Patient Guide Summary

A complete understanding of heart valve replacement requires years of study and practice. Therefore, discussion of these topics with your physicians will provide the foundation for therapeutic decisions you or a loved one will soon make.

Some pro's and con's related to prosthetic valve choice are detailed in the table below. Red text indicates the main points associated with each valve choice.

Pro for Replacement*			Con for Replacement*
Mechanical	Tissue	On-X Valve	Mechanical	Tissue	On-X Valve
Lifetime durability	50% or more of patients do not need blood thinner (anticoagulant)	Lifetime durability	Must take blood thinner (anticoagulant)	Up to 50% or more of patients eventually must take blood thinner (anticoagulant)	Must take blood thinner (anticoagulant) but it could be reduced for some patients.
Lower reoperation rates	Quiet-do not usually make noise	Lower reoperation rates	Make a clicking noise that is bothersome to some patients	Decreased survival rates	Many patients report not hearing the valve click
Better survival rates	Only homografts are efficient in small sizes	Better survival rates	Increased chance of bleeding	Repeat operation every five to fifteen years with associated risks, discomfort and recovery	Potential for reduced bleeding through patient self-testing of INR
Better efficiency in small sizes	----	Possibility of reduced blood thinner	----	Increased chance of bleeding for patients taking blood thinner	---
----	----	Best efficiency in small sizes	Can cause stroke	Can cause stroke	Can cause stroke
----	----	Lower complication rates	Scar tissue (pannus) ingrowth	Less efficient in small sizes	----
----	----	Quiet design	----	Scar tissue (pannus) ingrowth	----
----	----	Scar tissue ingrowth not observed

Red text indicates the main points associated with each valve choice.

The On-X Prosthetic Heart Valve offers an advanced mechanical choice that incorporates the best of both mechanical and tissue options.

Whatever valve you choose, valve replacement surgery can safely extend life and improve quality of life for those who need it. To find out more, please read this entire guide.

Options for Heart Valve Replacement*

Mechanical	Tissue	On-X Valve
Two leaflets (silicon-alloyed carbon) that do not open to 90°	Leaflets from cow or pig tissue treated with a preservation agent	Two leaflets (On-X carbon) that open to 90°
Short cylindrical carbon orifice	Plastic or metal frame to mount tissue	Near natural length/shape carbon orifice
Sewing cuff of synthetic fabric	Sewing cuff of synthetic fabric	Sewing cuff of synthetic fabric
______	OR, aortic root of pig or human donor that may be reinforced with synthetic fabric	Advanced features not included in other mechanical designs

*References for these summary tables are found in the following text.

Introduction

Heart valve surgery has proven to be quite successful over the past 30 years! Quality of daily life and general health are improved for the majority of patients who choose surgical treatment of heart valve disease. Knowledge of what to expect clarifies the process of going through a valve implant for you and your loved ones.

On-X Life Technologies, Inc., makers of the On-X Prosthetic Heart Valve, has prepared this information guide to give you a better understanding of heart valve replacement procedures. Information in this guide provides a fundamental understanding of your surgery and choices you may have. Clinical terms that are used throughout this guide will appear in blue bold lettering when first used. The highlighted clinical terms are defined under Definitions.

Because this guide will not answer every question, it is vital that you have good communication with your physicians prior to surgery. It is important that you prepare written questions for your physician to answer before you go to your appointments. Write down the physician's answers in the office so that you can refer to them later.

The Heart

The heart is critical to our lives. It is a pump that delivers blood together with life-maintaining nutrients to all parts of our bodies. Just as with other pumps often used in daily life, the heart's continual function may require repair.

Figure 1.
Interior of the Heart¹
Click to enlarge figure.

How does the heart work? It consists of four chambers (two atria and two ventricles) that beat regularly to push blood through the body and lungs (Figure 1). The flow of blood into and out of these chambers is regulated by four heart valves: two of the valves are located between the upper (atrial) and lower (ventricular) chambers, and two are located between the ventricles (lower chambers) and arteries (vessels that carry blood away from the heart). These valves open and close to regulate blood flow, opening to allow forward blood flow and closing to prevent backward blood flow. Without these valves working properly, the heart could not work effectively.

Figure 2.
Blood Flow
Path Through the Heart²
Click to enlarge figure.

Blood is brought to the right atrium of the heart from all parts of the body through the veins. Contraction of this atrium pushes the blood through the tricuspid valve into the right ventricle. From there, contraction of the right ventricle pushes the blood through the pulmonary valve into the pulmonary artery and the lungs, where carbon dioxide is exchanged for oxygen. The blood then flows back to the left atrium of the heart from the pulmonary veins. Contraction of the left atrium occurs at the same time as the right atrium and causes the blood to enter the left ventricle through the mitral valve. The blood is then pushed out of the left ventricle through the aortic valve into the aorta and the whole body. Left ventricle contraction occurs at the same time as right ventricle contraction (Figure 2).

continue to Heart Valve Disease »