Management of Anesthesia in Patients with Mitral Valve Prolapse (MVP)

I. Introduction

Mitral valve prolapse (MVP) is a condition where the mitral valve leaflets do not close completely, leading to blood regurgitation from the left ventricle back into the left atrium during each heartbeat. This increases the workload on the heart, causing various symptoms and potentially dangerous complications.

II. Classification of Mitral Valve Prolapse Severity

The severity of MVP is assessed based on the severity of blood regurgitation, usually measured by echocardiography:

• Grade 1:

• Regurgitation jet does not exceed 1/3 of the left atrium.

• Regurgitation jet length <1.5cm.

• Usually asymptomatic.

• Grade 2:

• Regurgitation jet does not exceed 2/3 of the left atrium.

• Regurgitation jet length 1.5-2.9cm.

• Mild symptoms like fatigue, dyspnea on exertion may occur.

• Grade 3:

• Regurgitation jet reaches the base of the left atrium.

• Regurgitation jet length 3-4.4cm.

• Clear symptoms such as dyspnea, chest pain, and lower limb edema.

• Grade 4:

• Regurgitation jet reaches the pulmonary veins.

• Regurgitation jet length >4.4cm.

• Severe symptoms, potentially leading to heart failure, arrhythmias, and sudden death.

III. Pathophysiology of Mitral Valve Prolapse

MVP causes various pathophysiological changes affecting both the upstream and downstream circulatory systems:

• Upstream:

• Left atrial dilation: Blood regurgitation into the left atrium increases left atrial pressure, leading to left atrial dilation.

• Pulmonary hypertension: Elevated left atrial pressure leads to increased pulmonary artery pressure, causing pulmonary hypertension.

• Right ventricular failure: Pulmonary hypertension increases the workload on the right ventricle, leading to right ventricular failure.

• Downstream:

• Left ventricular dilation and hypertrophy: To compensate for the blood regurgitation, the left ventricle pumps harder, leading to dilation and hypertrophy.

• Reduced cardiac output: The amount of blood pumped out of the heart decreases due to the regurgitation, resulting in reduced cardiac output.

Note: Any condition that increases peripheral resistance (e.g., hypertension, vasoconstriction) and bradycardia will worsen regurgitation and decrease cardiac output in patients with MVP.

IV. Anesthesia Considerations

• Spinal and epidural anesthesia are preferred as they cause vasodilation, beneficial for patients with MVP (but avoid excessive hypotension).

• Peripheral nerve blocks have no contraindications.

• General anesthesia has no contraindications.

V. Principles of Anesthesia Management in Patients with MVP

• Maintain a normal heart rate (80-100bpm). Bradycardia will worsen regurgitation and reduce cardiac output.

• Avoid hypertension and bradycardia.

• Vasodilators are beneficial because:

• They reduce left ventricular afterload.

• They decrease regurgitation.

• They increase cardiac output.

• Manage hypertension with deepening anesthesia or vasodilators.

• If hypotension occurs during surgery:

• Ensure adequate fluid resuscitation.

• Use inotropes to increase heart contractility.

• Pure vasoconstrictors are often poorly tolerated due to increased regurgitation.

• Preoperative cardiac medications (diuretics, vasodilators) should be resumed early postoperatively.

VI. Precautions

• Anesthesia management in patients with MVP should be performed by experienced and highly skilled anesthesiologists.

• Closely monitor blood pressure, heart rate, ECG, and other vital signs throughout the anesthesia procedure.

• Have emergency medications readily available, including inotropes, vasodilators, vasoconstrictors, and other emergency equipment.

VII. Conclusion

Anesthesia management in patients with MVP requires careful consideration, adhering to established principles and precautions to ensure patient safety. Close monitoring during and after surgery is crucial for early detection and timely management of complications.