When to intubate in GCS?

GCS ≤ 8 requires intubation for airway protection. The patient cannot protect their own airway at this level of consciousness. Motor score is the most prognostically important component.

What is the best initial fluid for sepsis resuscitation?

Lactated Ringer's (LR) is the preferred resuscitation fluid. The SMART trial (2018) showed balanced crystalloids reduced death, new renal failure, and persistent renal dysfunction compared to normal saline.

When to start vasopressors in septic shock?

Start norepinephrine (first-line vasopressor) if MAP remains < 65 mmHg after initial 30 mL/kg crystalloid resuscitation, or earlier if patient is profoundly hypotensive. Do not delay pressors to complete full fluid resuscitation.

Why can serum uric acid be normal during acute gout?

During acute inflammation, IL-6 increases renal urate excretion and redistributes urate from plasma to tissues. Up to 40% of acute gout flares have normal serum uric acid. Joint aspiration with polarized microscopy is needed for definitive diagnosis.

How do you distinguish lupus flare from infection in SLE?

Key clues: CRP is low/normal in flare but elevated in infection. Complement (C3/C4) drops in flare but is normal/elevated in infection. Procalcitonin is elevated in bacterial infection but normal in flare. Anti-dsDNA rises in flare, stable in infection.

What is the difference between DKA and HHS?

DKA features acidosis (pH 600), hyperosmolality (> 320), and minimal ketosis -typically in Type 2 DM. DKA requires insulin drip; HHS requires aggressive fluid resuscitation first.

When to give tPA in acute ischemic stroke?

IV alteplase (tPA) can be given within 4.5 hours of last known well time in eligible patients. CT head must rule out hemorrhage first. For large vessel occlusion, mechanical thrombectomy can be performed up to 24 hours with favorable imaging.

What antibiotics for community-acquired pneumonia?

Inpatient non-ICU: ceftriaxone + azithromycin. ICU: ceftriaxone + azithromycin (add vancomycin if MRSA risk). Outpatient healthy: amoxicillin. Outpatient with comorbidities: augmentin + azithromycin or respiratory fluoroquinolone. Duration: 5 days if clinically stable for 48 hours.

How to interpret iron studies?

Iron deficiency: low ferritin (< 30), high TIBC, low iron, low transferrin saturation (< 20%). Anemia of chronic disease: normal/high ferritin (acute phase reactant), low TIBC, low iron. A ferritin of 50-100 in an inflamed patient may still represent iron deficiency.

What is the correction rate for hyponatremia?

Correct sodium no more than 8 mEq/L in 24 hours to avoid osmotic demyelination syndrome (ODS). For symptomatic severe hyponatremia with seizures, give 3% hypertonic saline 100-150 mL bolus over 10-20 minutes. If overcorrected, use D5W + DDAVP rescue protocol.

When to start antibiotics in meningitis?

Within 30-60 minutes. Do NOT delay antibiotics for LP or CT. Draw blood cultures, start empiric antibiotics (vancomycin + ceftriaxone ± ampicillin if > 50 or immunocompromised), then perform LP when possible. Dexamethasone should be given before or with the first antibiotic dose.

DOACs vs warfarin in antiphospholipid syndrome?

DOACs are contraindicated in APS. The TRAPS trial (2018) showed rivaroxaban was inferior to warfarin with more thrombotic events in triple-positive APS patients. Warfarin with INR target 2-3 is the standard for APS, indefinitely.

How to manage scleroderma renal crisis?

ACE inhibitors (captopril) are life-saving -start immediately and titrate aggressively. Do NOT hold for rising creatinine. Steroids > 15 mg prednisone per day precipitate scleroderma renal crisis. ARBs are NOT a substitute -evidence is only for ACEi.

What are the 4 pillars of heart failure treatment?

Guideline-directed medical therapy (GDMT) for HFrEF: (1) ARNI or ACEi/ARB, (2) beta-blocker (carvedilol, metoprolol succinate, or bisoprolol), (3) MRA (spironolactone or eplerenone), (4) SGLT2 inhibitor (dapagliflozin or empagliflozin). All four should be initiated and titrated to target doses.

