Cardiac Rhythm Management (CRM) Vol 1 No 2

In a hospital supply chain setting, Cardiac Rhythm Management (CRM) refers to to pacemakers, defibrillators, and cardiac resynchronization devices (CRTs). These devices are designed to normalize the beating of the heart, and although they have improved the lives of millions of patients, they often represent the largest category of spend in a hospitals.

Although there are have been incremental changes in the technology over the last 30 years, they have focused on three general areas:

(1) Size reduction of the implant/battery life improvements: Pacemakers initially implanted were larger than a can of tuna, and primarily due to their size had to be implanted into the abdomen with wires routed up to the heart. As battery technology and circuitry improved, the devices became smaller and the battery longevity improved, and the devices began to be implanted in the upper chest where they typically are implanted today. Device manufacturers have to balance continued size reduction with the possibility of extended battery life. A typical non-CRT pacemaker today may last for 10 years. CRT or defibrillator devices typically have a shorter life of 5-10 years.

(2) Improved Software: Initial pacemakers were simply timed to give a pacing impulse to the heart on a fixed schedule or beats per minute. Improvements to software and sensing circuitry allowed the devices to detect when the heart needed to pump faster, like after exercise, or slower, during rest. Defibrillators sense abnormal heartbeat patterns to determine life-threatening arrhythmias which require a shock to reverse the arrhythmia, called “cardioversion” or “defibrillation” (hence their name of ICD: Implantable Cardioverter-Defibrillator). The defibrillators gradually became smart enough to reduce the number of “fase positives” in which a shock was delivered when it wasn’t necessary. Not only is the shock potentially painful, described by some patients as “being kicked in the chest”, but unnecessary shocks are not good for cardiac function and can deplete the battery of the implanted device.

(3) Improved Leads: The leads (wires going to the heart) implanted with pacemakers and defibrillators have gone through numerous changes during their development. Initially with proprietary designs, all current pacemaker and defibrillator wires are standardized so they may attach to all manufacturer’s devices, important if a vendor needs to be switched. Leads have different technologies for attaching to the heart which include a small screw, tines, or other mechanisms. Device manufacturers use different coatings, silicone, plastics, and have steadily reduced the diameter of the leads. Smaller diameter leads take up less space but may lead to premature fracture or breakage

The most recent innovation are “leadless” devices, such as the Medtronic Micra, which are implanted without any leads.
According to data assembled by iDataResearch of Vancouver, British Columbia, there were 408,000 pacemakers sold in the US in 2017; 160,000 implanted defibrillators, 119,000 CRT-Ds
(Cardiac Resynchronization Therapy—Defibrillators) and 23,500 CRT-Ps (Pacemakers). Since the implanted defibrillators have alimited battery life, especially after discharging several “jolts” to a patient, a certain percentage of the generators will need to be replaced. iDataResearch estimates that over 40% of the CRT-Ds and CRT-Ps are replacement devices.

Download the entire publication here: Curvo Spotlight CRM Vol 1 No 2

Editor – Stan Mendenhall

Associate Editor – Jake Titzer

Cartoons – Robin Wilt

Annie Gallup – Illustration and Graphic Design

Volume 1, Number 2

November 2018 Publication

2019-04-11T15:58:44+00:00November 29th, 2018|Spotlight|