News | Cardiac Diagnostics | August 10, 2016

Regular Exercise Can Lead to Heart Disease Misdiagnosis

Research finds heart enlargement common to athletes can occur in individuals who exercise as few as three hours per week

regular exercise, heart enlargement, heart disease misdiagnosis, MRC Clinical Sciences Centre study

People who exercise regularly may develop hearts that are larger (right), with thicker muscle and bigger chambers, than those who are more sedentary (left). Image courtesy of MRC Clinical Sciences Centre.

August 10, 2016 — Scientists have shown that people who exercise for even a few hours each week can enlarge their hearts. This is a normal and beneficial response to exercise, but until now has only been recognized in athletes. The researchers say that doctors should now consider an individual’s activity level before diagnosing common heart conditions.

“It’s well known that the hearts of endurance athletes adapt in response to exercise, a phenomenon called ‘athlete’s heart’. This study is the first to show that healthy adults who do regular exercise may also develop enlarged hearts. As a result, there’s a risk that some active adults could be misdiagnosed with heart disease,” said Declan O’Regan, of the MRC Clinical Sciences Centre, based at Imperial College London, and one of the lead scientists on the research. The findings were published recently in Circulation: Cardiovascular Imaging.

Scientists have not previously known the extent to which the hearts of healthy people adapt to the demands of moderate exercise. Over 1,000 people took part in this study, making it one of the largest of its kind. Participants selected one of four possible categories that best represented their activity level over the past year, according to how many hours of exercise they did each week. Around one-third of participants reported doing three to five hours of exercise, and the scientists found that one in five of these people had developed an enlarged heart as a result. Similar adaptations were seen in almost half of those who reported doing more than five hours of exercise.

The findings suggest that above a threshold of three hours, the more exercise you do, the more your heart is likely to adapt, and the more the exercise, the more pronounced the changes. “Going to the gym frequently increases the thickness of your heart muscle and the volume of your heart chambers, particularly the right ventricle. It’s a completely normal, healthy response. It shouldn’t be misdiagnosed as being heart disease,” said O’Regan.

These adaptations allow the heart to pump more blood, which helps to supply exercising muscles with the oxygen and nutrients they need. Changes to the heart’s thickness and volume happen in tandem, and this distinguishes them from the changes seen in disease, which occur in isolation.

Today, doctors across the world use a standard of set values to see if the thickness and volume of a person’s heart fall into the healthy or abnormal range. This helps to ensure consistency between different hospitals. According to O’Regan, the data that underpins these ranges comes from a relatively small study with people who were mainly sedentary. He says, “In this latest study, we looked at a much larger and broader group of people. We found that more people reported being active than had done in previous studies. Our recommendations reflect this growing participation in exercise.”

Updating the ranges to account for activity should be straightforward. Indeed, doctors already account for an individual’s height, age and gender, factors which are known to change the shape and structure of a person’s heart. Just like these factors, a person’s activity level could be established easily and quickly in the clinic.

“This study was based on an everyday clinical problem. We frequently look at cardiac scans where people have enlarged hearts, and whilst they may have a family history of heart disease, they also do regular exercise. So the question is, have they actually got inherited heart disease, or is it just that they’re active?” said O’Regan. Knowledge of a person’s exercise level can be used together with a heart scan and measures such as an electrocardiogram (ECG) to identify those who may need treatment.

At the beginning of the study, O’Regan and his colleagues, Stuart Cook and Timothy Dawes, both of the CSC, analyzed the genes of participants to rule out those with a family history and predisposition to heart disease. This allowed them to be confident that all of the eventual participants did indeed have healthy hearts, and any changes in their heart structure were the result of exercise.

Dr. Noel Faherty, research advisor at the British Heart Foundation, which helped fund the research, said, “The events in Rio will undoubtedly inspire many of us to put on our running shoes and get active. And this interesting research shows that even moderate physical activity is associated with changes in the heart’s size and shape, which are visible on a cardiac MRI [magnetic resonance imaging].

“Detectable changes to the heart on an MRI scan are common in elite endurance athletes but some heart conditions, like cardiomyopathy, can be diagnosed by detecting similar changes. This study demonstrates the importance of documenting the MRI appearance of healthy, active people’s hearts so normal adaptive changes are recognized by doctors and not mistaken for disease.”

For more information: www.circimaging.ahajournals.org

Related Content

The BardyDx Carnation Ambulatory Monitor (CAM) is a P-wave centric wearable ambulatory cardiac patch monitoring and arrhythmia detection device. 

The BardyDx Carnation Ambulatory Monitor (CAM) is a P-wave centric wearable ambulatory cardiac patch monitoring and arrhythmia detection device. 

