Care of pats with dysrhythmias Flashcards
atrial depolarization; contraction atria; first wave
P
total time for atrial to depolarize and time takes for impulse to travel from SA node through Purkinje fibers
PR interval -
big one; ventricular depolarization/contraction
QRS complex -
early ventricular repolarization
ST segment -
ventricular repolarization - back to resting state
T wave -
total time for depolarization and repolarization
QT -
Determine heart rate - in a 6 sec strip count number QRS complexes and x10
Determine heart rhythm – can be regular or irregular; same difference between R’s; use calibers and see if difference between Rs sim
Analyze P waves
Small square = .04; large .2
Measure PR interval (normal .12-.20)
Measure QRS duration (normal .06-.12)
Examine the ST segment
Interpret rhythm and differentiate normal and abnormal cardiac rhythms
ECG rhythm analysis
Are P waves present?
Are the P waves occurring regularly?
Is there one P wave for each QRS complex? Regularly - space in between each
Are the P waves smooth, rounded, and upright in appearance, or are they inverted?
Do all the P waves look similar?
Analyze P waves
Are PR intervals greater than 0.20 second?
Are PR intervals less than 0.12 second?
Are PR intervals constant across the strip?
Measure from the beginning of the P wave to the beginning of the QRS
Measure PR interval (normal .12-.20)
Are QRS intervals less than or greater than 0.12 second?
Are the QRS complexes similar in appearance across the ECG paper?
Measure from the beginning of the QRS to end of S wave
Measure QRS duration (normal .06-.12)
Elevation may indicate myocardial infarction, pericarditis, hyperkalemia
Depression is associated with hypokalemia, myocardial infarction, ventricular hypertrophy
Examine the ST segment
Normal strip
Rate: 60-100 beats/minute
Rhythm: atrial and ventricular rhythms are regular - measure from each P and R wave are equal and consistent
P waves: Present, consistent configuration, one P wave before each QRS complex
PR interval : 0.12-0.20 second and constant; within norm range
QRS duration: 0.06-0.12 second and constant; within norm range
R to R constant; P to P constant
No interventions required
Normal sinus rhythm (NSR)
Variant of NSR
Type sinus rhythm; some irregularity
Results from changes in intrathoracic pressure during breathing
Has all the characteristics of NSR except for its irregularity
The PP and RR intervals vary, with the difference between the shortest and the longest intervals being greater than 0.12 second (three small blocks)
Rate: Atrial and ventricular rates between 60 and 100 beats/minute; norm rate
Rhythm: Atrial and ventricular rhythms irregular, with the shortest PP or RR interval varying at least 0.12 second from the longest PP or RR interval
P waves: One P wave before each QRS complex; consistent configuration
PR interval: Normal, constant
QRS duration: Normal, constant
No interventions required.
Sinus arrhythmia (SA)
Any disorder of the heartbeat/electrical activity
Tachydysrhythmias – heart rates greater than 100 beats per minute; fast
Bradydysrhythmias – heart rates less than 60 beats per minute; slow
Premature complexes – early rhythm complexes; if they become more frequent, especially those that are ventricular, the patient may experience symptoms of decreased cardiac output; ectopy: early complex; early ventricular/atrial contraction - ventricular more serious and more frequent more serious
Repetitive rhythm complexes
Etiology – may occur for many reasons; MI, electrolyte imbalance - K/Mg; hypoxic, low blood volume, hypovolemia, caffeine, nicotine, stress
Can be classified by their site of origin in the heart (sinus, atrial, ventricular)
Managed with antidysrhythmic drug therapy depending on dysrhythmia
Dysrhythmias
Bigeminy
Trigeminy
Quadrigeminy
Repetitive rhythm complexes
Vaughn-Williams classification used to categorize drugs according to their effects on the action potential of cardiac cells (classes 1 through IV)
Other drugs – Digoxin, Atropine sulfate, Adenosine
Managed with antidysrhythmic drug therapy depending on dysrhythmia
Assess vital signs at least every 4 hours - monitor VS; assessment essential of pat; BP, dizzy, chest pain
Monitor for cardiac dysrhythmias
Evaluate and document patient’s response of dysrhythmia
Encourage patient to notify nurse if chest pain occurs
Assess for chest pain and respiratory difficulty - SOB
Assess peripheral circulation
Administer medication and monitor response
Monitor lab values - abnormalities in lab, Mg, Ca high risk for diff types dysrhythmias so need tight control
Monitor activity tolerance and schedule exercise/rest periods to avoid fatigue - SOB with activity
Promote stress reduction
Offer spiritual support
Close eye for pats with this or at risk
Care of pat with dysrhythmias
Common
Sinus tachycardia; heart rate greater than 100 beats/min.
