As tick season gets underway, a research team at Kingston Health Sciences Centre (KHSC) is developing a simple tool to help doctors more quickly identify and treat Lyme carditis, a heart problem that has recently been linked to Lyme disease, a bacterial infection caused by tick bites.
Lyme carditis is an electrical signalling problem in the heart that can rapidly progress to complete heart shutdown. “For some people, this heart problem can be the first and only sign of Lyme disease,” says Dr. Adrian Baranchuk, clinician-scientist at the KGH Research Institute, and Professor of Medicine, Queen’s University.
Dr. Baranchuk and his team developed an innovative strategy to treat Lyme carditis presenting with electrical shutdown, and now they want to share their knowledge with the medical community. To this end, they’ve created SILC (Suspicion Index of Lyme carditis), a short checklist of variables with a simple scoring system for identifying the condition.
“We have discovered that once this condition is identified, treatment with antibiotics, and sometimes an external, temporary pacemaker, can lead to complete recovery in two weeks or less. It can avoid the more invasive treatment of a permanent pacemaker,” says Dr. Baranchuk, who also heads the Heart Rhythm Service at KHSC’s Kingston General Hospital site.
Until recently, correct diagnosis of Lyme Carditis has been difficult because patients with it often don’t show the bull’s-eye rash caused by a tick bite (or may not remember being bitten), and other, vague symptoms of Lyme Disease, such as fever or muscle aches, can be easily mistaken for flu or other illnesses.
He and his team developed their tool after several patients — all male, all under 50, and all who had been doing outdoor activities – were admitted to the Kingston Health Sciences Centre’s cardiac unit over 18 months showing heart block symptoms. None had a previous history of heart problems. But when the first of these patients was subsequently diagnosed with Lyme disease, the team connected the dots. Once diagnosed, all of the patients subsequently recovered full heart function after treatment.
“If previously healthy young men show up with this heart problem, we want people to ‘Think SILC,’ ” he says. “Part of the challenge is that this condition may show up several weeks after a tick bite, when the rash is long gone. Our SILC tool can help doctors to consider Lyme Carditis as an alternative diagnosis.”
Currently the team is working to validate the tool. The first step has been to compare its scoring system against reports, going back to the 1970’s, of nearly 100 patients worldwide diagnosed with Lyme disease who also showed the electrical heart problem.
“We’re still pulling together the results, but they’re looking very promising,” Dr. Baranchuk says. If SILC shows it has appropriately scored these patients, then the next step will be to seek funding for a multi-centre study to trial the tool on a larger population.
In the meantime, Dr. Baranchuk and his team continue to publish articles and do outreach on this condition. “We are doing knowledge translation on two fronts so not just doctors but nurses on the front lines can identify it,” says Crystal Blakely, cardiac charge nurse at KHSC who helped identify the condition.
“It’s about educating medical practitioners to look for Lyme carditis symptoms and to use best practices for screening, diagnosis and treatment.”
