1.
ARRYTHMIAS
Presented by
RATHEESH R.L

2.
DEFINITION
• The term "arrhythmia" refers to any change from the normal
sequence of electrical impulses. The electrical impulses may
happen too fast, too slowly, or erratically – causing the heart to
beat too fast, too slowly, or erratically. When the heart doesn't
beat properly, it can't pump blood effectively
-American Heart Association

3.
ETIOLOGY
• Dysrhythmias occur as the result of various
abnormalities and disease rate.

4.
Cardiac conditions
• Cardiomyopathy
• Conduction defects
• Heart failure
• Myocardial cell degeneration & MI
• Valve disease

5.
Non cardiac condition
• Acid base imbalance
• Alcohol ,Caffeine & tobacco
• Connective tissue disorder
• Drugs & Toxicity
• Electric shock, hypoxia & shock
• Emotional crisis
• Herbal supplements
• Near drowning and poisoning
• Metabolic condition

6.
TYPES OF DYSRHYTHMIAS

7.
SINUS BRADYCARDIA
• The conduction pathway is the same as that in
sinus rhythm but the SA node fires at a rate
less than 60beats/min.

8.
Cont…Etiology:
Increased vagal tone
Hypothermia
Increased intraocular pressure
Administration of parasympathomimetic drugs &
adverse drug effects
Acute MI
Disease condition – hypothyroidism, increased ICP &
obstructive jaundice

9.
Cont..
Clinical manifestation:
At rest, asymptomatic
Pale, cool skin, hypotension, weakness and angina.
Dizziness or syncope
Confusion and disorientation
Shortness of breath

10.
Cont…
Clinical association- for aerobically trained athletes.
ECG characteristics:
Regular P waves by regular QRS complex

11.
Cont..
Therapy:
Atropine IV o.5mg to I mg
Dopamine- 5 to 20µg/kg/min
Epinephrine – 2 to 10µg/min
Isoproterenol- 2 to 10µg/min
Transcutaneous pacing

12.
SICK SINUS SYNDROME
• SSS also called sinus node dysfunction is a group of
abnormal heart rhythms causes by malfunction of
sinus node.
• Bradycardia-tachycardia syndrome

13.
Cont…
Etiology:
 Medication: digitalis, sympatholytic drugs
 Sarcoidosis, amyloidosis
 Cardiomyopathies
 CAD

14.
Cont…
Symptoms:
Dizziness
Palpitation
Chest pain
Angina
Shortness of breath
Fatigue & headache
Nausea and fainting

15.
Cont…
ECG Characteristics:
Combination of sinoatrial and atrioventricular
conduction disturbances.

16.
Cont…
• Treatment- artificial pacemaker

17.
SINUS TACHYCARDIA
• Sinus rate more than 100beats/min and is
normally due to increase in sympathetic
activity.
• Conduction pathway is same. Discharge rate
from the sinus node is increased.

18.
Cont…Etiology:
Physical and psychological stressors: exercise,
fever,pain, hypotension, hpovolemia, anemia,
hypoglycemia, MI, HF, anxiety
Adrenergic stimulation
Drugs
Pheochromocytoma
Caffeine

19.
Cont…
Clinical manifestation:
Patients intolerance to increased heart rate
Dizziness
Dyspnea
Hypotension
Increased myocardial oxygen consumption

20.
Cont…
ECG characteristics:
Treatment: no specific treatment
Rate: more
than 100
b/min
Rhythm : sinus PR interval:
</= 0.20sec
QRS complex-
normal

21.
PREMATURE ATRIAL CONTRACTION
PAC is a contraction originating from an ectopic focus in
the atrium in a location other than the sinus node

22.
Cont…
Etiology:
☺Hypoxia
☺Electrolyte imbalance
☺Hyperthyroidism
☺COPD
☺Heart disease- CAD
☺Valvular disorder

23.
Cont…
PATHOPHYSIOLOGY:
• The ectopic signal originates in the LA or RA and
travels across the atria by an abnormal pathway
creating a distorted P wave.
• At the AV node it may stopped (non conducted PAC),
delayed (lengthened PR interval) or conducted
normally.

