Download UCLA EKG Exam: Questions and Answers on Cardiac Rhythms and Electrophysiology and more Exams Nursing in PDF only on Docsity!
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ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
Junctional rhythm - ANSWERS-rhythm: regular rate: 40- 60 P wave: abnormal, ( inverted before or after, or hidden with QRS) site of pacemaker: AV node PR interval: <0.12 when present QRS: normal ( 0.04- 0.12) QT interval: normal ( 0.36- 0.46) conduction: 1:1 with abnormal P QUESTION 2 Causes of junctional rhythm - ANSWERS-digitalis toxicity acute MI
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QUESTION 3
TX of junctional rhythm - ANSWERS-usually none Symptomatic: atropine junctional rhythm rate junctional accelerated rhythm rate junctional tachycardia - ANSWERS-junctional rhythm: 40- 60 junctional accelerated: 60- 100 junctional tachycardia: > QUESTION 4 NSR with 1 PJC premature junctional ( rhythm, rate, P wave, site of pacemaker, QRS, ST segment, QT interval) - ANSWERS-rhythm: regular except for PJC rate: varies with underlying rhythm P wave: occur early, not present, or occurs after QRS complex site of pacemaker: ectopic junctional foci
END OF PAGE PR interval: normal, except for PVC QRS: widened in pVC QT: normal, but nor measurable in PVC QUESTION 8 causes of PVC - ANSWERS-- anxiety
- excess caffeine
- hypoxemia
- hypokalemia
- hypomagnesemia
- hypocalcemia
- myocarditis
- MI QUESTION 9 TX for PVC - ANSWERS-- treat underlying cause
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QUESTION 10
PVC classifications - ANSWERS-- unifocal: arising from a single ectopic focus, each PVC is identical
- multifocal: arising two or more ectopic foci, multiple QRS morphologies QUESTION 11 Patterns of PVC - ANSWERS-bigeminy: every other beat is PVC trigeminy: every third beat is PVC quadrigeminy: every fourth beat is a PVC Couplet: two consecutive PVC triplet: three consecutive PVC are considered as a run of VT QUESTION 12 Idioventricular rhythm - ANSWERS-Rhythm: regular rateL 20- 40
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- hypo magnesia
- MI
- CHF
- valvular disease
- hypoxemia TX of VT (pulseless, recurrent VT) - ANSWERS-- Pulseless: CPR and defib recurrent VT: automatic implantable cardioverson ( AICD) V- fib ; ( rhythm, rate, P wave, QRS, ST, QT) - ANSWERS-rhythm: chaotic, disorganized, may appear as coarse or fine fibrillary waves Rate: none P wave: absent Site of pacemaker: multiple ectopic foci in ventricles QRS: absent St segment: absent QT interval : absent
END OF PAGE causes of V- fibrillation - ANSWERS--CAD
- MI TX: V- fib - ANSWERS-- CPR, immediately followed by defib accelerated junctional into Torsedes de points ( rhythm, rate, p wave, site of pacemaker, pr, QRS) - ANSWERS-rhythm: underlying is regular, Toresedes is irregular with variation of V tach then twist rate: measurable in underlying rhythm only P wave: unable to determine Site of pacemaker; ventricle PR interval:absent QRS: measure in underlying rhythm only causes of torsades de pointe - ANSWERS--hypomagnesemia
- drugs inducing prolonged QT interval TX of accelerated junctional rhythm with torsedes de pointe - ANSWERS-IVPB magnesium sulfate if pulseless: CPR, defib, then IVPB mag
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- transvenous
- transcutaneous failure to capture - ANSWERS-- appears on EKG as a spike without P wave or QRS complex failure to sense - ANSWERS-a paced stimulus is not generated in a situation where expected: recognized by absent pacemaker spikes and ventricular asystole
- pacemaker fires anywhere in the intrinsic cycle electrically polarized at rest - ANSWERS-- inside of heart cell has a high potassium concentration, whereas the outside has a higher concentration of NA
- higher positive charge outside the cell cause more negative charge inside cell electrical potential - ANSWERS-difference between the charges outside and inside of the cell wall Depolarization - ANSWERS-NA moves into the cell rapidly in response to an electrical impulse
