Transcript Care of Patient With Dysrhythmias

Care of Patient With Dysrhythmias
Dr. Belal Hijji, RN, Phd
October 19 &24, 2011
Learning Outcomes
At the end of this lecture, students will be able to:
• Describe the normal electrical conduction of the heart.
• Discuss the characeristics of various types of sinus node and
ventricular dysrhythmias.
• Describe the nursing management of a patient with
dysrhythmias.
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Introduction
• For the heart to perform efficiently as a pump, it should have a
regular rate and rhythm. Without this, the heart is considered
dysrhythmic, which could be a dangerous condition.
• Dysrhythmias are disorders of the formation or conduction (or
both) of the electrical impulse within the heart that can cause
disturbances of the heart rate, rhythm, or both.
• Dysrhythmias may initially be evidenced by the hemodynamic
effect they cause (decreased blood pressure).
• Dysrhythmias are diagnosed by analyzing the ECG waveform.
They are named according to the site of origin of the impulse
and the mechanism of formation or conduction involved. For
example, an impulse that originates in the sinoatrial (SA) node
and that has a slow rate is called sinus bradycardia.
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FIGURE 1 The heart
conducts electrical activity,
which the ECG measures and
shows. The configurations of
electrical activity displayed
on the ECG vary depending
on the lead of the ECG and on
the rhythm of the heart.
Therefore, the configuration
of a normal rhythm tracing
from lead I differs from the
configuration of a normal
rhythm tracing from lead II,
lead II differs from lead III.
The same is true for abnormal
rhythms and cardiac
disorders. To make an
accurate assessment of the
heart’s electrical activity, the
ECG needs to be evaluated
from every lead. Here the
different areas of electrical
activity are identified by
color.
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Normal Electrical Conduction
• The electrical impulse, occurring at a range between 60 and
100 times/ minute (adult) , that stimulates the cardiac muscle
originates in the sinus node (SA node).
• The impulse quickly travels from the sinus node to the
atrioventricular (AV) node (Previous slide).
• The electrical stimulation of the atria causes them to contract.
The structure of the AV node slows the electrical impulse,
which allows time for the atria to contract and fill the
ventricles with blood before the electrical impulse travels very
quickly through the bundle of His to the right and left bundle
branches and the Purkinje fibers.
• The electrical stimulation of the ventricles causes them to
contract (systole). The ventricular cells electrically repolarize
(relax) and the ventricles then relax (diastole). The process
from sinus node electrical impulse generation (depolarisation)
through ventricular repolarization completes the
electromechanical circuit, and the cycle begins again.
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Types of Dysrhythmias
• Dysrhythmias include sinus node, atrial, junctional, and
ventricular dysrhythmias and their various subcategories.
• Due to time constraints, subsequent slides will focus on sinus
node and ventricular dysrhythmias.
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Sinus Node Dysrhythmias
• Sinus Bradycardia. Sinus bradycardia (Next slide) occurs
when the sinus node creates an impulse at a slower-thannormal rate. Causes include lower metabolic needs (eg, sleep,
athletic training, hypothermia, hypothyroidism), vagal
stimulation (eg, from vomiting, suctioning, severe pain,
extreme emotions), medications (beta-blockers), increased
intracranial pressure, and myocardial infarction (MI). The
treatment of choice of sinus bradycardia is atropine, 0.5 to 1.0
mg given rapidly as an intravenous (IV) bolus. Sinus
bradycardia characteristics are:
– Ventricular and atrial rate: Less than 60 in the adult
– Ventricular and atrial rhythm: Regular
– QRS shape and duration: Usually normal, but may be regularly
abnormal
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– P wave: Normal and consistent shape; always in front of QRS
– PR interval: Consistent interval between 0.12 and 0.20 seconds
– P: QRS ratio: 1:1.
FIGURE 2 Sinus bradycardia in lead II.
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• Sinus Tachycardia. Sinus tachycardia (See below) occurs
when the sinus node creates an impulse at a faster-than-normal
rate. It may be caused by acute blood loss, anemia, shock,
hypervolemia, hypovolemia, congestive heart failure, pain,
fever, exercise, or anxiety. Treatment is through abolishing the
cause. Calcium channel blockers (Nifedipine) and betablockers (Atenolol) can quickly reduce heart rate . The
characteristics of sinus tachycardia are:
– Ventricular and atrial rate: Greater than 100 in the adult
– Ventricular and atrial rhythm: Regular
– QRS shape and duration: Usually normal, but may be regularly
abnormal
– P wave: Normal and consistent shape; always in front of the
QRS, but may be buried in the preceding T wave
– PR interval: Consistent interval between 0.12 and 0.20 seconds
– P: QRS ratio: 1:1
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• Sinus Arrhythmia. Sinus arrhythmia (See below) occurs when
the sinus node creates an impulse at an irregular rhythm; the
rate usually increases with inspiration and decreases with
expiration. Sinus arrhythmias does not cause significant
hemodynamic effect and usually it is not treated. The ECG
criteria for sinus arrhythmia are:
– Ventricular and atrial rate: 60 to 100 in the adult
– Ventricular and atrial rhythm: Irregular
– QRS shape and duration: Usually normal, but may be regularly
abnormal
– P wave: Normal and consistent shape; always in front of QRS
– P-R interval: Consistent interval between 0.12 and 0.20 seconds
– P: QRS ratio: 1:1
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Ventricular Dysrhythmias
• Premature Ventricular Complex (PVC). PVC is an impulse
that starts in a ventricle and is conducted through the ventricles
before the next normal sinus impulse. PVCs can occur in
healthy people who use caffeine, nicotine, or alcohol. Other
causes include cardiac ischemia or infarction, increased
workload on the heart (eg, exercise, fever, hypervolemia, heart
failure, tachycardia), digitalis toxicity, or hypokalemia.
