This document discusses sinus and atrial arrhythmias. It classifies cardiac arrhythmias as bradyarrhythmias which decrease heart rate or tachyarrhythmias which increase heart rate. Sinus arrhythmias are a normal phenomenon where the heart rate increases with inspiration and decreases with expiration due to autonomic influences. Atrial arrhythmias include atrial premature beats, paroxysmal supraventricular tachycardia, atrial flutter, and atrial fibrillation which are abnormalities in the atria and can be caused by ectopic foci or reentry pathways. The mechanisms, ECG patterns, and classifications of these sinus and atrial arrhythmias are explained.

1. SINUS AND ATRIAL
ARRHYTHMIAS
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2. OBJECTIVE
• To know the cardiac arrythmias and their
classification clearly.
• To explain sinus and atrial arrhythmias clearly
• To list the mechanism regarding to sinus and
atrial arrthymias
• To relate the sinus and atrial arrhythmias to the
electrocardiogram

3. WHAT IS CARDIAC ARRYTHMIAS ?
• Disorder to rythmicity property of heart (rhythm
abnormality) – DYSRRHYTHMIA
• Electrical impulses that coordinate your
heartbeats don't work properly, causing your
heart to beat too fast, too slow or irregularly.
• CLASSIFICATION………

4. Cardiac
Dysrrythmias
Bradyarrhythmias
(decrease cardiac rate)
Disorder Of
SA Nodes
Atrial
Arrythmias
Cardiac
Disorder
Ventricular
Arrythymias
Tachyarrhythmias
(increase cardiac rate)
CARDIAC ARRYTHMIAS CLASSIFICATION

5. • Bradycardia: slow heart rhythm (less than 60
beats per minute)
• Tachycardia: fast heart rhythm (greater
than 100 beats per minute)

6. INTRODUCTION (sinus arrythmias)
• Normal physiological phenomeneon
• Do not experience cardiovascular symptoms
• Alteration heart rate in respiratory cycle hence
called respiratory sinus arrythmias
• Heart rate increase (inspiration) heart rate
decreased (expiration)
• Common in young adults and child

8. SINUS ARRYTHMIAS
• The sinus node rate can change with
inspiration/expiration, especially in younger
people. The heart rate speeds up with inspiration
(since it inhibits your vagal nerve) and decreases
with expiration (stimulates your vagal nerve).

9. SINUS ARRYTHMIAS MECHANISM
Autonomic activity
alteration
Inspiration –
sympathetic
discharge increase
expiration- -
parasympathetics
discharge increase
Bainbridge reflex
activation
During inspiration
– increase venous
return to right
atrium
Increase heart rate

10. SINUS ARRYTHMIAS MECHANISM
Irradiation from
inspiration center
Irradiation from
inspiratory center
increase to
vasomotor center
Increase heart rate
Atrial stretch
reflex activator
Increase venous
return stimulate
type-B atrial
stretch receptor
Increase heart rate

11. INTRODUCTION (atrial arrythmias)
• An atrial arrhythmia is an abnormality that occurs
in one of the two upper chambers of the heart, the
left or right atrium.
• Most common type of irregular heartbeat.
• Its frequency increases with age.
• At least 10 to 15 percent of people older than 70
years experience arrhythmias.
• CLASSIFICATION….

12. ATRIAL ARRYTHMIAS CLASSIFICATION
ATRIAL ARRYTHMIAS
Atrial
premature
beats
Paroxysmal
supraventric
ular
Atrial
fibrillation
Atrial flutter

13. 1. ATRIAL PREMATURE BEATS
• Due to premature discharge from ectopic atrial
focus.
• Atrial extrasystole
• Seen in physiology phenomenon like anxiety,
consumption, of excess tea of coffea, coronary
artery diseases and cardiomyopathies.

14. 2. PAROXYSMAL SUPRAVENTRICULAR
TACHYCARDIA (PST)
PARAOXYSMAL
SUPRAVENTRICULAR
TACHYCARDIA
Nodal PST Atrial PST

15. NODAL PST
AV nodal reentry due to dual
AV nodal pathway
Last a few minutes to hours
P wave difficult to identifies
because atria and ventricle
depolarized almost
simultaneously
ATRIAL PST
Atrial
discharge
regularly

16. 3 ATRIAL FLUTTER
Flutter wave appear in ECG
Saw tooth appearance
All impulse from atrial fail
from transmitted to ventricle
Due to intra-atrial reentry
4. ATRIAL
FIBRILLATION
Atria beat rapidly
but irregularly
Due to fibrilatory
wave
Presence of multiple
reentrant excitation
wave in atrial

17. SUMMARY
Cardiac Dysrrythmias
Bradyarrhythmias
(decrease cardiac rate)
Disorder Of SA
Nodes
Sinus
arrythmias
Atrial
Arrythmias
Atrial
fibrillation Atrial
flutter
Atrial
premature
beats
Paroxysmal
supraventricular
tachycardia
Cardiac
Disorder
Ventricular
Arrythymias
Tachyarrhythmias
(increase cardiac rate)

18. REFERENCE
• GK Pal, textbook of physiology