Arrhythmias Flashcards
Clinical uses of beta-blockers for arrhythmias
-arrhythmias involving catecholamines
-atrial arrhythmias
-post-MI prevention of ventricular arr.
-prophylaxis in long-QT syndrome
Clinical uses of Ca channel blockers for arrhythmias
-block re-entrant arrhythmias involving AV node
-protect ventricular rate in atrial flutter/Afib
What part of the heart creates the heart rate?
SA node
AFib Stage 3A =
paroxysmal - intermittent and terminates within ≤ 7 days of onset
AFib Stage 3B =
persistent - continuous and sustains for > 7 days and requires intervention
AFib Stage 3C
long-standing persistent = continuous for > 12 months
AFib Stage 3D =
successful ablation - freedom from AF after percutaneous or surgical intervention
AFib stage 4 =
permanent afib - no further attempts at rhythm control
Afib symptoms
palpitations, dizziness, fatigue, lightheadedness, SOB, hypotension, syncope, angina
Oral anticoagulants are recommended for patients with Afib and CHADS-VASC score of… (men and women)
men: ≥ 2
women: ≥ 3
Warfarin in ONLY preferred for afib patients when….
-patient has mechanical heart valve
-afib is associated with heart valve disease
otherwise DOAC is preferred
Warfarin or apixaban is preferred in what patients with afib?
end-stage CKD (CrCl < 15)
or
hemodialysis
What afib drugs for ventricular rate control have direct AV node inhibition?
-diltiazem
-verapamil
-beta-blockers
-digoxin
What 5 drugs are used for conversion to sinus rhythm?
-amiodarone
-ibutilide
-procainamide
-flecainide
-propafenone
What 6 drugs are used for maintenance of sinus rhythm?
-amiodarone
-dofetilide
-dronedarone
-sotalol
-propafenone
-flecainide
Amiodarone adverse effects (6)
-hypo/hyperthyroidism
-hepatotoxicity
-QT interval prolongation
-pulmonary fibrosis
-corneal microdeposits
-derm: blue/grey skin, photosensitvity
Describe SVT
regular rhythm
narrow QRS complexes
HR = 110-225 BPM
spontaneous initiation and termination
What drugs are used for termination of SVT?
adenosine
B-blockers
verapamil + diltiazem
What is the MOA for the drugs used for termination of SVT?
-inhibit AV node conduction
-terminates re-entrant pathway
What does VFib look like on an ECG?
irregular, disorganized electrical activity - no recognizable QRS complexes
The only effective treatment for Vfib is….
defibrillation
(drugs are only used to facilitate defibrillation, will not terminate Vfib alone)
Clinical features of Afib
Rhythm is irregularly irregular
P wave absent
No atrial depolarizations
Ventricular rate = 120-180bpm
Afib mechanisms
abnormal atrial/pulmonary vein automaticity
atrial reentry
supraventricular tachycardia predominant mechanism of reentry
AV node (60%)
Clinical features of ventricular tachycardia
regular rhythm
wide QRS complexes (PVCs) ≥ 3 consecutively
HR > 100 bpm
