dysrhythmias Flashcards
1
Q
dysrhythmias
A
abnormal cardiac rhythm
2
Q
ECG
A
- graphic tracing of electrical impulses produced by the heart
- waveforms represent activity of charged ions across membranes of myocardial cells
3
Q
phases of cardiac action potential
A
- phase 0
- phase 1,2,3
- phase 4
4
Q
ECG leads
A
- six leads (I, II, III, aVR, aVL and aVF) measure electoral forces in frontal plane
- six leads (V1-V6) measure forces in horizontal plane
5
Q
counting HR in ECG
A
- number of QRS complexes in 1 min
- R-R intervals in 6 seconds, and multiply by 10
- number of small squares between one R-R interval and divide the number by 1500
- number of large squares between one R-R interval and divide the number by 300
6
Q
client prep for ECG
A
- clip excessive hair on chest wall
- gently rub skin with dry gauze until skin is slightly pink
- may need to use alcohol for oily skin
- apply electrical conductive gel
7
Q
sinus bradycardia
A
- sinus node fires <60 bpm
- normal rhythm is aerobically trained
8
Q
sinus tachycardia
A
discharge rate from sinus node is increased
9
Q
premature atrial contraction (PAC)
A
- travel across atria by abnormal pathway
- distorted P wave
- may be stopped, delayed, or conducted normally at the AV node
- can result from: emotional stress, physical fatigue, use of caffeine and tobacco, hypoxia
- significance: isolated PACs are not significant in healthy hearts but in those with heart disease it can be a warning of more serious dysrhythmias
10
Q
paroxysmal supraventricular tachycardia (PSVT)
A
- originates in ectopic focus anywhere above bifurcation bundle of HIS
- run of repeated premature beats
- abrupt onset and termination
- clinical associations: overexertion, emotional stress, stimulates, CAD
- clinical significance: prolonged episode and HR > 180 may precipitate decreased CO, hypotension, dyspnea, angina
- tx: vagal manoeuvres (Valsalva stimulation, coughing, holding breath), IV adenosine
11
Q
atrial flutter
A
- recurring, regular, sawtooth-shaped flutter waves
- originates form single ectopic focus
- clinical associations: CAD, hypertension, mitral valve disorders, pulmonary embolus, chronic lung disease, cardiomyopathy, hyperthyroidism, medications (digoxin, quinidine, epinephrine)
- clinical significance: high ventricular rates (>100) and loss of atrial “kick” can decrease CO and precipitate HF
12
Q
atrial fibrillation
A
- total disorganization of atrial electrical activity due to multiple ectopic foci, resulting in loss of effective atrial contraction
- significance: decrease in CO, thrombi may form in atria, embolus may develop
- pts usually on blood thinners
13
Q
first degree AV block
A
- every impulse is conducted to the ventricles but duration of AV conduction is prolonged
- PR interval is long
- usually asymptomatic
- client should not be on beta blockers
14
Q
premature ventricular contractions (PVC)
A
- contraction originating in ectopic focus of the ventricles
- premature occurrence of a wide and distorted QRS complex
- associated with: stimulants, electrolyte imbalance, hypoxia, fever, exercise, MI, HF, CAD
- significance: benign in healthy heart, in heart disease can decrease CO and precipitate angina and HF if >10/minute
15
Q
ventricular tachycardia
A
- run of 3+ PVCs
- considered life threatening because of decreased CO and the possibility of deterioration to ventricular fibrillation
- no P or T waves, widened and more frequent QRS complex
- HR is >180
- sustained VT can cause hypotension, pulmonary edema, decreased cerebral flow and MI
