Antiarrhythmic Drugs Munir Gharaibeh MD, PhD, MHPE School of Medicine, The University of Jordan October 2019 Done by : Maryam Ali rythm of the heart starts from SA node---atrial tissues -----AV node ----ventricle bundle ----right and left bundle branches-----to while muscular to produce normal cardiac output
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Antiarrhythmic Drugs - JU Medicine · Antiarrhythmic Drugs Readily bind to activated channels or inactivated channels, but bind poorly to rested channels. i.e.: Use –Dependent or
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Antiarrhythmic Drugs
Munir Gharaibeh MD, PhD, MHPE
School of Medicine,
The University of Jordan
October 2019
Done by : Maryam Ali
rythm of the heart starts from SA node---atrial tissues -----AV node ----ventricle bundle ----right and left bundle branches-----to while muscular to produce normal cardiac output
Cardiac ArrhythmiasDefinition.
Etiology:
Hereditary
Acquired
Types:
Abnormalities of Impulse Formation:
Rate disturbances.
Triggered automaticity.
Abnormalities of Impulse Conduction:
Blocks.
Reentry.
Any disturbance in heart rhythm will affect the heart function
any disturbance in the electrical pathway
genetic causes of arrhymias or non-arrhythmias
two types of abnormalities:
electrical system in the SA , AV nodes or in ventrical and artrium
could be high or slow lead to tachycardia or bradycardia
heart blocks-----delay of transduction
abnormality in any part in the heart to produce actio potential
reciculation of cardiac action potential in the same place
Cardiac Causes of ArrhythmiasIschemic heart disease.
Inflammation.
Trauma e.g. heart surgery.
Congestive heart failure.
Hypotension.
October 19 3Munir Gharaibeh MD, PhD, MHPE
affect the muscleaffect the neuropathway
viral disease----causes ----endocarditis
having heart failure or maybe deathafter surgery
causing dialation , hypertrophy of the heart then cause heart failure
will affect baroreceptor---- to increase the heart rate--- then havingtachycardia
Non Cardiac causes ArrhythmiasElectrolyte imbalance.
Acid-Base imbalance.
Hypoxia.
Drugs:
– Digitalis
– Anesthetics
– Tricyclic
– Diuretics
– Bronchodilators: sympathomimetic.
Reflexes.
October 19 4Munir Gharaibeh MD, PhD, MHPE
most important cause-----> used in heart failure
antidepressant drug
useful in asthmawill stimulate the heart rate
such as GI reflexes , vasovegal reflexes--------> can cause bradycardia
lenovo
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October 19 5Munir Gharaibeh MD, PhD, MHPE
recording the heart electrical :1-indirect way -- ECG to record the heart rate2-direct way----electrons ----dont take place in humanonly in animals--as an experiment--
atrial contraction
ventrical contraction
repolarization
Ion Permeability Changes Potential Changes Genes and Proteins
October 19 6Munir Gharaibeh MD, PhD, MHPE
genes controll ofthe channels
ca current --- appears in phase 1,2,3
Na current -- starts at phase zero in a sudden way
they consumed energy -- found all over the bodysodium goes out , potassium enters
Cardiac Na+ channels
October 19 Munir Gharaibeh MD, PhD, MHPE 7
closed opene
-close from inside-no electrical activity-repolarization
lenovo
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lenovo
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lenovo
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lenovo
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October 19 Munir Gharaibeh MD, PhD, MHPE 8
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main channel Na+-termianated of the electricity-due to the different direction ofimpulses
- has important applicationin many drugs-main channel Ca+2
only phase 0,3,4NO--> 1,2all phases can be
found 1,2,3,4
lenovo
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lenovo
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October 19 Munir Gharaibeh MD, PhD, MHPE 9
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October 19 Munir Gharaibeh MD, PhD, MHPE 10
ability to produce (generate) impulses without any help--->by itself can generate impulses
Normal Circuitry
October 19 11Munir Gharaibeh MD, PhD, MHPE
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there are different direction of the impulsesthat will terminate the electricitywithout re-circulation
Re-entry Rhythm
October 19 12Munir Gharaibeh MD, PhD, MHPE
let's assume hera we have ischemiathat will block the pathway of some impulses leading to recirculation
here we have partial blockageto treat it we block whole areaby blocking Ca+2 channel