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71 Cards in this Set
- Front
- Back
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ECG
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see electrical activity of the heart
must check pulse and VS to confirm |
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SA node
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pacemaker - first
60-100 bpm depolarize atria |
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AV node
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second
1. slows impulse for atrial kick = 10-20% more blood 2. back-up pacemaker = rate of 40-60 bpm (junctional/nodal rhythm) |
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bundle of HIS
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continuation of AV node
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purkinje system
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1. carries impulse to ventricular conducting cells
2. back-up escape pacemaker (20-40 bpm) |
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sequence of cardiac activation
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SA node
rt then left atria (systole - blood to relaxed ventricles) AV node (slows) bundle of HIS to purkinje fibers ventricles (systole - blood out) |
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action potential
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1. action phase - depolarization= change in permeability; enough sodium in/potassium out
2. resting phase - repolarization - sodium out, potassium in via active transport |
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P wave
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atrial depolarization
upright, rounded, less than 0.12 seconds, 1 per cycle |
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QRS complex
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ventricular depolarization (intraventricular conduction time)
down (Q), up (R), down (S) interval - lasts 0.06 - 0.12 seconds |
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T wave
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ventricular repolarization - return to resting state (ventricles are filling with blood)
upward, downward, indicator of ischemia |
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PR interval
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electrical impulse down atrium to AV node (beginning of P wave to beginning of QRS)
0.12 - 0.20 seconds longer = delayed conduction |
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ST segment
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early repolarization of ventricles
can indicate myocardial injury end of QRS to beginning of T wave |
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U wave
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not normally present
indicates hypokalemia |
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Lead II
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upright waves
positive electrode in midclavicular 5th intercostal space |
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MCL I
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downward waves
positive electrode in 4th intercostal space to right of sternum |
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ECG paper
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1 mm sq = 0.04 seconds, 5 squares = 0.20 seconds
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isoelectric line
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baseline tracing
waves either above or below (positive or negative) |
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5 steps to evaluate
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1. rhythmn - R to R or P to P are the same (regularly irregular or irregularly irregular or regular)
2. Rate - 60 to 100 bpm 3. P wave - upright, after QRS, look alike 4. PR interval - 0.12 to 0.20 seconds, look alike and contant 5. QRS complex - less than 0.12 seconds, look alike and constant |
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normal sinus rhythm
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1. 1 upright and consistent P wave before each QRS
2. All PR between 0.12 and 0.2 seconds 3. consistent QRS of less than 0.12 seconds 4. consistnet R-R interval 5. HR of 60-100 bpm |
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arrhythmia
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loss of rhythm, regularity of heart
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dysrhythmia
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abnormal, disordered, or disturbed rhythm
most accurate |
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causes of dysrhythmia
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1. disturbance in formation of impulse
2. disturbance in conduction of impulse |
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unstable rhythm = hemodynamic instability
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altered mental status
chest pain hypotension difficulty breathing/CHF syncope |
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SA node dysrhythmia
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usually 60-100 bpm
generally not dangerous |
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sinus bradycardia
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rate of less than 60 bpm
everything else is normal |
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causes of sinus bradycardia
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meds (Ca channel blockers, beta blockes, dig)
vagus nerve stimulation acute coronary syndrome hypoxia hypothermia |
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S&S of sinus bradycardia
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fatigue, dizzy, SOB, weakness, syncope, hypotension, CHF, chest pressure, tightness, pain
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management of sinus bradycardia
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no atropine for postcardiac transplant patients
O2, IV ACLS algorithm - atropine, transubutaneous pacing, dopamine, epi, isoproterenol |
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sinus tachycardia
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HR faster than 100 BPM (101-180)
everything else is normal |
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sinus tachycardia causes
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physical activity, hemorrhage (1st SIGN), shock, meds, dehydration, fever, MI, electrolyte imbalance, fear, anxiety, compensate for hypoxia
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S&S sinus tachycardia
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angina, dyspnea, increases heart's workload
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sinus tachycardia management
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meds - dig, CCB, beta blockers
oxygen treat CAUSE!!!! |
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atrial dysrhythmias
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atria can become primary pacemaker if they fire faster than SA node
rhythm generally 100-200+ bpm P waves will look different |
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supraventricular dysrhythmia
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less than 0.12 seconds for QRS, normal
problem is above ventricles |
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ventricular dysrhythmia
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greater than 0.12 seconds = wide QR complex
problem is in ventricles |
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premature atrial contactions
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atria fire before SA node
shortened R to R interval |
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causes of PAC
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hypoxia, smoking, stress, MI, enlarged atria in valvular disorders, meds (dig), electrolyte imbalances, atrial fibrillation, heart failure
