The Normal Abnormal ECG Waveforms All Limb Leads

The Normal & Abnormal ECG

Waveforms

All Limb Leads

Lead Placement a. VF

EKG Distributions n n n Anteroseptal: V 1, V 2, V 3, V 4 Anterior: V 1–V 4 Anterolateral: V 4–V 6, I, a. VL Lateral: I and a. VL Inferior: II, III, and a. VF Inferolateral: II, III, a. VF, and V 5 and V 6

Rhythm n Sinus n n n Originating from SA node P wave before every QRS P wave in same direction as QRS

What is this rhythm? Normal sinus rhythm

What is the heart rate? www. uptodate. com 300 / 6 = 50 bpm 1500 / 30 = 50

The QRS Axis § Represents the overall direction of the heart’s activity § Axis of – 30 to +90 degrees is normal

The Quadrant Approach n QRS up in I and up in a. VF = Normal

Normal Intervals n PR n n QRS n n 0. 20 sec (less than one large box) 0. 08 – 0. 10 sec (1 -2 small boxes) QT n n n 450 ms in men, 460 ms in women Based on sex / heart rate Half the R-R interval with normal HR

RHYTHEM n n HR : Bradycardia or tachycardia Pause Premature beat blocks

What is this rhythm?

Premature Atrial Contractions Trigeminy pattern

What is this rhythm?

Tachyarrhythmia Regular n Narrow QRS n Wide QRS = VT or SVT +aberrancy Irregular- irregular n AF n MAT

Supraventricular Tachycardia Retrograde P waves Narrow complex, regular; retrograde P waves, rate <220

Ventricular Tachycardia

What is this rhythm?

Accelerated Idioventricular Ventricular escape rhythm, 40 -110 bpm Seen in AMI, a marker of reperfusion

Junctional Rhythm Rate 40 -60, no p waves, narrow complex QRS

AV- Blocks n AV blocks n First degree block n n Second degree block, Mobitz type 1 n n PR gradually lengthened, then drop QRS Second degree block, Mobitz type 2 n n PR interval fixed and > 0. 2 sec PR fixed, but drop QRS randomly Type 3 block n PR and QRS dissociated

What is this rhythm? First degree AV block PR is fixed and longer than 0. 2 sec

What is this rhythm?

First Degree Heart Block PR interval >200 ms

What is this rhythm? Type 1 second degree block (Wenckebach)

What is this rhythm?

First Degree Heart Block, Mobitz Type I (Wenckebach) PR progressively lengthens until QRS drops

What is this rhythm? Type 2 second degree AV block

What is this rhythm?

Second Degree Heart Block, Mobitz Type II PR interval fixed, QRS dropped intermittently

What is this rhythm? 3 rd degree heart block (complete)

What is this rhythm?

Bundle branch block n RBBB n LBBB

Left Bundle Branch Block Monophasic R wave in I and V 6, QRS > 0. 12 sec Loss of R wave in precordial leads QRS T wave discordance I, V 1, V 6 Consider cardiac ischemia if a new finding

Right Bundle Branch Block V 1: RSR prime pattern with inverted T wave V 6: Wide deep slurred S wave

Ischemia & MI

What do you see in this EKG? ST depression II, III, a. VF, V 3 -V 6 = ischemia

What is the diagnosis? Acute inferior MI with ST elevation in leads II, III, a. VF

Wellen’s Sign ST elevation and biphasic T wave in V 2 and V 3 Sign of large proximal LAD lesion

Lateral MI Reciprocal changes

Inferolateral MI ST elevation II, III, a. VF ST depression in a. VL, V 1 -V 3 are reciprocal changes

Anterolateral / Inferior Ischemia LVH, AV junctional rhythm, bradycardia

Right Ventricular Myocardial Infarction Found in 1/3 of patients with inferior MI Increased morbidity and mortality ST elevation in V 4 -V 6 of Right-sided EKG

Hyperkalemia Tall, narrow and symmetric T waves

Brugada Syndrome RBBB or incomplete RBBB in V 1 -V 3 with convex ST elevation

Atrial Flutter with Variable Block Sawtooth waves Typically at HR of 150

Torsades de Pointes Notice twisting pattern Treatment: Magnesium 2 grams IV

Digitalis Dubin, 4 th ed. 1989

Prolonged QT QT > 450 ms Inferior and anterolateral ischemia

Acute Pulmonary Embolism SIQIIITIII in 10 -15% T-wave inversions, especially occurring in inferior and anteroseptal simultaneously RAD

Wolff-Parkinson-White Syndrome Short PR interval <0. 12 sec Prolonged QRS >0. 10 sec Delta wave Can simulate ventricular hypertrophy, BBB and previous MI