News | Cardiac Diagnostics | July 29, 2021
July 29, 2021 — A recent clinical study from Overlake Medical Center utilizing the Bardy Diagnostics Carnation Ambula
The FDA has cleared Angel Medical Systems' second-generation AngelMed Guardian device. The implantable cardiac device detects and warns patients if they are having an acute coronary syndrome (ACS) event, including silent heart attacks. The new, second-generation device is enhanced with ease-of-use adaptations and an updated, long life battery that could potentially double the life of the implanted device

The FDA has cleared Angel Medical Systems' second-generation AngelMed Guardian device. The implantable cardiac device detects and warns patients if they are having an acute coronary syndrome (ACS) event, including silent heart attacks. The new, second-generation device is enhanced with ease-of-use adaptations and an updated, long life battery that could potentially double the life of the implanted device

News | Cardiac Diagnostics | July 01, 2021
July 1, 2021 — The U.S. Food and Drug Administration (FDA) has cleared the Angel Medical Systems Inc.
Ophthalmic optical coherence tomography (OCT) scan view of the macula in retina with vessels. Detecting heart disease with OCT imaging of the eye.Getty Images

Ophthalmic optical coherence tomography (OCT) scan view of the macula in retina with vessels. Getty Images
 

News | Cardiac Diagnostics | March 08, 2021
March 8, 2021 — In a new study from Shiley Eye Institute at UC San Diego Health, researchers have identified a potent
Alivecor's pocket ECG system allows consumers or cardiologists to record a single lead ECG. AI algorithms can determine if their ECG is normal or abnormal and identify the arrhythmia.

Alivecor's pocket ECG system allows consumers or cardiologists to record a single lead ECG strip on a smartphone. AI algorithms can determine if their ECG is normal or abnormal and identify the arrhythmia. 

News | Cardiac Diagnostics | March 03, 2021
March 3, 2021 — AliveCor recently announced a new collaboration with AstraZeneca to research new disease management s
A study of more than 100 million Americans in 3,123 counties found a correlation between cardiac death and their level of income. Getty Images Health disparities in cardiovascular disease.

A study of more than 100 million Americans in 3,123 counties found a correlation between cardiac death and their level of income. Getty Images

News | Cardiac Diagnostics | February 02, 2021
February 2, 2021 — A new study has found in the U.S.
A new study highlights the importance of continued public education regarding the risks of cigarette smoking and the failure of dual use with vaping to reduce cardiovascular risk. Getty Images

A new study highlights the importance of continued public education regarding the risks of cigarette smoking and the failure of dual use with vaping to reduce cardiovascular risk. Getty Images

News | Cardiac Diagnostics | January 06, 2021
January 6, 2021 — Smoking traditional cigarettes in addition to using e-cigarettes results in harmful health effects
The Mesuron Inc. Avalon-H90 uses magnetometers to detect myocarditis in patients without any physical contact. It uses ventricular repolarization dynamics analysis software to look for abnormalities. The vendor said it is more specific than using ECG. It detects the multidimensional dynamics of the electrical activity caused by differences in functions of electrical action potential of normal heart tissues and abnormal ones with hypoxia.

The Mesuron Inc. Avalon-H90 uses magnetometers to detect myocarditis in patients without any physical contact. It uses ventricular repolarization dynamics analysis software to look for abnormalities. The vendor said it is more specific than using ECG. It detects the multidimensional dynamics of the electrical activity caused by differences in functions of electrical action potential of normal heart tissues and abnormal ones with hypoxia. 

News | Cardiac Diagnostics | October 06, 2020
October 6, 2020 — A new technology being developed by U.S.-based Mesuron Inc.
With the advent and optimization of nuclear scintigraphy protocols using bone-avid radiotracers, cardiac amyloidosis caused by transthyretin protein (ATTR) can now be diagnosed noninvasively without a costly tissue biopsy. The radiotracer 99mTc-pyrophosphate (99mTc-PYP) binds to deposited ATTR amyloid fibrils in the myocardium and can be visualized using planar and SPECT imaging. Amyloidosis Patient Registry  #Amyloidosis

With the advent and optimization of nuclear scintigraphy protocols using bone-avid radiotracers, cardiac amyloidosis caused by transthyretin protein (ATTR) can now be diagnosed noninvasively without a tissue biopsy. The radiotracer 99mTc-pyrophosphate (99mTc-PYP) binds to deposited ATTR amyloid fibrils in the myocardium and can be visualized using planar and SPECT imaging. This is Figure 2, showing how SPECT imaging allows the reader to distinguish between blood pool activity (ventricular cavity, etc) and myocardial activity and identify regional myocardial differences in radiotracer uptake.

News | Cardiac Diagnostics | March 05, 2020
March 5, 2020 — More than 300 patients have joined the Amyloidosis Patient Registry and it is now available to the en