At the leading edge of heart and stroke care
February 12, 2015
February is Heart and Stroke Month, so the Gazette is reviewing some of the research and innovative new methods being conducted by physicians in the Faculty of Health Sciences who practice at Kingston General Hospital.
Advances in recent years have drastically changed the outlook for those suffering from cardiovascular disease. A host of new technologies, medications and procedures have increased survival rates and have smoothed out many of the bumps that were once a common part of the recovery process.
“Cardiovascular disease is no longer the number one cause of death in Canada,” says Dr. Chris Simpson, Chief of Cardiology at Queen’s. “All of the advances, both in technology and treatment, have improved the chances of survival and recovery.”
One of the areas where Dr. Simpson has been making strides is the utilization of new leadless pacemakers. The current generation of pacemakers are implanted surgically under the skin, with a long wire feeding from the pacemaker into the heart, delivering a pulse when necessary. The new generation have been miniaturized, compressing all of their hardware into a small, thin capsule which screws right into the heart.
They’re so small that the pacemakers can be implanted without major incisions, going through a vein in the groin and travelling up to the heart. The process creates no scars, requires no stitches and the pacemaker isn’t visible from outside the body.
“The Achilles heel of pacemaker insertion has always been infection, which will be drastically reduced with the new models,” says Dr. Simpson.
It’s just one of the many modern improvements to heart treatment happening at KGH-Queen’s.
Dr. Christine D’Arsigny (Respiratory and Critical Care Medicine) is treating arterial hypertension with new medications and has had very encouraging results.
“These new therapies we’re using have led to a dramatic impact on quality of life for those affected,” she says. “We’re continuing to learn more about the disease and perfecting our medication treatments.”
Pulmonary hypertension is an increase in blood pressure in the blood vessels within the lungs. Those afflicted are often struck by shortness of breath, dizziness, fainting and have a high death rate from the disease, if left untreated. Previously, treatment was limited to IV-therapy and organ transplantation, often not an option for people who were too sick to undergo surgery. This is also true for chronic thromboembolic pulmonary hypertension, another cause for pulmonary hypertension
The new drugs Dr. D’Arsigny is prescribing work to dilate the pulmonary vessels and change cell signalling, resulting in better blood flow through the lungs, a decrease in shortness of breath and alleviation of other symptoms. The end result is improved quality of life and improved survival.
“These oral medications have provided an excellent treatment option,” Dr. D’Arsigny says. “The improvements I’ve seen in some of my patients have been dramatic —I have had some patients go from barely walking without getting short of breath to thinking they can go skiing again.”
Solving the mystery of strokes
Promising new research has shed light on one of the longstanding mysteries of strokes. For nearly 30 per cent of stroke victims, the cause of the stroke is not readily apparent after medical examination. A new study, co-authored by Dr. Albert Jin (Neurology) and published in the New England Journal of Medicine, takes a big leap forward toward understanding the problem.
“We typically perform an electrocardiogram that runs for 24 hours, and it’s often not adequate” says Dr. Albert Jin.
He instead made use of a new cardiac monitoring method that tracked heart behaviour continuously for 30 days. This revealed that many of the strokes were caused by atrial fibrillation, an abnormal heart rhythm.
“Our detection rate increased sixfold, showing us that 18 per cent of people had atrial fibrillation," he says. "That translates to hundreds if not thousands of Ontarians each year that now have a recognized cause of stroke that we can treat.”
Another of the major causes of stroke is the formation of blood clots which restrict circulation to the brain. Dr. Jin is taking part in another new study that seeks to better treat these strokes. Current treatment focuses on medications which target and break up the blood clot; the new study supplements this treatment with ultrasound waves which help to further dissolve the clot.
By applying ultrasound waves to the brain, Dr. Jin is able to specifically target the clot, complementing the work of the medication. Though there are safety risks for ultrasound waves in lower frequencies (think of the booming bass of car stereo), the study makes use waves in a higher frequency.
“There’s been ample safety work done and it’s been demonstrated that ultrasound waves tuned to a higher frequency are safe,” Dr. Jin says.
Though the new study is only just beginning, work being done at KGH-Queen’s is making the prognosis for stroke victims brighter.
Treatment for strokes and heart-related health problems has long been hindered by a lack of information. When searching for the causes of a stroke, for example, technological limitations meant that doctors could only track a patient`s heart pattern for 24 hours at a time. They then had to project that information into the future, assuming the heart would function the same way for weeks at a time. That made heart monitoring a difficult process, says Dr. Adrian Baranchuk (Cardiology).
“The patient would have to reconnect to the monitor every day. It was inconvenient, it irritated the skin and people had to plan their lives around access to the heart monitor.”
That’s why Dr. Baranchuk has been eagerly putting into practice new technology that makes the whole process more reliable, safer and less invasive. He’s begun fitting his patients with a new monitor called the Reveal LINQ by Medtronic. At less than two inches in length, the monitor is so small that it removes the need for serious surgical insertion.
In a procedure that only takes about two minutes to conduct, Dr. Baranchuk makes a minor incision, inserts the monitor and bandages the patient up. The incision’s small size drastically reduces the risk of infection, removing the need for stitches and antibiotics and the monitor can function for three years, providing steady heart rhythm data.
“As a global approach, heart rhythm monitoring allows you to detect arrhythmias and decide whether someone needs medication, a pacemaker or other treatment,” says Dr. Baranchuk. “This is going to be future of heart monitoring.”