This study aims to describe the use of Cardiovascular Drugs in Pediatrics Cardiology unit Assiut University. As regard :

• indications of use .
• proper dosage.
• proper management of side effects of their use.

Arrhythmias occur in children and adolescents with congenital heart disease as well as those with structurally normal hearts. Antiarrhythmic medications primarily affect the ion channels in cardiac myocytes that are responsible for generating currents that create the action potential.

By altering the activity of these ion channels, the action potential is changed in an attempt to reduce the likelihood of sustained arrhythmias. There is awide range of antiarrhysmic drugs used in treatment Antiarrhysmics are therefore divided into five classes

Class I: Antiarrhythmics that affect sodium channels (slow depolarization) Class II: Drugs that counteract the sympathetic nervous system, predominantly beta-blockers Class III: drugs that affect the potasium channels ( prolong repolarization) Class IV: Drugs that affect calcium channels (Calcium channel blockers) Class V: Vagotonic drugs (Digoxin) and other miscellaneous drugs

Inclusion Criteria:

• All Patients with Arrhythmic cardiac diseases admitted at cardiology unit Assiut University Hospital aged from 1 month to 18 years

Exclusion Criteria:

• ● Patients with diseases rather than arrhythmic cardiac diseases

1- Patients' selection:- patients from 1 month age till 18 years on antiarrhythmic medications in Cardiology Unit Assiut University Hospital antiarrhytmic medications .