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Pts w/ Dysrhythmias
Care of Patients with Dysrhymias
Front | Back |
---|---|
Primary Pacemaker | SA Node |
P wave | Atrial Contraction |
T cells in AV junction | cause impulses to slow down or to be delayed in the AV node before proceeding to the ventricles |
PR Segment | Slow in impulses created by T cells in the AV junction |
Ventricular Beats/Rhythms | can come from a few nodal cells in the ventricles which occasionally demonstrate automaticity |
Cardiac Dysrhythmia | abnormal rhythms of the heart’s electrical system that can affect its ability to pump oxygenated blood throughout the body. |
Contractility | Mechanical activity of the heart |
SA Node | has greatest degree of automaticity |
Atrial Kick | Atrial contraction, ventricles fill with blood to allow for a greater CO |
ECG (EKG) | provides graphic reports of cardiac electrical activity |
electrode placement | same placement for male and female |
lead systems | made up of a positive pole and negative pole |
isoelectric line | baseline, when there is no current or flow in the heart |
lead axis | an imaginary line between the positive pole lead and the negative pole lead |
positive deflection | above baseline, toward positive pole |
negative deflection | below baseline, toward negative pole |
Lead I placement | - = right arm or under right clavicle + = left arm or under the left clavicle ground= rgt leg or lowest rib, left midclavicular line |
Lead II placement | - = right arm or under right clavicle + = left leg or lowest rib, left midclavicular line ground= rgt leg or under left clavicle |
Lead III placement | - = left arm or under left clavicle + = left leg or lowest rib, left midclavicular line ground= rgt leg or under rgt clavicle |
Lead aVR placement | - = average potential of left arm (or under the left clavicle) and left leg (or lowest rib, left midclavicular line) + = right arm or under right clavicle ground= right leg or lowest rib, right midclavicular line |
Lead aVL placement | - = average potential of right arm (or under the right clavicle) and left leg (or lowest rib, left midclavicular line) + = left arm or under the left clavicle ground= right leg or lowest rib, right midclavicular line |
Lead AVF placement | - = average potential of right arm (or under the right clavicle) and left arm (or under left clavicle) + = left leg or lowest rib, left midclavicular line ground= right leg or lowest rib, right midclavicular line |
Lead V1 placement | - = average potential of right arm, left arm, and left leg + = fourth ICS, right sternal border ground= right leg or lowest rib, right midclavicular line |
Lead V2 placement | - = average potential of right arm, left arm, and left leg + = fourth ICS, left sternal border ground= right leg or lowest rib, right midclavicular line |
Lead V3 placement | - = average potential of right arm, left arm, and left leg + = midway between V2 and V4 ground= right leg or lowest rib, right midclavicular line |
Lead V4 placement | - = average potential of right arm, left arm, and left leg + = fifth ICS, left midclavicular line ground= right leg or lowest rib, right midclavicular line |
Lead V5 placement | - = average potential of right arm, left arm, and left leg + = horizontal to V4, left anterior axillary line ground= right leg or lowest rib, right midclavicular line |
Lead V6 placement | - = average potential of right arm, left arm, and left leg + = horizontal to V4, left midaxillary line ground= right leg or lowest rib, right midclavicular line |
Standard 12 lead consists of | 12 leads or views, 6 leads are the limb leads, the other 6 leads are the chest leads (precordial) |
Standard bipolar leads consist of | 3 leads and each measure electrical activity between 2 points and a 4th lead the right leg acts as ground. Of the 3 measuring leads the right arm is ALWAYS NEGATIVE, the left leg is ALWAYS POSITIVE, and the left arm can be either. |
18 lead ECG | adds 6 leads on the horizontal plane on the right side of the chest to view the right side of the heart. Sometimes called the right sided ECG |
Unipolar limb leads consist of | a positive electrode only |
6 unipolar or V chest leads are determined by: | the placement of the chest electrode |
True or False: Positioning of the electrodes is crucial in obtaining an accurate EKG | True |
positioning is important with: | patients with chest deformities or large breasts |
How the patient is positioned and should breath during the test... | semi-reclined, breathing normally. any repetitive movement will cause an artifact and could lead to inaccurate EKG |