Atrial Fibrillation -Rate vs Rhythm Control -RoundsRx

🔍 Overview

Definition

Atrial fibrillation (AF) is an irregularly irregular supraventricular tachyarrhythmia caused by chaotic atrial electrical activity. No organized P waves on ECG -replaced by fibrillatory waves with an irregular ventricular response.

Classification

Type	Definition
Paroxysmal	Self-terminates within 7 days (usually < 48h)
Persistent	Lasts > 7 days, requires intervention to terminate
Long-standing persistent	Continuous > 12 months
Permanent	Rate control accepted; no further attempts at rhythm control
Valvular AF	AF with moderate-severe mitral stenosis or mechanical heart valve → requires warfarin (not DOACs)

Common Triggers & Causes

Hypertension -most common modifiable risk factor
Heart failure -AF and HF exacerbate each other
Valvular disease -especially mitral stenosis/regurgitation
Thyrotoxicosis -always check TSH in new AF
Alcohol -"holiday heart" (binge drinking → AF)
Post-operative -especially cardiac and thoracic surgery (30–50%)
PE -AF can be the first sign of PE
Sepsis / critical illness -new AF in ICU = search for underlying cause
OSA, obesity, advancing age, pericarditis

Always ask: What triggered this AF? New AF is often a symptom of something else (sepsis, PE, thyroid storm, ACS, volume overload). Treat the cause, not just the rhythm.

ECG Features

Absent P waves -replaced by irregular fibrillatory baseline
Irregularly irregular R-R intervals (the hallmark)
Narrow QRS (unless aberrant conduction or pre-existing BBB)
Ventricular rate typically 100–180 bpm if untreated (RVR)

⚡ Management

Is the Patient Hemodynamically Unstable?

Unstable = hypotension (SBP < 90), AMS, chest pain, acute pulmonary edema, or signs of shock. If YES → immediate synchronized cardioversion. Do not delay for rate control medications.

Unstable → Cardiovert

Synchronized DC cardioversion -120–200J biphasic. Sedate first if possible (propofol, etomidate, or midazolam). If first shock fails, escalate energy. Have pads and airway equipment ready. This is immediate -do not wait for anticoagulation status.

Stable → Rate Control

If hemodynamically stable with RVR (HR > 110), proceed to pharmacologic rate control. Choice depends on EF:

Rate Control in Afib with RVR -By EF

Setting	First-Line	Dose	Notes
Preserved EF (HFpEF or normal)	Diltiazem	0.25 mg/kg IV over 2 min → repeat 0.35 mg/kg in 15 min if needed → drip 5–15 mg/hr	Fastest onset. Can also use metoprolol. Avoid in pre-excitation (WPW).
Preserved EF (alternative)	Metoprolol tartrate	5 mg IV push q5 min × 3 doses → 25–100 mg PO BID	Good if also hypertensive or ACS. Safer than diltiazem in borderline EF.
Reduced EF (HFrEF, EF < 40%)	Amiodarone	150 mg IV over 10 min → 1 mg/min × 6h → 0.5 mg/min × 18h	Avoid CCBs and high-dose BB in HFrEF. Amio provides rate + rhythm control. Monitor QTc.
Reduced EF (alternative)	Digoxin	0.25–0.5 mg IV load → 0.125–0.25 mg PO daily	Slow onset (hours). No acute rate control. Add-on for refractory rate. Check levels (0.5–0.9 ng/mL). RATE-AF, 2020: digoxin non-inferior to bisoprolol for rate control in permanent AF.
Critical illness / ICU	Amiodarone or esmolol	Esmolol: 500 mcg/kg IV bolus → 50–200 mcg/kg/min drip	Esmolol = ultra-short acting β₁ blocker. Ideal for hemodynamic uncertainty -stops fast if BP drops.

NEVER give CCBs (diltiazem, verapamil) or BB in Afib with WPW (pre-excitation / delta wave on ECG). These block the AV node → forces conduction down accessory pathway → VF → death. Use procainamide or cardiovert.