- inside cell loses negative potential Replolarization - ANSWERS-ions return to their original resting state
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- heart cells restore their resting polarity 4 Phases of Electrophysiology of the heart cell - ANSWERS-Phase 0: Na flow in and rapid depolarization occurs when stimulated Phase 1: Rapid return to isoelectric level Phase 2: CA ions flow in and myocytes contract Phase 3: K flow out and rapid depolarization occurs Phase 4: Polarized resting phase Pacemaker cells - ANSWERS-- Sinoatrial node ( SA) node
- Atrioventricular node )AV node
- Purkinjie fibers SA node - ANSWERS--primary pacemaker
- Rate: 60- 100
- SA node depolarizes the atria via intro nodal tracts and Bachmann;s bundle = resulting in atrial contraction AV node - ANSWERS-- responsible for slowing down conduction from the atria to ventricles just long enough for atrial contraction to occur
- rate: 40- 60
END OF PAGE v5: between v4 and v v6: between midaxillary line and 5th intercostal space EKG paper - ANSWERS-- small box: 0.04 secs
- 5 small box: 0.2 secs
- 5 Large box= 1 second
- 300 large boxes = 60 secs PR interval - ANSWERS-0.12- 0.20 secs
- beginning of the P wave to beginning of the QRS QRS complex interval/ duration - ANSWERS-- 0.04- 0.12 secs
- ventricular deplolarization U wave - ANSWERS-- small low amplitude that follows T wave
- indicative of hypokalemia QT interval - ANSWERS-0.36- 0.44 secs
- measures beginning of ventricular replarization to end of reploarization medications that prolong QT interval - ANSWERS-- amiodarone
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- sotalol
- levofloxacin
- zofran
- celexa
- haloperidol
- benedryl
- erthyromycin Age specific heart rates - ANSWERS-NEONATES: awake 100-180 RR 30- 60 INFANTS: awake: 100-160, RR: 30- 60 TODDLER: (1-2 YRS): 80 - 110, RR 24- 40 PRESCHOOLER: 70 - 110, RR 22- 34 SCHOOL AGE:
END OF PAGE Rate < 60 P wave: present, upright, Site of pacemaker: SA node PR interval: normal ( 0.12-0.20) QRS: (0.04- 0.20) QT: < 0. Conduction: 1:1 relationship, each P wave followed by QRS Sinus Bradycardia TX ( if symptomatic) - ANSWERS--atropine IV with MD at bedside
- pacing Sinus bradycardia causes - ANSWERS-- normal for athletes
- conditions producing excess vagal stimulation or decreased sympathetic stimulation
- beta blockers
- calcium channel blockers
- obstructive sleep apnea
- prolongled hypoxia
- increased intracranial pressure
END OF PAGE Sinus tachycardia ( rhythm, rate, P wave, site of pacemaker, PR interval, QRS, QT interval, conduction) - ANSWERS-rhythm: regular rate: 100- 150 P wave: present, upright, site of pacemaker: SA node PR interval: 0.12-0. QRS: 0.04-0. QT interval: within normal, commonly shortened Conduction: 1:1 conduction, each QRS preceded by a P wave sinus tachycardia tx: - ANSWERS-treat underlying cause Sinus tachycardia causes - ANSWERS-- exercise
- pain
- stress
- fever
- anemia Premature Atrial Contraction ( rhythm, rate, P wave, site of pacemaker, PR interval, QRS, QT interval, conduction, causes) - ANSWERS-rhythm: irregular due to PAC rate: the same for atrial and ventricular
END OF PAGE atrial rate: not discernible ( too chaotic) site of pacemaker: multiple ectopic atrial foci PR: not measurable QRS: 0.04-0. QT interval; not measurable Conduction: atrial fib with ventricular response of ------ a- fib causes - ANSWERS-- CHF
- valvular disease
- common in COPD
- acute MI
- cardiomyopathy A-fib tx: - ANSWERS-control rate and rhythm:
- diltiazem
- metoprolol
- amiodorane
- anticoagulants Unstable:
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- cardioversion atrial flutter ( rhythm, rate, p wave, site of pacemaker, PR interval, QRS, ST segment, qt interval, conduction) - ANSWERS-rhythm: regular or irregular ventricular rate: can be regular atrial rate: conduction rate ( P waves before qrs x ventricular rate) site if pacemaker: re entry of atrial ectopy PR: not measurable: QRS: 0.04-0. QT: not Measurable conduction: variable causes of atrial flutter - ANSWERS-- ACS
- htn
- cardiomyopathy
- PE
- COPD A-flutter tx - ANSWERS--diltiazem
- metoprolol
- amiodorone
