Heart Identify the Basic Anatomy

Heart

Identify the basic anatomy and physiology of the heart- the human heart is actually a muscular organ that serves to pump blood through the body (circulation). It is divided into four main chambers -- the two upper are the left and right atria, the two bottom the left and right ventricle. The septum, or a thick wall of muscle, separates the right and the left side of the heart. In normal function, with each contraction (beat) of the heart, the right ventricle pumps oxygenated blood from the lungs into the left ventricle, which then pumps into the body. The heart is powered by electrical energy from the sinoatrial node which transfers the energy into the ventricles . Normally about the size of a fist, the human heart averages between 250-250 grams. It is enclosed in a protective sac that protects the heart, anchors its surrounding structures and prevents the overfilling of blood. The cycle of moving oxygenated blood into the tissues, releasing the oxygen, then returning to the lungs to be reoxygenated is called the circulatory process (MacDonald, 2009).

Identify indication for ECG -- Electrocardiography is a system in which the electrical impulses from the heart are measured by attaching amplifying sensors to the skin in different positions on the body to measure cardiac activity as the blood is pumped throughout the body. Indications for ECG are numerous: regular check-up and review; heart murmurs; seizures, perceived cardiac dysrhythmia, symptoms of infarction (numbness, fainting, pain in the chest) (Your Heart's Electrical System, 2009).

Describe electrode position for 12 leads ECG equipment -- Ten Electrodes are used for a 12-node ECG. These are placed according to the following table:

Electrode Label (U.S.A.)

Electrode Placement

RA

Right Arm, avoid thick muscle

LA

Let Arm, avoid thick muscle

RL

Right leg, lateral calf

LL

Left leg

V1

Fourth intercostal space, between ribs 4/5, to right of sternum

V2

Fifth intercostal space, between ribs 4/5, to left of sternum

V3

Between leads V2and 4

V4

In the fifth intercostal space, between ribs 5/6

V5

Horizontally, between V4, but in the anterior axillary line

V6

Horizontally, between V4 and 5 in the midaxillary line

(Source: AHA Diagnostic ECG Placement, n.d.)

Describe nursing interventions to ensure correct ECG recording -- Ensure the patient is warm and relaxed; shave electrode areas prior to cleaning; clean electrode areas with alcohol and let dry prior to applying electrode; press leads firmly into appropriate areas. (Ibid).

Identify all components of a normal ECG rhythm- a typical, or normal ECG tracing of the heartbeat consists of a P. wave, a QRS complex, a T. wave and a U. wave (visible in 50-75% of cases).

Identify basic ECG rhythms -- ECG rhythms are printed on graph paper, the smaller squares represent .04 second; 1 second 25 small squares, etc. The basic rhythms are:

(Source: ECG Tutorial, 2006).