Targets

Strategy	Target HR	Evidence
Lenient (most patients)	< 110 bpm at rest	RACE II, 2010: lenient was non-inferior to strict. Less drug side effects. Preferred initial approach.
Strict (if symptomatic)	< 80 bpm at rest	Use if persistent symptoms despite lenient control.

Workup in New Afib with RVR

12-lead ECG -confirm AF, rule out flutter, WPW, STEMI
TSH -always check. Thyrotoxicosis is a reversible cause.
BMP -electrolytes (K⁺, Mg²⁺ -both must be repleted), renal function
BNP/Echo -assess EF. Determines drug choice (CCB vs amio).
Troponin -RVR can cause demand ischemia
CBC -anemia worsens tachycardia and symptoms
Mg²⁺ -replete aggressively (target ≥ 2.0). Low Mg = refractory RVR.
Consider PE workup if new AF + dyspnea + tachycardia + hypoxia

Pearl: Always replete K⁺ > 4.0 and Mg²⁺ > 2.0 in AF with RVR. Hypomagnesemia is the most common missed cause of refractory rate control.

💊 Rate Control

Drug	Dose	Best For	Avoid In
Metoprolol succinate 1ST LINE	25–200 mg PO daily	First-line. HTN, HFrEF (evidence-based BB), ACS	Decompensated HF, severe bradycardia, asthma
Diltiazem (Cardizem) ER 1ST LINE	120–360 mg PO daily	Preserved EF. Fast symptom relief. COPD-safe.	HFrEF (EF < 40%), WPW, concurrent BB
Verapamil (Calan)	120–480 mg PO daily	Alternative CCB if diltiazem intolerant	Same as diltiazem. More constipation.
Digoxin (Lanoxin)	0.125–0.25 mg PO daily	Add-on if BB/CCB insufficient. HFrEF. Sedentary patients.	Renal failure (adjust dose), hypokalemia (toxicity risk). Target level 0.5–0.9 ng/mL.
Amiodarone (Cordarone) HFrEF ONLY	200 mg PO daily	HFrEF with refractory rate. Also provides rhythm control.	Long-term toxicities: thyroid, liver, lung, cornea, skin. Monitor TFTs/LFTs/PFTs q6 months.

⚡ Rhythm Control

When to Consider Rhythm Control

Symptomatic despite adequate rate control
Young patients with first episode
AF duration < 1 year (higher success of maintaining sinus)
Tachycardia-mediated cardiomyopathy
EAST-AFNET 4, 2020: early rhythm control (within 1 year of diagnosis) reduced cardiovascular outcomes vs rate control alone

Cardioversion Rules

If AF > 48 hours (or unknown duration): Must anticoagulate ≥ 3 weeks before elective cardioversion OR do TEE to rule out LAA thrombus first. Then anticoagulate ≥ 4 weeks after cardioversion regardless.

If AF < 48 hours: Can cardiovert without prior anticoagulation (but start anticoagulation based on CHA₂DS₂-VASc after).

Antiarrhythmic Agents

Drug	Use	Key Caution
Flecainide (Tambocor) 1ST LINE	No structural heart disease ("pill-in-the-pocket" for paroxysmal AF)	Contraindicated in CAD, HFrEF, structural disease (proarrhythmic). Must give with AV nodal blocker.
Propafenone (Rythmol)	Same as flecainide -no structural disease	Same contraindications. Also has mild BB activity.
Amiodarone (Cordarone)	Structural heart disease, HFrEF -most versatile	Long-term toxicities (thyroid, pulmonary fibrosis, hepatotoxicity, corneal deposits). Not first-line in young patients.
Dofetilide INPATIENT ONLY	HFrEF, structural disease. Inpatient initiation required.	QTc prolongation → Torsades. Must monitor QTc × 3 days inpatient. Renally dosed.
Sotalol	No severe structural disease. Combined BB + class III.	QTc prolongation. Avoid in HFrEF, renal failure. Monitor QTc closely.
Ibutilide	Acute pharmacologic cardioversion (IV only)	QTc prolongation → Torsades (risk ~4%). Monitor on telemetry × 4h. Have Mg²⁺ and defibrillator ready.