24.
Cont…
ECG characteristic:

25.
Cont…
Treatment:
Beta blockers

26.
ATRIAL FLUTTER
• It is characterized by large re-entry circuit within the
right atrium, usually encircling the tricuapid annulus
• “Impulses take a circular course around the atria,
setting up the flutter waves”

27.
Cont…
Etiology:
♥ Acute coronary syndrome
♥ Mitral and tricuspid valve disorders
♥ Hypoxia, HT, chromic lung disease
♥ Cardiomyopathy
♥ Pulmonary embolus & cor pulmonale
♥ Hyperthyroidism
♥ Drug induced

28.
Cont…
Clinical manifestation:
Can be asymptomatic
Palpitation
flutter can cause decrease cardiac output--- HF
ECG characteristics:
Classic- saw tooth pattern & no true P wave
Ventricular response- a function of AV node block or
conduction of atrial impulses.

29.
Cont…
Treatment:
Calcium
channel
blocker
Beta
adrenergic
blockers
To control
ventricular
rate

30.
Cont…
• Electrical cardio version
• Radio frequency catheter ablation
• High risk of stroke-
– Anticoagulate for 3 weeks if more than 48 hours
occurrence – 4 weeks
– IV heparin

31.
Radio frequency catheter ablation
It is a procedure that can cure many
types of fast heart beats. Using a special wires
or catheters threaded into the heart. Here
they are using radiofrequency energy.

32.
ATRIAL FIBRILLATION
• It is characterized by presence of
multiple, interacting re-entry circuit
looping around the atria.
• Total disorganisation of atrial electrical
activity due to multiple ectopic foci
resulting in loss of effective atrial
contraction

33.
Cont…
Etiology:
 Thyrotoxicosis, alcohol intoxication, caffeine use,
electrolyte disturbance, stress and cardiac surgery
Atrial impulse faster than the SA node impulses,
impulses take multiple , choatic, random pathways
through the atria

34.
Cont…
Clinical manifestation:
Atrial fibrillatory waves- AF with rapid ventricular
response
Thrombi form- 5 fold increase risk to get stroke
Decreased cardiac output.

35.
Cont…
ECG Characteristics:
“irregularly irregular rhythm- with variation in both
interval & amplitude from R wave to R wave”
Rate- wide ranging ventricular response to atrial rate of
300-400 beats/min

36.
Cont…
Treatment:
♫ Calcium channel blockers
♫ Beta adrenergic blockers
♫ Antiarrythmic drugs
♫ Anti coagulation therapy
♫ Maze procedure:
• Cryoablation (use of cold)
• Heat (high intensity ultrasound)

37.
Cont…
Rhythm control
• Immediate cardio version after administration of IV
heparin
• To restore sinus rhythm flecainide= 2mg/kg over
30min max dose 150mg
• INR to be maintained 2.0 to 3.0 for a minimum of 3
weeks

38.
Cont…
Rate control:
o Digoxin
o Beta blokers
o Rate limiting calcium antagonist
– Verapamil
– diltiazem
o Combination therapy:
• Digoxin + atenolol

39.
JUNCTIONAL TACHYCARDIA
• It originates in the area of the AV node, primarily
because the SA node has failed to fire or the signal
has been blocked.

40.
Cont…
• Impulse from the AV node usually moves in a
retrograde (backward fashion) that produce an
abnormal P wave just occuring before or after QRS
complex

41.
PAROXYSMAL SUPRAVENTRICULAR
TACHYCARDIA
Ectopic focus anywhere above the bifuraction of
the bundle of his.
Etiology:
Over exersion
Emotional stress
Deep inspiration
RHD, CAD, COPD & CHF

42.
Cont…
• PATHOPHYSIOLOGY:
Impulse arise and recycle repeatedly in the AV node
because of areas of unidirectional block in the
purkinjie fibers
Reexcitation of the atria when there is a one way
block

43.
Cont…
Clinical manifestation:
Prolonged episode and HR greater than
180beats/min
Decreased CO- Hypotension, dyspnea & angina
Anxious and uncomfortable
ECG Feature:

44.
Cont…
Treatment:
Vagal stimulation
IV adenosine
IV Verapamil- 5-10mg
Beta blockers
Cardio version

45.
PREMATURE VENTRICULAR
CONTRACTION
Originating ectopic focus in the ventricles.
Premature occurrence of a QRS complex which
is wide and distorted in shape.
Multifocal
PVC
Unifocal
PVC

46.
VENTRICULAR FIBRILLATION
• Ventricle consist of areas of normal myocardium
alternating with areas of ischemic, injured or
infracted myocardium, leading to chaotic pattern of
ventricular depolarization

47.
Cont…
Etiology:
♯ Acute coronary syndrome
♯ Stable to unstable VT
♯ PVC’S with R on T phenomenon
♯ Multiple drug
♯ Electrolyte disturbance
♯ Hypoxia, metabolic acidosis

48.
Cont…
Clinical manifestation:
Pulse disappears with onset of VF
Collapse, unconsiousness
Agonal breath
Onset of reversible death

49.
Cont…
TREATMENT:
• Defibrillation
• Oxygen, CPR, INTUBATION
• Epinephrine
• Vasopressin
• Antiarrythmic

50.
PULSELESS ELECTRICAL ACTIVITY
• PEA a situation in which electrical activity can be
observed on the ECG, but there is no mechanical
activity of the ventricles and the patient has no
pulse.

