Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
M6 13-005
Exam 4: Cardiovascular System; Cardiac Dysrhythmias
| Term | Definition |
|---|---|
| Conduction system of the heart | Autonomic Nervous System |
| Autonomic Nervous System | Sympathetic & Parasympathetic |
| Conduction System Heart Muscle Characteristics | Automaticity & Irritability |
| Automaticity & Irritability | Characteristics that affect the conduction system |
| SA Node | Site of normal impulse origin |
| Bachmann's | Impulse leaves the SA node, traveling through the atria via ____ |
| 40-60 BPM | Impulse wave continues to the AV node of the heart @ |
| Bundle of His | Divides into the right and left bundle branches that extend down either side of the interventricular septum |
| Purkinjie Fibers | Generates in impulse of 20-40 BPM |
| 20-40 BPM | Pukinjie Fibers impulse rate |
| Flow of electricity through hearts conduction system | SA node> AV node> Bundle of his, (right and left bundle branches) Purkinjie Fibers |
| EKG (ECG) | Graphic study of the recording of the electrical activity of the myocardium |
| Depolarization | the conducted cardiac impulse transiently reverses membrane polarity. In this depolarized phase the myocardium is incapable of further contraction. |
| Repolarization | The process whereby the membrane, cell, or fiber, after depolarization, is polarized again, with positive charges on the outer and negative charges on the inner surface. |
| EKG Machine | Records the heart's electrical activity from electrode sensors placed on the skin |
| Hoizontal axis | Represents time |
| Vertical Axis | Represents voltage |
| .02 Seconds | 1 square on rhythm strip equals |
| 1 second | 1 Block (5 squares) on rhythm strip equals |
| 3 seconds | 15 blocks on rhythm strip equals |
| Rate Determination Methods (4) | Cardiac Ruler Method, Six second Tracing Method, 300 Method, 1500 Method |
| P, Q, R, S, and T Waves | Components of the Normal ECG Complex |
| P Wave | First positive deflection representing depolarization of the atria. (0-0.2 seconds) |
| Q Wave | First NEGATIVE deflection after the P wave |
| R Wave | First POSITIVE deflection after the P wave |
| S Wave | NEGATIVE deflection after the R wave |
| QRS Complex | Represents ventricular depolarization. (0.06-0.12 Seconds) |
| PR Interval | Represents the time it takes an impulse to travel from the SA node across the atria t the AV node fibers (0.12-0.20) |
| T Wave | Represents repolarization of the ventricle |
| ST Segment | Represents early repolarization of the ventricular muscle. |
| Steps for interpreting the EKG | Systemic analysis, Determine Heart Rate, Determine Rhythm |
| Rhythm Strip | Find P waves, measure P-R interval, Measure the QRS complex, Find the T waves, Evaluate the ST segment, Measure the QT interval |
| Dysrhythmia | Any cardiac rhythm that deviates from normal conduction with normal intervals. Results from irritability of myocardial cells that generate impulses. |
| Normal Sinus Rhythm (NSR) (StriP) | Rate: 60-100 bpm Rhythm: Regular (Consistent R-R & P-P) P Wave: Present for each QRS complex, Normal config, normal P-R interval, Normal QRS interval, T wave upright |
| Types of Dysrhythmias | Sinus Tachycardia, Sinus Bradycardia, Supraventricular Tachycardia, Atrial Flutter/Fibrillation, Atrioventricular Block, Premature Ventricular Contracions, Ventricular Tachycardia, Ventricular Fibrillation |
| Dysrhythmias are a result of what? | Either an alteration of the formation of the impulse through the SA node to the rest of the myocardium or irritability of the myocardium cells. |
| Sinus Tachycardia (Strip) | Rate: greater than 100 Rhythm: Regular P Wave: present for each QRS complex, normal config, and each P wave is identical P-R interval: normal QRS Complex: Normal T Wave: Normal |
| Sinus Tachycardia (Etiology) | Sympathetic Nervous System stimulates the heart, increasing the rate. Increase is gradual. |
| Sinus Tachycardia (Causes) | Anxiety Exercise Fever Shock, hypotension Medications (i.e. vasopressors, albuterol) Hyperthyroidism. Heart failure, angina Stimulants (caffeine, nicotine, amphetamines) Hypothermia, Pain |
| Sinus Tachycardia (Manifestations) | Many Pt's asymptomatic, occasional palpitations, Hypotension, Angina, SOB, Diaphoresis, HF |
| Sinus Tachycardia (Medical Management) | Directed at treating the underlying cause, normally not caused by cardiac problem |