🔄 Updated Practice: Old teaching: rate control is preferred over rhythm control for most AF patients (based on AFFIRM, 2002). New evidence: EAST-AFNET 4, 2020 showed that EARLY rhythm control (within 1 year of diagnosis) reduces cardiovascular death, stroke, and HF hospitalization. Key word is "early" -the benefit diminishes if AF has been present for years. Consider early rhythm control especially in younger patients and those with HF.

💉 Anticoagulation & Stroke Prevention

CHA₂DS₂-VASc Score

Determines stroke risk and need for anticoagulation in non-valvular AF. Calculate for every AF patient.

Letter	Risk Factor	Points
C	Congestive heart failure (or LV dysfunction, EF ≤ 40%)	1
H	Hypertension (or on antihypertensive therapy)	1
A₂	Age ≥ 75 years	2
D	Diabetes mellitus	1
S₂	Stroke / TIA / thromboembolism (prior)	2
V	Vascular disease (prior MI, PAD, aortic plaque)	1
A	Age 65–74 years	1
Sc	Sex category -female	1

Maximum score: 9. Note: female sex alone (score = 1) does not warrant anticoagulation -it is a risk modifier, not an independent indication.

⚠️ Anticoagulate regardless of CHA₂DS₂-VASc score -the following carry stroke risk so high that the score doesn't apply:

Hypertrophic cardiomyopathy (HCM) with AF -Class I (2024 AHA/ACC HCM guideline). DOAC preferred.
Cardiac amyloidosis with AF -anticoagulate even if sinus rhythm if intracardiac thrombus on imaging.
Moderate-to-severe (rheumatic) mitral stenosis -warfarin only, NOT DOACs.
Mechanical heart valve -warfarin only (RE-ALIGN: dabigatran failed).
LA / LAA thrombus on TEE or cardiac CT -anticoagulate regardless of rhythm.
Peri-cardioversion -anticoagulate ≥ 3 weeks before + 4 weeks after, or TEE-guided.

Anticoagulation Decision

Score (Male / Female)	Annual Stroke Risk	Recommendation
0 (M) / 1 (F)	~0.2–0.6%	No anticoagulation recommended
1 (M) / 2 (F)	~1.3–2.2%	Consider anticoagulation (discuss with patient -benefit may outweigh bleed risk)
≥ 2 (M) / ≥ 3 (F)	~2.2–15%	Anticoagulate. DOACs preferred over warfarin for non-valvular AF.

Anticoagulant Options

Drug	Dose	Key Points
Apixaban (Eliquis) PREFERRED	5 mg PO BID (2.5 mg if ≥ 2 of: age ≥ 80, weight ≤ 60 kg, Cr ≥ 1.5)	Preferred DOAC. Lowest bleeding risk. ARISTOTLE, 2011: superior to warfarin for stroke prevention with less bleeding.
Rivaroxaban (Xarelto) ALTERNATIVE	20 mg PO daily with dinner (15 mg if CrCl 15–50)	Once daily. ROCKET-AF, 2011: non-inferior to warfarin. Must take with food for absorption.
Dabigatran (Pradaxa) ALTERNATIVE	150 mg PO BID (75 mg if CrCl 15–30)	RE-LY, 2009: 150 mg dose superior to warfarin for stroke; higher GI bleed. Reversible with idarucizumab.
Edoxaban (Savaysa)	60 mg PO daily (30 mg if CrCl 15–50, weight ≤ 60 kg, or P-gp inhibitor)	ENGAGE AF-TIMI 48, 2013: non-inferior to warfarin. Do NOT use if CrCl > 95 (reduced efficacy).
Warfarin (Coumadin) VALVULAR ONLY	Titrate to INR 2.0–3.0	Required for valvular AF (mechanical valve, moderate-severe mitral stenosis). TTR > 70% needed for benefit. Bridging with heparin may be needed.

Valvular AF = warfarin only. DOACs are NOT approved for mechanical heart valves (RE-ALIGN, 2013: dabigatran increased thromboembolism and bleeding vs warfarin in mechanical valves -trial stopped early) or moderate-severe mitral stenosis.

