Tachycardia

Question 1

Which general classification of antiarrhythmics should be avoided when treating Atrial Fibrillation in patients experiencing severe CHF and acute decompensated heart failure (ADHF)?

Answer 1

1. Calcium-channel blockers;

https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/

Note: “In congestive heart failure, patients with reduced ventricular function may not be able to counteract the inotropic and chronotropic effects of diltiazem, the result being an even higher compromise of function.”

https://en.wikipedia.org/wiki/Diltiazem

Question 2

Name nine risk factors for Atrial Fibrillation.

Answer 2

ATRIAL FIB

A - Alcohol

T - Thyroid (primarily hyperthyroidism)

R - Rheumatic Heart (as well as other valvular heart disease such as mitral valve stenosis)

I - Ischemia

A - Atrial Myxoma

L - Lung (PE, Emphysema)

F - Pheochromocytoma

I - Infection

B - Blood Pressure (HTN)

https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/

Question 3

Per FOAMCast, a target heart rate of < ___ BPM is acceptable when attempting rate control of stable atrial fibrillation in the ED.

Answer 3

1. 120;

https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/

Question 4

What is the general dose of Diltiazem for rate control of patients experiencing stable atrial fibrillation in an acute setting (first, second and third doses)?

Answer 4

1. 0.25 mg/kg (average 20 mg) IV over 2 min, may repeat after 15 minutes (if HR > 100 bpm) with 0.35 mg/kg (average 25 mg), then 5-15 mg/hr continuous IV drip infusion (for no longer than 24 hours);

https://www.acc.org/tools-and-practice-support/clinical-toolkits/atrial-fibrillation-afib/rate-rhythm-dosing-table/diltiazem

Question 5

ED cardioversion of stable, new-onset atrial fibrillation is appropriate in a select population, notably, when the onset is < ___ hours. The pooled literature suggests a thromboembolism rate of < ___ under these conditions.

Answer 5

1. 48;

Note: Rosen’s Emergency Medicine allows for cardioversion when onset is < 72 hours.

• https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*
  2. 0.8;

Major Memory System: A patient is cardioverted the safe way, in a Safeway (08 → 0.8).

Cohn BG, Keim SM, Yealy DM. Is Emergency Department Cardioversion of Recent-onset Atrial Fibrillation Safe and Effective? J Emerg Med. 2013;45(1):117–27.

Question 6

Atrial fibrillation featuring evidence of ___, (e.g., wide, polymorphic atrial fibrillation) should not be treated with AV nodal blocking agents (e.g. adenosine, beta-blockers, calcium-channel blockers, digoxin). Consider synchronized cardioversion or procainamide instead.

Answer 6

1. Pre-excitation syndrome (e.g. WPW);

Note: Blocking the AV node causes unopposed electrical conduction down the accessory pathway. Additionally, the accessory pathway in WPW responds paradoxically to the AV nodal blocking agents by further decreasing its refractory time.

https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/

Question 7

_(cardiac rhythm)_ is characterized by an irregular narrow complex tachycardia with p waves of at least three morphologies. As this rhythm can be difficult to differentiate, it is advisable to look for p waves in multiple leads, particularly ___.

Answer 7

1. Multifocal Atrial Tachycardia;
2. V2;
   * https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*

Question 8

Generally speaking, how should multifocal atrial tachycardia be treated? What treatment should generally be avoided?

Answer 8

1. Treat the underlying cause;
2. Cardioversion;
   * https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*

Question 9

___ is caused by chaotic, disorderly firing from a second focus within the atria, resulting in uncoordinated atrial contractions. On ECG, there are irregularly irregular narrow QRS complexes. In addition, no discernible ___ waves are noted, rather ___ waves are seen.

Answer 9

1. Atrial fibrillation;
2. P;
3. Fibrillatory (aka f waves);
   * https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*

Question 10

The underlying mechanism of WPW involves an ___ between the atria and the ventricles. It is a type of ___ syndrome.

