15 High Yield EKG

• P
• QRS
• Intervals
• ST

P

• regular: spacing between QRS same

QRS

Intervals

• atheletes (high vagal tones) and beta blockers prolong PR

ST

Practice 1

• easily identifiable P
• upright P in II, III, AVF: normal sinus P
• QRS: regular
• QRS: narrow
• PR: less than 1 block
• QT: less than half
• ST: no significant depression, elevation

Practice 2

• P: upright in II, III, AVF, normal sinus P
• RR: regular QRS
• QRS: wide in V1, upright QRS in V1 RBBB
• PR: not prolonged
• QT: less than 1/2
• ST: T inversion in V1, normal in RBBB

Practice 2

• P upright in II, III, AVF, sinus
• QRS wide, negative V1, LBBB
• peaked T and ST elevation in V1-3: common
• T inversion 1, L, V5, V6: normal in LBBB

Practice 4

• no clear P waves, afib
• irregularly irregular: QRS closer in some, farther apart in others

Practice 5

• sawtooth, aflut

Practice 6

• ventricle contracts on its own

• buried P waves at different rate as QRS (AV dissociation)

VFib

• top: VFIB, cardiac arrest

PAC, PVC

• top: early wide QRS, PVC, something stimulated ventricles to contract on its own (high catecholamines, infection, surgery)
• bottom: early narrow QRS with compensatory pause after