| Question | Answer |
| SA Node | Dominant pacemaker with intrinsic rate of 60-100 bpm |
| AV Node | Back up pacemaker. intrinsic rate of 40-60 bpm |
| Ventricular cells | back up pacemaker with 20-45 bpm |
| what is normal impulse conduction? | SA-AV-Bundle of His-bundle branches-purkinje fibers. |
| what does P wave represent? | atrial depolarization |
| what does QRS wave rep.? | Ventricular depolariztion |
| what does T wave rep? | Ventricular repolarizaton |
| what is the S-T segment? | atrial and ventricular repolarization, should be at baseline,
-Tall or spiked waves=Hyperkalemia,MI
-elevation=infarction
-depression=ischemia |
| ECG paper boxes | -Horizontally
small box=.04s
large box=.20s
-vertically
1 large box=0.5mv |
| What is duration of PR interval? | 0.12-0.20sec |
| What is duration of QRS interval? | 0.06-0.10sec |
| What is duration of ST segment? | not elevated or depressed. |
| normal heart rate =? | 60-100bpm |
| bradycardia=? | <60bpm |
| Tachycardia=? | >100bpm |
| Flutter=? | >200bpm |
| fibrillation=? | Too fast to count |
| How do you estimate heart rate? | count the # of R waves in a 6 sec. strip and X by 10. Or do
300
___
# of large blocks between R waves. |
| http://pediatriccardiology.uchicago.edu/PP/Images/Nsr.jpg | Normal sinus rhyth. |
| http://www.cardionetics.com/cardiology/_cardioimages/rhythms/ecg_sinus_bradycardia_1.jpg | bradycardia <60bpm
Tx:O2 and atropine |
| http://www.bannerhealth.com/NR/rdonlyres/5CFF4A7B-01B5-4B7A-BF9B-02737DF18C02/24236/tachycardia.jpg | tacycardia >101-160
Tx:o2 |
| http://www.ambulancetechnicianstudy.co.uk/images/Flutter.gif | Atrial flutter 250-350bpm
Tx:O2, digoxin, cardioversion,
beta blockers |
| http://www.jewishhospital.org/myjewishhospital/images/CV-07.jpg | atrial fibrillation 400-700bpm
chaotic and irregular rhyth.
causes: hypoxia,ischemic heart disease, MI
Tx:O2 digoxin, cardioversion,
beta blockers |
| http://www.txai.org/img/edu/PVC.jpg | PVC. rate depends on underlying rhyth. P wave absent.
Causes:caffeine, stress, alcohol,acidosis,MI, hypoxemia.
Tx:O2, Lidocaine or Amiodorone. |
| http://www.cprworks.com/vt | VTach.
Rate 100-200bpm rhythm regular.
no P waves, causes same as PVc
Tx: defib. if no pulse, lidocaine or amiodorone and cardioversion if pulse present. |
| http://www.learnekgs.com/V-Fib%20LARGE.jpg | V Fib
Rate:NONE rhythm: chaotic
pQRS wav: absent
No cardiac output or pulse
Causes: acute MI, untreated Vtach,hypothrermia, electrolyte imbalance, electric shock.
Tx: Defib., CPR, O2 |
| http://www.rnceus.com/ekg/asystole.gif | Asystole
Rate:none rhythm:none
Confirm in 2 leads first,
Causes: ischemia, infarct. hypoxia,hypothermia, drug od, acute resp. fail.
Tx: CPR, epi, atropine |
| What is ischemia? | decreased blood flow to the tissue;depressed or inverted T wave |
| what is meant by injury? | Acute damage to the tissue often from ischemia; elevated S-T segment |
| what is Infarction? | death of tissue; the end result of ischemia or injury. |
