Sunday, March 15, 2009

CARING FOR CLIENTS WITH CARDIAC DYSRHYTHMIAS

MEDICAL SURGICAL NURSING


CARING FOR CLIENTS WITH
CARDIAC DYSRHYTHMIAS



NORMAL




CARDIAC RHYTHM – the pattern or pace of the heartbeat, regular
or irregular


USUAL RHYTHM/NORMAL called normal sinus rhythm – box 32-1, fig
32-1, fig 32-2 (A)


DYSRHYTHMIA – or arrhythmia is a conduction disorder that
causes a rate that is either too fast, too slow and is either regular or
irregular


Most common cause is CAD




ARRHYTHMIAS THAT ORIGINATE IN THE SA NODE




SINUS BRADYCARDIA – fig 32-2, B; regular, less
than 60; found in clients with heart disorders, ICP, hypothyroidism,
digitalis toxicity. Can also be found in healthy athletes & laborers- may be
treated with drugs, Atropine.


SINUS TACHYCARDIA – fig 32-2, C; regular,
100-150. Found in healthy hearts with strenous exercise, anxiety, fear,
pain, fever, hyperthyroidism, hemorrhage, shock or hypoxemia – no treatment
necessary


Supraventricular Tachycardia-SVT – rate more
than 150 Dangerous because it decreases the cardiac output. Can cause heart
failure, hypotension, syncope & reduced renal output. Drugs used to slow the
rate, digitalis, adrenergic blockers, & calcium channel blockers



ATRIAL FLUTTER – originates outside the SA node
– atrial rate is 200-400. Slower ventricular rate/response Characteristic
sawtooth pattern fig 32-4




ATRIAL FIBRILLATION




fig 32-5 – no identifiable P wave seen


Several areas in the right atrium initiate impulses;
disorganized, rapid atrial activity. Irregular ventricular rate, may cause
decreased cardiac output. Treated with digitalis, Corvert, Tambocor or
Rythmol or elective cardioversion




ARRHYTHMIAS ORIGINATING IN THE AV NODE




HEART BLOCK


disorders in the conduction pathway that
interferes with the conduction of impulses from the SA node to the AV node
to the ventricles.


First degree – impulse delayed, PR interval
prolonged


Second degree – impulse delayed


Third degree or
complete
– fig 32-6
requires a pacemaker due to rate of 30-40 only. Cannot sustain life at a
rate that low




ARRHYTHMIAS ORIGINATING IN THE VENTRICLES




PREMATURE VENTRICULAR
CONTRACTIONS (PVC) occurs before the SA node initiates an impulse. No P
wave, wide and bizzare QRS Usually harmless, can be dangerous if are
precursors of lethal arrhythmias. Treatment for lethal PVCs is an IV bolus
of Lidocaine followed by a continuous infusion



Fig 32-7, fig 32-8


VENTRICULAR TACHYCARDIA


(VTACH) – impulse originates in the ventricle, very fast
150-250. Cardiac output decreased. May stop on it’s own or may go into
ventricular fibrillation



VENTRICULAR FIBRILLATION








The rhythm of the dying heart


usually preceded by PVCs and/or VTACH


fig 32-9



Assessment findings



No cardiac output. The ventricles are just quivering. Requires
immediate CPR with defibrillation






S/S – weakness, fatigue, anginal pain, fainting,
palpitations, fluttering feeling in the chest, hypotension. Skin pale, cool,
or diaphoretic or clammy if having pain


Assess the cardiac monitor & the pt, vs,
administer meds as ordered. May need to assist with cardioversion,
defibrillation or pacemaker insertion.




Medical & Surgical Management




Drug therapy table 32-1


Elective Electrical Cardioversion - table 32-1


Nonemergency procedure used to stop rapid, non-life threatening
atrial dysrhythmias


Defibrillation – table 32-1


Emergency procedure performed during resusitation




Automated Implanted Cardiac Defibrillator
(AICD)




An internal electrical device used for selected clients with
recurrent life-threatening tachydysthythmias


Consists of a generator with a battery & one lead placed in the
right ventricle


It senses the dysrhythm & delivers an electrical shock to
restore the heart to a life-sustaining cardiac rhythm


Clients must avoid devices with a magnetic field




PACEMAKERS




Used to treat slow abnormal heart rhythms; may
be temporary or permanent


demand or synchronous mode


fixed-rate or asynchronous mode


transcutaneous, usually temporary


transvenous, usually temporary


implanted, permanent


Radiofrequency Catheter Ablation- a heated
catheter tip is introduced transvenously into the heart & destroys the
tissue causing the dysrhythmia




Nursing Care – nursing process,

Client with a Dysrhythmia




Elective Electrical Cardioversion


Keep NPO


Consent form signed


Make sure an IV is established; give meds as
ordered to include sedatives


Make sure all equipment is in room


v/s after procedure


Defibrillation


Ensure that all equipment is in room


Perform CPR until ready to defibrillate


Pacemakers


Place on monitor & assess for the "spike" of the
pacer


Client & family teaching 32-1




General Nutritional Considerations




Clients with history of ETOH abuse are more at
risk for dangerous during withdrawal




General Pharmacologic Considerations




Administration of lidocaine can have serious adverse effects
including convulsions & cardiac arrest. Use very cautiously


Drug toxicity can occur even with normal doses of digitalis &
cardiac glycosides. Signs of toxicity are anorexia, n/v, visual disturbances
such as halos around dark objects, objects appearing green or yellow.
Withhold the drug & notify MD if heart rate is < 60beats/min




General Gerontologic Considerations




Older adults have an increased risk for dysrhythmias due to
cardiac degenerative changes


Sinus bradycardia and heart block are common dysrhythmias in
older adults



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