Hearts Kept Ticking with Titanium

Medical implant providers should conduct material verification of all metals

You will see many heart-shaped items this Valentine’s Day. Boxes of chocolates, greeting cards, and balloons are just a few of the many heart-related gifts that can be seen in almost every store window. A heart-related item you may not see while walking down the street, however, is a pacemaker. Pacemakers are medical implant devices that can stimulate the human heart muscle and regulate the heartbeat. Each year, tens of thousands of people get them implanted in an effort to keep their hearts beating at a healthy rate. (You can see an animation of how a pacemaker works on the American Heart Association website.)

An article in the U.S. National Institutes of Health’s National Library of Medicine describes a pacemaker as an implant that is made up of three major components: device pulse generator, device controller-monitor, and leads. The casing for the components is usually made of Titanium, Number 22 on the periodic table. Why would titanium be used in the human body? According to the National Institute article,

“Titanium and two of its alloys, niobium and tantalum, are biocompatible, they exhibit physical and mechanical properties superior to many other metals. The modulus of elasticity (measure of stiffness) of titanium and its alloys range between 100-120GPa. Extreme resistance to corrosion and durability make titanium and its alloys ideal materials for hermetically sealed pulse generator cases for cardiac pacemakers….

… titanium allowed patients to safely use appliances such as microwave ovens because titanium helps to shield the internal components and reduce the external electromagnetic interference.”

Ensuring that the correct metals are used in these implants is critical. Medical implant providers should conduct material verification of all metals that are being used in the manufacturing of their products. Portable X-ray fluorescent analyzers are ideal for ensuring material chemistry specifications are met. XRF is a nondestructive technique that can determine the elemental composition of a sample within seconds, helping to ensure that no incorrect or out-of-specification metal alloys caused by material mix-ups, lost traceability, incorrect weld chemistry and dilution, or even counterfeit materials enter the manufacturing process. With all types of manufacturing operations facing increasingly stringent industrial safety regulations and fines, today’s best practices include testing 100% of critical materials as part of a QA/QC program. And when it comes to medical implants, lives may depend on the correct identification. What if that shiny metal that was delivered at the dock wasn’t titanium at all? What if that silver grey metal contained alloying elements that shouldn’t be there?

The Titanium Information Group explained in one of their data sheets that “Corrosion of implanted metal by body fluids, results in the release of unwanted metallic ions, with likely interference in the processes of life. Corrosion resistance is not sufficient of itself to suppress the body’s reaction to cell toxic metals or allergenic elements such as nickel, and even in very small concentrations from a minimum level of corrosion, these may initiate rejection reactions. Titanium is judged to be completely inert and immune to corrosion by all body fluids and tissue, and is thus wholly bio-compatible.”

That’s good news to the many patients who have had their lives extended with these medical devices. However, there is a small number of people who are actually allergic to titanium. Patients who have metal allergies can even suffer from chronic fatigue syndrome as a result of titanium in their body.

There are some alternatives in these rare cases. One article published on behalf of the European Society of Cardiology reported that after a patient had an allergic reaction to the metal components in their standard pacemaker, a gold-plated generator and polyurethane leads were implanted. This replacement is considered effective in selected cases and did indeed work for this patient.

As most of us know, gold is one of the top ten most precious metals, but in the case of cardiac pacemakers, titanium is a pretty precious metal as well.

Editor’s Note: Take care of your heart this Valentine’s Day. Take two minutes to read the Warning Signs of Heart Failure.