The heart rate can be determined by identifying 6-seconds on the electrocardiogram paper and counting the number of QRS complexes in the 6-
second strip. The number of QRS complexes in 6 seconds multiplied by 10 gives the heart rate for 1 minute. HR = #QRS * 10

First, find a specific R wave that falls on a heavy black line. Then count off “300, 150, 100, 75, 60, 50” for each heavy black line that follows until the next R wave falls. To find the specific heart rate, determine the difference in rate between the dark lines that encircle the R wave (e.g., 300 − 150 = 150), and divide this number by 5 (the number of small boxes between the dark lines). Between 150 and 300, the distance between each small box is equivalent to 30 beats. Between 100 and 150, the distance between each small box represents 10 beats.

Count the number of large boxes between two R waves and divide this number into 300. HR = 300 / #LargeBoxes

Count the number of large boxes between the R waves, multiply this number by 5, and divide the product into 1500. HR = 1500 / (#LargeBoxes * 5)

The heart rate can be determined by identifying 6 seconds on the electrocardiogram paper and counting the number of QRS complexes in the 6-
second strip. The number of QRS complexes in 3-seconds multiplied by 10 gives the heart rate for 1 minute. HR = #QRS * 10

The heart rate can be determined by identifying 6 seconds on the electrocardiogram paper and counting the number of QRS complexes in the 6-
second strip. The number of QRS complexes in 10-seconds multiplied by 10 gives the heart rate for 1 minute. HR = #QRS * 10

Count the number of large boxes between two R waves and divide this number into 1500. HR = 1500 / #LargeBoxes

Count the number of large boxes between the R waves, multiply this number by 5, and divide the product into 300. HR = 300 / (#LargeBoxes * 5)

HR < 60 bpm

HR > 100 bpm

RR interval varies throughout

RR interval is regular, but occasional pauses appear

P-waves are inverted, absent, or retrograde

ST-segment elevation

HR < 60 bpm

HR > 100 bpm

Arrhythmic P-wave and QRS-complex

P-waves may be merged with previous T-wave

P-waves are inverted, absent, or retrograde

P-waves are absent

RR interval varies throughout

HR < 60 bpm

HR > 100 bpm

P-waves and RR-intervals vary

P-waves may be merged with previous T-wave

ST-segment elevation

RR interval is regular, but occasional pauses appear

HR < 60 bpm

Arrhythmic P-wave and QRS-complex

P-waves running independent of QRS-complexes

Extra QRS-complexes that are wide and bizarre-looking

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

P-waves and RR-intervals vary

Sine wave

Absent P-waves with wide QRS-complexes

Absent P-waves with irregularly irregular QRS-complexes

Arrhythmic P-wave and QRS-complex

P-waves are inverted, absent, or retrograde

Arrhythmic P-wave and QRS-complex

Absent P-waves with wide QRS-complexes

Sawtooth patterned QRS-complexes

Absent P-waves with irregularly irregular QRS-complexes

HR between 40- and 60-bpm

HR > 100-bpm

P-waves may be absent

PR-intervals and RR-intervals vary

HR between 100- and 200-bpm

Arrhythmic P-wave and QRS-complex

HR < 60 bpm

PR-interval prolonged (>0.20-seconds)

P-waves may be merged with previous T-wave

PR-intervals may be difficult to determine

ST-segment may be elevated or depressed

HR >= 160-bpm

P-waves are inverted, absent, or retrograde

HR between 40- and 60-bpm

P-waves are inverted, absent, or retrograde

HR between 40- and 60-bpm

HR between 100- and 200-bpm

P-waves and RR-intervals vary

RR interval varies throughout

Sawtooth patterned QRS-complexes

P-waves may be absent or retrograde

HR between 40- and 60-bpm

HR > 100-bpm

Sawtooth patterned QRS-complexes

Absent P-waves with irregularly irregular QRS-complexes

3+ PVCs occur in a row

P-waves may be absent or retrograde

HR > 100-bpm

P-waves running independent of QRS-complexes

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

T-waves inverted

ST-segment elevation

PR-interval prolonged (>0.20-seconds)

Progressive prolongation of the PR interval until finally one impulse is not conducted through to the ventricles (no QRS-complex following a P wave). The cycle then repeats itself.

Extra QRS-complexes that are wide and bizarre-looking, without a P wave, and followed by a complete compensatory pause.

ST-segment elevation

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

Arrhythmic P-wave and QRS-complex

Progressive prolongation of the PR interval until finally one impulse is not conducted through to the ventricles (no QRS-complex following a P wave). The cycle then repeats itself.

2-4 extra P-waves before each QRS-complex

P-waves running independent of QRS-complexes

HR > 100-bpm

ST-segment elevation

T-waves inverted, or ST-segment depression

2-4 extra P-waves before each QRS-complex

P-waves running independent of QRS-complexes

HR between 30- and 50-bpm

PR-interval prolonged (>0.20-seconds)

P-waves may be absent or retrograde

ST-segment elevation

P-waves running independent of QRS-complexes

HR between 30- and 50-bpm

PR-interval prolonged (>0.20-seconds)

2-4 extra P-waves before each QRS-complex

Progressive prolongation of the PR interval until finally one impulse is not conducted through to the ventricles (no QRS-complex following a P wave). The cycle then repeats itself.

P-waves may be absent or retrograde

Extra QRS-complexes that are wide and bizarre-looking, without a P wave, and followed by a complete compensatory pause.
ST-segments and T-waves for these extra QRS-complexes may slope in the opposite direction.

P-waves running independent of QRS-complexes

HR between 30- and 50-bpm

PR-interval prolonged (>0.20-seconds)

Progressive prolongation of the PR interval until finally one impulse is not conducted through to the ventricles (no QRS-complex following a P wave). The cycle then repeats itself.

Ventricular Rate between 100- and 250-bpm

P-waves are absent

3+ PVCs occur in a row

Ventricular Rate between 100- and 250-bpm

P-waves running independent of QRS-complexes

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

PR-intervals and RR-intervals vary

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

Absent P-waves with irregularly irregular QRS-complexes

Absent P-waves with wide QRS-complexes

Sawtooth patterned QRS-complexes

Sine wave

HR > 100 bpm

T-waves inverted

ST-segment depression

ST-segment elevation

HR < 60 bpm

Sine wave

Absent P-waves with irregularly irregular QRS-complexes

ST-segment elevation

ST-segment depression

T-waves inverted

The ECG results in a picture of grossly irregular up and down fluctuations of the baseline in an irregular zigzag pattern.

HR < 60 bpm

P-waves may be absent