Residency · Residency · Anesthesiology

Valvular Heart Disease: Hemodynamic Goals by Lesion

Aortic Stenosis (AS)

Pathophysiology

Aortic stenosis produces a fixed obstruction to left ventricular outflow, forcing the ventricle to generate higher pressures to eject blood. Over time, this leads to concentric LV hypertrophy with increased wall thickness. The hypertrophied ventricle becomes stiff and noncompliant, developing significant diastolic dysfunction. Adequate filling depends heavily on preload and the contribution of atrial contraction. Coronary perfusion is compromised from two directions simultaneously: myocardial oxygen demand is elevated because of the increased muscle mass, while supply is reduced through decreased diastolic perfusion and subendocardial compression from elevated intracavitary pressures. Severe AS is defined by a valve area below 1.0 cm2, a mean gradient above 40 mmHg, or a peak velocity above 4 m/s.

Hemodynamic Goals -- "Slow, Full, Tight, Sinus"

The hemodynamic management of aortic stenosis follows the mnemonic "Slow, Full, Tight, Sinus." The heart rate should be kept slow to allow adequate diastolic filling time and coronary perfusion. Sinus rhythm must be maintained because the atrial kick is critical; atrial fibrillation can cause a 25-40% drop in cardiac output. Preload should be kept full because the hypertrophied ventricle requires adequate volume to fill through its stiff walls, and hypovolemia is poorly tolerated. Afterload (SVR) must be maintained because coronary perfusion depends on aortic diastolic pressure; vasodilation can be catastrophic. Contractility should be preserved, as negative inotropes are poorly tolerated. Spinal and epidural anesthesia should be avoided due to the risk of precipitous SVR reduction. Tachycardia, hypovolemia, and vasodilators are the most dangerous hemodynamic insults. Hypotension should be treated with phenylephrine, a pure alpha agonist that maintains SVR without causing tachycardia.

Aortic Regurgitation (AR)

Pathophysiology

Aortic regurgitation produces volume overload of the left ventricle, leading to eccentric hypertrophy with chamber dilation. The regurgitant fraction depends on the severity of valvular incompetence, the duration of diastole, and the aortic-to-LV pressure gradient during diastole. Chronic AR allows compensatory dilation with preserved ejection fraction over time, while acute AR causes sudden volume overload with pulmonary edema and hemodynamic collapse.

Hemodynamic Goals -- "Full, Fast, Forward"

The management of aortic regurgitation follows the mnemonic "Full, Fast, Forward." The heart rate should be kept slightly fast at 80-100 bpm; a faster rate shortens diastole and thereby reduces the time available for regurgitation. Preload should be maintained because the volume-loaded ventricle requires adequate filling. Afterload should be reduced because lower SVR promotes forward flow and diminishes the regurgitant fraction. Contractility should be maintained or augmented. Bradycardia must be avoided because it prolongs diastole and increases regurgitation. Excessive afterload increases are harmful, and an intra-aortic balloon pump is contraindicated because it augments diastolic aortic pressure and worsens regurgitation. Vasodilators such as nitroprusside and hydralazine, as well as inodilators like milrinone, can be beneficial.

Mitral Stenosis (MS)

Pathophysiology

Mitral stenosis creates a fixed obstruction to LV filling at the mitral valve, most commonly from rheumatic disease. The obstruction elevates left atrial pressure, leading progressively to pulmonary hypertension and, in late stages, right ventricular dysfunction. Cardiac output depends on diastolic filling time and the contribution of atrial contraction to transmitral flow. Severe MS is defined by a valve area below 1.0 cm2 or a mean gradient above 10 mmHg.

Hemodynamic Goals -- "Slow, Sinus, Dry"

The management of mitral stenosis follows the mnemonic "Slow, Sinus, Dry." The heart rate should be kept slow at 60-80 bpm because a slower rate prolongs diastolic filling time across the stenotic valve; tachycardia reduces transmitral flow and raises left atrial pressure, making it the most dangerous hemodynamic derangement in MS. Sinus rhythm is essential because loss of atrial contraction is devastating; atrial fibrillation is a common complication. Preload requires careful management: excess volume causes pulmonary edema, so euvolemia or slight hypovolemia is the target. Afterload should be maintained to avoid hypotension. Factors that increase pulmonary vascular resistance, including hypoxia, hypercarbia, acidosis, and high airway pressures, must be avoided. LV function is usually preserved in MS, but the right ventricle may need support. Tachycardia and fluid overload are the most dangerous insults.