51.
Cont…
• Cardiac conduction impulses occur in organized
pattern , but this fails to produce myocardial
contraction (electromechanical dissociation) or
insufficient filling during diastole or ineffective
contractions

52.
Cont…
Clinical manifestation:
Collapse, unconscious
Agonal respiration or apnea
No pulse

53.
ASYSTOLE
• Total absence of ventricular electrical activity,
• Occasional P wave can be seen

54.
HEART BLOCK
• Heart block is an abnormal heart rhythm
where the heart beats too slowly
(bradycardia).

55.
• They are further classified as,
First degree heart block ( first degree AV block)
 second degree heart block (second degree AV
block)
 third degree heart block (third degree AV block)

56.
FIRST DEGREE HEART BLOCK
• First-degree atrio-ventricular block (AV block), or PR
prolongation, is a disease of the electrical conduction system
of the heart in which the PR interval is lengthened beyond
0.20 seconds.

57.
The following are the most common causes of first-
degree AV block:
• Intrinsic AVN disease
• Acute myocardial infarction (MI), particularly acute
inferior wall MI
• Myocarditis
• Electrolyte disturbances (eg, hypokalemia,
hypomagnesemia)
• Drugs (especially those drugs that increase the refractory
time of the AVN, thereby slowing conduction)

58.
First Degree Heart Block (1º)
• SA Node – normal
• Normal P wave
• AV Node conducts more slowly than normal
• Prolonged PR Interval
• Rest of conduction is normal
• Normal QRS

59.
Significance
• Clinical significance
• None
• Treatment
• None
• Note – this can progress to 2º or 3º heart block

60.
Second Degree Heart Block (2º)
• Mobitz Type I (Wenkebach)
• Mobitz Type II

61.
Second Degree Heart Block (2º)
Mobitz Type I
(Wenkebach)
• Conduction through the AV Node –
progressively delayed until a drop beat is
seen

62.
Second-degree atrio-ventricular (AV) block, or
second-degree heart block, is characterized by
disturbance, delay, or interruption of atrial impulse
conduction through the AV node to the ventricles.

63.
CAUSES
• Drugs (beta-blockers, calcium channel blockers,
amiodarone)
• Cardiomyopathy
• rheumatic fever, myocarditis
• varicella-zoster virus infection
• Rheumatic diseases
• Hypoxia
• Hyperkalemia
• Hypothyroidism
• inferior wall myocardial infarction

64.
Second Degree Heart Block (2º)
Mobitz Type I
(Wenkebach)
• PR Interval prolongs with each beat until
a dropped beat is seen
• The PR Interval is NOT constant
• After each dropped beat, the PR interval
is normal and the cycle starts again

65.
Significance
• Clinical Significance
• Slight symptoms e.g.. Lethargy,
Confusion
• Treatment
• Pacemaker if during day &/or
symptoms
• No treatment if at night
• Note – this can progress to 3º Heart
Block

66.
Second Degree Heart Block (2º)
Mobitz Type II
• Conduction through the AV node is constant.
• PR interval is normal and constant
• Occasionally a dropped beat is seen

67.
Significance
• Clinical significance – this is more
significant disease
• Treatment – pacemaker
• Note – this can progress to 3º Heart Block

68.
Third Degree Heart Block (3º)
(Complete)
• Complete failure of the AV Node
• No impulses from Sinus Node will pass
through to the ventricles
• Some part if the conducting system will
take over as pacemaker of the heart
(even a myocardial cell 10-15 bpm)

69.
Third-degree atrioventricular (AV) block, also referred to
as third-degree heart block or complete heart block, is a
disorder of the cardiac conduction system where there is
no conduction through the atrioventricular node.

70.
Third Degree Heart Block (3º)
(Complete)
• P wave rate – normal
• Ventricular rate – slow
• Ventricular complex may be broad
• Idioventricular rhythm
• Complete dissociation between P
waves & QRS

71.
Significance
• clinical significance
• Symptoms LOC, Confusion,
Dizziness, Low BP
• Can lead to standstill, VT or VF
(stokes Adams)
• Treatment - pacemaker