2. Myocardial Cell
Atria : Myocardial Cells
Ventricle: Myocardial cells
SA Node, AV Node, Purkinjee Fibers
Gap Junctions
Myocardium : Na Ca K Dependent
SA node & AV node : Ca Dependent
Depolarization Repolarization
Plateau Phase
3. Understanding Vector
.
Atria : Myocardial Cells
Ventricle: Myocardial cells
SA Node, AV Node, Purkinjee Fibers
Positive wave towards
positive charge
+
Negative wave towards
negative charge
+
Depolarization
--
+++
Negative wave away
from positive charge
Repolarization
More cells: Larger vector
Specialized conduction: Faster vector
Direction of Vector
Stimulus
20. Left Ventricular Hypertrophy
ROMHILT ESTES POINT CRITERIA
Axis, V1, V6, Strain pattern
Atria abnormality
Other abnormalities
SOKOLOW – LYON CRITERIA
S V1 + R V5 or V6 > 35 mm ( > 3.5 mV)
R wave in V5 or V6 > 26 mm (> 2.6 mV)
37. Ectopic
Premature Atrial Ectopic
Junctional Rhythm
Premature Ventricular Ectopic
Rate
Regularity
Narrow / wide QRS
P wave morphology
Relation of P & QRS
Other Clues
• 3 to 30 seconds it is Non Sustained Tachy
• > 30 Sec it is Sustained Tachycardia
• PB follow every alternate normal beat: Bigeminy
• PB follow every second normal beat: Trigeminy
Abnormal P wave
Normal QRS complex
Incomplete Compensatory pause
Wide QRS complex
Complete Compensatory pause
Inverted P wave
Normal QRS complex
Incomplete Compensatory pause
38. Brady Arrhythmias
FAILURE OF ELECTRICAL IMPULSE
GENERATION (Sinus node Dysfunction)
FAILURE OF EFFECTIVE
CONDUCTION ( AV Node Block)
Sick Sinus Syndrome
Sinus Bradycardia
Inability to increase rate with increased sympathetic activity
Absence of escape rhythms when sinus rate slows
Tachy-brady syndrome
39. Tachyarrhythmias - Mechanisms
INCREASED
AUTOMATICITY
RE ENTRY
TRIGGERED ACTIVITY
Wide Complex Tachycardia
Ventricular tachycardia
Other: SVT with BBB
SVT with WPW syndrome
(Antidromic AVRT)
A fib/A flutter with variable conduction