Heart Valves

Whats the function of heart valves

The valves ensure that blood flows in a single pathway through the heart by opening and closing in a particular time sequence during the cardiac cycle. Normal valves permit blood to flow in only one direction

Causes of Valve Dysfunction

  • Disease (bacterial, viral) and inflammation

  • Congenital heart defects

  • Ischemic heart disease

  • Cardiac hypertrophy or dilation
    as occurs in heart failure

  • Ruptured chordae tendineae

Heart Valve Disease Classification

There are two general types of cardiac valve defects: stenosis and insufficiency

Valvular Stenosis results from a narrowing of the valve orifice that is usually caused by a thickening and increased rigidity of the valve leaflets, often accompanied by calcification.

Valvular Insufficiency occurs when the valve leaflets do not completely seal when the valve is closed. This causes regurgitation of blood (backward flow of blood) into the proximal chamber.

Clinical Symptoms of Heart Valve Disease

Valvular stenosis and insufficiency can have serious cardiac consequences, and produce the following clinical symptoms:

  • Shortness of breath/dyspnea

  • Fatigue

  • Reduced exercise capacity

  • Light headedness or fainting (syncope)

  • Heart failure

  • Pulmonary hypertension

  • Pulmonary/systemic edema

  • Chest pain (angina)

  • Arrhythmias

  • Blood clots (thromboembolism) which can cause stroke

Postoperative Tips for Cardiac Surgery

AORTIC STENOSIS PostOP

  1. Decreased ventricular compliance due to hyper trophy requires higher pulmonary capillary wedge pressure 18 to 20 mmHg in order to prevent hypovolemia. Cardiac output and blood pressure are critically dependent on adequate preload. Be very careful with vasodilators and diuretics.

  2. Hypertension threatens the aortic suture lines. It is critical to maintain a systolic blood pressure less than 120 mmHg with a beta blocker like Esmolol

  3. Damage to the bundle of HIS can cause complete heart block or a bundle branch block.

  4. Atrial fibrillation must be aggressively treated because the hypertrophic ventricle depends on synchronized atrial and ventricular contractions to maintain or ensure hemodynamic stability.

AORTIC REGURGITATION PostOP

  1. Be aware of postop development of left ventricular failure even if pre-op ejection fraction was good. Inotropes vasodilators and balloon pump may be required postoperatively.

  2. Surgical injury to the AV node may result in a heart block.

MITRAL STENOSIS PostOP

  1. There may be an injury to circumflex artery aortic valve AV node or conduction system.

  2. May need support for RV dysfunction

  3. When mitral valve competence is restored increased LV filling may result in pressure and volume overload which may cause LV failure. Inotropes and vasodilators may be required. may need support for RV dysfunction.

  4. It’s essential to maintain preload.

  5. Diurese carefully

MITRAL REGURGITATION PostOP

  1. Repair and replacement may cause heart failure.

  2. Inotropes vasodilators IABP may be needed

  3. Expect ventricular irritability and ectopy.

  4. If sudden hemodynamic instability or pulmonary edema occurs, valve dysfunction or suture failure should be suspected

  5. PostOP mortality rate for mitral regurgitation with pulmonary edema is as high as 85%.

To learn more, tap the resources button below

Cheryl