ECG

Question 1

Normal sinus rhythm

Answer 1

begins in SA node travels to rest of heart. 60-100bpm

Question 2

sinus bradycardia

Answer 2

<60bpm. normal rhythm

Question 3

Sinus tachycardia

Answer 3

> 100bpm. normal rhythm

Question 4

sinus arrhythmia

Answer 4

sinus rhythm but quickening/ slowing of implus from SA node that produces beat to beat variation in rate

Question 5

Sinus Arrest

Answer 5

sinus rhythm but with intermittent failure of impuls in SA or AV node that results in loss of P or QRS waves

Question 6

premature atrial contraction

Answer 6

ectopic focus in atrium initiates pulse before SA node. p wave is premature. very common but may lead to atrial flutter, tachycardia or fib

Question 7

atrial flutter

Answer 7

ectopic very rapid tachycardia. 250-350bpm. occurs with valvular disease, ischemia, MI, hypertension, COPD, etc. get palpitations, lightheaded, angina

Question 8

Atrial fibrilation

Answer 8

common arrhythmia where atria are depoloraized 350-600x/min. palpitations, fatigue, dyspnea, syncope, chest pain

Question 9

1st degree AV block

Answer 9

PR interval longer than 0.2 sec. no real symoptoms or change in cardiac funciton

Question 10

2nd degree AV block

Answer 10

AV conduction disturbance where impulses btwn atria and ventricles fail intermittently.

Question 11

3rd degree AV block

Answer 11

all impulses blocked at the AV node and none a transmitted to ventricles. atria and ventricles are paced independently with atria >vent. medical emergency requiring pacemaker

Question 12

Premature ventricular contractions

Answer 12

ectopic ventricle focus. p wave absent QRS has wide aberrant shape. common from anxiety caffeine, stress, smoking, heart disease

Question 13

V-tach

Answer 13

3 or more PVCs at ventricular rate >150bpm. longer than 30sec is life threatening, can progress to V-fib. caused by MI, cardiomyopathy, valvular disease

Question 14

V-Fib

Answer 14

ventricles do not beat n coordinated fashion, quiver/ fibrillate. No cardiac ouput, unconscious. required defibrillation

Question 15

Ventricular asystole

Answer 15

ventricular standstill with no rhythm. ECG =straight line, requires defibrillation.

Question 16

ST segment depression

Answer 16

sign of ischemia, digitalis toxicity, hypokalemia

Question 17

ST segment elevation

Answer 17

earliest sign of MI. can also indicate benign early repoloraization in normal heart

Question 18

Qwave

Answer 18

marker of infarction; loss of positive electrical voltage from necrosis. Q wave longer than .04 msec and larger than 1/4 amplitude of the R wave

Question 19

T wave inversion

Answer 19

occurs hours or days after MI as a result of delay in repolarization produces by injury. also occurs after R/L BBB, after CVA.

Question 20

indications for terminating exercise stress test

Answer 20

• Drop in SBP >10mmHg despite inc in workload
• mod/severe angina (3/4)
• increasing nervous system symptoms (ataxia, dizziness)
• poor perfusion (cyanosis, pallor)
• v tach sustained
  1. 0mm elevation in ST segment

Question 21

exercise stress test interpretation

Answer 21

neg test= low probability of CAD

pos test= high probability of CAD

Question 22

normal PR interval

Answer 22

.12-.20 sec

Question 23

Normal QRS

Answer 23

.04-.10 normal ventricular conduction

Question 24

Rate pressure product (RPP)

Answer 24

index of myocardial O2 consumption and coronary blood flow. can correlate to onset of angina. RPP=HRxSBP. Can be used to prescribe exercise below level that would produce angina.