🔄 Updated Practice: Old teaching: warfarin is the standard anticoagulant for AF. Current practice: DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) are preferred over warfarin for non-valvular AF -better safety profile, no INR monitoring, fewer drug-food interactions. Warfarin is still required for: mechanical heart valves (RE-ALIGN -DOACs caused thromboembolism), moderate-severe mitral stenosis, and antiphospholipid syndrome (TRAPS -DOACs increased thrombosis).

HAS-BLED Score (Bleeding Risk)

Use to identify modifiable bleeding risk factors -NOT to withhold anticoagulation. A high HAS-BLED score means fix the modifiable risks, not stop the DOAC.

Letter	Risk Factor	Points
H	Hypertension (uncontrolled, SBP > 160)	1
A	Abnormal renal/liver function (1 pt each)	1–2
S	Stroke (prior)	1
B	Bleeding (history or predisposition)	1
L	Labile INR (if on warfarin, TTR < 60%)	1
E	Elderly (age > 65)	1
D	Drugs (antiplatelets, NSAIDs) or alcohol (≥ 8 drinks/week) (1 pt each)	1–2

Score ≥ 3 = high bleeding risk. Address modifiable factors (control BP, stop NSAIDs, reduce alcohol, optimize INR). Do not withhold anticoagulation based on HAS-BLED alone.

Swipe for more examples

📋 Case 1, New Afib with RVR Management

Patient: 72F presents with palpitations, HR 142, irregularly irregular, BP 108/72. No prior Afib history.

Step 1 -Rate Control:
Metoprolol (Lopressor) 5mg IV push over 2 min. Repeat q5min × 3 doses (max 15mg). HR → 118.
Additional: metoprolol (Lopressor) 5mg IV → HR 98. Start metoprolol tartrate (Lopressor) 25mg PO q6h.
If HFrEF (EF < 40%): Avoid diltiazem -contraindicated (negative inotrope worsens HF). Use amiodarone (Cordarone) 150mg IV over 10 min → 1mg/min × 6h → 0.5mg/min × 18h. If preserved EF but hypotensive: diltiazem (Cardizem) 0.25 mg/kg IV bolus → drip 5-15 mg/hr is acceptable.

Step 2 -Anticoagulation:
CHA₂DS₂-VASc: Age 72 (+1), Female (+1) = 2 → Anticoagulate.
Start apixaban (Eliquis) 5mg PO BID (preferred DOAC). Reduce to 2.5 mg BID if ≥ 2 of: age ≥ 80, weight ≤ 60 kg, Cr ≥ 1.5 mg/dL. Note: 2 of 3, not all 3, residents commonly miss this and underdose.

Step 3 -Assess for Cause:
TSH (hyperthyroidism?), TTE (structural heart disease, valvular?), BMP (electrolytes), troponin (ACS trigger?).

Step 4 -Rate vs Rhythm Control:
New-onset, symptomatic → consider cardioversion if < 48h onset OR TEE-guided if > 48h. Otherwise rate control + anticoagulation × 3 weeks → then cardioversion.

📋 Case 2, Afib with WPW (Pre-excitation)

Patient: 32M presents with HR 220, irregular wide-complex tachycardia. Known WPW. BP 100/62. ECG shows irregularly irregular wide QRS with varying morphology.

CRITICAL, Do NOT give AV nodal blockers:
No diltiazem, no metoprolol, no digoxin, no adenosine. These block the AV node and force conduction down the accessory pathway → can degenerate to VF.

Treatment:
Procainamide 20-50 mg/min IV (slows accessory pathway conduction).
If unstable → synchronized cardioversion.
If VF → defibrillate immediately.

Key Lesson:
Irregular wide-complex tachycardia = Afib with WPW until proven otherwise. AV nodal blockers can kill. Procainamide or cardiovert.

📋 Case 3, New Afib in Sepsis

Patient: 68F admitted with pneumonia and septic shock, develops new Afib with RVR (HR 148). No prior cardiac history. This is likely rate-related, not a primary arrhythmia.

Treatment, Treat the underlying cause FIRST:
Fluids, antibiotics, source control. The Afib is a symptom of the sepsis, not the primary problem.

