T5: Dysrhythmias, Defib, Pacemakers Flashcards
parasympathetic nervous system ____ the rate of the SA node
decreases
sympathetic nervous system ____ the rate of the SA node
increases
SA node is the
pacemaker of the heart
bpm of SA node
60-100 beat/minutes
what are the secondary pacemakers
AV node and Purkinje fibers
bpm of av node
40-60 bpm
bpm of purkinje fibers
20-40 bpm
placing 12-lead ECG
-Clip excessive hair on chest wall
-Rub skin with dry gauze
-May need to use alcohol for oily skin
-Apply electrode pad
-Artifact-movement or poor lead contact
when a client presents with a dysrhythmia what should the nurse do
assess the clinical status of the patient, do not treat the monitor
normal sinus rhythm (NSR)
*refers to a rhythm that starts in the SA node at a rate of 60 to 100 times per minute and follows the normal conduction pathway.
sinus tachycardia
*normal sinus rhythm. The sinus rate is 101 to 200 beats/minute
sinus tachycardia is associated with
*physiologic and psychologic stressors
treatment for sinus tachycardia
*Guided by cause (e.g., treat pain)
*Vagal maneuver
*β-blockers (metoprolol)
sinus bradycardia
*the conduction pathway is the same as that in sinus rhythm but the SA node fires at a rate less than 60 beats/minute
Sinus bradycardia may be a normal sinus rhythm in
*aerobically trained athletes and in some people during sleep.
clinical manifestations of sinus bradycardia
*Hypotension
*Pale, cool skin
*Weakness
*Angina
*Dizziness or syncope
*Confusion or disorientation
*Shortness of breath
treatment for sinus bradycardia
Unstable: atropine
stable: pacemaker
*Stop offending drugs
atrial fibrillation
*characterized by a total disorganization of atrial electrical activity due to multiple ectopic foci resulting in loss of effective atrial contraction.
*rate may be as high as 350 to 600 beats/minute.
in a fib the P wave is replaced by
*chaotic, fibrillatory waves.
a fib caused a
decrease in CO and an increased risk for stroke and clots
treatment for a-fib
*Drugs to control ventricular rate and/or convert to sinus rhythm (amiodarone and ibutilide most common)
*Electrical cardioversion
*Anticoagulation
*Radiofrequency ablation
*Maze procedure with cryoablation
Paroxysmal Supraventricular Tachycardia (PSVT)
A dysrhythmia originating in an ectopic focus anywhere above the bifurcation of the bundle of His. P wave is often hidden in preceding T wave, but if seen may have an abnormal shape. The PR interval may be shortened or normal, and QRS is usually normal.
BPM for PSVT
150 to 220 beats/minute
PSVT is associated with
*overexertion, stress, deep inspiration, stimulants, disease, digitalis toxicity, hormones, anesthesia
clinical manifestations of PSVT
*HR is 150-220 beats/minute (add for clarification)
*HR > 180 leads to decreased cardiac output and stroke volume
*Hypotension
*Dyspnea
*Angina
what medication should be given if the patient is symptomatic with PSVT
IV adenosine
treatment for PSVT
*Vagal stimulation
*IV adenosine
*IV β-blockers
*Calcium channel blockers
*Amiodarone
*DC cardioversion
Adenosine half life
10 seconds
first degree heart block
*a type of AV block in which every impulse is conducted to the ventricles but the time of AV conduction is prolonged. After the impulse moves through the AV node, the ventricles usually respond normally.
clinical manifestations first degree heart block
*Typically not serious
*Patients asymptomatic