What can we learn about our heart from a cardiac stress test?

Upper Kananaskis Lake, Alberta, Canada. (Dr. Noorali Bharwani)
Upper Kananaskis Lake, Alberta, Canada. (Dr. Noorali Bharwani)

Let us start by understanding the difference between cardiac stress test and cardiac Holter monitor.

What is cardiac stress test?

Robert Arthur Bruce (1916-2004) was an American cardiologist who invented the treadmill cardiac stress test used to diagnose heart disease. Patient’s heart signals are monitored on a treadmill set at successive stages of difficulty. Bruce also created the Bruce Protocol in the early 1960s, monitoring the heart signals of a patient on a treadmill.

Why is cardiac stress test important? Some heart problems only appear when your heart needs to work harder. Cardiac stress test helps to show how your heart copes under stress.

A cardiac stress test is done in a controlled clinical environment. It measures the heart’s ability to respond to external stress.  The stress response is induced by exercise or by intravenous injection of a medication.

What is cardiac Holter monitor?

Norman “Jeff” Holter (1914 – 1983) was an American biophysicist who invented the Holter monitor, a portable device for continuously monitoring the electrical activity (ECG) of the heart for 24 hours or more. Holter donated the rights to his invention to medicine.

The test is used to identify any heart rhythm problems. The device is the size of a small camera. It has wires with silver dollar-sized electrodes that attach to your skin.

Who needs cardiac stress test?

Any person who has a worrisome symptom like chest pain – especially in older men with risk factors for heart disease. An exercise stress test is not 100 per cent accurate. But it helps decide what the next step should be.

When to get a cardiac stress test?

The U.S. Preventive Services Task Force, an independent panel that makes recommendations to doctors, urges physicians not to routinely offer exercise stress testing to people without symptoms or strong risk factors for coronary artery disease.

Main indication for ordering stress test is when a person complaints of chest pain. Chest pain is not an uncommon complaint. Chest pain can have many possible causes besides heart disease.

For example, chest pain can be due to indigestion, anxiety, or muscle injury. If your doctor finds that you probably don’t have a heart problem, you may not need a stress test at all, says Choosing Wisely (2017 Consumer Reports. Developed in cooperation with the American Society of Nuclear Cardiology).

If you do have a heart problem, your first choice should often be a simple stress test without imaging. This test has little risk and is inexpensive. It is usually accurate for people with a low risk of heart problems.

Imaging stress tests are usually safe and can use little or no radiation. But for people at low risk, the tests may produce false alarms. This can lead to follow-up tests that you don’t really need. The extra tests can expose you to more radiation. Inappropriate testing can also lead to unnecessary treatment, says Choosing Wisely.

An imaging stress test can cost 10 times more than a regular stress test. You should only get an imaging stress test when it will help your doctor manage your disease or lead you to a better treatment. Discuss your symptoms with your family doctor. We can learn a lot from cardiac stress test if appropriately ordered.

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High-Rise Buildings Present Challenge in Cardiac Arrest

Disneyland. (Dr. Noorali Bharwani)
Disneyland. (Dr. Noorali Bharwani)

If there is a life-threatening emergency in a high-rise building then it is longer to rescue the people trapped in the building. In case of fire there are problems related to evacuation, accessibility, smoke movement and fire control.

What happens if you have a heart attack (cardiac arrest) in a high-rise building?

A study shows patients residing on higher floors of high-rise buildings in Toronto had lower survival after out-of-hospital cardiac arrest. Most out-of-hospital cardiac arrests occur in residential areas, and these cases are associated with poorer outcomes than nonresidential cardiac arrests, says an article in the Canadian Medical Association Journal (CMAJ).

Studies have shown that the mean time from ambulance arrival on scene to patient contact was 2.8 minutes for people on the first two floors but 3.1 minutes for those on the 3rd to 9th floors and 3.3 minutes for those on the 10th floor or higher.

Cardiac arrests on higher floors had longer rescue times, which contributed to poorer outcomes.

There are a number of issues which affect access in a high-rise building. For example:

  • Lack of witnesses to provide immediate help, CPR (Cardio Pulmonary Resuscitation) or call to paramedics.
  • There are barriers to elevator access. Studies have shown additional elevator stops happened in 18.6 per cent of high-rise residential calls. Elevators were not easily accessible in 33.9 per cent of all paramedic calls to apartment buildings.
  • Requirement for an entry code to a building (67.6 per cent of all access barriers), lack of directional signs (82.6 per cent) and inability to fit the ambulance stretcher into the elevator (67.9 per cent).
  • CPR in elevators is challenging.

What would help?

  • Train the family members of those at risk to do CPR.
  • Place automated external defibrillators strategically in certain residential locations.
  • Smartphone technology can link residents who are trained first responders to defibrillators in their neighbourhoods and to victims of cardiac arrest in apartments.

Recently another article in CMAJ (January 18, 2016) discussed this subject. During the study period, 7842 cases of out-of-hospital cardiac arrest met the inclusion criteria. Of these 76.5 per cent of patients had cardiac arrest below the third floor and 23.5 per cent of the patients had cardiac arrest on the third floor or higher.

The authors found survival was greater on the lower floors (4.2 per cent v. 2.6 per cent). They also found survival was 0.9 per cent above floor 16, and there were no survivors above the 25th floor. Wow, that can make you nervous!

