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Before You Begin
AFib Classification — Know These First
Before proceeding, classify the patient's AFib pattern. This single determination drives your entire management strategy downstream — monitor choice, cardioversion timing, and rhythm control candidacy all depend on it.
First-Detected
New-Onset AFib
First documented episode, regardless of whether prior undetected episodes occurred. Onset may be unknown.
Implication: Full workup required. Assume unknown duration unless patient can pinpoint onset with confidence.
Self-Terminating
Paroxysmal AFib
Episodes that start and stop on their own, typically within 7 days (usually <48 hrs).
Implication: Monitor burden with MCOT. May spontaneously convert — avoid premature cardioversion decisions.
Sustained >7 Days
Persistent AFib
Sustained more than 7 days, or requiring cardioversion to terminate. Does not self-terminate.
Implication: TEE-guided DCCV pathway. Rhythm control still feasible and often appropriate.
Continuous ≥12 Months
Long-Standing Persistent
Continuous AFib for 12 months or more. Sometimes called "permanent" when rate control accepted.
Implication: Discuss rhythm vs. rate control goals with patient. EP referral for ablation consideration if appropriate.
Agreed Rate-Control-Only Strategy
Permanent AFib
Patient and provider have jointly decided to pursue rate control only — rhythm control is no longer being pursued. This is a clinical decision, not just a duration classification.
Implication: Continue anticoagulation and rate control indefinitely. No cardioversion planned. Revisit decision annually.
⚠ Key Teaching Point
"New-onset" does not mean the patient has only been in AFib briefly — it means it's the first time we're detecting it. Always assume duration is unknown unless the patient can pinpoint an exact start time with absolute confidence. When in doubt, treat as unknown.
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Step 1
Confirm the Diagnosis
Start with a 12-lead EKG. Confirm the triad: irregularly irregular rhythm, absent distinct P waves, and a fibrillatory baseline. Note rate, QRS width, and any ST changes.
🚨 Wide Complex — Stop Here
If you see a wide complex tachycardia, consider aberrant conduction or pre-excitation (WPW). Do not proceed independently — escalate to attending immediately before initiating any rate control agent.
EKG Interpretation Checklist
| Finding | What to Look For | Clinical Significance |
|---|---|---|
| Rhythm | Irregularly irregular — no two R-R intervals equal | The hallmark of AFib |
| P waves | Absent; replaced by chaotic fibrillatory baseline | Confirms atrial fibrillation |
| QRS width | Narrow (<120 ms) vs. wide (≥120 ms) | Wide = aberrancy or WPW — escalate |
| Ventricular rate | Count rate; document | Guides urgency and rate control target |
| ST changes | Depression, elevation, or inversions | May indicate concurrent ACS — escalate |
| Delta waves | Slurred upstroke of QRS | Suggests WPW — escalate immediately |
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Step 2
Assess Hemodynamic Stability
Stability Assessment Flow
Patient presents with new-onset AFib
Is the patient hemodynamically stable?
BP adequate · No acute pulmonary edema · No angina · Alert
BP adequate · No acute pulmonary edema · No angina · Alert
Unstable
🚨 Emergency
ED Transfer / Urgent Synchronized Cardioversion
Do not manage outpatient
ED Transfer / Urgent Synchronized Cardioversion
Do not manage outpatient
Stable
✓ Proceed with outpatient workup
Most clinic presentations
Most clinic presentations
Signs of Instability — Any One = Emergency
Hypotension (SBP <90) · Acute pulmonary edema · Active chest pain / ischemia · Altered mental status or syncope. Transfer immediately. Do not delay for workup.
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Step 3 — Do This Early
Anticoagulation — Start Now, Almost Always
Core Principle
Anticoagulation is the default. The question is not "does this patient need it?" — it's "is there a reason they can't have it?" Do not wait for echo results, monitor data, or the next visit. Start OAC today unless a clear contraindication exists.
CHA₂DS₂-VASc Calculator
Score: 0
C Congestive Heart Failure
+1
H Hypertension
+1
A₂ Age ≥ 75
+2
D Diabetes Mellitus
+1
S₂ Prior Stroke / TIA / Thromboembolism
+2
V Vascular Disease (MI, PAD, aortic plaque)
+1
A Age 65–74
+1
Sc Female Sex
+1
Score: 0 — OAC generally not indicated (reassess annually)
Click risk factors above to calculate score.
