Chapter 4 Flashcards

Question

What are some causes of MAT?

Answer 1

Exact mechanisms of MAT is unknown but may involve altered automaticity or triggered activity Most often seen in older adults with severe chronic obstructive pulmonary disease (COPD) Also seen in setting of acute coronary syndromes, heart failure, pneumonia, hypoxia, valvular heart disease, hypokalemia, hypomagnesemia, or theophylline or digoxin toxicity

Answer 2

Common symptoms include palpitations, lightheadedness, anxiety, dyspnea, chest discomfort, and syncope Challenge to treat - best to consult a cardiologist before starting treatment Efforts are focused on managing the underlying cause Patients with MAT who do not respond to medical therapy may require AV nodal ablation with subsequent cardiac pacemaker implantation

Answer 3

Begin above the bifurcation of the bundle of his Include rhythms that begin in the — SA node / atrial tissue / AV junction

Answer 4

Supraventricular rhythms with a ventricular rate faster than 100bpm at rest Onset of SVT symptoms often begins in adulthood Can affect the quality of life Complaints of lightheadedness are common A drop in blood pressure typically occurs during SVT and is greatest in the first 10 to 30 seconds

Answer 5

3rd most common SVT. Regular rhythm that arises from an ectopic focus in the atria at a rate faster than 100bpm and does not require the AV node’s participation to maintain the dysrhythmia.

Answer 6

Rhythm: regular Rate: 101 - 250bpm P waves: one P wave precedes each QRS complex in lead II; these P waves differ in shape from sinus P waves an isoelectric baseline is usually present between P waves; if the atrial rhythm originates in the low portion of the atrium, P waves will be negative in the inferior leads; with rapid rates, it may be challenging to distinguish P waves from T waves PR interval: may be shorter or longer than normal; may be difficult to measure because P waves may be hidden in the T waves of preceding beats QRS duration: 0.11 sec or less unless abnormally conducted

Answer 7

Describes a rapid, regular SVT that starts and ends suddenly

Answer 8

1. Acute illness with excessive catecholamine release 2. Digitalis toxicity 3. Electrolyte imbalance 4. Heart disease — coronary artery disease / valvular disease / cardiomyopathy / congenital heart disease 5. Infection 6. Pulmonary embolism 7. Stimulant use — caffeine / albuterol / theophylline / cocaine

Answer 9

1. Acute changes in mental status 2. Asymptomatic 3. Dizziness or lightheadedness 4. Dyspnea 5. Fatigue 6. Fluttering sensation in the chest 7. Hypotension 8. Ischemic chest discomfort 9. Palpitations 10. Signs of shock 11. Syncope or near syncope

Answer 10

If symptomatic because of the rapid rate: 1. Apply a pulse oximeter and administer oxygen, if indicated 2. Obtain vital signs 3. Establish IV access 4. Obtain a 12 lead ECG 5. Vagal maneuvers 6. Adenosine 7. Beta blockers 8. Calcium channel blockers 9. Synchronized cardioversion

Answer 11

Carotid sinus massage Application of a cold stimulus to the face Valsalva maneuver

Answer 12

Can interrupt Reentry pathways involving the AV node Rapid onset of action Short half-life

Answer 13

Delivery of an electrical shock to the heart timed to occurring during QRS Used to treat rhythms with a creaky identifiably QRS complex and a rapid ventricular rate in a patient with a pulse and signs of hemodynamic compromise Examples of rhythms treated with cardioversion include narrow-QRS tachycardias, A-Fib, atrial flutter, and monomorphic ventricular tachycardia

Answer 14

Most common SVT Results from a Reentry circuit that uses two separate pathways leading into the AV node 1. One pathway conducts impulses rapidly but has a long refractory period (slow recovery time) 2. The other pathway conducts impulses slowly but has a short refractory period (fast recovery time) 3. Under the right conditions, these fast and slow pathways can form an electrical circuit or loop (Reentry circuit)

Answer 15

Rhythm: ventricular rhythm is usually very regular Rate: 150-250bpm P waves: often hidden in the QRS complex; if the ventricles are stimulated first and then the atria, a negative P wave will appear after the QRS in leads II, III, and aVF; when the atria are depolarized after the ventricles, the P wave typically distorts the end of the QRS complex PR interval: P waves are not seen before the QRS complex; therefore, the PR interval is not measurable QRS duration: 0.11sec or less unless abnormally conducted

Answer 16

Can occur at any age but is most often seen in young adults who have no structural heart disease or ischemic heart disease AVNRT also occurs in individuals with: 1. Chronic obstructive pulmonary disease 2. Coronary artery disease 3. Valvular heart disease 4. Heart failure 5. Digitalis toxicity

