Clinical Treatment of Arrhythmias Flashcards
Sinus bradycardia is defined as a heart rate less than ____________.
55 bpm
Sinus node arrest results in ____________.
temporary cessation of any depolarization
Chronotropic incompetence is ___________.
the inability of the heart to increase its rate in response to increased stress
A Mobitz 1 block results in _____________.
progressively prolonged PR interval until a ventricular beat is lost
A Mobitz 2 block block results in ___________.
periodically missed QRS wave with constant PR intervals
In what two scenarios would you treat bradycardia?
(1) when patients are symptomatic–regardless of the location of the block; and (2) when the rhythm is infranodal
How should bradyarrhythmias be treated?
(1) by addressing the underlying cause–such as Lyme disease, hypothyroidism, ischemia, or neurologic issues; (2) by withdrawing the offending medication; (3) addressing acute problems with ß-agonists or transcutaneous pacing; and (4) implanting pacemakers
What is MAT?
Multifocal atrial tachycardia; a form of atrial tachycardia characterized by multiple ectopic sites of pulse initiation; this is diagnosed by multiple morphologies of P waves on an ECG
Cardiologists treat irregular supraventricular tachycardia with _____________.
shock (only when the patient is symptomatic and unstable), rate control, anti-arrhythmics, or cardioversion
Cardiologists treat regular supraventricular tachycardias with __________.
adenosine, class I antiarrhythmics, calcium-channel blocks, or vagal maneuvers (to slow the conduction); and ablation of the errant pathways
How does adenosine work?
It slows conduction to the AV node.
AVNRT is __________.
Atrioventricular node re-entrant tachycardia
AVNRT results from ______________.
re-entry of depolarization through the slow pathway that some people have
AVRNT will display a ___________ ECG pattern.
additional P wave buried in the right side of the QRS wave
What are accessory pathways?
Pathways that connect the atria to the ventricles, allowing propagation from the atria to pre-excite part of the ventricles.
What is AVRT?
Atrioventricular re-entrant tachycardia; a form of arrhythmia that results from accessory pathways.
What is the ECG pattern of AVRT?
A delta wave–a slightly wider QRS wave, but only in the beginning
What causes AT?
Atrial tachycardia results from extra hotspots of automaticity within the atria.
What are the three types of bradyarrhythmias?
AV block, bundle blocks, and SA node malfunction
What is the only longterm treatment for bradycardiac arrhythmias?
Pacemakers
Other than junctional rhythm, what can cause an ECG without P waves?
1:1 atrial flutter or AV-nodal re-entrant tachycardia
Hyperthyroidism can cause ______________.
atrial fibrillation
Class IC agents are contraindicated in ______________.
those with coronary artery disease
Those who have ventricular tachycardia who are unstable should be ___________ while those who are stable should receive ___________.
shocked; amiodarone, lidocaine, or procainamide
If ventricular tachycardia does not arise from structural heart disease (like CHF), then the cause is either _______ or ________.
idiopathic; due to a focal arrhythmogenic trigger
Defribllators are only given to those with ventricular tachycardia if _______________.
they have had prior cardiac arrest or have concurrent heart disease
What is Wolf-Parkinson-White syndrome?
AVRT–a form of regular supraventricular tachycardia that leads to a delta wave; delta waves are slower upstroke of QRS