Anticoagulation Decision Thresholds
| CHA₂DS₂-VASc Score | Men | Women | Recommendation |
|---|---|---|---|
| 0 | Low risk | — | OAC not indicated; reassess annually |
| 1 | Consider OAC | Low risk | Discuss risk/benefit; lean toward treating in most cases |
| 2 | Initiate OAC | Consider OAC | Anticoagulate; discuss bleeding risk for women |
| ≥ 3 | Initiate OAC | Initiate OAC | Anticoagulate — do not delay |
⭐ Preferred OAC: Apixaban (Eliquis) — First Choice in This Practice
| Scenario | Dose | Notes |
|---|---|---|
| Standard dosing | 5 mg BID | No food restrictions; superior bleeding profile (ARISTOTLE trial) |
| Dose reduce to 2.5 mg BID | 2.5 mg BID | If ≥ 2 of: age ≥80 · weight ≤60 kg · Cr ≥1.5 mg/dL |
| Severe renal impairment (CrCl <25) or dialysis | 2.5 mg BID | Preferred even here; discuss with attending if uncertain |
Alternative DOACs — If Apixaban Contraindicated or Not Tolerated
| Agent | Class | Dose | Key Consideration |
|---|---|---|---|
| Rivaroxaban (Xarelto) | DOAC | 20 mg QD with dinner | Must be taken with evening meal for absorption |
| Dabigatran (Pradaxa) | DOAC | 150 mg BID | Avoid if CrCl <30; reduce to 75 mg BID if CrCl 15–30 |
| Warfarin (Coumadin) | VKA | Titrate to INR 2–3 | Only if DOAC contraindicated: mechanical valve, mod-severe MS, or reliable INR monitoring preferred |
True Contraindications — The Short List
Active life-threatening hemorrhage · Recent high-risk intracranial bleed (discuss timing with attending) · Severe thrombocytopenia (platelets <50k) · Recent major surgery with uncontrolled bleeding risk.If you're unsure whether a contraindication is real or relative — ask before withholding OAC. Undertreating stroke risk in AFib causes serious, preventable harm.
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Step 4
Initial Lab Workup
Order All of the Following
| Lab | What You're Looking For | Clinical Importance |
|---|---|---|
| CBC | Anemia, thrombocytopenia, leukocytosis | Anemia → trigger; thrombocytopenia → affects OAC choice; leukocytosis → infection trigger |
| CMP | K⁺, Mg²⁺, creatinine, LFTs | Electrolytes critical for cardioversion success; creatinine essential for DOAC dosing |
| TSH | Hyperthyroidism | Common, reversible trigger — must rule out before aggressive rhythm control |
| PT / INR | Baseline coagulation status | Baseline before initiating anticoagulation |
| BNP or NT-proBNP | Heart failure | Elevated BNP (>100 pg/mL) suggests underlying HF — changes management |
| Lipid Panel | Cardiovascular risk | Baseline cardiovascular risk stratification |
| HbA1c | Undiagnosed or poorly controlled diabetes | CHA₂DS₂-VASc factor; affects risk stratification |
| Urinalysis | Occult UTI or infection | Particularly in elderly — infection is a common and reversible AFib trigger |
⚡ Electrolyte Targets Before Cardioversion
Correct K⁺ to ≥ 4.0 mEq/L and Mg²⁺ to ≥ 2.0 mg/dL before any cardioversion attempt. Electrolyte abnormalities significantly reduce success rates and increase post-cardioversion arrhythmia risk.
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Step 5
Transthoracic Echo (TTE)
Order a TTE on all new-onset AFib patients. This is not optional. The results will directly change medication selection and rhythm control candidacy.
What You're Looking For — and Why It Matters
| Echo Finding | Threshold | Clinical Impact |
|---|---|---|
| Ejection Fraction | EF < 40% (HFrEF) | Avoid non-DHP CCBs (diltiazem, verapamil); prefer beta-blockers; changes antiarrhythmic options |
| Left Atrial Size | LA diameter > 5.0 cm | Predicts lower likelihood of maintaining sinus rhythm long-term; influences rhythm control decision |
| Valvular Disease | Moderate-severe mitral stenosis | Warfarin only — DOACs are contraindicated in rheumatic MS |
| Wall Motion Abnormalities | Regional WMAs | May indicate underlying CAD — consider stress testing or cardiology discussion |
| Elevated RVSP | RVSP > 40 mmHg | Pulmonary hypertension present — may complicate rate and rhythm management |
| Pericardial Effusion | Any significant effusion | May indicate pericarditis or systemic cause — escalate |
TEE vs. TTE — Know the Difference
TTE is the initial imaging study for all new AFib patients. TEE (transesophageal echo) is not routine at this step — it is reserved for pre-cardioversion LAA thrombus exclusion when duration is unknown or >12–24 hours. See Step 8.
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Step 6 — Critical Decision Point
Quantify AFib Burden — Order MCOT or 7-Day Event Monitor
For all hemodynamically stable patients who are tolerating the rhythm and are not going straight to cardioversion, order ambulatory cardiac monitoring to quantify AFib burden before committing to a cardioversion strategy.