Rate Control:
Esmolol drip (short-acting, titratable), better than diltiazem in sepsis because diltiazem drops BP. Target HR < 110 (not < 80).

Do NOT cardiovert:
Rhythm will likely convert once sepsis resolves.

Anticoagulation:
CHA₂DS₂-VASc assessment, but defer starting anticoagulation until sepsis is stabilized.

Key Lesson:
New Afib in sepsis is usually a symptom, not the disease. Treat the infection. Use esmolol for rate control. Don't chase rhythm conversion.

🧪 Workup

Initial Workup -New Atrial Fibrillation

12-lead ECG -confirm AF (irregularly irregular, no P waves). Rule out flutter, WPW (delta wave).
TSH -hyperthyroidism is a reversible cause. Check in ALL new AF.
BMP -electrolytes (K⁺, Mg²⁺), Cr (for DOAC dosing)
CBC -anemia can worsen rate, infection can trigger AF
TTE (echocardiogram) -assess LV function (EF), valvular disease, LA size, wall motion abnormalities
Troponin -if chest pain or concern for ACS as trigger
BNP/NT-proBNP -if concern for heart failure
Consider: D-dimer/CTPA if PE suspected, sleep study if OSA suspected, alcohol history ("holiday heart")

CHA₂DS₂-VASc score should be calculated at diagnosis and documented -it determines anticoagulation need. See Management tab.

💊 Medications

Key Medication Classes -Atrial Fibrillation

Full drug tables with dosing, indications, and contraindications are in the Management tab (Rate Control, Rhythm Control, and Anticoagulation sections).

Category	First-Line	Key Pearl
Rate control	Metoprolol (Lopressor) (HFrEF) or Diltiazem (Cardizem) (preserved EF)	Diltiazem contraindicated if EF < 40%. Target HR < 110 at rest RACE II, 2010.
Rhythm control	Flecainide (Tambocor) (no structural disease) or Amiodarone (Cordarone) (HFrEF)	Flecainide is proarrhythmic in CAD/HFrEF. Amiodarone has cumulative organ toxicity.
Anticoagulation	Apixaban (Eliquis) 5 mg BID PREFERRED	Lowest bleeding risk among DOACs ARISTOTLE, 2011. Warfarin only for valvular AF (mechanical valve, MS).
Acute RVR	Diltiazem (Cardizem) 20 mg IV bolus → drip 5–15 mg/hr	Fastest onset. Can repeat bolus q15 min. Transition to PO within 24h.

⚡ Summary

Summary

Rate Control

BB or non-DHP CCB (diltiazem). Target HR < 110 at rest [RACE II]. Digoxin add-on if refractory. Avoid CCB in HFrEF.

Rhythm Control

Consider if symptomatic, new-onset (< 1 year), younger patient. Cardioversion + flecainide/amiodarone or catheter ablation.

Anticoagulation

CHA₂DS₂-VASc ≥ 2 (men) or ≥ 3 (women) → DOAC (apixaban, rivaroxaban). Warfarin only if mechanical valve or severe MS.

Stroke Risk

CHA₂DS₂-VASc: CHF(1), HTN(1), Age≥75(2), DM(1), Stroke/TIA(2), Vasc disease(1), Age 65-74(1), Sex female(1).

Acute RVR

Stable: IV diltiazem 20 mg → drip. Unstable: synchronized cardioversion 120-200J biphasic. Replete K⁺ and Mg²⁺.

Don't Miss

Check TSH (hyperthyroid), echo (structural), sleep study (OSA -#1 modifiable risk factor for AF recurrence).

📄 One Pager

Atrial Fibrillation -Quick Reference Card

Print this page (Ctrl/Cmd + P) for a complete reference card.

