Atrial Fibrillation and Cardiac Arrythmias

Question 1

what are clinical presentations of arrhythmias?

Answer 1

• palpitations
• chest pain
• shortness of breath, exercise intolerance
• lightheadedness, dizziness
• syncope
• caridac arrest

Question 2

• fever, pain, anemia, hypoxemia, anxiety, hyperthyroidism, pheochromocytoma
• treat the patient not the pulse rate
• inappropriate tachycardia: underlying cause is ruled out, consider beta-blocker, ablation procedure

Answer 2

sinus tachycardia

Question 3

• macro-reentrant arrhythmia around a functional or anatomical circuit
• most common type of flutter
• atrial rate is 240-340bpm
• often counterclockwise
• leads II, III, AVF- negative; V1 positive

Answer 3

typical atrial flutter

Question 4

• macro-reentrant circuit is unknown
• atrial rate is typically faster (340-430bpm)
• similar acute and chronic mangament but different ablation strategy

Answer 4

atypical atrial flutter

Question 5

what diagonostic maneuver is used for atrial flutter?

Answer 5

• adenosine or valsalva maneuver- will not terminate the tachycardia

Question 6

acute management of atrial flutter?

Answer 6

Rate control

• Beta blockers
• calcium channel blockers
• +/- digoxin

Anticoagulation

• heparin/ low molecular weight heparin
• warfarin
• dabigatran/ rivaroxaban/ apixaban/ edoxaban

Question 7

when is cardioversion safe in atrial flutter?

Answer 7

• if less than 48 hours—> cardioversion (pt must be on IV heparin)
• if longer than 48h–> adequate anticoagulation x 3 weeks–> cardioversion
• if no appropriate anticoagulation—> TEE to exclude an atrial clot

Question 8

what types of cardioversion methods are there?

Answer 8

electrical cardioversion
chemical cardioversion (IV ibutilde, amiodarone)

Question 9

chronic management of atrial flutter

Answer 9

If patient is asymptomatic

• rate control with beta blockers, calcium channel blockers +/- digoxin
• anticoagulation

If patient is symptomatic

• Anti-arryhthmics (e.g, felcainide, propafenone, amiodarone)
• electrophysiology study with RF ablation

Question 10

• Includes several types of tachycardia that originate in the atria
• atrial rate usually in the 140-240bpm range
• p waves have different morphology than sinus P waves
• different mechanisms: automatic, triggered, reentrant

Answer 10

atrial tachycardia

Question 11

medical management of atrial tachycardia?

Answer 11

rate control

• beta blockers, calcium channel blockers +/- digoxin
• anti-arrythmics (e.g, flecainide, propfane, amiodarone)

If refractory to medical therapy

• electrophysiology study with RF ablation

Question 12

• dual AV node physiology with a slow and fast pathway
• during tachycardia there is conduction through the slow and fast pathways in opposite directions
• ECG: narrow QRS without P waves or they are present at the end of QRS
• it can terminate with Valsalva maneuvers or adenosine

Answer 12

AV nodal reentrant tachycardia

Question 13

Medical treatment for AV nodal re-entrant tachycardia?

Answer 13

Medical Therapy

• Beta-blockers
• calcium channel blockers
• anti-arrhythmics

Invasive therapy

• EP study and RF ablation
• indicated if refractory to medical therapy or intolerance to medication

Question 14

• Accessory pathway or bypass tract between the atrium and the ventricle
• pathways are located around the tricuspid or mitral annulus
• multiple pathways can co-exist in a single patient
• ECG indicates the presence of a short PR-interval and a delta wave
• the delta wave represnet early activation of the ventricles through the accessory pathway or bypass tract

Answer 14

Wolf-Parkinson-White syndrome

Question 15

when do patients have narrow QRS in WPW? when do they have wide?

Answer 15

• Narrow QRS tachycardia is the most frequently observed arrythmia
• patients can develop a wide QRS tachycardia if there is anteroretrograde conduction through the accessory pathway

Question 16

managment of WPW?

Answer 16

• best therapy of tachycardias involving a bypass tract is an EP study with RF ablation
• Avoid AV nodal blocking agents (beta blockers, calcium channel blockers, digoxin) as they can lead to preferential conduction through the accessory pathway
• anti-arrythmic agents (class I, III) have relative limited efficacy

Question 17

• wide QRS complex tachycardia originated from the ventricles
• there is AV dissociation on the ECG
• two types: in the presence of structural heart disease, in the absense of structural heart disease

Answer 17

Ventricular Tachycardia

Question 18

• its origin can be in the right ventricle or left ventricle
• patients present with palpitations and dizziness, frequently related to exercise
• sudden death is very rare
• tx: Beta blockers, calcium channel blockers
• final therapy: EP study with RF ablation
• ICD implantation is not indicated

Answer 18

VT in the “normal” heart

Question 19

• most occur in the presence of ischemic heart disease
• reentrant mechanism around a scar in the ventricle
• patients present with syncope, very symptomatic/hypotensive or with sudden death
• treatment: ICDs with the option of anti-arrhythmics (amiodarone, sotalol mexiletine)
• pallative therapy with EP study and RF ablation

Answer 19

VT in structural heart disease

Question 20

indications for pacemakers?

Answer 20

• symptomatic bradycardia
• high grade heart block (mobitz type II, complete)
• symptomatic sinus pauses/sick sinus syndrome
• inappropriate chronotropic response to exercise
• presence of bradycardia and need to add beta-blockers and/or calcium channel blockers for treatment of concomitant cadiovascuar disease (e.g, coronary artery disease)

Question 21

• the most common sustained cardiac arrhythmia
• irregularly irregular supraventricular tachycardia
• ECG: fine oscillations of the baseline
• absence of organized atrial activity
• atrial rate 400-600bpm

Answer 21

atrial fibrillation

Question 22

what types of atrial fibrillation are there? define them

Answer 22

• Lone: “afib for a day or two- no triggering factor”; paroxysmal, persistent or permanent without evidence of heart disease
• paroxysmal (40%): self termination within 7 days (usually < 24hrs) +/- recurrent
• persistent: fails to self terminate, lasts > 7 days. requires termination (medical or electrical)
• permanent: persistent af > 1 year (refractory to cardioversion or cardioversion never tried)

Question 23

Management of stable atrial fibrillation

Answer 23

Rate control

• Rate control with beta blockers or non-DHP calcium. channel blockers
• digoxin may be used when beta blockers or calcium channel bockers are contraindicated

Question 24

management of unstable atrial fibrillation? what long-term management is available for Afib?

Answer 24

• Direct current (synchronized) cardioversion

Long term management

• rate control usually preferred over rhythm control for long-term management
• direct current (synchronized cardioversion)
• radiofrequency catheter ablation or surgical “MAZE” procedure
• anticoagulation: similar CHAD2D2-VASc) for nonvalvular atrial fibrillation in patients at risk for embolization

Question 25

what does the CHA2DS2-VASc calculate the risk for? when would anticoagulation therapy be recommended?

Answer 25

* measures the risk of embolization in nonvalvular atrial fibrillation patients Recommended therapy * score greater than > 2: Moderate to high risk: chronic oral anticoagulation recommended * 1= low risk: based on clinical judgement, consideration of risk to benefit assesment & discussion with patient, anticoagulation may be recommended * 0 = very low risk: no anticoagulation needed