Godfather
11-23-2011, 04:40 PM
Traffic planning for the heart
It happens every day in every hospital in the country. A patient comes in complaining of crushing chest pain and shortness of breath. He is whisked away by a team of specialists, poked, prodded, tested and scanned. Tests show that the main coronary artery is blocked with plaque, causing a heart attack, so bypass surgery is scheduled for the next morning.
Meanwhile, in another part of the same hospital, another patient is sitting comfortably in the cardiologist's office. She, too, has near 100% blockages in her main coronary artery, but experiences no pain, no breathing discomfort and is sporting a healthy glow in her cheeks. She's here for her annual stress test, where she'll pedal a bike as hard as she can to see how well her cardiovascular system is holding up.
But how can these two people both have near 100% blockages in their coronary arteries and yet appear so different? The answer may lie in one of the many great benefits afforded people who exercise regularly, which is exactly what the second patient has done three times a week since her teen years.
The coronary arteries are small vessels that supply the heart with oxygen-rich blood. As you start to exercise, the work on the heart increases, and the need for blood increases. A healthy set of coronary arteries is more than capable of delivering enough blood to the heart muscle, but in a person with coronary artery disease, a buildup of plaque clogs the vessels, limiting blood flow.
The process can be slowed (and even reversed) by eating healthier, quitting smoking, losing weight and of course exercising regularly. But in most cases, this buildup is progressive over time, and can eventually lead to complete blockages. This is where the effects of regular physical activity really paid off for that second patient.
As the plaque in her coronary arteries was slowly accumulating, she continued to challenge her heart through regular exercise. Because of the need to deliver blood through increasingly narrow blood vessels, her body saw fit to create new blood vessels throughout her heart, a process known as collateral circulation. These extra vessels were able to pick up the slack from the underperforming main artery, allowing her heart to continue to receive a healthy supply of blood, and minimizing the risk of heart attack.
Imagine a city planner properly anticipating increased traffic flow over the years, and investing in sufficient road construction to meet the demands: In the event the main road is closed, traffic can still flow.
On the other hand, the person awaiting surgery is more like a city planner who relies on one main road. He spent years under-investing in building new arteries, and now when the main road closes, all traffic stops dead (pun intended).
For exercisers whose collateral circulation proves not to be enough, and they suffer a heart attack anyway, we have more good news. Data from emergency departments and lab studies alike show that regular exercisers are 1.5 to 2.5 times more likely to walk away from a heart attack than those who are inactive. These studies also remind us exercise need not be outlandish to encourage the development of new arteries around the heart. Working the whole body at a pace you can hear your breathing, three or four times per week, for 30 minutes at a time, will do the trick.
- Paul VanWiechen is a certified exercise physiologist and director of exercise physiology at Cleveland Clinic Canada (clevelandclinic.ca).
It happens every day in every hospital in the country. A patient comes in complaining of crushing chest pain and shortness of breath. He is whisked away by a team of specialists, poked, prodded, tested and scanned. Tests show that the main coronary artery is blocked with plaque, causing a heart attack, so bypass surgery is scheduled for the next morning.
Meanwhile, in another part of the same hospital, another patient is sitting comfortably in the cardiologist's office. She, too, has near 100% blockages in her main coronary artery, but experiences no pain, no breathing discomfort and is sporting a healthy glow in her cheeks. She's here for her annual stress test, where she'll pedal a bike as hard as she can to see how well her cardiovascular system is holding up.
But how can these two people both have near 100% blockages in their coronary arteries and yet appear so different? The answer may lie in one of the many great benefits afforded people who exercise regularly, which is exactly what the second patient has done three times a week since her teen years.
The coronary arteries are small vessels that supply the heart with oxygen-rich blood. As you start to exercise, the work on the heart increases, and the need for blood increases. A healthy set of coronary arteries is more than capable of delivering enough blood to the heart muscle, but in a person with coronary artery disease, a buildup of plaque clogs the vessels, limiting blood flow.
The process can be slowed (and even reversed) by eating healthier, quitting smoking, losing weight and of course exercising regularly. But in most cases, this buildup is progressive over time, and can eventually lead to complete blockages. This is where the effects of regular physical activity really paid off for that second patient.
As the plaque in her coronary arteries was slowly accumulating, she continued to challenge her heart through regular exercise. Because of the need to deliver blood through increasingly narrow blood vessels, her body saw fit to create new blood vessels throughout her heart, a process known as collateral circulation. These extra vessels were able to pick up the slack from the underperforming main artery, allowing her heart to continue to receive a healthy supply of blood, and minimizing the risk of heart attack.
Imagine a city planner properly anticipating increased traffic flow over the years, and investing in sufficient road construction to meet the demands: In the event the main road is closed, traffic can still flow.
On the other hand, the person awaiting surgery is more like a city planner who relies on one main road. He spent years under-investing in building new arteries, and now when the main road closes, all traffic stops dead (pun intended).
For exercisers whose collateral circulation proves not to be enough, and they suffer a heart attack anyway, we have more good news. Data from emergency departments and lab studies alike show that regular exercisers are 1.5 to 2.5 times more likely to walk away from a heart attack than those who are inactive. These studies also remind us exercise need not be outlandish to encourage the development of new arteries around the heart. Working the whole body at a pace you can hear your breathing, three or four times per week, for 30 minutes at a time, will do the trick.
- Paul VanWiechen is a certified exercise physiologist and director of exercise physiology at Cleveland Clinic Canada (clevelandclinic.ca).