Page 193 - Critical Care Nursing Demystified

178 CRITICAL CARE NURSING DeMYSTIFIED

Sometimes you have early or late beats that can make the rhythm irregular.
These are called ectopic beats as they are usually generated from outside the
normal nerve conduction system of the heart. There are two types of ectopic
beats: premature or escaped beats. We call early beats premature beats as they
come before we anticipate them, just like a premature baby comes before those
nine months that the parents had anticipated him or her. In this case, the
P wave will be before the second caliper point. Interestingly, premature beats
can come in an organized pattern but throw the rhythm off. We have words to
describe these as well. They include
• Bigeminy – a normal beat, a premature beat (pattern of 1:1)
• Trigeminy – two normal beats, a premature beat (pattern of 2:1)
• Quadrigeminy – three normal beats, a premature beat (pattern of 3:1)

• Couplets – two premature complexes in a row
Occasionally, when the rate is very slow, another lower pacemaker can take
over, then your beats will come in later than anticipated. There will be a slow-
ing down of the rhythm because these beats come late. These we call escaped
beats. Because any cardiac cell can become a pacemaker, it makes interpreting
the rhythm a bit complicated. If you do not know exactly what you are seeing, 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.
the best advice is to describe it as best you can.

NURSING ALERT

No one is perfect, and if you give a strip to three different nurses, you might get three
different answers. The important thing is if you do not know what it is, go through the
organized assessment, using it to describe what you are seeing.

Step Four: Rhythm—Determine the Ventricular Rhythm

The ventricular rhythm is very similar to step three except now we see if the
QRS complexes all come in a regular pattern. This time we measure from one
QRS to another. This is sometimes called the R-to-R interval. The ventricular
rhythm in our strip in Figure 4–5 is regular.
Okay, we have now completed rate and rhythm; time to go on to conduction, for
which we will continue to use our paper OR calipers to determine time in seconds.

Step Five: Conduction—Measuring the PRI

Okay, we are almost done, and you have been really patient. We now have three
more steps to do and they all include using the calipers or paper to measure time