Mitral Regurgitation (MR)

Pathophysiology

Mitral regurgitation causes systolic regurgitation of blood into the left atrium, producing volume overload of both the LA and LV. Acute MR results in a sudden increase in LA pressure, pulmonary edema, and cardiogenic shock. Chronic MR allows compensatory LA dilation and eccentric LV hypertrophy. Importantly, the ejection fraction in chronic MR may overestimate true contractile function because the ventricle ejects partly into the low-pressure left atrium, making the "work" of ejection artificially easier.

Hemodynamic Goals -- "Full, Fast, Forward"

The management of mitral regurgitation follows the same "Full, Fast, Forward" principles as aortic regurgitation, since both are regurgitant lesions. The heart rate should be slightly fast at 80-100 bpm to reduce regurgitant time per cardiac cycle. Preload should be maintained because the volume-loaded ventricle requires adequate filling. Afterload should be reduced to promote forward flow into the aorta rather than backward flow into the LA. Contractility should be maintained or augmented. Bradycardia increases the regurgitant fraction, and myocardial depression and excessive SVR increases are harmful.

Summary of Hemodynamic Goals by Valve Lesion

Mitral Valve Prolapse (MVP)

Mitral valve prolapse is usually a benign condition, and anesthetic management is generally routine. If significant MR coexists, management follows the MR hemodynamic goals. Hypovolemia and conditions that reduce LV volume should be avoided because prolapse worsens with decreased preload. Endocarditis prophylaxis is no longer routinely recommended per current AHA guidelines.

Combined and Mixed Valve Lesions

Mixed Aortic Disease (AS + AR)

When aortic stenosis and regurgitation coexist, the hemodynamic goals inherently conflict: AS favors a slow heart rate while AR favors a fast one. The key is to identify and prioritize the dominant lesion. In general, a moderate heart rate of 70-80 bpm represents a reasonable compromise, with maintained preload, SVR, and contractility. TEE is essential for assessing the relative severity of each lesion in real time.

Combined Mitral and Aortic Disease

Combined mitral and aortic valve disease is common in rheumatic heart disease. Management requires determining which lesion is hemodynamically dominant and prioritizing those goals. Pulmonary vascular resistance management is critical because pulmonary hypertension is common. Fluid management demands a careful balance between underfilling (which worsens AS and MR) and overfilling (which worsens MS and causes pulmonary edema).

Prosthetic Valves

Mechanical Valves

Mechanical valves require lifelong anticoagulation with warfarin, with the target INR specific to the valve type and position. Perioperative anticoagulation bridging follows ACCP and AHA guidelines. The thrombotic risk is higher for mitral-position valves compared to aortic, and for older-generation valves compared to newer designs. On auscultation, mechanical valves produce a characteristic metallic click; its absence raises concern for valve thrombosis or pannus formation.

Bioprosthetic Valves

Bioprosthetic valves do not require long-term anticoagulation, needing only aspirin after an initial 3-6 month period. However, they degenerate over time (typically 10-20 years) and may eventually require reoperation or transcatheter valve-in-valve replacement. They carry lower thrombotic risk but higher structural failure rates compared to mechanical valves.

Anesthetic Considerations for Prosthetic Valves

Perioperative management of patients with prosthetic valves requires maintaining anticoagulation goals and minimizing the heparin-free interval. Endocarditis prophylaxis is recommended per AHA guidelines for dental procedures. The expected hemodynamic profile of the specific valve should be known, as a mild transvalvular gradient is normal for prosthetic valves. Preoperative TEE assessment of valve function is valuable.

Hypertrophic Obstructive Cardiomyopathy (HOCM)

Pathophysiology

HOCM is characterized by asymmetric septal hypertrophy that creates dynamic left ventricular outflow tract obstruction. Unlike the fixed obstruction of aortic stenosis, the degree of obstruction in HOCM is dynamic and worsens with decreased preload, decreased afterload, increased contractility, and tachycardia. Systolic anterior motion (SAM) of the mitral valve contributes to both the obstruction and coexisting mitral regurgitation.