Answer 10

1. Accessory pathway (aka accessory electrical conduction pathway);
2. Pre-excitation;
   * https://en.wikipedia.org/wiki/Wolff–Parkinson–White_syndrome*

Question 11

Individuals with WPW have an accessory pathway that communicates between the atria and the ventricles, in addition to the AV node. This accessory pathway is known as the ___.

Answer 11

1. Bundle of Kent;

https://en.wikipedia.org/wiki/Wolff–Parkinson–White_syndrome

Question 12

If a person with WPW experiences episodes of ___, the ECG shows a rapid polymorphic wide-complex tachycardia (without torsades de pointes). This combination of atrial fibrillation and WPW is considered dangerous, and most antiarrhythmic drugs are contraindicated.

Answer 12

1. Atrial Fibrillation;

https://en.wikipedia.org/wiki/Wolff–Parkinson–White_syndrome

Question 13

What is the definitive treatment for WPW?

Answer 13

1. Destruction of the abnormal electrical pathway by radiofrequency catheter ablation;

https://en.wikipedia.org/wiki/Wolff–Parkinson–White_syndrome

Question 14

Name the three key ECG features of pre-excitation syndrome (e.g. WPW).

Answer 14

1. PR Interval < 0.12 sec;
2. QRS Interval >= 0.12 sec;
3. Delta Wave;
   * https://ecgwaves.com/topic/pre-excitation-avrt-wolff-parkinson-white-wpw-syndrome/*

Question 15

Pre-excitation causes secondary ___ changes. The _(same as 1.)_ segment is directed ___ to the ___ wave.

Answer 15

1. ST-T;
2. Oppositely;
3. Delta;
   * https://ecgwaves.com/topic/pre-excitation-avrt-wolff-parkinson-white-wpw-syndrome/*

Question 16

During pre-excitation, a positive delta wave will result in a ___ deflected ST-T segment.

Answer 16

1. Negatively;

Note: ST segment depression and T wave inversion are also typical during pre-excitation.

https://ecgwaves.com/topic/pre-excitation-avrt-wolff-parkinson-white-wpw-syndrome/

Question 17

Patients with WPW can be asymptomatic or may present with severe tachydysrhythmias. The most common presenting dysrhythmia is ___ (70-80%) and second is ___ (10-30%).

Answer 17

1. AVRT;
2. Atrial Fibrillation;
   * https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*

Question 18

In WPW-related tachydysrhythmias, the patient can conduct ___ (down the AV node and back up the accessory pathway), ___ (down the accessory pathway and up the AV node) or in both directions.

Answer 18

1. Orthodromically;
2. Antidromically;
   * https://foamcast.org/2014/09/21/episode-15-atrial-fibrillationflutter/*

Question 19

Describe the “Modified Valsalva Maneuver” utilized for conversion of stable SVT to Sinus Rhythm in the REVERT trial.

Answer 19

1. In a semi-recumbent position, patients produce 40 mm Hg pressure (which may be approximated in the field by blowing hard enough into a 10 mL syringe to cause the plunger to move) for 15 seconds, and are then repositioned supine with a passive leg raise to 45 degrees immediately after the valsalva strain;

https://rebelem.com/the-revert-trial-a-modified-valsalva-maneuver-to-convert-svt/

Question 20

With regards to the conversion of stable SVT to Sinus Rhythm one minute after intervention, The REVERT trial demonstrated the efficacy of the Standard Valsalva Maneuver at ___% and the Modified Valsalva Maneuver at ___%.

Answer 20

1. 17;
2. 43;

Major Memory System: The passive leg raise utilized during a Modified Valsalva Maneuver causes a worm (43) to be squeezed from the patient’s dick (17).

https://rebelem.com/the-revert-trial-a-modified-valsalva-maneuver-to-convert-svt/

Question 21

___ is a broad term which refers to tachycardias originating above the ventricles, including the regular rhythms of sinus tachycardia, atrial tachycardia, AVNRT, AVRT, and the irregular rhythms of multifocal atrial tachycardia, atrial fibrillation, and some forms of atrial flutter. ___ is a term that is widely considered a synonym, but which generally excludes _(rhythm)_ and focuses primarily on _(rhythm)_ and _(rhythm)_.

