EKG and Cardiovascular Testing

electrocardiogram (EKG)

A cardiac test that records electrical activity of the heart, provides information about heart rate and rhythm, and can show evidence of a previous heart attack.

P wave

Represents atrial depolarization, contraction of the atria.

QRS wave

Represents ventricular depolarization, contraction of the ventricles. (Atrial repolarization is not visible but occurs during this phase.)

T wave

Represents ventricular repolarization, relaxation of the ventricles.

U wave

Not always visible but represents a repolarization of the bundle of His and Purkinje fibers

PR interval

Starts at the beginning of the P wave and ends at the beginning of the Q wave. Represents the time from the beginning of atrial depolarization to the beginning of ventricular depolarization.

QT interval

Starts at the beginning of the Q wave and ends at the end of the T wave. Represents the time from the beginning of ventricular depolarization to the end of ventricular repolarization.

ST segment

Starts at the end of the S wave and ends at the beginning of the T wave. Represents the time from the end of ventricular depolarization to the beginning of ventricular repolarization.

Sinus Rythms

normal rythms originating from the firing of the sinoatrial (SA) node and are characterized by the presence fof one P wave for each QRS interval

Sinus Bradycardia

Heart rate les sthan 60 bpm

Sinus Tachycardia

Heart rate greater than100 bpm

Sinus Arrest

A break in normal EKG, SA node fails to fire, it is not significant unless the person experiences symptoms such as shortness of breath, fainting, or chest pain, or it lasts more than 6 seconds

atrial flutter

A single area within the atrial tissue firing at a faster rate than the rate the ventricles are responding to.

Atrial fibrillation

rapid, disorganized firing of multiple sites within the atrial tissue

premature atrial conractions

the atria are triggered to contract earlier than they should.

premature ventircular conractions

Premature contractions in the ventricles

ventricular tachycardia

A regular, fast rhythm characterized by large, irregular, wide QRS complexes on the EKG.

ventricular fibrillation

A type of abnormal heart rhythm in which ventricles twitch or quiver, not pumping blood to the rest of the body.

artifact

Alteration or interference on the EKG that is not related to cardiac electrical activity; appears as distorted lines or waves.

V1 (red)

right side of the sternum at the fourth intercostal space

V2(yellow)

left side of the sternum, directly across from V1 at the fourth intercostal space

V4(blue)

left side of the chest, fifth intercostal space, midclavicular line

V3 (green)

left side of the chest, midway between V2 and V4* (goes after V4)

V5 (orange)

left side of the chest, fifth intercostal space, anterior axillary line

V6 (purple)

left side of the chest, fifth intercostal space, midaxillary line

White lead wire (limb)

right arm

black lead wire (limb)

left arm

red lead wire (limb)

left leg

green lead wire (limb)

right leg

Stess Testing

Monitoring the heart during exercise on a treadmill or stationary bike to evaluate how the heart responds to stress.

Holter monitor

A portable device for cardiac monitoring that is worn for at least 24 hours.