Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Pllana, Q.
Drug Treatment of Cardiac Arrhythmias
Humanmedizin; [ Diplomarbeit ] Medical University of Graz; 2014. pp. 68
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Donnerer Josef
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- Abstract:
- Unlike other muscles in the body which depend on nerve connections to receive electrical impulse, the heart has its own electrical generator called ”Sinus Node". The sinus node is responsible for an impulse generation that spreads in regular way through the heart, synchronizing the heart rate and cardiac output depending from body requirements. Any factor that causes dysfunction on the impulse generation or dysfunction on impulse conduction can lead to arrhythmia. Cardiac arrhythmias can affect any age. Most of the cardiac arrhythmias are harmless, but some of them can be life threatening such as ventricular fibrillation, which is the most common cause of cardiac arrest resulting in sudden cardiac death. Diagnosis of disorders and treatment with antiarrhythmic medications are essential in order to prevent further complications of cardiac arrhythmia. The main point of this research is to understand what is the role of antiarrhythmic medications, how do these medications affect heart rate including their detailed mechanism of action, potential dangerous side effects, and the potentially dangerous interactions between antiarrhythmic drugs and other drugs. This thesis is based on the existing research literature. For this purpose various resources were used such as pharmacology textbooks, journals, publications, literature-databases (PubMed) and internet sources. Antiarrhythmic drugs achieve their effect by blocking receptors or ion channels in the heart. In 1970 Vaughan Williams classified the antiarrhythmic drugs into four classes: Class I-Na+ channel blockers; Class II- ß blockers; Class III-K+ channel blockers; Class IV-Ca2+ channel blockers.The class I and III were mainly used as cardioversion agents while the class II and IV were used to control and maintain the heart rate. The most important ones are the class III antiarrhythmic drugs because they block many receptors at the same time, thus terminating many of the arrhythmia disorders. Such interference with receptors and ion channels may not only terminate cardiac arrhythmias, but it can also provoke them. Their pharmacokinetics as well as their pharmacodynamics must be taken into consideration, especially in co-morbid patients, because the risk of interactions between these drugs is very high. The use of the antiarrhythmic drugs was limited due to their cardiac and system toxicity; only some of them were continuously used for more than 20 years. The novel antiarrhythmic drugs are more specific than the older ones, although they have much of the same efficacy as the old ones. A new generation of antiarrhythmic drugs promises more specificity and efficiency as well as less adverse effects.