Answer 21

1. Supraventricular Tachycardia (SVT);

• https://foamcast.org/2015/09/09/episode-34-tachyarrhythmias/*
• https://www.hopkinsmedicine.org/heart_vascular_institute/conditions_treatments/conditions/supraventricular_tachycardia.html*
  2. Paroxysmal Supraventricular Tachycardia (PSVT);
  3. Sinus Tachycardia;
  4. AVRT;
  5. AVNRT;
• http://hqmeded-ecg.blogspot.com/2017/08/what-happens-when-you-give-adenosine-to.html*

Question 22

The Single Syringe Administration of Diluted Adenosine trial proved that when diluted in ___ mL of 0.9% Sodium Chloride solution, the use of prescribed doses of Adenosine for the conversion of stable SVT in adults is at least as effective as traditional techniques (Adenosine flushed afterwards with normal saline).

Answer 22

1. 20;

• https://foamcast.org/2015/09/09/episode-34-tachyarrhythmias/*
• McDowell M, Mokszycki R, Greenberg A, et al. Single Syringe Administration of Diluted Adenosine. Acad Emerg Med. 2019 Oct 30. [ePub ahead of print]. [PMID 31665806]*

Question 23

It is typical for Atrial Flutter to produce ___ flutter waves in V1 that preceed the QRS complexes. It is important to remember that sinus P waves are ___ in V1. This distinction can be used to help differentiate what may appear at first glance to be Sinus Tachycardia from what is actually Atrial Flutter.

Answer 23

1. Upright (aka positive);
2. Biphasic;

Note: Atrial Flutter with 2:1 conduction is a PSVT mimic.

http://hqmeded-ecg.blogspot.com/2017/08/what-happens-when-you-give-adenosine-to.html

Question 24

Adenosine’s mechanism of action can be thought of as a “temporary paralyzing” of ___ tissue.

Answer 24

1. Supraventricular;

https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/

Question 25

Pharmacologically, adenosine \_\_\_-polarizes the cell by stimulating an inward \_(electrolyte)\_ current and temporarily inhibiting \_(electrolyte)\_ migration. In doing so, the pacemaker activity of the SA node, spontaneous atrial activity and conduction through the AV node are dramatically slowed or temporarily stopped.

Answer 25

1. Hyper; 2. Potassium; 3. Calcium; * https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/*

Question 26

According to JEMS, adenosine has ___ effects on accessory pathways, such as those seen in WPW syndrome. The Pierce County PCPs, however, state that adenosine ___ inhibit reentry pathways.

Answer 26

1. No; ## Footnote * https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/* 2. May; * Pierce Co. EMS Procedures and PCPs, June 2019, Appendix O, Adenosine*

Question 27

Under what respiratory condition should adenosine be withheld from a patient with a history of asthma or COPD?

Answer 27

1. Wheezing present prior to adenosine administration; Note: Adenosine may cause bronchospasm. *https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/*

Question 28

Generally speaking, ___ is the drug of choice for PSVT in pregnant patients.

Answer 28

1. Adenosine; ## Footnote *https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/*

Question 29

What three tachycardic rhythms does JEMS indicate are absolute contraindications to the use of adenosine?

Answer 29

1. Atrial flutter; 2. Atrial fibrillation; 3. Sinus tachycardia; * https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/*

Question 30

What rhythms can adenosine safely be used to differentiate (i.e., as a diagnostic aid)? What other two rhythms may be *inadvertently* differentiated with Adenosine, but should never be treated with the drug?