– In the absence of disease, PVCs are not serious. In the patient with
an acute MI, PVCs may indicate the need for more aggressive
therapy.
– Initial treatment includes correcting the cause, if possible. Lidocaine
(Xylocaine) is the medication most commonly used for immediate, shortterm therapy. No need for long-term pharmacotherapy for only PVCs.
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• Ventricular Tachycardia (VT). VT (See below) is defined as
three or more PVCs in a row, occurring at a rate exceeding 100
beats per minute. The causes are similar to those for PVC. VT is
usually associated with CAD and is an emergency because the
patient is usually unresponsive and pulseless. In an unconscious
and pulseless patient, defibrilation is the treatment of choice. VT
characteristics are:
– Ventricular and atrial rate: Ventricular rate is 100 to 200 beats per
minute; atrial rate depends on the underlying rhythm (eg, sinus
rhythm)
– Ventricular and atrial rhythm: Usually regular; atrial rhythm may
be regular.
– QRS shape and duration: Duration is 0.12 seconds or more;
bizarre, abnormal shape.
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• Ventricular Fibrillation. Ventricular fibrillation is a rapid and
disorganized ventricular rhythm that causes ineffective
quivering [trembling, shivering] of the ventricles. Its causes
are the same as for VT, untreated or unsuccessfully treated
VT, or electrical shock. Patient’s heart beat is inaudible, pulse
impalpable, and absent respirations. Cardiac arrest and death
are imminent if ventricular fibrillation is not immediately
corrected through defibrillation. Ventricular fibrillation has the
following characteristics:
– Ventricular rate: Greater than 300 per minute
– Ventricular rhythm: Extremely irregular
– QRS shape and duration: Irregular, unrecognizable QRS
complexes
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Nursing Management of a Patient With Dysrhythmias
• Assessment:
– Obtain health history to identify any previous occurrences of
decreased cardiac output, including syncope (fainting), fatigue,
lightheadedness, dizziness, chest discomfort, and palpitations.
– Identify coexisting conditions that may be the cause of the
dysrhythmia (eg, heart disease, chronic obstructive pulmonary
disease).
– Review medications as some (Digoxin) can cause dysrhythmias.
– Conducts a physical assessment to observe for signs of
diminished cardiac output (changes in LOC. Inspect the skin
(may be pale and cool). Assess signs of fluid retention (neck
vein distention; crackles and wheezes in the lungs).
– Auscultates for extra heart sounds (S3 and S4). Measure blood
pressure, and determines pulse pressures. A declining pulse
pressure indicates reduced cardiac output.
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Nursing Management of a Patient With Dysrhythmias
• Nursing Diagnoses:
– Decreased cardiac output
– Anxiety related to fear of the unknown
– Deficient knowledge about the dysrhythmia and its treatment
• Planning and Goals
– Eradication or reduction in the incidence of the dysrhythmia (by
decreasing contributory factors)
– Maintenance of cardiac output
– Minimising anxiety
– Acquiring knowledge about the dysrhythmia and its treatment
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Nursing Management of a Patient With Dysrhythmias
• Nursing Interventions:
– Monitoring and managing dysrhythmias
• Record BP, HR and rhythm, rate and depth of respirations,
and breath sounds to determine the dysrhythmia’s
hemodynamic effect.
• Ask patients about episodes of lightheadedness, dizziness, or
fainting.
• Obtain a 12-lead ECG to continuously monitor the patient
and to track the dysrhythmia.
• Administer antiarrhythmic medications as prescribed.
• Assess for factors that contribute to the dysrhythmia (eg,
caffeine, stress, nonadherence to the medication regimen)
and assist the patient in making lifestyle changes that adress
these issuses.
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Nursing Management of a Patient With Dysrhythmias
• Nursing Interventions (Continued…..):
– Minimising anxiety
• At the time of dysrhythmic event, maintain a calm and
reassuring attitude to foster a trusting relationship with the
patient and assists in reducing anxiety.
• Promote a sense of confidence in living with a dysrhythmia.
For example, while administering a medication at a
dysrhythmia event and it begins to reduce the incidence of
dysrhythmia, communicate that information to the patient.
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Nursing Management of a Patient With Dysrhythmias
• Nursing Interventions (Continued…..):
– Teaching patient self-care
• Present the information in terms that are understandable and
in a manner that is not frightening or threatening.
• Explain the importance of taking medications regularly to
maintain therapeutic serum levels of antiarrhythmic agents
• If dysrhythmia is potentially lethal, establish with the patient
and family a plan of action to take in case of an emergency.
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Nursing Management of a Patient With Dysrhythmias
• Evaluation: The patient
– Maintains cardiac output
• Demonstrates HR, BP, RR, and LOC within normal ranges
• Demonstrates no or decreased episodes of dysrhythmia
– Has reduced anxiety
• Expresses a positive attitude about living with the dysrhythmia
• Expresses confidence in ability to take appropriate actions in an
emergency
– Expresses understanding of the dysrhythmia and its treatment
•
•
•
•
Explains the dysrhythmia and its effects
Describes the medication regimen and its rationale
Explains the need for therapeutic serum level of the medication
Describes a plan to eradicate or limit factors that contribute to the
occurrence of the dysrhythmia
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• States actions to take in the event of an emergency