Hemodynamic Goals -- Similar to AS with Additional Considerations

The hemodynamic goals for HOCM resemble those for aortic stenosis but with an important additional feature: decreased contractility is not just tolerated but is actually beneficial. Preload should be kept full to maintain ventricular volume and reduce obstruction. Afterload should be kept high to maintain ventricular dimensions and reduce the outflow gradient. Heart rate should be slow to reduce the dynamic obstruction and improve filling. Contractility can be deliberately decreased because this reduces the obstruction. Hypovolemia, vasodilation, sympathetic stimulation, inotropes, and IABP must all be avoided. Phenylephrine is the vasopressor of choice because it provides pure alpha stimulation without beta-mediated increases in contractility. Beta-blockers are beneficial, as they reduce both heart rate and contractility. If hemodynamic collapse occurs, treatment consists of volume, phenylephrine, and esmolol -- essentially the opposite of standard shock management; epinephrine must be avoided.

<image>A summary diagram showing four major valve lesions with hemodynamic goal mnemonics: Aortic Stenosis ("Slow, Full, Tight, Sinus" with corresponding arrows for HR down, preload up, SVR up, sinus rhythm), Aortic Regurgitation ("Full, Fast, Forward" with HR up, preload up, SVR down), Mitral Stenosis ("Slow, Sinus, Dry" with HR down, sinus rhythm, avoid fluid overload), and Mitral Regurgitation ("Full, Fast, Forward" with HR up, preload up, SVR down). Each panel includes a simplified pressure-volume loop for the lesion.</image>

<image>A pressure-volume loop comparison showing four pathologic states overlaid on a normal PV loop: (1) aortic stenosis — tall narrow loop with high peak systolic pressure and concentric hypertrophy indicator, (2) aortic regurgitation — wide loop with large total stroke volume but reduced forward flow, (3) mitral stenosis — small loop with reduced preload (low EDV), (4) mitral regurgitation — wide loop with large total SV including regurgitant volume into LA. Each loop color-coded with annotations explaining the pathophysiology.</image>

<image>A clinical decision diagram for HOCM showing factors that worsen vs. improve dynamic LVOT obstruction: left column (worsen) includes decreased preload (hemorrhage, Valsalva), decreased afterload (vasodilators, neuraxial), increased contractility (inotropes, sympathetic stimulation), tachycardia; right column (improve) includes increased preload (IV fluids), increased afterload (phenylephrine), decreased contractility (beta-blockers), bradycardia. Center shows a cross-sectional echo image of SAM with the M-mode pattern of LVOT obstruction. Emergency management protocol at the bottom.</image>

Clinical Pearls

The mnemonic "Slow, Full, Tight" for aortic stenosis and "Full, Fast, Forward" for regurgitant lesions (AR and MR) provides a reliable framework for bedside hemodynamic management. In aortic stenosis, the most dangerous hemodynamic events are hypotension and tachycardia, both of which reduce coronary perfusion while the hypertrophied heart has increased oxygen demand; hypotension should be treated with phenylephrine, not ephedrine, which causes tachycardia. Mitral stenosis patients decompensate most rapidly with tachycardia, and new-onset atrial fibrillation in MS is a medical emergency requiring urgent rate control. In HOCM, the obstruction is dynamic, and standard resuscitation with inotropes and vasodilators makes it worse; treatment requires volume, phenylephrine, and beta-blockers, which is the opposite of typical shock management. For mixed valve lesions, the dominant pathology should be identified and its hemodynamic goals prioritized, with TEE providing invaluable real-time assessment. The ejection fraction in chronic MR overestimates true contractile function because the ventricle ejects into a low-pressure LA; an EF of 60% in severe MR may actually represent significant myocardial dysfunction.

References

• Nishimura RA, et al. 2017 AHA/ACC focused update of the 2014 guideline for the management of patients with valvular heart disease. J Am Coll Cardiol. 2017;70(2):252-289.
• Mittnacht AJC, et al. Anesthesia for valvular heart disease. In: Kaplan JA, ed. Kaplan's Cardiac Anesthesia, 7th edition.
• Frogel J, Galusca D. Anesthetic considerations for patients with advanced valvular heart disease undergoing noncardiac surgery. Anesthesiol Clin. 2010;28(1):67-85.
• Hensley FA, et al. A Practical Approach to Cardiac Anesthesia, 6th edition.
• Miller RD, et al. Miller's Anesthesia, 9th edition. Chapter on Cardiac Anesthesia.

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