| Sinus Bradycardia (Strip) | Rate: Less than 60 BPM. Rhythm: R-R & P-P intervals are regular P Wave: Present for each QRS complex, normal configuration, and each P wave identical PR interval: Normal QRS Complex: Normal T Wave: Normal |
| Sinus Bradycardia (Etiology) | Parasympathetic nervous system is stimulated, causing the SA node to slow |
| Sinus Bradycardia (Underlying Causes) | Normal in the well-conditioned athlete Medications (B-blockers, digoxin) Hypothyroidism Cardiac diseases; predominately acute MI Sleep Hypothermia Vagal stimulation (i.e., vomiting, bearing down, holding breath) Intracranial tumors |
| Sinus Bradycardia (Manifestations) | May be asymptomatic Fatigue Hypotension, Lightheadedness, and syncope |
| Sinus Bradycardia (Medical Management) | Atropine (0.6-1.0 mg IVP) Transcutaneous pacing, until transvenous pacer available Dopamine (5-20ug/kg/min) Epinephrine (2-10ug/min) Isoproteronol (2-10ug/min) |
| Supraventricular Tachycardia (Strip) | Rate: usually 150-250 Rhythm: Regular P Wave: Present for each QRS complex, normal configuration, and each P wave is identical PR Interval: Normal QRS Complex: Normal T Wave: Normal |
| Supraventricular Tachycardia (Etiology) | Cause not typically associated with heart disease |
| Supraventricular Tachycardia (Manifestation) | Palpitations, angina, lightheadedness, fatigue SOB, dyspnea Change in LOC |
| Supraventricular Tachycardia (Medical Management) | Determine Pt tolerance of dysrhythmia Focus is aimed at decreasing the heart rate and eliminating the underlying cause Adenosine: 6mg-12mg-12mg |
| Atrial Flutter (Strip) | Rate: Variable Rhythm: Regular or irregular P Wave: Multiple P's/QRS PR Interval: Varies (have to count it) QRS complex: Varies T Wave: May not be visible |
| Atrial Fibrillation (Etiology) | Atherosclerosis Cardiac surgery, acute MI Mitral valve disease, cardiac stretch Digitalis preparations HF, cardiomyopathy, HTN, volume overload COPD (Chronic Obstructive Pulmonary Disease) Thyrotoxicosis |
| Atrial Flutter/Fibrillation (Manifestations) | Palpations Lightheadedness Syncope Angina Change in LOC Pulmonary Edema Decreased Cardiac Output Thrombi form that may cause embolism |
| Atrial Flutter/Fibrillation (Medical Management) | Focused on controlling rate, converting rhythm and providing anticoagulation. Synchronized cardioversion: if unstable, or unresponsive to meds Calcium channel Blockers Digoxin Amiodarone Heparin/Coumadin |
| Amiodarone | used to help keep the heart beating normally in people with life-threatening heart rhythm disorders of the ventricles (the lower chambers of the heart that allow blood to flow out of the heart). |
| Atrioventricular Blocks | A defect in the AV slows or impairs conduction |
| 3 Types of Atrioventricular Blocks | First Degree AV Block Second Degree AV Block (Types I & II) Third Degree AV Block |
| First Degree AV Block (Strip) | Delayed conduction through the AV Node causes prolonged PR INterval |
| Second Degree AV Block (Type I) | Mobitz I Wenckelbach |
| Second Degree AV Block (Type II) | Mobitz II Classical |
| Third Degree AV Block | Complete Heart Block complete AV Dissociation |
| Premature Ventricular Contractions | Extra, abnormal heartbeats that begin in one of your heart's two lower pumping chambers (ventricles). |
| Premature Ventricular Contractions (Etiology) | Irritability of the ventricular musculature |
| Premature Ventricular Contractions (Strip) | Rate: Varies Rhythm: Usually regular w/ PVC coming earlier than next expected P Wave: No t visible, hidden in the PVC PR interval: not visible QRS Complex: Wide and bizarre (greater than 0.12 seconds "sore-thumb" appearance) T Wave:dflect opposite QR |
| Premature Ventricular Contractions (P Wave) | the SA node continues to transmit impulses- but the impulses does not reach the ventricles because the ventricle is depolarized by the PVC |
| Premature Ventricular Contractions (Medical Management) | Focus on treating the underlying cause. Evaluate Electrolytes Assess for hypoxia and treat prn Monitor for effect on hemodynamics |
| Ventricular Tachycardia (Strip) | Rate: 140-240 BPM Rhythm: Regular Pwave: not visible QRS Complex: wide and bizarre (Greater than 0.12 secs) T Wave: usually deflected opposite to the QRS complex & difficult to see |
