Cardiovascular Critical Care I

Supraventricular Tachyarrhythmias

Type

Rhythm

P-wave

Attributes

Atrial Rate

(beats/min)

Description

Multifocal atrial

tachycardias

(MATs)

Irregular

> 3 different

types of

distinct P

waves

100–130

Can be misdiagnosed as AF

Commonly associated with respiratory disease, HF,

critical illness

May be exacerbated by electrolyte abnormalities or

toxicity with digoxin or theophylline

Ventricular Arrhythmias

Type

Description

Premature ventricular

complexes (PVCs)

Results from an ectopic ventricular focus conduction that can be identified by the

lack of a preceding P wave. Commonly benign or asymptomatic but may be of

concern if present in patterns or in patients with advanced heart disease

Bigeminy: Every other beat is a PVC

Trigeminy: Every third beat is a PVC

Couplets: Patterns of two consecutive PVCs

Triplets: Patterns of three consecutive PVCs

Ventricular Arrhythmias

Type

Description

Ventricular

tachycardia (VT)

Potentially lethal wide QRS complex tachycardia characterized according to

morphology and duration; can degenerate into ventricular fibrillation (VF) or

asystole

Monomorphic VT: When every QRS complex appears the same and the rate is

regular (100–200 beats/min); commonly caused by reentry circuit related to

myocardial scar or fibrosis

Polymorphic: When the QRS complexes continually vary in shape and rate; most

commonly caused by myocardial ischemia, but other causes include multiple

ectopic foci or torsades de pointes from QT prolongation.

Non-sustained VT: Self-terminating episodes lasting for < 30 s

Sustained VT: If VT persists for more than 30 s, produces severe symptoms,

including syncope, or requires termination by administration of an

antiarrhythmic drug or direct cardioversion/defibrillation

VT storm: ≥ 3 episodes of sustained VT in a 24-h period

Ventricular fibrillation

(VF)

Life-threatening arrhythmia with a chaotic ECG with no discernible QRS,

representing rapid disorganized conduction with no resultant coordinated

ventricular contractions

aOther arrhythmias beyond the scope of this review include sick sinus syndrome (tachy-brady syndrome).

Management of tachyarrhythmias with a pulse includes the following strategies:

Stabilization of patient: See Figure 9

Atrial tachyarrhythmias

Appendix A)

2002;324:1264-7; BMJ 2002;324:1201-4; Circulation 2012;125:381-9; Heart Fail Rev 2014;19:285-93; J Am Coll

Cardiol 2018;72:1677-749) (continued)