Who is responsible for the interpretation of the EKG? | Physician |
What should the tech do if there are abnormalities? | Alert the nurse/Dr. |
True/False: The nurse can direct the tech to take a 12 lead if patient is experiencing chest pain. | True |
Continuous EKG monitoring: | the electrodes are NOT placed on the limbs because movement of the extremities causes noise or motion artifact on the EKG |
Place electrodes on the ______ (a more stable area) to minimize artifacts and obtain clear signal | trunk |
Five Lead, placement: | 1. Rgt arm below rgt clavicle 2. left arm below lft clavicle 3. rgt leg electrodes on lowest palpable rib on the R midclavicular line 4. left leg electrode on lowest palpable rib on the L midclavicular rib 5. placed to obtain one of the 6 chest leads |
the clarity of the continuous EKG monitor recordings is affected by: | skin prep and electrode quality |
To ensure the best signal: | clean the skin (shave if necessary), make sure the area for electrode placement is dry; the gel on each must be moist and fresh |
Attach the electrode to: | the lead cable and then contact site, the area should be free of lotion, tincture, or other that could cause skin impedance |
electrodes cannot be placed: | over scars or irritated skin |
electrodes CAN be placed by: | an UAP, but the nurse must determine with lead to select and check for correct electrode placement |
assess the quality of the: | EKG rhythm transmission monitoring system |
True/False: patient in critical care or bed rest, EKG cables can be hard wired system | True (wall mount) |
Ambulatory patients can be attached to a: | telemetry unit (battery operated) |
The nurse remains responsible for: | accurate EKG rhythems interpretation, as well as for pt assessment and management |
The shape of the P wave may be: | positive, negativem or biphasic (both positive and negative) deflection, depending on the lead selected |
The PR segment is isoelectric line from the end of the P wave to beginning of QRS complex, this shows the time when: | electrical impulse is traveling through the AV node, where it is delated |
PR interval: | measured from beginning of the P wave to the end of the PR segment |
PR interval represents: | time required for atrial contraction as well as the impulse delay in the AV node |
PR interval time measurement: | 0.12-0.20 (5 small blocks) |
QRS complex | represents ventricular contraction the shape depends on the lead selected |
QRS time measurement: | 0.04-0.10 seconds (up to 3 small blocks) |
Q wave: | 1st negative deflection not present on all leads, when it is present it represents initial ventricular septal depolarization |
When the Q wave is abnormally present it represents: | myocardial necrosis |
R wave: | 1st positive deflection, may be small, large, or absent depends on the lead |
S wave: | The negative deflection following the R wave and not present in all leads |
QRS duration: | represents time required for depolarization of both ventricles, it is measured from the beginning of the QRS complex the J point where the QRS complex ends and the ST segment begins |
ST segment: | normally an isoelectric line and represents early ventricular repolarization |
ST Segment occurs from : | J point to beginning of T wave |
ST segment varies with changes in: | heart rate, med admin, and electrolyte disturbances |
ST segment normally not: | elevated more than 1 mm or depressed more than 0.5 mm from isoelectric line, its amplitude measured at a point 1.5-2mm after the J point |
St elevation or depression can be caused by: | myocardial injury, ischemia, infarction, conduction, abnormalities or the admin of meds |
T wave follows the ST segment and represents ventricular repolarization: | usually positive, rounded and slightly asymmetric |
T wave become tall and peaked, inverted (negative) or flat as a result of: | myocardial ischemia, potassium, or calcium imbalances, medications, or ANS affects |
R on T phenomenon | if an ectopic stimulus excites the ventricles at this time it may cause ventricular irritability, lethal dysrhythmias and possible cardiac arrest in a vulnerable heart |
U wave: | represents late ventricle repolarization |
U wave may suggest: | electrolyte imbalance (particularly hypokalemia), be sure this is not mistaken for a P wave and notify HCP and request K level be obtained |
QT interval: | represent the total time required for ventricle contraction and relaxation and is measured from the beginning oft eh QRS complex to the end of the T wave |