Preferred Monitor: MCOT (Mobile Cardiac Outpatient Telemetry)
MCOT provides continuous real-time rhythm transmission and is the preferred monitor when available and covered. A 7-day event monitor is an acceptable and widely covered alternative. Either is appropriate — the goal is at least 7 days of continuous data.
Why This Step Matters Before Cardioversion
A patient in paroxysmal AFib may spontaneously convert — cardioverting them prematurely is unnecessary. A patient in persistent AFib (continuous, 100% burden) will not self-terminate and needs a planned cardioversion strategy. You need this data before committing to a pathway.
Monitor Result → Management Pathway
Review MCOT / Event Monitor Results at Follow-Up
✓ Paroxysmal Pattern
Episodes that start and stop; <100% burden
AFib is intermittent and self-terminating. Patient may be converting on their own. Cardioversion may not be necessary at this time.
→ Optimize rate control · Confirm OAC · Consider antiarrhythmic or EP referral if symptomatic
⚠ Persistent Pattern
Continuous AFib; 100% (or near-100%) burden
AFib is not self-terminating. Cardioversion is needed to restore sinus rhythm. This patient will not spontaneously convert.
→ Proceed to TEE-guided DCCV pathway (Step 8)
✓ Mostly Sinus
AFib resolved; brief or no episodes captured
Patient has likely spontaneously converted. AFib was transient or triggered. No cardioversion needed at this time.
→ Continue OAC · Reassess CHA₂DS₂-VASc · Treat triggers · Follow up
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Step 7 — All Patients
Rate Control
Initiate rate control in every patient while awaiting monitor results and workup completion. Rate control is not the final strategy — it is the bridge to whatever pathway comes next.
Lenient target: Resting HR <110 bpm (acceptable initially for most) · Strict target: HR <80 bpm (if symptomatic, reduced EF, or HF attributable to rate)
Rate Control Agent Selection
| Agent | Class | Starting Dose | Key Notes |
|---|---|---|---|
| Metoprolol succinate | Beta Blocker | 25–50 mg QD | First-line in most patients. Safe in HFrEF. Titrate to effect. |
| Carvedilol | Beta Blocker | 3.125 mg BID | Preferred if concurrent HFrEF. Alpha-blocking properties also lower BP. |
| Diltiazem CD | CCB | 120–180 mg QD | Good option in normal EF. ABSOLUTELY AVOID if EF <40%. |
| Verapamil SR | CCB | 120–240 mg QD | Avoid if EF <40%. Avoid in WPW — can precipitate VF. |
| Digoxin | Glycoside | 0.125–0.25 mg QD | Third-line. Useful in sedentary/HF patients. Narrow therapeutic window; monitor levels and renal function. |
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Step 8 — Persistent AFib Only
TEE-Guided DCCV Pathway
Once monitor results confirm persistent AFib (continuous, non-self-terminating, 100% burden), proceed with the TEE-guided cardioversion pathway. This step applies to patients in whom rhythm restoration is the goal and who are appropriate DCCV candidates.
TEE-Guided DCCV Pathway
MCOT confirms: Persistent AFib (100% burden, non-paroxysmal)
Confirm Prerequisites (see checklist below)
Schedule TEE to rule out LAA thrombus
LAA Thrombus Found
Do NOT cardiovert
Anticoagulate ≥3 months
Repeat TEE before proceeding
Anticoagulate ≥3 months
Repeat TEE before proceeding
No Thrombus
Proceed to TEE/DCCV
Performed by Dr. Rasch · Scripps Prebys Cardiovascular Institute, La Jolla · Typically early AM
Performed by Dr. Rasch · Scripps Prebys Cardiovascular Institute, La Jolla · Typically early AM
Post-DCCV: Continue OAC ≥4 weeks minimum
(Indefinitely if CHA₂DS₂-VASc warrants)
(Indefinitely if CHA₂DS₂-VASc warrants)
Prerequisites Checklist — Confirm All Before Scheduling DCCV:
- Patient on therapeutic apixaban (confirm adherence — ask specifically)
- TTE completed and reviewed; EF and valvular status known
- Electrolytes corrected: K⁺ ≥ 4.0 mEq/L and Mg²⁺ ≥ 2.0 mg/dL
- Heart rate adequately controlled pre-procedure
- Reversible triggers addressed (TSH, OSA, alcohol, HTN, electrolytes)
- Notify Nancy (Dr. Rasch's scheduler) — check the TEE/DCCV order box and the patient's paper checkout sheet; she will coordinate all scheduling
📋 Scheduling TEE/DCCV — Practice Workflow
All TEE and DCCV procedures are performed by Dr. Rasch at the Scripps Prebys Cardiovascular Institute, La Jolla — typically scheduled in the early morning.To schedule: Notify Nancy (Dr. Rasch's scheduler) by checking the TEE/DCCV order box and noting it on the patient's paper checkout sheet. Nancy will handle all coordination with the patient and the facility — no further action needed from the provider.
