Ch 26 Cardiac arrhythmias
what type of clients does sinus tachycardia occur in?
clients with healthy hearts in response to strenuous exercise, anxiety, fear, pain, fever, hyperthyroidism, hemorrhage, shock, or hypoxemia
what type of pacemaker self-activates when the client's pulse falls below a certain level?
demand mode
Fill in the blank Prior to cardioversion, a sedative like ______ is used. To increase a dangerously slow HR, atropine may be used.
diazepam(valium)
Fill in the blank Occasionally, the ____ ________ ____ , one that initiates an electrical impulse independently of the SA node, can lead to more serious arrhythmias such as supraventricular tachycardia.
ectopic pacemaker site
what is a nonemergency procedure done by a physician to stop rapid, but not necessarily life-threatening atrial arrhythmias?
elective electrical cardioversion
what type of pacemaker produces an electrical stimulus at a preset rate?
fixed-rate mode *less common than demand mode
what refers to disorders in the conduction pathway that interfere with the transmission of impulses from the SA node through the AV node to the ventricles?
heart block
what is an internal electrical device used for selected clients with recurrent life threatening tachydysrhythmias?
implantable cardioverter defibrillator *check q3-4 months *restrict driving for 1 week
what is a totally implanted electrical device used to manage a chronic bradyarrhythmia?
implanted pacemaker *mainly for second or complete heart block *reassess client after 3 months, then 6
the most common cause for an arrhythmia?
ischemic heart disease
usual cardiac rhythm
normal sinus rhythm
what provides an electrical stimulus to the heart muscle to treat an ineffective slow rhythm?
pacemaker
cardiac rhythm
pattern of the heartbeat
Fill in the blank The neural tissue in the atrial conduction system initiates an early electrical impulse called a ______ ,which is identified by an irregularity in the underlying rhythm.
premature atrial contraction
what is a ventricular contraction that occurs early and independently in the cardiac cycle before the SA node initiates an electrical impulse ?
premature ventricular contraction typically harmless
what causes PVC?
r/t anxiety, stress, fatigue, alcohol withdrawal, tobacco use
what is a procedure in which a heated catheter tip destroys arrhythmia producing tissue?
radiofrequency catheter ablation
what is an arrhythmia that proceeds normally through the conduction pathway but at an slower rate?
sinus bradycardia
what is an arrhythmia that proceeds normally through the conduction pathway but faster?
sinus tachycardia treatment: treat underlying cause
what is an arrhythmia in which the HR has a consistent rhythm but beats at a dangerously high rate? >150 BPM *diastole is shortened *cardiac output is low
supraventricular tachycardia
fill in the blank An external _____ _____ is an emergency measure for maintaining adequate HR?
transcutaneous pacemaker
The leads of a ____ ____ are inserted during open heart surgery.
transthoracic pacemaker
What type of temporary pacemaker is a pulse-generating device that sometimes is necessary for management of transient bradyarrhythmia's?
transvenous pacemaker
what is the rhythm of a dying heart?
ventricular fibrillation Treats with CPR
what is caused by a single, irritable focus in the ventricle that initiates then continues the same repetitive pattern (150-250BPM)?
ventricular tachycardia
fill in the blank digitalis and diuretics are withheld for ___ to ___ hrs before cardioversion?
24-72
Diagnostic study for cardiac arrhythmias
* electrophysiology studies: location of origin; determines best method for preventing further episodes
signs and symptoms of premature ventricular contractions?
* fluttering sensation in chest * pallor *nervousness * sweating *faintness
A HR slower than 60 BPM is pathologic in clients with....
* heart disorders * increases ICP * hypothyroidism * digitalis toxicity
Etiology of Cardiac Arrhythmias
* myocardial ischemia * lack of oxygenated blood * conduction system susceptible to disturbances due to anxiety, pain, endocrine disorders, electrolyte imbalances, valvular heart disease, IV catheters, and drug effects
Types of arrhythmias originating from the ventricles?
* premature ventricular contractions * ventricular tachycardia * ventricular fibrillation
candidates for implanted cardioverter defibrillator?
* survived one episode of cardiac arrest from a ventricular dysrhythmia * have recurrent episodes of ventricular tachycardia *risk for sudden cardiac death due to structural heart disease
signs/symptoms of cardiac arrhythmias
* weak, tired * CP * faint * tachyarrhythmias: palpitations or flutter in chest, low BP. irregular pulse * skin pale and cool * confusion
what are the 3 degrees of heart block?
*1 and 2= impulse delayed *3rd= impulse never gets through, ventricles develop own rhythm separate from atrial rhythm; treated by pacemaker
What are some reasons an premature atrial contraction occurs?
*caffeine *nicotine *sympathetic NS stimulants * response to heart disease and or metabolic disorders(hyperthyroidism)
Treatment and drugs for A-fib?
*ibutilide(Corvert) * flecainide( Tambocor) * propafenone(Rythmol) * elective cardioversion * digitalis * maze procedure or surgical ablation *verapamil *amiodarone * anticoagulant
examples of arrhythmias originating in the atria?
*sinus bradycardia *sinus tachycardia * premature atrial contractions * supraventricular tachycardia * atrial flutter * afib
PVC patterns suggest myocardial irritability: name them
1. six or more per min 2. bigeminy: every other beat 3. couplets: 2 4. runs of PVCs : three or more in a row 5. multifocal PVC: more than one location 6. R wave falls on T wave of complex(R-on-T phenomenon)
what are the 3 types of temporary pacemakers?
1. transcutaneous 2. transvenous 3. transthoracic
during _____, several areas in the right atrium initiate impulses resulting in disorganized rapid activity. The atria quiver rather than contract
A-fib
what analyzes the hearts rhythm to determine if defibrillation is needed?
AED
what cholinergic blocking agent is given IV and increases a slow HR?
Atropine sulfate * 0.5 mg q3-5min until maximum dose of 3
Characteristics of normal sinus rhythm
HR 60-100 BPM SA node initiates impulse impulse travels to AV node in 0.12-0.2 second
what is the treatment for an serious PVC?
IV bolus of lidocaine (Xylocaine) * watch for toxicity
Fill in the blank age increases the risk for arrhythmias as a result of decreased number of cells in the __ node and altered function of the cells from accumulated fat and calcium.
SA node
T or F. Healthy athletes with a HR of less than 60 BPM is normal?
T *it reflects a well-toned heart
T or F One of the chief complications of a-fib is blood clots that may cause stroke
True
arrhythmia (dysrhythmia)
abnormally slow or rapid HR
where can cardiac arrhythmias originate?
atria, AV node, or ventricles
what is an disorder in which a single atrial impulse outside the SA node causes the atria to contract at an exceedingly rapid rate ( 200-400 contractions/minute)?
atrial flutter
asystole=?
cardiac arrest
use of drugs to eliminate an arrhythmia is referred to?
chemical cardioversion