Term
| Treatment options for arrhythmias |
|
Definition
| devices (pacemaker/defibrillator), surgery, drugs |
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|
Term
|
Definition
| unidirectional block, retrograde conduction, conduction time>ERP |
|
|
Term
|
Definition
| slowing AP conduction so that retrograde impulses meet refractory tissue |
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|
Term
| Drugs exhibiting use dependence (anti-arrhythmics) |
|
Definition
| Na channel blockers, Ca channel blockers |
|
|
Term
| K+ channel blockade molecular changes |
|
Definition
| Prolongs repolarization, increases ERP, slows AP conduction, stops reentry |
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|
Term
| Class I antiarrhythmics: target |
|
Definition
|
|
Term
| Class IA antiarrhythmics: target |
|
Definition
| Na and K channel blockers |
|
|
Term
| Class I antiarrhythmics: pharm effects |
|
Definition
| Use dependence, slowed AP conduction abolishes reentry, block of diastolic current suppresses ectopic pacemakers |
|
|
Term
| Class I antiarrhythmics: uses |
|
Definition
| atrial reentrant arrythmias, ventricular reentrant arrythmias. Use is decreasing because of toxicity |
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|
Term
| Class I antiarrhythmics: types |
|
Definition
| procainamide (IA), lidocaine (IB), flecainide (IC) |
|
|
Term
| Class I antiarrhythmics: adverse effects |
|
Definition
| CNS (headache, dizziness, tinnitus), torsade de pointes, ventricular arrythmias, myocardial depression, muscarinic blockade->enhanced AV conduction, a-adrenergic blockade->hypotension, lupus-like syndrome (procainamide). High K+ enhances the toxicity of Na channel blockers because it produces partial membrane depolarization-->more channels in the inactivated state. |
|
|
Term
| Class II antiarrhythmics: types |
|
Definition
| Propranolol, metopronol, Esmolol, acebutolol |
|
|
Term
| Class II antiarrhythmics: useful effects |
|
Definition
| block of catecholamine induced cardiac effects, suppression of ectopic pacemakers, slowed AV conduction |
|
|
Term
| Class II antiarrhythmics: uses |
|
Definition
| catecholamine induced arrhythmias, slowing ventricular rate during atrial tachycardias, post MI suppression of ectopic pacemakers |
|
|
Term
| Class III antiarrhythmics: types |
|
Definition
|
|
Term
| Class III antiarrhythmics: target |
|
Definition
|
|
Term
| Class III antiarrhythmics: adverse effects |
|
Definition
| reverse use dependence, torsade de pointes, B-block (sotolol)->heart block, bronchospasm, hyptension |
|
|
Term
| Class III antiarrhythmics: uses |
|
Definition
| arrhythmias that are refractory to other safer drugs |
|
|
Term
|
Definition
| verapamil (Ca channel blocker) |
|
|
Term
| Class IV drugs: mechanism |
|
Definition
| blockade of Ca channels in the SA and AV node |
|
|
Term
|
Definition
|
|
Term
| Class IV drugs: pharm effects |
|
Definition
| Abolishes reentry in Ca dependent cells, suppresses ectopic pacemakers if due to Ca |
|
|
Term
| Class IV drugs: adverse effects |
|
Definition
| myocardial depression, CHF, SA and AV node depression (symptomatic bradycardia) |
|
|
Term
|
Definition
| AV nodal reentry tachycardia, slowing the ventricular rate in atrial flutter or fib |
|
|
Term
|
Definition
| purinergic receptors, type I |
|
|
Term
| Adenosine: useful effects |
|
Definition
| increases outward K+ to hyperpolarize the membrane, decreases inward Ca current |
|
|
Term
|
Definition
|
|
Term
| Adenosine: adverse effects |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| AV nodal rentry tachycardia |
|
|
Term
|
Definition
| K, Na, Ca channels and b-receptors |
|
|
Term
|
Definition
|
|
Term
| Amiodarone: pharm effects |
|
Definition
| slowed conduction abolishes reentry, reduced inward diastolic current decreases ectopic automaticity |
|
|
Term
| Amiodarone: adverse effects |
|
Definition
| bradycardia, myocardial depression, CHF, pulmonary fibrosis, hepatocellular necrosis, neurological effects, thyroid dysfunction, microcrystalline deposits in the skin and cornea |
|
|
Term
|
Definition
| 5-10 day half life, metabolized by CYP3A4 |
|
|
Term
|
Definition
| arrhythmias resistant to other drugs, VT/VF, other arrhthmias |
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