Answer 17

1. Hypoxia 2. Stress 3. Anxiety 4. Caffeine 5. Smoking 6. Sleep deprivation 7. Many medications

Answer 18

Possible assessment findings and symptoms: 1. Chest pain or pressure 2. Dizziness 3. Dyspnea 4. Heart failure 5. Lightheadedness 6. Nausea 7. Neck pulsations 8. Palpitations (common) 9. Signs of shock 10. Syncope 11. Weakness

Answer 19

1. Apply pulse oximeter — administer supplemental oxygen, if indicated 2. Obtain vital signs 3. Establish IV access 4. Apply cardiac monitor 5. Obtain 12 lead ECG 6. Vagal maneuvers 7. Adenosine 8. Calcium channel blockers or beta blockers

Answer 20

Unstable patient — signs/symptoms of hemodynamic compromise are present) 1. Apply pulse oximeter — administer oxygen, if indicated 2. Establish IV access 3. Administer sedation — if the patient is awake and time permits 4. Synchronized cardioversion

Answer 21

Antrioventricular Reentrant tachycardia (AVRT) involves a pathway of impulse conduction outside the AV node and bundle of his Preexcitation -impulse begins above the ventricles but travels via a pathway other than the AV node and bundle of his -the supraventricular impulse excites the ventricles earlier than normal

Answer 22

Rhythm: regular unease associated with A-Fib Rate: usually 60-100bpm if the underlying rhythm is sinus in origin P waves: normal and positive in lead II unless WPW is associated with A-Fib PR interval: 0.12sec or less if P waves are observed because the impulse travels very quickly across the accessory pathway, bypassing the normal delay in the AV node QRS duration: usually more than 0.12sec; slurred upstroke of the QRS complex (delta wave) may be seen in one or more leads Summary — Short PR interval / Delta wave / QRS widening / Secondary ST and T wave changes

Answer 23

Initial slurred deflection at the beginning of the QRS complex that may be positive or negative

Answer 24

Premature activation of the ventricles by a supraventricular impulse arising from the censors pathway

Answer 25

Most people with WPW syndrome have no associated heart disease WPW syndrome is one of the most common causes of tachydysrhythmias in infants and children Although the accessory pathway in WPW syndrome is believed to be congenital in origin, the symptoms associated with Preexcitation often do not appear until the patient is a teenager or young adult

Answer 26

1. Anxiety 2. Chest discomfort 3. Dizziness 4. Lightheadedness 5. Palpitations (common) 6. Shortness of breath during exercise 7. Signs of shock 8. Weakness

Answer 27

If the patient is symptomatic because of the rapid ventricular rate, treatment will depend on the following 1. Severity of patients symptoms 2. Width of the QRS complex (wide or narrow) 3. Regularity of the ventricular rhythm Consultation with a cardiologist is recommended

Answer 28

Ectopic atrial rhythm in which an irritable site within the atria fires regularly at a very rapid rate F waves (capital F) Regularly irregular No P waves

Answer 29

Rhythm: atrial regular; ventricular regular or irregular depending on AV conduction and blockade Rate: atrial rate typically ranges from 240-300bpm; ventricular rate varies and is determined by AV blockade; the ventricular rate will usually not exceed 180bpm as a result of the intrinsic conduction rate of the AV junction P waves: no identifiable P waves; saw-toothed flutter waves are present PR interval: not measurable QRS duration: 0.11sec or less but may be widened if flutter waves are buried in the QRS complex or abnormally conducted

Answer 30

1. Cardiac surgery 2. Cardiomyopathy 3. Chronic lung disease 4. Complication of myocardial infraction 5. Digitalis or quinidine toxicity

Answer 31

Often precipitated by brief episodes of AT or by A-Fib — may last for seconds to hours and occasionally persists for 24hrs or longer Chronic atrial flutter is unusual — rhythm usually converts to sinus rhythm or A-Fib either on its own or with treatment

Answer 32

Occurs because of altered automaticity in one or several rapidly firing sites in the atria or Reentry involving one or more circuits in the atria

Answer 33

No P waves Has f waves (tiny waves — don’t maintain same morphology) Rhythm is irregular Can’t calculate PRI — no P waves

Answer 34

Can occur in patients with or without detectable heart disease or related symptoms Increased risk of stroke 1. Atria do not contract effectively 2. Blood pools within the atria, forming clots 3. Clot dislodges and moves to artery in the brain

Answer 35

Cardiovascular conditions: 1. Coronary artery disease 2. Dilated cardiomyopathy 3. Heart failure 4. Hypertension 5. Hypertrophic cardiomyopathy 6. Ischemic heart disease 7. pericardial disease 8. Rheumatic heart disease 9. Stroke, transient ischemic attack, thromboembolism 10. Valvular disease 11. Vascular disease

Answer 36

Potentially reversible causes: 1. Electrocution 2. Excessive alcohol intake (holiday heart) 3. Hyperthyroidism 4. Myocardial infraction 5. Myocarditis 6. Open heart or thoracic surgery 7. Pericarditis 8. Pneumonia 9. Pulmonary embolism

