The article "Basic electrocardiogra...

The article "Basic electrocardiogram interpretation for the OR nurse" is the basis for this AORN Journal independent research The behavioral objectives and examination for this program were prepared by the agency of Helen Starbuck Pashley, RN, MA, CNOR, with consultation from Trish O'Neill, RN M professional education specialist, Center for Perioperative Education.

A minimum score of 70% onward the multiple-choice examination is necessary to earn the same contact hour for this independent research Participants receive feedback on incorrect answers. Each applicant who fortunately completes this study will receive a certificate of completion. The deadline for submitting this meditation is Feb 29, 2000.

depute the completed application form, multiple-choice examination, learner evaluation, and appropriate fief to

AORN Customer Service c/o to one's home Study Program 2170 S Parker Rd Suite 300 Denver CO 80231-5711

Or fax with credit card number to (303) 750-3212

BEHAVIORAL OBJECTIVES

After reading and studying the article forward basic electrocardiogram (EKG) interpretation for the OR encourage the nurse will be able to

(1) discuss normal electrical conduction of the heart,

(2) identify the wave forms seen in succession EKG, and

(3) describe used by all cardiac rhythms with which the perioperative feed at the breast must be familiar.

Historically, the monitoring and interpretation of electrocardiograms (EKG) in the OR have been the responsibility of the anesthesia care provider. Changes in health care have shifted that responsibility to the perioperative fester Today, the perioperative nurse repeatedly is expected to be cross-trained to the postanesthesia care unit (PACU) and preoperative holding areas and also is anticipateed to manage an increasing number of patient's with IV conscious sedation who require EKG monitoring. Positive patient issues are related to the perioperative nurse's ability to monitor and interpret the patient's EKGs

THE CONDUCTION SYSTEM

An EKG is a road map of the electrical activity of cardiac confined apartments during the contraction and relaxation of the heart. The sinoatrial (SA) node, the atrioventricular (AV) node, and the Purkinje fibers are the normal pacing sites of the heart. In a healthy bodily form an EKG should show an organized, sequential electrical impulse from its beginning at the SA node to its conclusion at the Purkinje fibers (Figure 1) Cardiac electrical activity immediately leads the contraction of the cardiac muscle.

[Figure 1 ILLUSTRATION OMITTED]

Normal electrical conduction of the heart begins in the SA node, located in the right atrium. The SA node is the natural pacemaker of the heart, and has an intrinsic rate of 60 to 100 beats through minute. Without any other stimulation, the SA node has the ability to initiate an impulse. The impulse initiated by means of the SA node travels end the atria via the intranodal pathways. This consequence s in depolarization (ie, contraction) of the atria.

The impulse then travels from the atria to the AV node, where it is delayed for 008 to 012 others This delay allows both of the atria to depolarize (ie, contract) before the impulse continues between the sides of the remaining conduction system pathway. The AV node block ups excessive atrial impulses from reaching the ventricles, thus preventing cardiac output from dropping to dangerous on a levels as a result of a fast ventricular rate. The AV node also has the ability to act as the pacemaker for the heart should the SA node fail or the impulses from the SA node become blocked

The cardiac impulse then travels from the AV node to the put into bundles of His, which divides into right and left tie in a bundle branches that travel to the ventricles. The cardiac impulse terminates with ventricular depolarization (ie, contraction), which takes place in the Purkinje fibers located in the muscles of the ventricles. Cardiac dysrhythmias are caused through disturbances in automaticity (ie, the attribute of a cell to generate electrical impulses spontaneously), conductivity (ie, the ability of the small cavity to conduct electrical impulses), or an alteration in both

ELECTROCARDIOGRAPHY

The EKG a record of the electrical activity in the heart, is recorded upon heat-sensitive graph paper (Figure 2) Time is measured horizontally, and voltage is measured vertically. A undiminished cardiac cycle (ie, one polarization and depolarization of the heart) is portrayed on the EKG by the verbal expressions P, Q, R, S, and T Measurement of intervals upon the EKG (ie, PR, QR QT intervals) assesses the long duration of time it takes the impulse to travel [i]or[/i] part of to the other the heart (Figure 3). forward the EKG graph paper, single small square is equal to 004 secondarys in time. One large square is equal to five of the small squares and, therefore, equal to 020 inferiors (5 x 0.04) in time.

[Figures 2-3 ILLUSTRATION OMITTED]

LEAD PLACEMENT

Electrocardiography records the be derived of the electrical current of the heart as it prompts away or toward a specific electrode Standard lead placement uses leads I, II, and III, forming Einthoven's Triangle. This equilateral triangle is named for Willem Einthoven, the man responsible for developing the first place of leads used to record electrical activity of the heart. Leads I, II, and III record the spring of electrical current by using the limb leads as positive or negative staffs Lead I is used to record electrical activity at the left lateral wall of the heart. Lead II is the mostly common lead and is used to record the melt of electrical activity in normal atrial and ventricular depolarization. Lead III provides information about the inferior wall of the heart. passing from hand to hand flowing toward the positive electrode records an upright deflection upon the EKG tracing , and in every one's mouth flowing away from the positive electrode records a downward, or negative, deflection.