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S&S of PAC
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generally none, possible palpitations
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CN 3 output to ocular muscles is primarily affected by
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vascular diseases (DM) due to decreased diffuse to the interior
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atrial flutter
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atria flutter at 250-350 bpm
F waves instead of P waves, picket fence appearance may have normal QRS complex |
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atrial flutter causes
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rheumatic, ischemic heart disease, CHF, hypertension, pericarditis, PE, post-op CABG
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atrial flutter rules
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1. rhythm is regular or irregular
2. HR varies 3. P waves into F waves 4. PR interval - not measurable 5. QR complex is less than 12 seconds |
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S&S of atrial flutter
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none, sometimes palpitations, angina, dyspnea
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managing atrial flutter
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control ventricular rate, convert rhythm
cardioversion (greater than 150 = stat) CCb + beta blockers control rate digoxin converts rhythm quinidine, procainamide, propranol slow HR |
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atrial fibrillation
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rapid and chaotic atrial rate - 250-600 bpm
ventricular rate lower as AV node blocks most impulses |
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atrial fibrillation complications
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increased risk of thrombus due to poor emptying of atrial blood
left ventricular failure |
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rule of atrial fibrillation
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rhythm - irregularly irregular
HR - atrial not measurable, ventricular either controlled (under 100 bpm) or rapid (over 100 bpm) P waves - no identifiable PR waves- none measured becuase no P waves QRS complex - 0.06 seconds to 0.10 seconds) |
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causes of atrial fibrillation
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rheumatic, ischemic heart disease, heart failure, hypertension, pericarditis, PE, post-op coronary artery bypass surgery
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symptoms of atrial fibrillation
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feel irregular rhythm - palpitations, skipping heart beat
faint radial pulse due to decreased stroke volume |
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atrial fibrillation management
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unstable: cardioversion stat
stable meds (CCB, BB, dig), anticoagulant therapy, cardioversion also: dual chamber pacing, implanted cardioverter defibrilators, ablation, maze) |
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meds for atrial fibrillation
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dofetilide, quinidine, flecainide, propafenone, ibutilide IV
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premature ventricular contractions
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occur before SA
ectopic focus (other than SA node) wide and bizzare QRS complex |
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PVC shapes
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unifocal - originate from one spot
multifocal - several irritable areas (look different) bigimeny - every other beat trigeminey - every third beat quadgeminy - every 4th beat couplet - 2 together run/ventricular tachycardia = 3 or more together |
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causes of PVC
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alcohol, caffeine, anxiety, hypokalemia, cardiomyopathy, ischemia, MI
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PVC rules
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1. rhythm - interrupted
2. HR - depends on rhythm 3. P waves - absent before PVC QRS complex 4. PR interval - none for PVC 5. QRS complex- greater than 0.12 seconds, t wave in opposite direction of QRS complex |
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S&S of PVC
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skipped beat, palpitation
decreasd cardiac output = dizzy, fatigue, severe dysrhythmias |
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PVC interventions
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needed only if more than 6 a minute, regularly occuring, multifocal, fall on t-wave, caused by acute MI
meds: procainamide, lidocaine |
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ventricular tachycardia
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3 or more PVCs in a row
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causes of VT
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myocardial irritability, MI, cardomyopathy
also respiratory acidosis, hypokalemia, dig toxicity, cardiac cath, pacing wires |
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VT rules
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1. rhythm: regular
2. HR: 150-250 BPM, slow is below 150 bpm 3. P waves: absent 4. Pr interval: none 5. QRS complex: greater than 0.12 seconds |
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S&S of VT
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sudden onset of rapid heart rate
dyspnea, palpitations, light-headed angina cardiac arrest |
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management of VT
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may need CPR, defib
stable: meds (amiodarone, procainamide, sotalol, lidocaine, phenytoin, BB; also magnesium) |
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ventricular fibrillation
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many ectopic ventricular foci fire at same time
chaotic ventricular activity - no waves ventricle cannot initiate contraction |
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causes of ventricular fibrillation
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hyperkalemia, hypomagnesemia, electrocution, CAD, MI, surgery
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ventricular fibrillation rules
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1. rhythm: chaotic, irregular
2. heart rate: not measurable 3. P waves - none 4. PR interval - none 5. QRS complex: none |
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ventricular fibrillation S&S
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lose consciousness
no heart sounds, no peripheral pulses, no blood pressure respiratory arrest, cyanosis, pupil dilation |
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ventricular fibrillation management
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defibrillation
CPR, AED Endotracheal entubation, ventilation for respiration meds: epi, vasopressin, amiodarone, lidocaine, magnesium, procainamide |
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asystole
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absence of electric activity in cardiac muscle; usually preceded by ventricular fibrillation
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asystole causes
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ventricular fibrillation, loss of cardiac muscle due to MI
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asystole rules
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rhythm: none
heart rate: none p waves: none Pr interval: none QRS complex: none |
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asystole management
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CPR, endotracheal intubation, transcutaneous pacing, epi/atropine
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