⚠ Post-DCCV Anticoagulation — Do Not Stop
Continue OAC for a minimum of 4 weeks post-cardioversion regardless of CHA₂DS₂-VASc score. Atrial stunning after cardioversion creates a temporary high-thromboembolic risk window. If CHA₂DS₂-VASc warrants ongoing anticoagulation (≥2 men / ≥3 women): continue indefinitely.
Key Teaching Point — Sinus Rhythm ≠ No Stroke Risk
Patients can have silent AFib recurrences without symptoms. Do not stop anticoagulation simply because a patient is now in sinus rhythm. Unless CHA₂DS₂-VASc is truly 0 (men) or 1 (women) — anticoagulation continues regardless of rhythm status.
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Step 9
Identify and Treat Reversible Triggers
Always screen for modifiable contributors. Treating triggers is often as important as pharmacologic management — and neglecting them is the most common reason for AFib recurrence after cardioversion.
Reversible Triggers — Screen All Patients
| Trigger | How to Screen | Why It Matters |
|---|---|---|
| Hyperthyroidism | TSH (already ordered in Step 4) | Treat thyroid disease first — rhythm control will fail without it |
| Obstructive Sleep Apnea | STOP-BANG questionnaire; refer for sleep study | OSA strongly drives AFib recurrence; CPAP compliance reduces burden significantly |
| Uncontrolled Hypertension | Office BP; home BP log | Most modifiable structural risk factor — optimize BP aggressively |
| Obesity | BMI; weight history | >10% weight loss shown to meaningfully reduce AFib burden in multiple trials |
| Alcohol Use | Detailed intake history; "holiday heart" | Even moderate intake associated with AFib; counsel on reduction or cessation |
| Stimulants / Decongestants | Full medication and supplement review | Pseudoephedrine, stimulant supplements, excessive caffeine can trigger episodes |
| Electrolyte Abnormalities | CMP (already ordered) | K⁺ and Mg²⁺ deficiency drive arrhythmia — correct proactively |
| Acute Illness / Infection | History, UA, CBC | AFib may fully resolve with treatment of underlying cause — particularly common in pneumonia and sepsis |
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Step 10
Follow-Up Plan
1–2 Weeks
Review Monitor Results — Critical Visit
Review MCOT or event monitor data. Classify as paroxysmal vs. persistent. This determines the downstream pathway. Discuss findings with patient and outline next steps clearly.
2–4 Weeks
Rate, Renal Function & OAC Check
Recheck resting heart rate and EKG. Renal function recheck (DOAC dosing). Confirm OAC adherence and tolerance. Address any side effects. Review echo results if not yet discussed.
1 Week Post-DCCV (Dr. Rasch)
Post-Procedure Follow-Up Visit + 12-Lead EKG
Dr. Rasch will see the patient personally within 1 week of the TEE/DCCV. Obtain a 12-lead EKG at this visit to confirm the patient remains in sinus rhythm. If AFib has recurred, antiarrhythmic initiation or EP referral for ablation will be discussed at this visit.
3 Months
Full Rhythm & Rate Reassessment
Comprehensive rhythm status review. Revisit cardioversion or ablation candidacy if AFib has recurred or persisted. Reassess rate control adequacy. Discuss long-term strategy with patient.
Ongoing / Annual
Annual Maintenance
Annual EKG. Renal function recheck (DOAC dosing adjustment). Reassess CHA₂DS₂-VASc score — score may increase with aging. OSA screening if not already done. Reinforce lifestyle modifications.
Patient Education — Reinforce at Every Visit
Stroke warning signs and when to call 911 · Never stop anticoagulation without calling the office first · Symptoms of AFib recurrence to watch for · Lifestyle: BP control, weight loss, alcohol reduction, CPAP adherence if OSA
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Step 11
Escalate to Attending If…
The following situations require attending involvement before proceeding. When in doubt — always better to ask.
🚨 If Transferring a Patient to the ER — Follow This Exact Sequence
- Ask front-desk staff to request hospital transfer via campus security (typically by golf cart). Request EMS only if the patient is critical.
- Call the Scripps ER triage officer directly at 760-633-7686 and notify them of the pending transfer and the patient's condition.
- Complete and sign the clinic note immediately so it is available for ED staff to review on arrival.
Hemodynamically unstable at any point during evaluation
Wide complex tachycardia or any concern for WPW / pre-excitation
Significantly reduced EF found on echo (HFrEF)
LAA thrombus identified on TEE — do not cardiovert
Unclear anticoagulation candidacy: active bleeding, recent surgery, thrombocytopenia, intracranial history
Initiating antiarrhythmic medications (flecainide, sotalol, amiodarone, dofetilide) — always attending decision
Patient is a catheter ablation candidate — refer to Electrophysiology
Any scenario where you are uncertain — always better to ask than to proceed alone.