Heart Rate On Ecg

HEART RATE ON ECG

BY Dr.Kashif

CALCULATION OF HEART RATE After checking the label, speed and ECG standard move to the rate and rhythm lead ( lead II ) which is given as a long strip at the end. Determine whether the rhythm is regular or irregular by noticing the distance between successive QRS complexes. If distance is equal between all QRS complexes rhythm is regular and if distance between QRS complexes is unequal rhythm is irregular. There are separate methods for regular rhythm and irregular rhythm

RULE OF 1500 FOR REGULAR RHYTHM Heart Rate =

1500 No: of small boxes between two QRS complexes

Heart Rate =

1500 / 32

=

46

beats per minute

RULE OF 300 FOR REGULAR RYTHM Heart Rate =

300 No: of large boxes between two QRS complexes

Hear rate =

300 / 6.2

=

48 beats per minute

The Rule of 300 It may be easiest to memorize the following table: # of big boxes Between QRS complexes 1

Heart Rate

2

150

3

100

4

75

5

60

6

50

300

Q. CALCULATE THE HEART RATE USING RULE OF 300

HEART RATE IN IRREGULAR RYTHM First mark the distance between two QRS complexes. This distance should be equal between all QRS complexes. If it is unequal it means rhythm is irregular & following methods are used to calculate heart rate. A. RULE OF 10 SECOND H.R

=

Number of QRS complexes in 10 seconds x 6

B. RULE OF 6 SECONDS H.R = Number of QRS complexes in 6 second strip

x 10

C. RULE OF 3 SECOND H.R =

Number of QRS complexes in 3 second strip x 20

Q. CALCULATE THE HEART RATE USING 6 SECOND RULE

1. 2. 3.

6 second strip is selected between two red arrows Number of QRS complexes counted in 6 seconds is 14 Heart rate= 13 x 10 = 130 beats per minute

Q. CALCULATE THE HEART RATE USING 3 SECOND METHOD

SINUS RHYTHM Normal rhythm of heart is called as Sinus rhythm As the impulse normally originates from Sinus node so it is called Sinus rhythm Heart rate is between 60 ---- 100 beats per minute

NORMAL ECG AND SINUS RHYTHM

Arrhythmias Disorders of rhythm

SINUS TACHYCARDIA In this the impulse originates in SA node so it is also sinus rhythm. But the firing rate of SA node is increased to more than 100. So the heart rate is more than 100 beats per minute. There is no other abnormality in ECG except the fast heart rate.

SINUS TACHYCARDIA

SINUS

BRADYCARDIA

In this rhythm also the impulse originates from SA NODE SO IT IS Sinus rhythm. Firing rate of SA node is decreased below 60. So heart rate is also less than 60 beats per minute. There is no other abnormality in ECG except heart rate less than 60 beats per minute

Sinus bradycardia

SINUS ARRYHTYHMIA Rhythm strip of ECG shows variation in rhythm with different phases of respiration During inspiration the heart rate is increased while during expiration heart rate is decreased. Therefore during inspiration rhythm is fast and during expiration rhythm is slow. This variation in ECG rhythm with respiration is called as Sinus arrhythmia

Expiration

inspiration

Sinus Arrhythmia

Inspiration Expiration

PREMATURE BEATS OR EXTRASYSTOLES Any part of heart other than SA node may discharge an occasional impulse This part is called as ectopic focus and beat which is produced by it is called as premature beat. TYPES OF PREMATURE BEATS TYPE

FOCUS

P WAVE

QRS COMPLEX

Compensatory pause

APC

Atria

present

normal

present

JPC

AV node

absent

normal

present

VPC

ventricle

absent

Wide & bizarre

Present / absent

APC

JPC

VPC

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