From the Guidelines
An athlete's heart size can be considered normal with a left ventricular end-diastolic diameter of up to 60 mm and a maximal LV wall thickness of less than 12 mm, with scaling to body surface area (BSA) advised for accurate assessment. When evaluating the size of an athlete's heart, it's essential to consider the context of exercise capacity and body size, as left ventricular cavity is strongly related to these factors 1. The European Association of Preventive Cardiology (EAPC) and European Association of Cardiovascular Imaging (EACVI) joint position statement provides guidance on the indication and interpretation of cardiovascular imaging in athletes, including echocardiography to define the upper limits of athlete's LV hypertrophy 1. Key points to consider when assessing an athlete's heart size include:
- Left ventricular end-diastolic diameter can be increased in athletes, with 14% having a diameter greater than 60 mm, mostly in endurance athletes 1
- Maximal LV wall thickness is typically less than 12 mm in Caucasian athletes, with only 2% ranging from 13 to 16 mm, and none exceeding 16 mm 1
- Scaling measurements to BSA is recommended, with upper limits in athletes reported as less than 35 mm/m2 in males and 40 mm/m2 in females 1
- Septal wall thickness is generally thinner in women, with an average of 9 mm and an upper limit to be considered in the context of overall cardiac assessment 1.
From the Research
Size of an Athlete's Heart
The size of an athlete's heart can vary depending on several factors, including the type of sport, intensity of training, and individual characteristics.
- Studies have shown that athletes who participate in endurance sports, such as long-distance running, may have larger coronary arteries and increased left and right ventricular enlargement and hypertrophy 2.
- The magnitude of these physiological changes is predominantly determined by demographic factors, including age, gender, size, ethnicity, and sporting discipline 3.
- A small minority of male athletes may exhibit substantial increases in cardiac size that overlap with the phenotypic manifestation of cardiomyopathies 3.
- Echocardiographic measurements of ventricular and atrial dimensions and ventricular wall thickness may be smaller than those obtained through cardiac MRI, and may require correction for accurate assessment of an athlete's heart 4.
Factors Influencing Heart Size
Several factors can influence the size of an athlete's heart, including:
- Type and intensity of training: Endurance training has been shown to increase coronary artery size and left and right ventricular enlargement and hypertrophy 2.
- Demographic factors: Age, gender, size, ethnicity, and sporting discipline can all impact the size of an athlete's heart 3.
- Individual characteristics: Genetic factors may also play a role in determining the final size of the coronary vessels 2.
Measurement and Assessment
The size of an athlete's heart can be measured and assessed using various techniques, including:
- Echocardiography: This method can provide measurements of ventricular and atrial dimensions and ventricular wall thickness, but may require correction for accurate assessment 4.
- Cardiac MRI: This method can provide more accurate measurements of ventricular and atrial dimensions and ventricular wall thickness, but may be more expensive and less accessible than echocardiography 4.