Page 204 - Critical Care Nursing Demystified

Chapter 4 CARE OF THE PATIENT WITH CRITICAL CARDIAC RHY THM DISTURBANCE NEEDS 189

They can also be named according to what they look like. There can be
• Unifocal or uniform – all looking alike

• Multifocal or multiform – all looking different
• Couplets – two in a row
• R on T phenomena – PVCs falling on top of the T wave

NURSING ALERT

PVCs can cause decreased cardiac output and multiple PVCs per minute, those falling
on the T wave and multifocal PVCs can cause advanced irritability, watch out for
their occurrence. Advanced irritability leads to more lethal rhythms where there is no
cardiac output.

Ventricular Tachycardia (VT)
This rhythm is one that can lead to cardiac arrest. VT occurs when there are more
than three PVCs occurring in a row. VT can have a pulse but may not have one, so
it important to assess the patient when you see this on the cardiac monitor.
• RATE: No atrial; ventricular is 100 to 250. Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
• RHYTHM: Ventricular rhythm is regular.
• CONDUCTION: PRI is absent; QRS is wide and bizarre. QT is there but
difficult to measure.

NURSING ALERT
Always assess the patient for a pulse or the absence of a pulse in this rhythm; the
treatment depends on this. Check the electrolytes for imbalances, too.

Ventricular Fibrillation (VF)
Ventricular fibrillation occurs when there is electrical activity but with no
regular form. The rhythm is chaotic with no discernible wave forms that occur.
It is often caused by a large MI and is the most frequent cause of cardiac arrest.
Clinically, without a cardiac monitor, the critical care nurse cannot tell VF from
asystole. There is no pulse or breathing with VF, so the protocol for cardiac
arrest is initiated with defibrillation as soon as possible.
• RATE: Atrial rate is not countable; ventricular rate is chaotic or has no
characteristics of ventricular depolarization.
• RHYTHM: Extremely irregular with no discernable rhythm.

• CONDUCTION: No conduction intervals measurable.