Ajmaline

An alkaloid used in the treatment of cardiac arrhythmias

Ajmaline
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Ajmaline is an alkaloid used primarily in the treatment of cardiac arrhythmias. It is derived from the roots of the plant Rauvolfia serpentina and is known for its ability to block sodium channels in the heart, which helps to stabilize the cardiac action potential.

Pharmacology

Ajmaline is classified as a Class Ia antiarrhythmic agent according to the Vaughan Williams classification. It works by inhibiting the fast inward sodium current in cardiac cells, which prolongs the action potential duration and refractory period. This action helps to prevent abnormal electrical activity in the heart that can lead to arrhythmias.

Clinical Use

Ajmaline is used in the diagnosis and treatment of certain types of ventricular arrhythmias, particularly in conditions such as Brugada syndrome. It is often administered intravenously in a hospital setting due to its potent effects and the need for careful monitoring of the patient's electrocardiogram (ECG).

Mechanism of Action

Ajmaline blocks the sodium channels in the heart, which are responsible for the rapid depolarization phase of the cardiac action potential. By inhibiting these channels, ajmaline slows down the conduction of electrical impulses through the heart, which can help to restore normal rhythm in cases of arrhythmia.

Side Effects

Common side effects of ajmaline include hypotension, bradycardia, and dizziness. Due to its effects on cardiac conduction, it can also cause proarrhythmia, which is the induction of new arrhythmias. Therefore, its use is typically restricted to controlled environments where patients can be closely monitored.

Brugada Syndrome

Ajmaline is particularly useful in the diagnosis of Brugada syndrome, a genetic disorder that can lead to sudden cardiac death. In patients suspected of having Brugada syndrome, an ajmaline challenge test may be performed. This involves administering ajmaline and monitoring the ECG for characteristic changes, such as the "coved" ST-segment elevation in the right precordial leads.

Related Pages

• Antiarrhythmic agent
• Brugada syndrome
• Sodium channel
• Cardiac arrhythmia

Gallery

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  Ajmaline in crystalline form

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  Normal sinus rhythm

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  ECG changes in Brugada syndrome

Ajmaline

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  Chemical structure of Ajmaline

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  3D model of Ajmaline from crystal structure

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  Ajmaline

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  Labeled diagram of sinus rhythm

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  Brugada syndrome EKG schema