Answer 30

1. ¹SVT with abberancy from VT; ## Footnote Note: ²Adenosine *can* convert regular, monomorphic VT to a sinus rhythm, especially in young people, so it does not _definitively_ rule-out VT if conversion of a wide-complex tachycardia is achieved. ¹ However, there is a 36-fold increase in the likelihood of a supraventricular origin if the wide complex tachycardia converts to sinus with adenosine and a nine-fold increased likelihood of VT if it doesn't respond to escalating doses of adenosine. * ¹- https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html* * ²- https://lifeinthefastlane.com/cardiovascular-curveball-013/* 2. Atrial Fibrillation; 3. Atrial Flutter; Note: Adenosine reveals flutter waves by eliminating QRS complexes through AV nodal blockade. _Note 2: Per *https://elearning.heart.org/scorm/launchsco/28828621/1296*, the AHA states "Although it [adenosine] doesn't terminate Atrial Flutter or Atrial Fibrillation, it will slow AV conduction, allowing for identification of flutter or fibrillation waves, thereby allowing confirmation of the underlying tachyarrhythmia."_ * https://www.jems.com/2012/09/07/patient-cardiac-rhythm-important-ems-ade/* * http://hqmeded-ecg.blogspot.com/2017/08/what-happens-when-you-give-adenosine-to.html*

Question 31

Adenosine is categorized as a US FDA pregnancy category ___ drug.

Answer 31

1. C; ## Footnote *- https://www.drugs.com/pregnancy/adenosine.html* Note: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Use is recommended only if clearly needed and the benefit outweighs the risk.

Question 32

Name the three supraventricular rhythms which represent absolute contraindications to the use of adenosine.

Answer 32

1. Atrial fibrillation; 2. Atrail flutter; 3. Sinus tachycardia; Note: According to the AHA, " *https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html*

Question 33

In cases for which there’s any chance that sinus tachycardia is the etiology of a patient’s elevated heart rate, ___ should be administered prior to considering adenosine.

Answer 33

1.A fluid bolus (Jems recommends a rapid fluid bolus of 250 cc); ## Footnote Note: Any slowing by just a few beats per minute (rather than a dramatic conversion to a normal sinus rhythm) confirms the diagnosis of sinus tachycardia due to volume depletion. *https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html*

Question 34

Adenosine slows or blocks \_\_\_grade (atrial to ventricular) conduction through the AV node but doesn’t affect ___ or ___ tracts like those seen in ___ syndrome.

Answer 34

1. Ante; 2. Accessory; 3. Bypass; 4. WPW; Note: Because of this, adenosine can be dangerous when given to patients with atrial fibrillation, especially if they have a bypass track. Numerous reports show patients degenerating into rapid atrial fibrillation with rates at 250 or greater and becoming hemodynamically unstable. *https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html*

Question 35

Adenosine can convert relatively stable Atrial Flutter with 2:1 conduction and a heart rate of 150 to ___ conduction with a heart rate of ___ and cause rapid clinical decompensation.

Answer 35

1. 1:1; 2. 300; Note: Atrial Flutter with 2:1 conduction is a PSVT mimic. *https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html*

Question 36

Investigators found that 6 mg of adenosine converted ~\_\_\_% of patients and that 12 mg converted ~\_\_\_% of patients without an increase in toxicity.

Answer 36

1. 60 (62.3%); 2. 90 (91.4%); Major Memory System: Don **Hodges** (60) drinks **booze** (90) until his heart stops. *https://www.jems.com/articles/print/volume-37/issue-9/patient-care/patient-cardiac-rhythm-important-ems-ade.html*

Question 37

Atrial Flutter does not use the ___ for part of its re-entrant loop, as do AVNRT and AVRT.

Answer 37

1. AV node; ## Footnote *http://hqmeded-ecg.blogspot.com/2017/08/what-happens-when-you-give-adenosine-to.html*

Question 38

Patients with atrial flutter often alternate between fib and flutter, and produce thrombi during episodes of \_\_\_. Hence, cardioversion of atrial flutter may involve a risk of thromboembolism if the onset of atrial flutter is not within ___ hours of ED presentation.

