Tachy-Arrhythmias

Question 1

Sinus tachycardia

Answer 1

Regularity
-regular

Atrial rate
-100-180

Ventricular rate
-100-180

Origin
-Sinus node

P wave
-precedes every QRS

Adenosine
-gradual slowing

Question 2

Atrial fibrillation

Answer 2

Regularity
-irregularly irregular

Atrial rate
-400-600

Ventricular rate
-75-175

Origin
-atria

P waves
-absent

Adenosine

• slows regular
• irregularity remains

Question 3

Atrial flutter

Answer 3

Regularity

• regular
• sometimes alternating block

Atrial rate
-250-350

Ventricular rate

• 75-150
• 3:1 or 2:1 block is most common

Origin
-tricuspid annulus

P waves
-saw tooth in II

Adenosine
-reduces conduction eg 4:1

Question 4

AVNRT

Answer 4

Regularity
-regular

Atrial rate
-180-250

Ventricular rate
-180-250

Origin
-AV node

P waves
-in QRS complex

Adenosine
-stops

Question 5

Atrial tachycardia

Answer 5

Regularity
-regular

Atrial rate
-120-250

Ventricular rate
-75-200

Origin

• atria, not SA node
• focal or multi focal

P waves

• precedes QRS
• not sinus morphology
• single morphology in focus, varying morphology in multi focal

Adenosine
-temporary AV block

Question 6

AVRT

Answer 6

Regularity
-regular

Atrial rate
-150-250

Ventricular rate
-150-250

Origin

• Orthodromic: AV node -> ventricles -> accessory pathway -> AV node
• Antidromic: AV node -> accessory pathway-> ventricles -> AV node

P waves
-Orthodromic: retrograde, RP

Question 7

AV junctional tachycardia

Answer 7

Regularity
-regular

Atrial rate
-60-100

Ventricular rate
-70-130

Origin
-AV node

P waves
-RP

Question 8

SVT with a errands

Answer 8

Regularity
-depends on SV rhythm

Atrial rate
-100-250

Ventricular rate
-75-200

Origin
-atria

P waves
-absent

QRS

• wide
• LBBB or RBBB morphology

Adenosine
-temporary increase in block