Mitral regurgitation and mitral stenosis
Stem
A 52-year-old woman, 64 kg, with rheumatic mitral stenosis needs urgent repair of an incarcerated inguinal hernia. Echo last month showed a mitral valve area of 1.1 cm², an enlarged left atrium, mild mitral regurgitation and an estimated pulmonary artery systolic pressure of 55 mmHg. She is in atrial fibrillation on metoprolol and warfarin, which was held; INR is now 1.4. In pain, her heart rate is 112 and blood pressure 128/80.
Question
What are your hemodynamic goals, and how will you anesthetize her?
Ideal answer
HeadlineSevere mitral stenosis, area at or below 1.5 cm²: output depends on diastolic filling time across a fixed orifice.1 Slow the rate first: analgesia and more beta-blocker.
- Rate first: treat pain, more beta-blocker before induction, because tachycardia and lost atrial kick tip her into pulmonary edema; beta-blockers lower rate and the transmitral gradient.1
- Arterial line, then slow opioid-based induction, etomidate or careful propofol; no ketamine or pancuronium, which drive heart rate.
- Phenylephrine to maintain systemic resistance, because it raises resistance without speeding the heart.
- Preload adequate, not excessive; oxygenation, CO2, temperature tight: fluid in small boluses, because her left atrium is near the edema threshold, and nothing that raises pulmonary vascular resistance.
- Extubate awake and pain-free; valve consultation afterward, because symptomatic severe stenosis indicates balloon commissurotomy at a valve center.2
Breaking down the answer
- Severity sets the plan — severe: area 1.5 cm² or less or pressure half-time 150 ms or more; normal 4 to 5 cm².1 Elective moderate-to-severe valve disease gets echo and repair evaluation first; urgency is why I proceed.3
- Slow and sinus if possible — onset of AF and a faster rate cause abrupt deterioration because diastolic filling time shrinks;1 the move examiners grade first.
- Contrast with regurgitation — in MR, the opposite: normal-to-fast rate, lower afterload for forward flow, preserved preload. In acute MR, nitroprusside, nitroglycerin or a balloon pump improves forward stroke volume before surgery.4
- Right ventricle — hypoxia, hypercarbia and acidosis raise pulmonary pressure on an already loaded RV; I keep coronary perfusion pressure up. Vasopressin is an option because it spares pulmonary resistance. Severe stenosis with pulmonary hypertension needs evaluation.2
- Anticoagulation — AF with rheumatic mitral stenosis needs a vitamin K antagonist, not a DOAC.5 I restart warfarin with the surgeon once bleeding risk allows.
Follow-up question
Two minutes after intubation her heart rate jumps to 150 in atrial fibrillation, blood pressure falls to 72/40 and oxygen saturation drifts to 91% with rising airway pressures. What do you do?
Follow-up answer
HeadlineRapid AF in severe mitral stenosis: low output and acute pulmonary edema, unstable. I tell the room, call for the defibrillator and help.
I stop the surgeon from starting and perform synchronized cardioversion now, because she cannot fill at this rate. While the pads go on, phenylephrine for pressure, more oxygen, PEEP. If cardioversion fails or AF recurs, I slow the ventricular rate with esmolol titrated against pressure, or amiodarone. I check potassium, magnesium and a gas, deepen anesthesia if light, and use TEE for left atrial thrombus burden and right ventricular function. I reassess saturations and pressures; if she stays edematous she goes to the ICU ventilated.
Pitfalls that cost points
- Ephedrine or a fluid bolus for hypotension in mitral stenosis.
- Giving MS goals for MR, or the reverse.
Rapid-fire
Q: When is surgery recommended for asymptomatic severe primary MR? A: When ejection fraction is 60% or less or end-systolic diameter is 40 mm or more; repair is preferred to replacement.2
Q: Why is an EF of 55% worrying in severe MR? A: The ventricle ejects into the low-pressure atrium, so a normal-looking EF hides early dysfunction.
Q: What treats secondary MR first? A: Guideline-directed heart failure therapy, with transcatheter edge-to-edge repair if anatomy is favorable.2
Q: What suggests severe acute MR when the color jet looks small? A: Acute heart failure with a hyperdynamic left ventricle.4
Q: What else commonly unmasks mitral stenosis? A: Pregnancy, because blood volume rises.1
Numbers to know
| Item | Value |
|---|---|
| Normal mitral valve area | 4–5 cm²1 |
| Severe MS | Area 1.5 cm² or less; pressure half-time 150 ms or more1 |
| Severe MR | Vena contracta >7 mm, EROA >0.40 cm², regurgitant volume >60 mL, fraction >50%4 |
| Primary MR surgery trigger | EF 60% or less, or LVESD 40 mm or more2 |
Links
- Aortic stenosis, Atrial fibrillation: new onset and chronic, Pulmonary hypertension and right ventricular failure, Vasopressors and inotropes: choosing and titrating
- Atlas: Basic valvular lesions on 2D and color
- 2020 ACC/AHA guideline for valvular heart disease
Sources
- 1.Mitral Stenosis · Merck Manual Professional Edition · merckmanuals.com
- 2.2020 ACC/AHA Heart Valve Disease Guideline: Key Perspectives, Part 2 · American College of Cardiology, 2020 · acc.orgMitral stenosis stage D, PMBC; primary MR surgery thresholds; secondary MR and TEER.
- 3.2024 ACC/AHA guideline on perioperative cardiovascular management before noncardiac surgery: What's new? · Cleveland Clinic Journal of Medicine, 2025 · ccjm.orgTTE for known or suspected moderate-to-severe valve disease; evaluate for repair or replacement before elective noncardiac surgery.
- 4.Mitral Regurgitation · Merck Manual Professional Edition · merckmanuals.com
- 5.2020 ACC/AHA Heart Valve Disease Guideline: Key Perspectives, Part 1 · American College of Cardiology, 2020 · acc.orgVKA for AF with rheumatic mitral stenosis.
Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.