Their conclusion: “In high-rise buildings, the survival rate after out-of-hospital cardiac arrest was lower for patients residing on higher floors. Interventions aimed at shortening response times to treatment of cardiac arrest in high-rise building may increase survival.” This kind of action can alleviate other disasters like fire.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!

February Means Heart Month – Have You Been Kind to Your Heart Lately?

Joggers in Seville, Spain. (Dr. Noorali Bharwani)
Joggers in Seville, Spain. (Dr. Noorali Bharwani)

February is Heart Month. The month is almost over but we are still recovering from the chocolates and dinners we had for Christmas, New Year’s parties and Valentine’s Day. Wow… isn’t that something? Who decides on all these occasions where you eat, drink and be merry? That person is a genius.

We got to have fun to stay healthy. As long as our drinking and eating is within reasonable limits. What is reasonable depends on what common sense dictates, what science says and what your heart says.

Your heart has to be healthy to give you good advice. OK, if you have a bad heart then that tells you something as well. Also remember, your heart muscle is the hardest working muscle in the body. It pumps out two fluid ounces – sixty milliliters – of blood at every heartbeat. Every day, the heart pumps at least 2,500 gallons or 9,4500 litres of blood. The heart has the ability to beat over three billion times in a person’s life. That is one more reason to keep the heart healthy and strong.

In spite of all the insults we inflict on our indispensable heart, it continues to take care of us as long as it can. It is relentless in its function. The heart has to be strong for it to pump blood forcefully to all parts of our body – our brain, our fingertips and our toes are miles apart… so to speak. But the blood still gets there most of the time.

Two elements will predict your heath in 2015 and beyond: what you do for yourself and what fate does for you. We have no control over the later but we can do something over things we have control.

You can control what you eat. You can control how much exercise you do. You can control your weight (not so easy, right?). You can control how much alcohol you drink and whether you are going to smoke.

All these subjects are covered in my easy to read book (Dr. B’s Eight Steps to Wellness). Regular physical activity is a very important component in our fight to keep our heart healthy, blood pressure low and prevent stroke. But don’t over do it if you are not in a good shape. About five per cent of the deaths occur after heavy exertion such as shoveling snow, recreational jogging or sexual activity. In U.S. this accounts for 25,000 deaths a year. Similar statistics are reported from Canada and Europe.

I thought death during sexual activity occurs only in the movies… just kidding. If you are not fit then be careful.

There are three main risk factors that are associated with complications during exercise: age, presence of heart disease, and intensity of exercise. If you exercise regularly then you should be pretty safe. But if you are a new starter (after reading this column) then better check with your doctor and start slowly. As they say, “Slow and steady wins the race.”

Eat, drink and be merry… but be heart smart.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!

There are Significant Technical Advances in Heart Surgery

Bird, looking for something? (Dr. Noorali Bharwani)
Bird, looking for something? (Dr. Noorali Bharwani)

I met a gentleman who has had a stroke, suffers from coronary artery disease and has a malfunctioning aortic valve – a valve in the left lower chamber of the heart from where the blood is pumped out to the rest of the body.

I also read in my book (Dr. B’s Eight Steps to Wellness – page 90) that the heart muscle is the hardest-working muscle in the body. It pumps out 60 milliliters of blood at every heartbeat. Every day, the heart pumps out at least 10,000 liters of blood. The heart has the ability to beat over three billion times in a person’s life. Isn’t that something?

The heart is like a grand central station. If the central station breaks down then all the lines come to a stop. We don’t want that. So we need to keep our heart healthy. But if you are unlucky like the gentleman I mentioned earlier, then you have to look for medical and/or surgical help.

Pursuing a healthy life style in terms of regular exercise, healthy eating and no smoking is a good thing. If you inherit bad genes then you have to increase your efforts to prevent the disease. If you need medications then your good doctor will help you with that.

There are surgical options for coronary artery disease. If putting stents in plugged vessels does not help then surgical treatment is required. Coronary artery bypass graft (CABG) surgery has become a routine procedure.

The majority of coronary surgical procedures are performed for multiple vessel disease. Overall, the mortality rate of coronary artery surgery is low, at around two to three per cent, although this benefit is offset by a complication rate of 20 to 30 per cent. It is important to evaluate various physical, psychological and social side effects of CABG as well.

Now the technology has improved to a point where patients with more advanced coronary artery disease and extensive coexisting conditions are taken care of. “Off-pump” procedures, in which the heart does not have to be stopped, were developed in the 1990s. These patients generally have fewer complications, less leg pain, and shorter hospital stays.

Options for treating damaged aortic valve are many. The valve can be repaired or replaced in many ways. In the United States, surgeons perform about 99,000 heart valve operations each year. Valve replacement is most often used to treat aortic valves in the left lower chamber of the heart. Your surgeon may choose a mechanical valve, which is usually made from materials such as plastic, carbon, or metal. Mechanical valves are strong, and they last a long time.

Your surgeon may choose a biological valve, which is made from animal tissue or taken from the human tissue of a donated heart. The procedure may be open-heart surgery or the new technique of minimally invasive valve surgery thorough small openings in the chest wall. In some cases, minimally invasive valve surgery can be done using a robot.

Minimally invasive surgery cannot be done in patients who have severe valve disease, have clogged arteries or are overweight.

Research shows around two per cent of people treated with aortic valve replacement will die in the first 30 days after surgery. However, the risk of death from surgery is far lower than that associated with not treating severe aortic disease.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!