Circulatory System and EKG Flashcards
Electrocardiograph
Instrument used to recored the electrical acidity of the heart
Electrocardiogram (ECG)
Is the graphic representation of this activity
- Heart at rest state and only records about 10s of activity
Ischemia
A deficiency of blood on a body part usually caused by a blocked artery
Cardiac cycle
1 heartbeat: Contraction of the atria and contraction of the ventricles and the relaxation of the entire heart
P Wave
Contraction of the atria on martial depolarization
QRS Wave
Electrical activity associated with the contraction of the ventricles or ventricle depolarization
- R wave is taller then P wave
T Wave
Electrical recovery of the ventricles or ventricular repolarization
- Artial depolarization is masked or Hidden by the QRS and does not appear as a seperate wave
U Wave
Small wave the tis associated in some as yet undefined way with depolarization of the Purkinje fibers or depolarization of the papillary muscles of the heart
Baseline
Horizontal line that separates waves. Resting or polarized state
Interval
The length of one or more waves a segment
PR segment
The time interval from the end of the atrial depolarization to the beginning of the ventricular depolarization
ST segment
Time interval from the end of the ventricular depolarization to the beginning of repolarization of the ventricles.
PR Interval
The time interval from the beginning of the atrial depolarization to the beginning of the ventricular depolarization.
QT Interval
The time interval from the beginning of the ventricular depolarization to the end of repolarization of the ventricles.
Electrocardiograph paper
1mm high x 1mm wide
- Large square made of 25 small squares is 5mm high and 5mm wide
- Heat sensitive and pressure sensitive
Amplitude
1m small squares
- 1mV = 10mm
Lead
- Tracing the electrical activity of the heart b/w 2 electrodes
- 10 leads are attached patient and are used to make the 12 electrical photos of the heart
- 4 Limb lead wires: Right arm, left arm, right leg, and left leg
- 6 Chest lead wires: V1-6
- Right leg is the ground lead
Electrolyte
Substancee that facilitates the transmission of th heart electrical impulses
- Out of data it can dry out and not transmit good signal
Bipolar leads
- Lead I,II, and III
- Use the two limb electrodes to record activity
- Lead I- Activity b/w right arm and left arm
- Lead II- Activity b/w rich arm and left leg
- Lead III- Left arm and left leg
Augmented Leads
- aVR (right arm), aVL ( left arm) and aVF (left leg or foot)
- aVR- activity b/w right arm and center point b/w the left arm and left leg
- aVL- Left arm and center point b/w the right arm and left leg
- aVF- Current b/w left leg and center point between the right and left arms
- Leads I,II,III, aVR, aVL, aVF- provide photos of the heart activity from side to side and from top to bottom of the heart
Chest Leads (precordial )
- V1-6
- Record heart voltage from front to back
- V1 - 4th intercostal space, right of the sternum
- V2- 4th intercostal space at left of the sternum
- V3- midway between 2 and 4
- V4- 5th intercostal space at auction of left midclavicular line
- V5- Horizontal level of V4 at left anterior axillary line
- V6- Horizontal level of V4 at midaxillary line
Artifacts
Recordings that are not natural and interfere with ECG cycle
Muscle Artifacts
- Fuzzy, irregular baseline’
- Involuntary movement (somatic tremors) and voluntary movement
Wandering Baseline Artifacts
- Loose electrodes
- Dried out electrolyte
- Body creams
- Excessive movement of the chest during respiration
60- Cycle Interference Artifacts (AC artifact)
- Small straight, spiced lines that are consistent causing the baseline to be thick and unreadable
- Lead wires not following body contor
- Appliances in the room
- Wiring in the walls
- Improper grounding the electrocardograph
Interrupted Baseline Artifact
-Caused by the metal tip of a lead wire becoming detached or by a frayed or broken patient cable
Holter Monitor
- Portable ambulatory monitoring system used for the continuous recording of the electrical activity of the heart for 24 hr or longer
- Ambulatory electrocardiographic monitor (AEM)
- Purpose: Detect cardiac abnormalities that occur while the patient is engaged in his or her normal daily routine
Normal Heart Ranges
60 to 100 beats per minute
Sinus bradycardia
Slower the 60 beats per minute
Tachycardia
100+ beats per minute
Pulmonary function test (PFT)
To access lung fxn which assists in the detection and eval of pulmonary disease
Spirometry
Noninvasive screening test
- Measures how much air is pushed out of lungs and how fast it is pushed out
Circulatory system
Cardiovacular: Heart, blood, and blood vessels
Lymphatic: lymph, lymphatic vessels, and organs
Heart
- Normal adult pumps 5L of blood every minute
- Thoracic cavity
- Posterior to the sternum and anterior to the vertebral column and rest on the diaphragm
- Apex: level to the 5th intercostal space
- Base: Superior portion is level of the 2nd rib
- Average size: 9cm wide and 12cm long
Fibrous pericardium
Outer-layer of the pericardium consist of tough, white fibrous connective tissue
Parietal pericardium
The fibrous pericardium is lines with serous membrane
Visceral pericardium
Attached to the vessels to the base of the heart, the parietal pericardium reflects onto the surface of the heart
Pericardial cavity
A small space b/w the parietal and visceral layers
- Reduces friction b/w membranes as they run against each other during contractions
Epicardium
Thin protective layer that is firmly anchored to the underlying muscles
- = Visceral pericardium
Myocardium
Thick middle layer. Forms the bulk of the heart wall and is composted of cardiac muscles tissue
Endocardium
Inner lining of the wall. Smooth permits blood to move easily through the heart
Artia
Thin-walled chambers that receive blood from the veins
Ventricles
Thick walled cambers the forcefully pump blood out of the heart
