Measure S in V1 + R in V5/6. Look if greater than 35.
ST depression +/- t wave inversion, no Q waves
ST elevation, no Q waves
T wave inversion high (<15 min) with convex ST elevation --> ST decreases and TWI deepens --> Q-wave (hrs-days)
Acute anterior myocardial infarction
ST-T changes in V1-4
Old anterior myocardial infarction
Q waves in V1-V4
Acute inferior myocardial infarction
ST-T changes leads II, III, aVF
Old inferior myocardial infarction
Q waves in leads II, III, aVF
Acute posterior myocardial infarction
STD and large TWI in V1-3; mirror of STE in V8-9
Old posterior myocardial infarction
Large pathologic R waves V1-3 (mirror Q)
P', often hidden in preceding ST-T.
No QRS because PAC hits AV node still refractory
Conducted PAC with aberration
Wide QRS due to refractory BB/fascicle
Wide, notched, or slurred QRS that is premature related to R-R AND not preceded by P wave. Compensatory pause following.
Irregularly irregular wide or narrow complex QRS
Multifocal Atrial Tacycardia
Irregularly irregular narrow complex QRS with multiple forms of p waves. rate > 100
Irregularly irregular with narrow complex QRS with multiple forms of p waves. rate 60-100
Regular narrow QRS complex atrial activity with saw tooth pattern and periodic narrow complex QRS
1st degree AV block
Long PR (>0.20, five boxes)
2nd degree AV block, Type 1 (wenckebach)
PR longer, RR shorter, then non-conducted P. Benign, not progressing to complete block; do not treat unless symptoms, don't pace.
2nd degree AV block, Type 2 (Mobitz)
PR constant, RR constant. Progresses to complete block and hemodynamic compromise; urgently PACE
2:1 AV block
When you see this, you cannot tell if it is type 1 or type 2.
3rd degree AV block
AV dissociation with narrow QRS; tx: urgent ventricular PACE
AV dissociation with wide QRS; tx: urgent ventricular PACE
Tall, peaked T waves
1st degree AV block, flat, wide P waves
Disappearance of P waves, with arrythmias
Wide QRS (>0.12), terminal forces (2nd half of QRS) oriented towards left and posterior (LV depolarizes after RV). "M shape". Terminal S in V1. Terminal R in I, aVL
Wide QRS (>0.12), terminal forces (2nd half of QRS) oriented towards right and anterior (RV depolarizes after LV). Terminal R' in V1 (rSR'). Terminal S in I, aVL.
QRS fusion: early ventricular activation of accessory AV pathway, then activation through normal AV/BB system. Short PR (<0.12), slurring (delta wave)
One spike --> wide QRS (different morphology than intrinsic QRS)
Atrial-ventricular sequential pacemaker
Spike --> abnormal P (atrial capture) --> second spike --> wide QRS (ventricular capture)
Normal p-wave axis and morphology but <60 bpm
Normal p-wave axis and morphology but >100 bpm
Supraventricular tachycardia (SVT)
Regular narrow QRS complex tachycardia that starts abruptly with PAC, narrow QRS, ends abruptly.
AVNRT (AV nodal reentrant)
Type of SVT (Regular narrow QRS complex tachycardia), due to dual AV nodal pathways. Fast pathway (long refractory) used during sinus rhythm. If PAC, fast is refractory so slow pathway used, but then retrograde via fast.
AVRT (AV reciprocating)
Type of SVT (Regular narrow QRS complex tachycardia) seen in WPW
Ventricular tachycardia (VT)
Rapid succession of 3+ PVCs with regular wide QRS complex with rate >100/ min
Ventricular fibrillation (VF)
Asynchronous ventricular contraction; no identifiable waves; coarse or fine VF. "R on T" --> TdP or VT --> this --> asystole; tx: SHOCK