ATRIAL FIBRILLATION -AT A GLANCE

📋 Diagnose: Irregularly irregular, no P waves, narrow QRS
🧪 Workup: ECG, TSH, BMP (K⁺/Mg²⁺), TTE, troponin if ACS concern
⚡ Acute RVR: Unstable → cardiovert. Stable → diltiazem 20 mg IV → drip
💊 Rate control: Metoprolol (HFrEF) or Diltiazem (preserved EF). Target HR < 110.
⚡ Rhythm control: Flecainide (no structural disease) or Amiodarone (HFrEF)
💉 Anticoag: CHA₂DS₂-VASc ≥ 2M/3F → Apixaban 5 mg BID (preferred DOAC)
📈 Monitor: HR, rhythm, K⁺/Mg²⁺, renal function, QTc if on AAD
📣 Present: See Rounds tab

📋 On Rounds

Pimp Questions

Why can't you give diltiazem in Afib with WPW?

CCBs and beta-blockers slow AV nodal conduction. In WPW, an accessory pathway (Bundle of Kent) bypasses the AV node. Blocking the AV node forces all conduction down the accessory pathway → extremely rapid ventricular rates → ventricular fibrillation → cardiac arrest. Use procainamide or synchronized cardioversion instead.

What CHA₂DS₂-VASc score triggers anticoagulation?

≥ 2 in males, ≥ 3 in females → anticoagulate (DOACs preferred). Score of 1 (male) or 2 (female) → consider anticoagulation. Score 0 (male) or 1 (female, sex point only) → no anticoagulation. Female sex alone doesn't warrant treatment -it's a modifier.

When must you use warfarin instead of a DOAC?

Valvular AF: mechanical heart valve or moderate-severe mitral stenosis. RE-ALIGN, 2013 showed dabigatran was harmful in mechanical valves -increased stroke and bleeding vs warfarin. Also consider warfarin if severe renal failure (CrCl < 15), antiphospholipid syndrome, or patient preference/cost.

What is the most commonly missed cause of refractory Afib with RVR?

Hypomagnesemia. Always check and replete Mg²⁺ > 2.0. Low magnesium destabilizes cardiac membrane potentials and makes rate control drugs less effective. IV magnesium 2g over 15 min can help convert or slow AF even before other agents kick in.

What did EAST-AFNET 4 show about rhythm control?

EAST-AFNET 4, 2020: early rhythm control (within 1 year of AF diagnosis) reduced a composite of cardiovascular death, stroke, and HF hospitalization compared to rate control alone. This shifted practice toward more aggressive early rhythm control, especially in patients with recent-onset AF and cardiovascular comorbidities.

Clinical Examples

📋 Case 1, New AF with RVR in HFpEF

Patient: 74 y/o F with HTN, DM2, HFpEF (EF 55%), presents with palpitations and dyspnea. HR 148, irregularly irregular.

Key findings: BP 142/88, K⁺ 3.4, Mg 1.2, TSH normal, troponin negative. CHA₂DS₂-VASc = 5.

Management:

Replete Mg > 2.0 and K⁺ > 4.0 first, most commonly missed cause of refractory RVR
Diltiazem 20 mg IV bolus x2, then drip 10 mg/hr (CCB safe in preserved EF)
Transition to diltiazem ER 180 mg daily
Apixaban 5 mg BID (CHA₂DS₂-VASc ≥ 2) ARISTOTLE, 2011

Teaching point: Always replete Mg and K⁺ before concluding rate control is failing. Hypomagnesemia is the most commonly missed cause of refractory AF with RVR.

📋 Case 2, AF with RVR in HFrEF

Patient: 66 y/o M with HFrEF (EF 30%), worsening dyspnea, HR 140. Known paroxysmal AF, non-compliant with metoprolol.

Key findings: BP 98/62, JVP elevated, bibasilar crackles. BNP 4,200. Echo: EF 28%.

Management:

IV amiodarone 150 mg over 10 min then drip (CCBs contraindicated in HFrEF)
Restart metoprolol succinate once rate controlled
IV furosemide for congestion (warm and wet)
Consider early rhythm control EAST-AFNET 4, 2020

Teaching point: Diltiazem and verapamil are contraindicated in HFrEF, negative inotropes that worsen heart failure. Use amiodarone or digoxin for rate control.

📋 Case 3, AF with WPW (Pre-excitation)

Patient: 28 y/o M with palpitations and near-syncope. HR 210, irregular wide-complex tachycardia. Known WPW.

