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Patient
Young man 22 years of age, asymptomatic, with no prior history and a normal cardiac ultrasound (same patient as tracing 1);
Trace
Reversal of electrodes V1 and V5 with a tall R wave in V1 and poor R wave progression in the precordium in V5;
Trace
Reversal of electrodes V1 and V2; the pattern is more difficult to identify; the R wave is taller in V1 than in V2 contrary to the S wave;
Trace
Placement of V1 and V2 electrodes two intercostal spaces too high; incomplete right bundle block pattern with rSr' complexes;
Trace
Placement of electrodes V1, V2, V3 two intercostal spaces too low; early transition with R/S ratio > 1 from V2 onward;
Exergue
A reversal between 2 precordial electrodes is suspected in the absence of smooth R wave progression from V1 to V5.
Misplacement of precordial electrodes is common and can be divided into reversal of two precordial electrodes and displacement of one or more electrodes one or two intercostal spaces above or below the recommended sites.