| Ventricular Tachycardia (P Wave) | SA node continues to transmit impulses normally, until it becomes hypoxic, but impulses are not transmitted to ventricle, as ectopic focus is depolarizing ventricles |
| Ventricular Tachycardia (Etiology) | Acute MI, Hypoxemia, Metabolic Acidiosis (especially lactic acidosis), Electrolyte disturbances (K+ & Mg+), Toxicity to certain drugs, such as digitalis or isoproterenol |
| Ventricular Tachycardia (Clinical Manifestations) | Fatigue, SOB, Dyspnea, Lightheadedness, syncope, hyptotension, shock, chest pain, pulselessness |
| Ventricular Tachycardia (Medical Management) | Depends on if rhythm os stable or unstable and whether VT is confirmed or suspected. |
| Ventricular Tachycardia (Drug Therapy) | Amidarone, Lidocane, Magnesium, Procinamide |
| Ventricular Fibrillation | Rapid and disorganized ventricular pulsation. Produces clinical death & must be reversed immediately, or Pt will die. SAWTOOTH!!! |
| Ventricular Fibrillation (Strip) | Rate: Unmeasurable Rhythm: Irregular P Wave: Not present PR Interval: Not present QRS Complex: Not measurable (no definable complexes) T Wave: not present |
| Ventricular Fibrillation (Etiology) | Myocardial ischemia or infarct Deteriorating ventricular rhythms (such as V-Tach) Acidosis Electrolyte imbalances Hypothermia Digitalis or quinidine toxicity |
| Ventricular Fibrillation (Manifestations) | Loss of conciousness Loss of pulse, respiration and blood pressure Death |
| Ventricular Fibrillation (Management) | Check pulse Airway: open the airway Breathing Circulation |
| Abnormality in ST | Rate too high |
| Abnormality in SB | Rate too low |
| Abnormality in SVT | Rate too high May also have shortened PR interval |
| Abnormality in A Flutter | Atrial rate too high May be irregular Ventricular rate may also be high |
| Abnormality in A Fib | No P waves Irregularly irregular Ventricular rate may also be high |
| Abnormality in First Degree AV Block | Prolonged PR interval |
| Abnormality in Second Degree AV Block (Type I) | Irregular Consecutively prolonged PR interval until a QRS complex is dropped More Ps than QRSs |
| Abnormality in Second Degree AV block (Type II) | Irregular P waves are not conducted More Ps than QRSs |
| Abnormality in Third Degree AV Block | No relationship between P and QRS More Ps than QRSs Prolonged QRS |
| Abnormality in PVC | Prolonged QRS |
| Abnormality in V Tach | Rate too high No visible P waves QRS prolonged |
| Abnormality in V Fib | No discernible waveforms |
| Antiarrhythmic Agents | Suppression of cardiac arrhythmias |
| Antiarrhythmic Agents (Action) | Correct arrhythmias bey a variety of mechanisms, depending on the group used |
| Antiarrhythmic Agents (Therapeutic Goal) | Dcrease symptomatology and increase hemodynamic performance. |
| Antiarrhythmic Agents (Choice) | Depends on etiology of arrhythmia and individual patient characterisitc |
| Antiarrhythmic Agents Class 1A (Drug) | Disopyramide Procainamide Quinidine |
| Antiarrhythmic Agents Class 1B (Drug) | Lidocane |
| Antiarrhythmic Agents Misc (Drug) | Adenosine Digoxin |
| Antiarrhythmic Agents 1A (Mechanism) | Depresses Na conductance, increases action Potential duration (APD) and effective refractory period (ERP), decreases membrane responsiveness |
| Antiarrhythmic Agents 1B (Mechanism) | Increases K conductance, decreases APD and ERP |
| Antiarrhythmic Agents Misc. (Mechanism) | Slows conduction through the AV node. Decreases conduction velocity and prolongs the effective refractory period in the AV node. |
| Antiarrhythmic Agents Nursing Implications | Monitor BP, Pulse, and ECG before and routinely throughout therapy. Check Apical pulse before administering meds. Withhold if <50 or >120bpm. Monitor I&Os and daily weights. |
| Cardioversion | Used for tachydysrhythmias when pharmacological intervention has been unsuccessful or the patient is compromised by a decreased cardiac output. |
| Current is discharged during cardioversion | At the QRS Complex |
| Pacemaker | Battery-operated device that initiates and controls the heart rate Used for patients with bradydysrhythmias, tachydysrhythmias, or 2nd and 3rd degree heart block that cannot be controlled with medications alone |
| Pacemaker dysfunction S/S | Change in LOC, Bradycardia, Hypotension |
Created by:
jtzuetrong
Popular Medical sets