TACHYDYSRHYTHMIAS

Question 1

MANAGEMENT: UNSTABLE TACHYDYSTHYTHMIAS

Answer 1

Check alertness / responsiveness
Check Pulse
Check Breathing

1. IV Access, Oxygen, Monitor, Pads, resuscitation cart and airway equipment at bedside
2. ASSESS STABILITY:
   Altered Mental Status
   Hypotension (SBP < 90)
   Mottling
   Ischemic Chest Pain
   Dyspnea from Pulmonary Edema
   Ventricular rates approaching 300
3. P Waves?
   p waves = sinus rhythm
4. Regular or Irregular?
5. QRS Wide (>/0.120 ms) or QRS Narrow (<0.120 ms)?
   WPW Afib?

UNSTABLE TACHYDYSRHYTHMIA OR STABLE VT: SYNCHRONIZED

Narrow Regular: 100 - 200 J Biphasic

Narrow Irregular: 150 - 200 J Biphasic

Stable Wide Regular: 100 - 200 J Biphasic

Unstable Wide Regular: 200 J biphasic. If unsuccessful, defibrillate

Wide Irregular: defibrillation

CHEMICAL CARDIOVERSION OF STABLE MONOMORPHIC VT:

Chemical cardioversion of stable monomorphic ventricular tachycardia

Procainamide 20-50 mg/min or 100 mg IV q5min until hypotension, dysrhythmia terminated, or QRS widens by more than 50% (max of 17 mg/kg)

Amiodarone IV bolus 150 mg IV over 10 min followed by continuous infusion at 1 mg/min IV × 6 h then 0.5 mg/min × 18 h (MAX 2.2 g/24 h)
Bedside Ultrasound: LV function

OTHER:

Consider trial of Calcium Chloride 1 g IV bolus for hyper K

Assess QT after cardioversion for polymorphic VT. Give 2 g magnesium for prolonged QT. Normal QT give amiodarone

Emergent coronary angiography for Refractory VT secondary to ACS

LABS:
Electrolytes
Extended lytes
Troponin

Question 2

DDx

Answer 2

NARROW REGULAR
Sinus Tachycardia
Orthodromic WPW
SVT (AVNRT)
Atrial Flutter 2:1

NARROW IRREGULAR
Multifocal Atrial Tachycardia
Afib
Atrial Flutter with Variable Block

WIDE REGULAR
Antidromic WPW
Monomorphic VT
SVT with Abberancy

Consider hyperkalemia, acidosis, Na channel blockade

QRS > 140 ms is more likely VT

In the abscence of underlying medical causes, assume VT unless proven otherwise

WIDE IRREGULAR OR POLYMORPHIC COMPLEX (BEAT TO BEAT VARIATION IN QRS)
Afib with Aberrancy (MCC)
Polymorphic V Tachor Torsades
WPW with AFib

Question 3

MANAGEMENT: STABLE NARROW REGULAR

Answer 3

Modified Valsalva Maneuver

Adenoside (if regular):
First dose 6 mg rapid IV push, followed by NS flush

Second dose 12 mg if required

Diltiazem: 10-20 mg IV over 2 minutes
OR
2.5 mg / min (max 60 mg in 30 min)

Cardioversion 25-100 J biphasic

Question 4

MANAGEMENT: STABLE NARROW IRREGULAR

Answer 4

AFib & AFlutter:
Metoprolol 2.5-5 mg IV, 25-50 mg PO
OR
Diltiazem: 10-20 mg IV over 2 minutes
2.5 mg / min (max 60 mg in 30 min)
OR
Cardioversion 150-200 J biphasic

MAT: Treat underlying cause

Question 5

MANAGEMENT: STABLE WIDE REGULAR

Answer 5

Cardioversion:
100 J Biphasic

Consider adenosine only if regular and monomorphic

Consider antiarrythmic: Procainamide
15-17 mg/kg IV at a rate of 20 to 50 mg/min over 30 min until arrythmia suppressed, hypotension ensues, QRS duration increases > 50%, or max dose 17 mg/kg given

Infusion: 1 - 4 mg / min, avoid if prolonged QT or CHF

Amiodarone
First dose 150 mg over 10 min

Repeat as needed if VT occurs

THEN
360 mg IV infusion over 6 hrs
THEN
540 mg IV infusion over 18 hrs
Consider expert consultation

Question 6

MANAGEMENT: STABLE WIDE IRREGULAR OR POLYMORPHIC COMPLEX (BEAT TO BEAT VARIATION IN QRS)

Answer 6

Afib with Aberrancy:
AV nodal blocking agent
Cardioversion 200 J

Polymorphic VTach / Afib WPW:

DO NOT GIVE AV BLOCKING AGENTS

ASSUME AFIB WITH WPW

2 g magnesium

Cardioversion 200 J, if unsuccessful defibrillate