Treatment for sinus tachycardia is to treat the underlying cause. Caffeine, alcohol, nicotine, and some medications may increase the heart rate. Remove offending agent
Initially CO increase with ST but if for too long period time demands of heart and myocardial O2 demands so great that heart not able sustain - compensatory mechanisms wear out
Rate: 101-160 beats/min
Rhythm: regular
P waves: Present, consistent configuration, one P wave before each QRS complex - just fast
PR interval : 0.12-0.20 second and constant
QRS duration: 0.06-0.12 second and constant; looks norm
Regular wave
Sinus dysrythmia - sinus tachycardia (ST)
Commonly seen
Rate: Less than 60 beats per minute
Rhythm: regular
P waves: Present, consistent configuration, one P wave before each QRS complex
PR interval : 0.12-0.20 second and constant; norm
P to P and R to R consistent
QRS duration: 0.06-0.12 second and constant; norm
In many cases, the cause may be unknown.
Myocardial O2 demands low because not pumping fast - low CO because not beating as fast
Treatment depends on pat - if symptomatic (diaphoresis, chest pain, dyspnea, syncope, dizziness, weakness, confusion, hypotension): if do give them something: Atropine 0.5 mg IV, IV fluids, oxygen, monitor VS
First thing do if any dysrhythmia is assess the pat
Pacing may be required: Temporary versus permanent
Sinus dysrythmia - sinus bradycardia (SB)
Ectopic beat/focus of atrial tissue fires an impulse before next sinus impulse is due - atrial tissue shoots impulse that causes premature beat; outsync norm SA node regulating
Premature P wave may not always be clearly visible because it can be hidden in the preceding T wave - not always obvious; not typ have symp but monitor for pat
A PAC is usually followed by a pause
Atrial dysrhythmia - premature atrial complexes (PAC)
Tachycardia being cause by something above ventricles: means atria
Rapid stimulation of atrial tissue occurs at rate of 100-280 beat/minute in adults
P waves may not be visible, because they are embedded in the preceding T wave - going so fast
Paroxysmal supraventricular tachycardia (PSVT) rhythm is intermittent, initiated suddenly by a premature complex such as a PAC and terminated suddenly with or without intervention
Sometimes nonsustained; not know have it; short; if sustained will have symp or feel palpitations in chest - send on heart monitor and see when having episodes of SVT - monitor for; check BP and s/s of pat and if symptomatic/not
Atrial dysrhythmia - supraventricular tachycardia (SVT)
Most common dysrhythmia - VERY COMMON
Associated with atrial fibrosis and loss of muscle mass - quivers and not contract normally
Common in heart disease such as hypertension, heart failure, coronary artery disease
Many other risk factors
Cardiac output can decrease by as much as 20% to 30% - atria not fully ejecting so not fully filling ventricles so CO is affected
Above rhythm: Atrial fibrillation
Seen often in pulm pats
Rate: Atrial (350-400 beats/minute) - can vary but very irregular looking, ventricular variable, rate varies; atrial rate very fast
Rhythm: irregularly irregular, always irregular
P waves: Normal P waves are absent; not discernable; little pumps
PR interval : Not discernible; not able measure
QRS duration: 0.06 to 0.12 second; norm
Not regular between R to R
Very fast atrial rate; irregular ventricular rate; no discernable P waves and no way measure PR interval
Atrial fibrillation (AF)
Assess pat first always for fatigue, weakness, shortness of breath, dizziness, anxiety, syncope, palpitations, chest discomfort or pain, hypotension; make sure getting good full assessment
Very High risk for PE, VTE, stroke - atria quivering and not fully emptying since not ejecting some blood stays back in atria before moves into ventricles and when pools blood clots and when atria quivering clot gets pushed out and goes anywhere; high risk for emboli
Drug therapy
Want stop dysrhythmia, slow down HR and prevent clots
Assessment and treatment of AF
Calcium channel blocker such as diltiazem (Cardizem)
Aminodarone (Cordarone) – class 3 antiarrythmic agent
Beta blockers such as metoprolol (Toprol) and esmolol (Brevibloc) – slows ventricular response; slows down HR
Digoxin (Lanoxin) – for patients with heart failure and AF; slows down HR
Anticoagulants – Heparin, enoxaparin (lovenox), warfarin (coumadin), other newer drugs are now available; unless risk too great
Antiplatelet – Aspirin, clopidogrel (Plavix); may also do in addition/instead of anticoag
Drug therapy
