A Fib Flashcards
What is the greatest adverse effects of antiarrhythmic drugs?
Arrhythmia
SHould all arrhythmias be treated?
No
What are the 2 main goals of arrythmia pharmacotherapy?
Control heart rate
Control coagulation
____ is a measure of conduction time from atrium to
ventricle
PR interval
_________ indicates the time required for all of the
ventricular cells to be activated
he QRS duration
_____ reflects the duration of the ventricular action
potential
he QT interval
What are the 2 disturbances that all arrhythmias result from?
(1) disturbances in impulse formation
(2) disturbances in impulse conduction
What is one of the most common risks of a fib that is untreated?
Cerebral ischemia/stroke via blood clot due to a fib
- characterized by disorganized, rapid, and
irregular atrial activation with loss of atrial
contraction and with an irregular ventricular
rate that is determined by AV nodal conduction - the ventricular rate tends to be rapid and
variable, between 120 and 160 beats/min, but
in some patients, it may exceed 200 beats/min - patients with high vagal tone or AV nodal
conduction disease may have slow ventricular
rates
A fib
— episodes that start spontaneously and stop
within 7 days of onset
— often initiated by small reentrant or rapidly
firing foci in sleeves of atrial muscle that extend
into the pulmonary veins (PV)
— catheter ablation that isolates these foci usually
abolishes paroxysmal AF, although some
patients also have initiating foci in other
locations.
Paroxysmal A fib
What is typically present in persistent a fib?
Fibrosis
What other heart condition is common to increase the risk for?
Heart failure
▪ Signs & Symptoms
* irregular and rapid heartbeat
— wearables helping to identify
* heart palpitations or rapid thumping
inside the chest
* dizziness, sweating and chest pain or
pressure
* shortness of breath or anxiety
* tiring more easily when exercising
* fainting (syncope)
A fib
What is the class 1 Singh/Vaughan-Williams (Mechanism-
Based) Classification used to treat a fib?
Na channel blocker
Lidocaine
What is the class 2 Singh/Vaughan-Williams (Mechanism-
Based) Classification used to treat a fib?
Beta blocker
Esmolol
What is the class 3 Singh/Vaughan-Williams (Mechanism-
Based) Classification used to treat a fib?
Potassium blocker
amiodarone
What is the class 4 Singh/Vaughan-Williams (Mechanism-
Based) Classification used to treat a fib?
Calcium blocker
Dilatezem
What are the most common types of drugs due to increased effects to help control ventricular rate by slowing av node conduction?
Beta blockers: Esmolol
Calcium blockers: Dilatezem
Which agents prolong action potentials and block potassium channels?
Amiodarone
— can be useful to lessen stress and anxiety that may come from anticipation of a dental procedure
* perhaps prevent/reduce increased release of catecholamines that can exacerbate AFib or other arrhythmias
— diazepam, alprazolam, lorazepam, etc
anxiolytics
— non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin
— interfere with anticoagulants that are highly bound to plasma proteins (e.g. warfarin)
analgesics
- can signficiantly inhibit cytochromes P-450 in liver and GI tract
macrolide antibiotics (e.g. erythromycin, azithromycin, clarithromycin)
- can inhibit the organic cation transporter in the kidney to inhibit renal elimination of some drugs
trimethoprim (e.g. sulfamethoxazole-trimethoprim)
- many potential adverse effects
- can inhibit cytochromes P-450 and some can affect cardiac ion currents
fluoroquinolones (e.g. ciprofloxacin, ofloxacin, levofloxacin)