Answer 38

1. Fibrillation; 2. 48; * http://hqmeded-ecg.blogspot.com/2017/08/what-happens-when-you-give-adenosine-to.html*

Question 39

A ___ is a rare benign tumor of the heart. These growths are the most common primary cardiac tumor in adults, and are most commonly found within the ___ atrium.

Answer 39

1. Myxoma; 2. Left; * https://en.wikipedia.org/wiki/Cardiac\_myxoma*

Question 40

Rheumatic heart disease is a condition in which permanent damage to \_(structures)\_ is caused by \_(disease)\_. This process generally begins with the development of \_(disease)\_ due to ___ bacteria.

Answer 40

1. Heart valves; 2. Rheumatic fever; 3. Strep throat; 4. Streptococcal (there are many different types); * https://chw.org/medical-care/herma-heart/conditions/rheumatic-heart-disease*

Question 41

Name the two most common alterable risk factors for Atrial Fibrillation.

Answer 41

1. Hypertension; 2. Valvular heart disease (e.g., rheumatic heart disease); * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 42

Atrial Fibrillation is often treated with medications to slow the heart rate to a near normal range (known as \_(therapy)\_) or to convert the rhythm to normal sinus rhythm (known as \_(therapy)\_).

Answer 42

1. Rate control; 2. Rhythm control; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 43

Most persons diagnosed with Atrial Fibrillation are at high risk of \_(adverse event)\_, and are prescribed ___ medications.

Answer 43

1. Stroke (aka CVA); 2. Anti-clotting (aka anticoagulants); * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 44

\_\_\_ is the most common serious abnormal heart rhythm. Studies performed in 2014 demonstrated that it affects about \_\_\_% of the population of the developed world.

Answer 44

1. Atrial Fibrillation; 2. 2.5; Major Memory System: Bumba performs vigorous **anal** (25 → 2.5) on GamGam, their hearts palpitating. *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 45

The risk of a blood clot forming in the left atrial chamber of the heart, breaking off, and then traveling in the bloodstream can be assessed using the ___ or ___ scores.

Answer 45

1. CHADS₂; 2. CHA₂DS₂-VAS_c; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 46

Many of the symptoms associated with uncontrolled Atrial Fibrillation are a menifestation of ___ due to the reduced cardiac output.

Answer 46

1. Congestive Heart Failure (CHF); ## Footnote *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 47

Consumption of ___ beverages does not appear to be associated with Atrial Fibrillation, but excessive consumption of ___ beverages is linked to the disease.

Answer 47

1. Caffeinated; 2. Alcoholic; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 48

In Atrial Fibrillation, the normal regular electrical impulses generated by the sinoatrial node in the right atrium of the heart are overwhelmed by disorganized electrical impulses usually originating in the roots of the \_\_\_.

Answer 48

1. Pulmonary veins; ## Footnote *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 49

The primary pathologic change seen in Atrial Fibrillation is progressive ___ of the atria due primarily to atrial \_\_\_.

Answer 49

1. Fibrosis; 2. Dilation; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 50

What are the common abbreviations for Atrial Fibrillation and Atrial Flutter, respectively?

Answer 50

1. AF; 2. AFL; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 51

A ___ is a wearable ambulatory heart monitor that continuously monitors the heart rate and heart rhythm for a short duration, typically 24 hours.

Answer 51

1. Holter monitor; ## Footnote *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 52

The \_\_\_, located in the left atrium, is the place where a blood clot forms in more than 90% of cases in non-valvular (or non-rheumatic) atrial fibrillation.

