Arrhythmias - Therapy Flashcards
<p>What is an arrhythmia?</p>
<p>–Any deviation from the normal rhythm of the heart</p>
<p>•<strong>Sinus arrhythmia</strong></p>
<p><strong>•Supraventricular arrhythmia</strong></p>
<p>–Atrial fibrillation</p>
<p>–SVT (junctional)</p>
<p><strong>•Ventricular arrhythmia</strong></p>
<p>–Ventricular tachycardia</p>
<p>–Ventricular fibrillation</p>
<p>•(<strong>Heart block)</strong></p>
<p>What is heart block?</p>
<p>Heart blockis an abnormalheartrhythm where theheartbeats too slowly (bradycardia). In this condition, the electrical signals that tell theheartto contract are partially or totally blocked between the upper chambers (atria) and the lower chambers (ventricles).</p>
<p>How are the electrical signals different in atrial fibrillatino?</p>
<p>Electrical signals are disorganised in atrial fibrillation</p>
<p>What is the pathology associated with this ECG?</p>
<p>Ventricular fibrillation</p>
<p>Note - P waves are absent</p>
<p>What is the pathology associated with this ECG?</p>
<p>Ventricular tachycardia</p>
<p>What is the pathology associated with this ECG?</p>
<p>Atrial fibrilaltion</p>
<p>What is responsible for the uneven distribution of ions which accounts for the uneven resting membrane potential?</p>
<p>•Sodium-potassium ATPase pump</p>
<p>What causes myocardial muscle to contract?</p>
<p>Movement of ions across the myocyte cell membrane - propagation of an electrical impulse - leads to myocardial muscle contraction</p>
What are the different phases of the action potential?
<p>What are the different classes of drugs that are used to treat arrhythmias?</p>
<p>•Class 1</p>
<p>–Class Ia</p>
<p>–Class Ib</p>
<p>–Class Ic</p>
<p>•Class II</p>
<p>•Class III</p>
<p>•Class IV</p>
<p>•Other</p>
What are class 1 anti arrhythmic drugs?
<p>What is the action of Class 1 a drugs?</p>
<p>Block sodium channels</p>
<p>Delay repolarisation</p>
<p>Increase action potential duration</p>
<p>What can class 1 a drugs be used for?</p>
<p>AF</p>
<p>Premature atrial/ventricular contractions</p>
<p>Ventricular tachycardia</p>
<p>Wolff-Parkinson-white syndrome</p>
<p>Name some class 1 a drugs</p>
<p>Disopyramide</p>
<p>What are the actions of 1 b drugs?</p>
<p>Block sodium channels</p>
<p>Accelerate repolarization</p>
<p>Decrease the action potential duration</p>
<p>What can class 1 b drugs be used for?</p>
<p>Used for ventricular dysrhythmias only (premature ventricular contractions, ventricular tachycardia, ventricular fibrillation)</p>
<p>What are the common type 1b drugs?</p>
<p>phenytoin, lidocaine</p>
<p>What is the effect of class 1c drugs?</p>
<p>•Block sodium channels (more pronounced effect)</p>
<p>•Little effect on action potential duration or repolarization</p>
What are class 1 c drugs used for?
Severe ventricular dysrhythmias
May be used in atrial fibrillation/flutter
<p>What are class 1 c drugs used for?</p>
<p>Severe ventricular dysrhythmias</p>
<p>May be used in atrial fibrillation/flutter</p>
<p>Give an example of a class 1 c drug</p>
<p>Flecainide</p>
<p>What are the Class 2 drugs?</p>
<p>Beta Blockers</p>
<p>What stage of the heart cycle do beta blockers act on?</p>
<p>Phase 4 depolarisation</p>
<p>What is the effect of beta blockers on the transmission of impulses in the heart?</p>
<p>Reduces thetransmission of impulses in the heart’s conduction system</p>
<p>What type of heart dysrhythmia are beta blocers used for?</p>
<p>•General myocardial depressants for both supraventricular and ventricular dysrhythmias</p>
<p>•Now first line for atrial fibrillation (Bisoprolol)</p>
<p>What are examples of beta blockers?</p>
<p>Atenolol and Bisoprolol</p>
<p>What are class 3 drugs?</p>
<p>Amiodarone and sotalol</p>
<p>What stage of the action potential do amiodarone and sotalol funciton in?</p>
<p>•Increase action potential duration</p>
<p>•Prolong repolarization in phase 3</p>
<p>What type of dysrhythmia is amiodarone and sotalol used for?</p>
<p>•Used for dysrhythmias that are difficult to treat</p>
<p>•Life-threatening ventricular tachycardia or fibrillation, atrial fibrillation or flutter—resistant to other drugs</p>
<p>Sustained ventricular tachycardia</p>
<p>What are type 4 drugs?</p>
<p>Calcium channel blockers</p>
<p>What stage of the actionpotential do calcium channels function in?</p>
<p>Depress phase 4 depolarisation</p>
<p>What type of dysrhythmia are CCB's used for?</p>
<p>•Used for paroxysmal supraventricular tachycardia; rate control for atrial fibrillation and flutter</p>
<p>What drugs are Antidysrhythmics but don't fit into one particular class?</p>
<p>Digoxin, adenosine</p>