Types of heart blocks with it's ecg variations

Types of heart blocks

1. TYPES OF
HEARTBLOCK
-
ECG
VARIATIONS
Presentation by

C Selin Mishma
3rd Sem BSc (N)

2. INTRODUCTION
Heart block also called AV block is when the
electric signal that controls heartbeat to
completely or partially blocked, which
makes your heart beat slowly or skip beat and
can't pump properly.
Fainting, tiredness, shortness of breath are
some common symptoms.

3. WHAT IS HEART BLOCK?
●Heart block is a disorder with the heart’s electrical
system,which makes your heart beat and control
over your heart rate and rhythm .
●This condition is also called Atrioventricular block
or conduction disorder.

4. WHAT HAPPENS IN A
HEARTBLOCK ?
●There is a interference with the electrical signals that
usually travel from the atria to the ventricles.
●If the electrical Signals cannot move from atria to ventricles
the impulses can't reach bundle of his followed by purkinje
fibres.
●Hence heart don't pump properly.

5. BASICS OF ECG

6. ‘ - ‘ denotes relaxation of heart
‘ + ‘ denotes contraction of heart
-To + shows graph above the
baseline
+To - shows graph below the
baseline

7. ●Thin Lines:
1 mm intervals or 0.04 sec
●Thick lines:
5 mm intervals or 0.2sec
●1 thick lined box (5 small boxes)
= 0.20 sec or 5mm
●5 thick lines boxes (25 small boxes)
= 1 second

8. P wave - Duration: < 0.12s OR 3 small box
Amplitude: < 2.5mm OR 2.5 small boxes
PR interval - Duration: 0.002- 0.2s OR 3-5 small boxes
QRS Complex - Duration: 0.06- 0.10s OR 1.5-2.5 small boxes,
Amplitude: 6 to 10 small boxes
ST segment - Duration: 0.08s OR 3 - 5 small boxes

9. TYPES OF HEARTBLOCK
Heart blocks can range from mild to severe, depending on
whether the electrical signal can get through, and how often.
Heart block types are:
1.First-degree heart block: The electrical impulse still
reaches your ventricles, but moves more slowly than
normal through the AV node. This is the most mild type of
heart block.

10. 2. Second-degree (incomplete) heart block: With this
type, your heart’s impulses only get to the lower
chambers some of the time.
● The electrical signal gets slower and slower until your
heart actually skips a beat.
● While most of the electrical signals reach your ventricles,
every so often, some don’t. Your heartbeat becomes
irregular and slower than normal.

11. 3. Third-degree heart block:
● This is a complete blockage of the electrical signal
from your atria to your ventricles.
● Third-degree block negatively affects your heart’s
ability to pump blood out to your body. This form of
heart block is serious and usually requires a
pacemaker for treatment.

12. FIRST DEGREE HEARTBLOCK
●All the arterial impulses are conducted to
the ventricles but are delayed.

●Every PR is followed by QRS Complex but
PR interval is prolonged ( 0.38s or 9 boxes)

13. SECOND DEGREE HEARTBLOCK
All P waves are not followed by QRS Complex i.e., all the
impulses are not conducted to ventricles.

TWO TYPES :
1.Type I 2nd degree heartblock
2.Type ll 2nd degree heartblock

14. 1.TYPE I SECOND DEGREE - MOBITZ TYPE 1
This is a less serious form of second-degree heart block. The
electrical signal gets slower and slower until your heart
actually skips a beat.
PR interval progressively lengthens until a P wave Is not
conducted to ventricles.

15. 2. TYPE II SECOND DEGREE - MOBITZ TYPE 2
●While most of the electrical signals reach your ventricles, every so
often, some don’t. Your heartbeat becomes irregular and slower
than normal. This form of second-degree heart block is more
serious and may warrant a pacemaker.
●PR interval is constant but P waves are not followed by QRS
Complex.

16. THIRD DEGREE HEARTBLOCK
●This is a complete blockage of the electrical signal from your
atria to your ventricles.
●Atrial impulses are not conducted with ventricles.
●P waves have no relationship With QRS Complex.

17. CONCLUSION
Heart block occurs when the electrical
signals from the top chambers of your heart
don't conduct properly to the bottom
chambers of your heart.
About 5 to 10% of patients with an inferior
wall MI will develop a complete heart block
Many are treated and prevented during
earlier stage itself.

18. THANK
YOU