25. II. DIAGNOSTIC TEST RESULTS
ECG
electrophysiological (EP)
testing
His bundle study
III. LAB FINDINGS:
hyperkalemia (>5mEq/L)
Hypocalcemia (<4.5mEq/L)
hypomagnesemia(<2.5mEq/L)
26. Mechanism of
Arrhythmogensis
1.
Disorder of impulse formation.
a) Automaticity.
b) Triggered Activity.
1) Early after depolarization.
2) Delayed after depolarization.
2.
Disorder of impulse conduction.
a)
b)
3.
Block – Reentry.
Reflection.
Combined disorder.
29. Duration:
i) paroxysmal- self terminating
episodes upto 7 days
ii) persistent -non self terminating
more than 7 days
iii) permanent - not responding to
cardioversion attempts
iv) recurrent: returning after once
stopped.
30. Strategies of Antidysrhythmic
Agents
A. Alter automaticity
i. decrease slope of Phase 4 depolarization
ii. increase the threshold potential
iii. decrease resting (maximum diastolic) potential
B. Alter conduction velocity
i. mainly via decrease rate of rise of Phase 0
upstroke
ii. decrease Phase 4 slope
iii. decrease membrane resting potential and
responsiveness
C. Alter the refractory period
i. increase Phase 2 plateau
ii. increase Phase 3 repolarization
iii. increase action