patients)that a lifetime ofcontinual study and refresher courseswill accompanyyour practice

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