This document discusses disturbances of heart rate and how to determine heart rate from an ECG. It provides examples of different types of tachycardias and bradycardias, including sinus tachycardia, sinus bradycardia, supraventricular tachycardia, junctional bradycardia, ventricular tachycardia, third-degree heart block, atrial flutter, atrial fibrillation, and accelerated junctional rhythm. It emphasizes looking at rhythm, rate, and the width of QRS complexes to determine the underlying rhythm disturbance.

1. ECG BASICS 3
DISTURBANCES OF RATE

2. WHAT IS NORMAL
THE NORMAL ADULT HEART RATE IS BETWEEN 60-80
BPM IN A RESTING ADULT HEART
WELL CONDITIONED ATHLETES MAY HAVE A RESTING
HEART RATE BELOW THIS
THERE ARE TWO WAYS TO DETERMINE THE HEART RATE
ON AN ECG

3. BUT FIRST
NOTE WE HAVE
THIN AND
THICK LINES,
AND BLOCKS
EACH SMALL LINE REPRESENTS 0.04 SECS
AND THE DISTANCE BETWEEN EACH BLOCK IS
0.2 SECS

4. COUNT THE NUMBER OF BIG BLOCKS BETWEEN R-
WAVES, CHOOSE AN R THAT FALLS ON A THICK LINE
DIVIDE 300 BY THIS NUMBER, IN THIS CASE ALMOST 4 BLOCKS, 300/4 = 75

5. ALTERNATIVELY
YOU CAN JUST REMEMBER THE SEQUENCE
300
150
100
75
60
50
42
37
300
150
100 60 42 33
75 50 37

6. GOT IT?!
IF YOU CANT REMEMBER JUST LOOK AT
THE TOP OF YOUR ECG PRINTOUT.
MOST MACHINES WORK OUT THE RATE
FOR YOU!

7. REMEMBER
YOU STILL NEED TO CHECK YOUR AXIS AND
RHYTHM IN ALL ECGS

8. LETS TRY SOME

9. CHECK THE RHYTHM THEN THE RATE OR
VICE VERSA
CAN YOU MAKE A DIAGNOSIS?

10. A SINUS TACHYCARDIA
NOTICE THE CONSISTENT P-WAVES BEFORE EACH QRS

11. RHYTHM THEN RATE
CAN YOU MAKE THE DIAGNOSIS

12. A SINUS BRADYCARDIA
AGAIN NOTE THE CONSISTENT P-WAVES

13. ALSO NOTE THE WIDTH OF THE
COMPLEXES
CAN YOU MAKE THE DIAGNOSIS

14. A SUPRAVENTRICULAR
TACHYCARDIA
NOTE THE ABSENCE OF P-WAVES AND THE NARROW COMPLEXES

15. THIS IS A JUNCTIONAL BRADYCARDIA
NOTE THE ABSENCE OF P-WAVES, THIS MEANS THE RHYTHM IS GENERATED BY THE VENTRICLES
ONLY

16. THIS IS AN OBVIOUS TACHYCARDIA
WHAT TYPE IS IT?

17. THIS IS A VENTRICULAR TACHYCARDIA
NOTE THE WIDE QRS COMPLEXES

18. AS A GENERAL RULE
THIN COMPLEXES MEAN THE ELECTRICAL ACTIVITY
ORIGINATES IN THE ATRIA
THICK COMPLEXES IMPLY THE STIMULUS OR
PACEMAKER IS THE AV NODE OR LOWER

19. ANOTHER BRADYCARDIA
CAN YOU MAKE THE DIAGNOSIS?
THINK BACK TO OUR PREVIOUS LECTURE

20. THIS IS A 3RD DEGREE HEART BLOCK
NOTE THE WIDE COMPLEXES, AND THAT THERE IS NO CONNECTION BETWEEN THE P-WAVES AND QRS COMPLEXES
NOTE THAT THE P-WAVES ARE OCCURRING AT A REGULAR RATE, AS ARE THE QRS COMPLEXES, BUT IT IS OCCURRING INDEPENDENTLY

21. A TACHYCARDIA
IT DOES LOOK STRANGE, CAN YOU MAKE THE DIAGNOSIS?

22. THIS IS ATRIAL FLUTTER
ITS DIFFICULT BECAUSE THE T-WAVES ARE BURIED

23. THIS IS A
MORE TYPICAL
EXAMPLE
AGAIN NOTE THE ABSENCE OF THE T-WAVES

24. ANOTHER TACHY
NOTE THE IRREGULARITY, CAN YOU MAKE THE DIAGNOSIS?

25. THIS IS ATRIAL FIBRILLATION
NOTE THE IRREGULARITY AND ABSENCE OF P-WAVES
AS COMPARED TO SVT WHICH OCCURS WITH MILITARY PRECISION BETWEEN THE QRS COMPLEXES

27. ONE FINAL ONE
DR OF THE WEEK TO WHOEVER MAKES THE DIAGNOSIS

28. AN ACCELERATED JUNCTIONAL RHYTHM
NOTE THE ABSENCE OF P-WAVES BUT ITS NOT AS FAST AS AN SVT

29. I HOPE THIS WILL PROMPT YOU TO GO AND LEARN MORE
ABOUT RATE ABNORMALITIES
ONCE YOU ARE COMFORTABLE RECOGNISING THE
DIFFERENT RHYTHMS AND TACHY/BRADYS, WE WILL
LEARN ABOUR TREATMENT
THANK YOU