Answer 52

1. Left atrial appendage; ## Footnote *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 53

Atrial Fibrillation Classification System: \_\_\_ - Only one diagnosed episode; \_\_\_ - Recurrent episodes that stop on their own in less than seven days; \_\_\_ - Recurrent episodes that last more than seven days; \_\_\_ - An ongoing long-term episode;

Answer 53

1. First detected; 2. Paroxysmal; 3. Persistent; 4. Permanent; Note: Episodes that last less than 30 seconds are not considered in this classification system. *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 54

About \_\_\_% of people with Atrial Fibrillation have permanent AF, while \_\_\_% have paroxysmal AF and \_\_\_% have persistent AF.

Answer 54

1. 50; 2. 25; 3. 25; Major Memory System: **Lassie** (50) swims down the **Nile** (25) in an **O'Neill** (25) wetsuit, her heart palpitating from fear of piranhas. *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 55

The main goals of treatment of Atrial Fibrillation are to prevent ___ instability and \_\_\_. ___ or ___ control are used to achieve the former, whereas ___ is used to decrease the risk of the latter.

Answer 55

1. Circulatory; 2. Stroke; 3. Rate; 4. Rhythm; 5. Anticoagulation; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 56

What does DOAC stand for, with regard to anticoagulation?

Answer 56

**DOAC** ## Footnote **D - D**irect **O - O**ral **A - A**nti **C - C**oagulant *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 57

Name four (of six listed) anticoagulants commonly used for stroke prevention during Atrial Fibrillation.

Answer 57

1. Warfarin (Coumadin); 2. Heparin (and other drugs ending with the suffix -parin); 3. Apixaban; 4. Rivaroxaban; 5. Edoxaban; 6. Dabigatran; Memory Aid for #s 4-6: A _pixy_ flies by a _river_ on the planet _Endor_, when suddenly _da big train_ whooshes by. *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 58

What does NOAC stand for, with regard to anticoagulation?

Answer 58

**NOAC** ## Footnote **N - N**ovel **O - Oral** **A - Anti** **C - C**oagulant *https://www.pharmacytimes.com/contributor/sean-kane-pharmd/2016/09/noac-doac-or-tsoac-what-should-we-call-novel-oral-anticoagulants*

Question 59

A(n) ___ is a rare tumor of adrenal gland tissue. It results in the release of too much epinephrine and norepinephrine, hormones that control heart rate, metabolism, and blood pressure.

Answer 59

1. Pheochromocytoma; ## Footnote *https://medlineplus.gov/ency/article/000340.htm*

Question 60

With regards to AF, studies suggest that ___ control is more important in the acute setting, whereas ___ control is more important in the chronic phase.

Answer 60

1. Rhythm; 2. Rate; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 61

In the setting of Atrial Fibrillation with Rapid Ventricular Response, intravenous ___ significantly increases the chances of successful rate and rhythm control in the urgent setting without major side-effects.

Answer 61

1. Magnesium; ## Footnote *https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 62

Rate control of Atrial Fibrillation is achieved with medications that work by increasing the degree of block at the level of the \_\_\_, decreasing the number of impulses that conduct into the \_\_\_.

Answer 62

1. AV node; 2. Ventricles; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 63

Rate control of Atrial Fibrillation can generally be accomplished with ___ blockers, ___ blockers and cardiac \_\_\_. In addition to these agents, \_(medication)\_ has some AV node blocking effects and can be used in individuals when other agents are contraindicated or ineffective (particularly fue to hypotension).

Answer 63

1. Beta (preferably the "cardioselective" beta blockers such as metoprolol); 2. Calcium channel (non-dihydropyridine, e.g., diltiazem or verapamil); 3. Glycosides (e.g., digoxin); 4. Amiodarone; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 64

Name two (of four listed) drugs which may be used to chemically cardiovert Atrial Fibrillation.

Answer 64

1. Amiodarone; 2. Procainamide (especially in pre-excited atrial fibrillation); 3. Propafenone; 4. Flecainide; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*

Question 65

Name two types of ablation which may be considered for rate control of Atrial Fibrillation.

Answer 65

1. Radiofrequency; 2. Cryoablation; * https://en.wikipedia.org/wiki/Atrial\_fibrillation*