Answer 37

Cardiology consult Treatment strategies — rate control / rhythm control Consider synchronized cardioversion if the patient is hemodynamically unstable

Answer 38

C AVNRT, which is caused by reentry in the area of the AV node, is the most common type of SVT in adults

Answer 39

B A supraventricular rhythm originates from a site above the bifurcation of the bundle of his, such as the SA node, atria, or AV junction

Answer 40

A With AFib, rapid impulses cause the muscles of the atria to quiver (fibrillation), resulting in ineffective atrial contraction, decreased stroke volume, a subsequent decrease in cardiac output, and loss of atrial kick

Answer 41

D With atrial flutter, atrial waveforms are produced that resemble the teeth of a saw or a picket fence; these are called flutter waves or F waves

Answer 42

A, E, F The WPW patter includes a triad (meaning 3) of ECG findings that consist of the following: 1. A short PRI, 2. A delta wave, 3. A wide QRS. In addition, secondary ST and T wave changes are often present

Answer 43

A A PRI cannot be measured with AFib because there are no P waves associated with dysrhythmia

Answer 44

D Signs and symptoms experienced during a tachydysrhythmia are usually primarily related to a decrease in the length of time spent in diastole. Remember that as the heart rate increases, there is less time for the ventricles to fill and less blood for the ventricles to pump out with each contraction. Thus, excessively fast heart rate can lead to decrease cardiac output

Answer 45

D When compared with the P-P intervals of the underlying rhythm, a PAC is premature — occurring before the next expected sinus P wave. PACs are identified by early (premature) P waves, positive (upright) P waves (in lead II) that differ in shape from sinus P waves (atrial P waves may be flattened, notched, pointed, biphasic, or lost in the preceding T wave) and early P waves that may or may not be followed by QRS

Answer 46

B A compensatory pause is a delay that occurs following a premature beat that resets the SA node. A series of waveforms is called a complex. The cardiac cycle period during which cardiac cells cannot be stimulated to conduct an electrical impulse, no matter how strong the stimulus, describes the effective (absolute) refractory period. The period during the cardiac cycle during which cardiac cells can be stimulated to conduct an electrical impulse, if exposed to a stronger than normal stimulus, describes the relative refractory period

Answer 47

A, F ECG characteristics of WAP include: Rhythm: irregular Rate: 60 to 100bpm — if faster than 100bmp name is multifocal atrial tachycardia P waves: size, shape, and direction may change from beat to beat; may be upright, inverted, biphasic, rounded, flat, pointed, notched, or buried in the QRS PRI: varies QRS: 0.11sec or less

Answer 48

D Information relayed by the patient as part of the history can provide important clues to her cardiovascular (and pulmonary) status. Ask questions to determine the patient’s description of her symptoms when and how often they occur, how long they last, possible triggers, and what measures she has taken to relieve them. A complaint of palpitations, warrants, timely assessments, and intervention, whether or not the rhythm is regular. It is essential to determine if chest pain or discomfort, difficulty breathing, or shortness of breath, accompany her palpitations. Some practitioners recommend having the patient “tap out” the rhythm of the palpitations to help determine rhythmicity. Palpitations that occur regularly with a sudden onset and usually are caused by AVNRT or AVRT. Irregular palpitations may be the result of premature comp, a fib, or multifocal atrial tachycardia. Patient may report palpitations when there is no evidence of a rhythm disturbance on the cardiac monitor. this occurs most often in patients with anxiety disorders, although symptoms, such as chest pain or discomfort, dyspnea, palpitations, edema, and syncope are classic cardiac disease symptoms. They may also occur because of other organ system diseases (such as musculoskeletal, pulmonary, renal, and gastrointestinal)

Answer 49

B The rhythm shown is AVNRT at 188bpm

Answer 50

D The PRI cannot be measured because the are no P waves visible

Answer 51

B The patient is symptomatic but stable. Because atropine is administered to increase heart rate and this patient is already tachycardic, contraindicated in this situation. Vagal maneuvers may be tried. If vagal maneuvers were unsuccessful, anticipate orders for IV administration of adenosine. Chest compressions are not indicated (the patient is responsive, breathing, and pulse). Oxygen administration is not indicated because the patients oxygen saturation is 97% on a room air. Sedation and cardioversion would be appropriate if the patient were unstable (showing signs of hemodynamic compromise)

Answer 52

Wolf - Parkinson - White (WPW) pattern

Answer 53

Palpitations

Answer 54

Preexcitation

Answer 55

Delta wave

Answer 56

Atrial kick

Answer 57

Accessory pathway

Answer 58

Vagal maneuvers

Answer 59

Heart failure

Answer 60

Uncontrolled

Answer 61

Nonconduted PAC

Answer 62

Beta blockers

Answer 63

Aberrantly conducted PAC

Answer 64

Hypertension

Answer 65

Anticoagulant

Chapter 4 Flashcards

(96 cards)