Key findings: BP 86/54, ECG: irregularly irregular wide-complex tachycardia with delta waves and varying QRS morphology.

Management:

DO NOT give AV nodal blockers (diltiazem, beta-blockers, digoxin, adenosine), risk of VF
Hemodynamically unstable, synchronized cardioversion 120-200J biphasic
If stable: IV procainamide (slows accessory pathway conduction)
Refer for EP study and catheter ablation of accessory pathway

Teaching point: In AF with WPW, AV nodal blockers force conduction through the accessory pathway → VF → cardiac arrest. Procainamide or cardioversion are the only safe options.

Sample Presentation

📋 Afib with RVR

"Mrs. Johnson is a 72-year-old woman with HTN, DM, and HFpEF (EF 55%) who presented with palpitations and HR 148, found to be in new-onset atrial fibrillation with RVR. She was hemodynamically stable. TSH was normal. K⁺ 3.6, Mg 1.4 -both repleted. She received diltiazem 20 mg IV bolus × 2 then started on a diltiazem drip at 10 mg/hr with rate down to 92. She was transitioned to diltiazem ER 180 mg daily. Her CHA₂DS₂-VASc is 4 (HTN, DM, age 65–74, female) -we started apixaban 5 mg BID for stroke prophylaxis. Echo showed no structural abnormality. Plan to reassess for rhythm control as outpatient."

Monitoring -Atrial Fibrillation

Parameter	Frequency	Target / Action
Heart rate	Continuous telemetry inpatient; daily resting HR outpatient	Resting HR < 110 bpm (lenient) RACE II, 2010. Stricter < 80 if symptomatic.
Rhythm	Telemetry inpatient; ambulatory monitor (Holter/Zio) outpatient	Assess AF burden, recurrence after cardioversion, breakthrough episodes on AAD
Electrolytes (K⁺, Mg²⁺)	Daily inpatient; q3–6 months outpatient	K⁺ > 4.0, Mg²⁺ > 2.0 -low levels promote AF and reduce AAD efficacy
Renal function	At DOAC initiation, then q6–12 months	Adjust DOAC dose per CrCl. Apixaban: 2.5 mg dose if ≥ 2 of (age ≥ 80, wt ≤ 60, Cr ≥ 1.5).
TSH	At diagnosis; annually if on amiodarone	Amiodarone causes both hyper- and hypothyroidism (iodine load)
LFTs, PFTs, TFTs	q6 months if on amiodarone	Monitor for hepatotoxicity, pulmonary fibrosis, thyroid dysfunction
QTc	Baseline + 3 days inpatient if starting dofetilide/sotalol	Hold if QTc > 500 ms. Dofetilide requires inpatient initiation.

📄 One Pager

Cardiology · One Pager

Atrial Fibrillation

Rate control (BB or CCB) + anticoagulation (DOAC if CHA₂DS₂-VASc ≥ 2). Treat triggers: TSH, OSA, alcohol, electrolytes.

🧪 Diagnosis

Irregularly irregular rhythm. No discrete P waves. Can be paroxysmal, persistent, or permanent. Check TSH, echo, electrolytes.

🚨 Acute RVR

IV diltiazem 20 mg → drip 10 mg/hr. Alternative: metoprolol 5 mg IV. Replete K⁺ > 4, Mg > 2. Unstable → cardioversion 120-200J biphasic.

💊 Long-Term

Rate control: BB or CCB (target HR < 110 [RACE II]). Rhythm control if symptomatic/young/new-onset. Anticoag: CHA₂DS₂-VASc ≥ 2M / ≥ 3F → DOAC (apixaban preferred).

💊 Key Drugs

Diltiazem ER180-360 mg daily

Metoprolol XL25-200 mg daily

Apixaban5 mg BID

Amiodarone200 mg daily (rhythm)

⚠️ Pitfalls

CCB in HFrEF (negative inotrope → worsens HF)
Not anticoagulating based on CHA₂DS₂-VASc
Not checking TSH (hyperthyroidism is reversible cause)
Not screening for OSA (#1 modifiable risk factor for AF recurrence)