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
9. Cont..
Clinical manifestation:
At rest, asymptomatic
Pale, cool skin, hypotension, weakness and angina.
Dizziness or syncope
Confusion and disorientation
Shortness of breath
12. 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
13. 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
18. 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.
24. 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.
27. 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”
29. 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.
32. 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
33. 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.
34.
35. 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
36. 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
38. 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
41. 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
42. Cont…
Rate control:
o Digoxin
o Beta blokers
o Rate limiting calcium antagonist
– Verapamil
– diltiazem
o Combination therapy:
• Digoxin + atenolol
43. 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.
44. 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
46. 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
51. 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
52. Cont…
Etiology:
♯ Acute coronary syndrome
♯ Stable to unstable VT
♯ PVC’S with R on T phenomenon
♯ Multiple drug
♯ Electrolyte disturbance
♯ Hypoxia, metabolic acidosis
56. 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.
57. 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
60. HEART BLOCK
• Heart block is an abnormal heart rhythm
where the heart beats too slowly
(bradycardia).
61. • 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)
62. 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.
63.
64. 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)
65. 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
68. Second Degree Heart Block (2º)
Mobitz Type I
(Wenkebach)
• Conduction through the AV Node –
progressively delayed until a drop beat is
seen
69. 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.
71. 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
72. 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
73. 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
75. 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)
76. 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.
77. 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
78. Significance
• clinical significance
• Symptoms LOC, Confusion,
Dizziness, Low BP
• Can lead to standstill, VT or VF
(stokes Adams)
• Treatment - pacemaker