Atrial Arrhythmias

Question 1

Afib Patho

Answer 1

• Atrial Structure Abnormalities: atrial dilation (increased pressure, heart failure), fibrosis, ischemia
• Inflammation, oxidative stretch
• Hyperthyroidism
• Alcohol and drug use
• Genetic variants
• Need to assess patients for rate and rhythm control and stroke prevention when deciding treatments

Question 2

Afib Risk Factors

Answer 2

• Hypertension
• Heart disease, esp heart failure
• Hyperthyroidism
• Excessive to moderate alcohol
• Obesity
• Sleep apnea
• Fish oil?
• Non modifiable: age

Question 3

Afib Symptoms

Answer 3

• Palpitations (Plus SOB/lightheaded = triad)
• Fatigue
• Syncope
• Dyspnea
• Dizziness
• Angina
• OR no noticeable symptoms at all

Question 4

Types of AF

Answer 4

• Paroxysmal AF: terminates spontaneously or w/ intervention within 7 days of onset, may recur variably
• Persistent AF: continuously sustained >7 days
• Long-standing persistent AG: continuously > 12 mo in duration
• Permanent AF
• Nonvalvular AF: absence of rheumatic mitral stenosis, mechanical/bioprosthetic heart value or mitral valve repair

Question 5

Permanent AF

Answer 5

• Used when patient/clinician make joint decision to stop further attempts to restore and/or maintain sinus rhythm
• Acceptance of AF represents therapeutic attitude on part of patient/clinician instead of inherent pathophysiological attribute of AG
• Acceptance may change symptoms, efficacy of interventions, and patient/clinician preferences evolve

Question 6

Rate Control Approach

Answer 6

• Anticoagulation + ventricular rate control
• No cardioconversion, patient remains in Afib indefinitely
• AA NOT used, only drugs that slows conduction through AV node
• Decrease ventricular response rate, reasonable for symptomatic management of AF (resting HR < 80)
• Lenient rate-control strategy (resting HR < 110) may reasonable as long as patient remains asymptomatic and LV systolic fxn is preserved
• Use drugs that decrease AV node conduction

Question 7

Rhythm-control Approach

Answer 7

• Anticoagulation + ventricular control + AA
• AA or DCC are used to cardiovert patient to normal rhythm
• AA or catheter ablation are then used to maintain normal rhythm
• Rate controlling drugs are frequently maintained in event of breakthrough episodes of Afib

Question 8

Rhythm vs Rate Control

Answer 8

• Rate control may be only option in some patient in which normal rhythm can’t be maintained (permanent AF) or due to AE of drugs/risks
• Rhythm control is preferred in patient with symptoms despite rate control, including those with persistent symptoms of HF
• Outcomes appear to be similar between the two approaches

Question 9

Rate Control General Monitoring

Answer 9

• Ventricular response rate: measure pulse
• BP: most rate control drugs can decrease BP
• Ca+ channel blockers can cause constipation/heart burn
• B-blockers can cause fatigue and decrease exercise tolerance
• Digoxin Monitoring

Question 10

Digoxin Monitoring

Answer 10

• Monitor serum levels: <1 is best, take [trough], bad if >1.5
• Monitor bradycardia
• N/V, halo vision
• Caution in renal dysfxn
• Hypokalemia can increase toxicity
• Toxicity can lead to fatal brady/tachyarrhythmias

Question 11

Rhythm Control General Monitoring

Answer 11

• Need to monitor for AE and DDI for AA selected (QTc monitoring, or warfarin + amiodarone)
• Afib Burden: how often do patients go back into Afib

Question 12

Pill-In-Pocket

Answer 12

• Option for those doing rhythm control method
• Self administer single pill of AA at onset of palpitations
• Class IC flecainide and propafenone act rapidly and are effective
• Combine with B-blocker or non-dihydropyridine CCB

Question 13

Afib + Stroke

Answer 13

• Inadequate blood flow in areas => blood clot
• Blood clots dislodge and travel to brain
• Leads to stroke

Question 14

Stroke Risk Scores

Answer 14

• CHADS2 or CHA2DS2-VASc (recommended to use nonvalvular AF)
• All use selected clinical characteristics to predict the risk of stroke
• All scores provide a rough estimate of risk of thrombosis in a population at similar risk as patient being reviewed

Question 15

IV to PO Transistion

Answer 15

• Need to convert patients from IV to PO before discharge
• Different anticoagulants will have different approaches
• Start warfarin while on heparin (takes days to work)
• Transition to NOAC usually requires stopping IV heparin and starting NOAC at same time (check drug info sources)

Question 16

When to Cardiovert

Answer 16

• First/isolated episodes: convert and send home to see what happens (no AA, maybe rate control)
• Second/Third episodes: decision to try AA or keep in AF and use rate control. Either is appropriate, based on patient specific preferences
• Cardioconvert in symptomatic patients despite good rate control, if AA can’t prevent recurrence => ablation of areas causing AF