QT interval will vary with: | pt. age, gender, changes with HR, lengthen with slower HR and short with fast HR |
torsades de pointes | a prolonged QT interval a type of ventricular tachycardia |
artifact: | an interference seen on the monitor strip may look like a fuzzy baseline, cause by pt movement, defective, loose electrolodes, improper grounding. some artifacts might mimic lethal dysrhytmias |
(regarding artifacts) assess the pt to: | differentiate artifact from actual lethal rhythms |
Determining HR 6 second strip method: | the HR can b e determined by counting the number of QRS complexes in 6 seconds and multiplying by 10 to calculate HR for a full minute this method is the least accurate but is the method to check for irregular rhythm |
Big Block Method: | for accuracy, used if the QRS complexes are regular or evenly paced |
Big Block Method Counting: | count the number of big blocks between the same point in any 2 successive QRS, divide into 300 |
memory method: | relies on memorizing a sequence (this is Big Block method with the math already done), this method is used in hospitals for calculatin6 step rhythm method using tool called on EKG caliperg HR for regular rhythms |
TRUE/FALSE: Use caution and confirm the HR is correct by assessing the Pt's HR directly | True |
6 step method using tool called an EKG caliper | 1. Determine HR, 2. determine heart rhythm, 3. analyze the p waves, 4. measure the PR interval, 5. measure the QRS duration, 6. interpret the rhythm |
Supraventricular or above the ventricles: | when the QRS is narrow this indicated impulse not formed in ventricles |
NSR (normal sinus rhythm) | originates from the SA node, has rate 60-100, regular rhythm, p waves present and one before each QRS complex, PR interval 0.12-0.2, QRS duration 0.04-0.1, |
sinus arrhythmia | a variant of NSR results from changes in intrathroacic pressure during breathing this doesn't mean without rhythm just the HR increases slightly during each inspiration and decreases with expiration, seen in health adults and kids |
sinus arrhythmia irregularities: | irregular RR and PP interval varying at least 0.12 sec from longest PP or RR interval |
sinus arrhythmia usually due to: | nonrespiratory causes such as digitalis or morphine, these drugs enhance the vagal tone and cause decreased HR and irregularity unrelated to respiratory cycle |
Dysrhythmia | any disorder of the heart beat |
dysrhythmias mat result from: | disturbance in electrical conductivity, and mechanical response of myocardium, a disturbance in impulse formation, disturbance in impulse conduction (delay or blocks) or combination of any |
tachydysrhythmias: | HR gerater than 100 bpm major concern with pt with CAD |
tachydysrhythmias are serious due to: | shortening of diastolic time and coronary perfusion time, increases CO and BP however this continued rise in HR decreases the ventricular filling time,therefore CO and BP will decrease reducing aortic pressure and perfusion pressure,increase work of hear |
pts with tachydemia may have: | palpitations, chest discomfort (pressure or pain), restlessness and anxiety, pale, cool, skin, syncope (blackout) from hypotension, tachyd may also lead to HF. |
bradydysrhytmias: | occur when HR is less than 60 BPM |
Bradydysrhytmias are significant due to: | -myocardial O2 demand is reduced from the slow HR which can be beneficial -coronary perfusion pressure may decrease if the HR is too slow to provide adequate CO and BP, this is a serious consequence |
Pt. may tolerate bradyd well if the BP is adequate if not: | this may lead to myocardial ischemia, infarction, other dysrhythmia’s, hypotension and HF |
premature complexes: | early rhythm complexes occur when cardiac cell or cell group other than the SA node becomes irritable and fires an impulse before the next sinus impulse is produced The abnormal focus is called an ectopic focus |
Bigeminy: | exists when normal complex and premature complexes occur alternately in a repetitive 2 beat pattern with a pause occurring after each premature complex so that they occur in pairs |
Trigeminy: | repeated 3 beat pattern usually occurring as a 2 sequential normal complexes followed by a premature complex and a pause with the same pattern repeating itself in triplets |
Quadgeminy: | 4 beat pattern occurring in 3 sequential normal complexes followed by premature and a pause repeating in a 4 beat pattern |
Escape complexes or escape rhythms may occur when | the SA node fails to discharge or is blocked or when a sinus impulse fails to depolarize the ventricles due to an AV block |