STEP 2: CARDS: ArRyThMiAs Flashcards
(19 cards)
Supraventricular tachycardia (SVT)
A tachycardia originating in the following:
Sinus node
AV node
Atrial myocardium
Bundle of His above the bifurcation
What are the kinds of arrythmias included in SVTs?
Reentrant tachycardias: e.g., AVNRT, AVRT
Atrial tachycardias: focal AT, multifocal AT, Afib, Atrial flutter
Inappropriate sinus tachycardia
Junctional tachycardia
Paroxysmal SVT (PSVT)
Any SVT with a narrow QRS complex and an abrupt onset
Paroxysmal SVT, Most commonly caused by AV nodal reentry
an arrhythmia with an abrupt onset and termination that can last from seconds to days
Paroxysmal tachycardia
Atrioventricular nodal reentrant tachycardia (AVNRT);Caused by two alternative electrical pathways within the AV node, forming a reentry circuit. HR: 150–220/minute
Rhythm: regular
P wave: rarely visible
Acute management of stable patients includes vagal maneuveurs and adenosine
A class V anti-arrhythmic drug that causes a short-term heart block by slowing down conduction in the atrioventricular node. In reference to molecular biology, it is also a nucleoside unit in RNA that is derived from the purine adenine.
Adenosine
Atrial fibrillation with rapid ventricular response
6-lead ECG (paper speed 25 mm/s)
– Heart rate: ~135/min
– Irregularly irregular RR intervals (examples indicated by black overlay)
– Normal axis
– Absent P waves
– Coarse fibrillatory waves (f waves; examples indicated by red overlay) can be seen between the QRS complexes. These are characterized by low amplitude, high frequency, and irregular morphology, and should not be confused with P waves or flutter waves.
The absence of P waves with irregularly irregular RR intervals and an elevated heart rate indicates atrial fibrillation with rapid ventricular response.
The absence of P waves with irregularly irregular RR intervals and an elevated heart rate indicates
atrial fibrillation with rapid ventricular response.
12-lead ECG (paper speed: 25 mm/s)
– Regular sinus rhythm
– Rate 68/min
– Normal axis (R > S in leads I and aVF)
– Short PR interval (112 ms)
– Wide QRS complexes (126 ms) with delta waves (the slurred initial portion of the QRS complex; zoom box)
A short PR interval and widened QRS complexes with delta waves are the characteristic ECG findings of Wolff-Parkinson-White (WPW) syndrome. If seen in asymptomatic patients with no evidence of arrhythmia, this constellation of findings is referred to as the “WPW pattern”.
wide complex tachy
A category of tachyarrhythmias (i.e., pulse >100 bpm) characterized by a wide QRS complex (> 120 ms; or 3 small squares on the ECG). Includes monomorphic ventricular tachycardia, polymorphic ventricular tachycardia (e.g., torsades de pointes), supraventricular tachycardia with variable conduction (e.g., with bundle branch blocks or accessory pathways), pacemaker-associated tachycardia, and tachyarrhythmias caused by drugs or metabolic conditions that widen the QRS interval.
Multifocal atrial tachycardia
12-lead ECG (paper speed: 25 mm/s)
- Heart rate ∼ 160
- Irregularly irregular rhythm with wide variation in RR intervals (overlay) and variable PP, PR, and QT intervals
- ≥ P wave morphologies in the same lead (marked in rhythm strip II: normal, inverted, biphasic)
- Isoelectric baseline between P waves
- Narrow QRS complexes with similar morphology throughout
An irregularly irregular tachycardia with an isoelectric baseline and three or more distinct P wave morphologies in a single lead is consistent with multifocal atrial tachycardia.
Wide vs narrow tachy
wide is greater than 0.12 and narrow is less than 0.12
When assessing tachycardia, the EKG demonstrates regular rhythm with P waves visible & normal morphology, preceding every QRS. What kind of tachy is this?
regular ole’ Sinus Tachycardia
When assessing tachycardia, the EKG demonstrates P waves hidden or pseudo R’/S
AVNRT (most common regular SVT)
When assessing tachycardia, the EKG demonstrates P waves visible after QRS (retrograde)
Orthodromic AVRT, look at III in the image to see the retrograde p waves
When assessing tachycardia, the EKG demonstrates P waves visible before QRS, but abnormal morphology
Atrial Tachycardia
When assessing tachycardia, the EKG demonstrates Sawtooth flutter waves (often 150 bpm)
Atrial Flutter with 2:1 block
When assessing tachycardia, the EKG demonstrates No P waves, irregularly irregular
Atrial Fibrillation with RVR
When assessing tachycardia, the EKG demonstrates Multiple P wave morphologies, irregular?
Multifocal Atrial Tachycardia (MAT)
An irregularly irregular tachycardia with an isoelectric baseline and three or more distinct P wave morphologies in a single lead is consistent with multifocal atrial tachycardia.
