Athlete’s Heart
|
Athlete’s heart is a constellation of structural and functional changes that occur in the heart of people who train for prolonged durations (eg,> 1 hour most days) and/or frequently at high intensities. The changes are asymptomatic; signs include bradycardia, a systolic murmur, and extra heart sounds. Electrocardiographic (ECG) abnormalities are common. Diagnosis is clinical or by echocardiography. No treatment is necessary. Athlete’s heart is significant because it must be distinguished from serious cardiac disorders.
1. Symptoms and Signs of Athlete’s Heart
There are no symptoms. Signs vary but may include
These signs reflect structural cardiac changes that are adaptive for intense exercise. 2. Diagnosis of Athlete’s Heart
Findings are typically detected during routine screening or during evaluation of unrelated symptoms. Most athletes do not require extensive testing, although ECG is often warranted. If symptoms suggest a cardiac disorder (eg, palpitations, chest pain), ECG, echocardiography, and exercise stress testing are done. Athlete's heart is a diagnosis of exclusion; it must be distinguished from disorders that cause similar findings but are life threatening (eg, hypertrophic cardiomyopathy, dilated cardiomyopathy, ischemic heart disease, arrhythmogenic right ventricular dysplasia). Cardiac magnetic resonance (CMR) imaging may be helpful when findings from other diagnostic modalities are inconclusive. ECGNumerous changes in rhythm and ECG morphology can occur; they correlate poorly with level of training and cardiovascular performance. The most common ECG finding is
Rarely, heart rate is < 40 beats/minute. Sinus arrhythmia often accompanies the slow heart rate. Resting bradycardia may also predispose to
Other ECG findings that may occur include
However, third-degree AV block is abnormal and should be investigated thoroughly. These ECG and rhythm changes have not been associated with adverse clinical events, suggesting that various arrhythmias are not abnormal in athletes. The arrhythmias are usually abolished or substantially reduced after a relatively brief period of deconditioning. EchocardiographyEchocardiography can usually distinguish athlete’s heart from cardiomyopathies (see table Features Distinguishing Athlete's Heart From Cardiomyopathy), but the distinction is not always clear because there is a continuum from physiologic to pathologic cardiac enlargement. The zone of overlap between athlete’s heart and cardiomyopathy is left ventricular septal thickness:
In this overlap area, the presence of mitral valve systolic anterior motion strongly suggests hypertrophic cardiomyopathy. Also, diastolic indexes may be abnormal in cardiomyopathy but are usually normal in athlete's heart. In general, echocardiographic changes correlate poorly with level of training and cardiovascular performance. Trace mitral regurgitation and tricuspid regurgitation are commonly detected. Of note, reduction of physical training will result in regression of cardiac enlargement in patients with athlete's heart but not in those with cardiomyopathy. Exercise echocardiography may help to differentiate athlete's heart from dilated cardiomyopathy. In one study, a change during exercise in left ventricular ejection fraction (LVEF) ≤ 11% and a peak LVEF ≤ 63% during exercise predicted dilated cardiomyopathy with a sensitivity of 85.7% and specificity of 92% . Cardiac magnetic resonance (CMR) imagingAlthough confirmation in large studies is pending, data so far suggest that CMR may also help differentiate athlete's heart from cardiomyopathy. In hypertrophic cardiomyopathy , CMR may identify focal hypertrophy not identified on the echocardiogram, particularly in the apex, anterior free wall, and posterior septum. Delayed imaging after injection of contrast may show a typical pattern of mid-wall fibrosis in some patients with hypertrophic cardiomyopathy, particularly in left ventricular wall segments that exhibit maximal hypertrophy. However, this finding is absent in up to 60% of patients with hypertrophic cardiomyopathy. Delayed enhancement on CMR is also evident in nonischemic dilated cardiomyopathy and may help differentiate dilated cardiomyopathy from athlete's heart. However, the finding is absent in 68% of patients with genetically proven dilated cardiomyopathy. T1 and T2 mapping, extracellular volume quantification, late gadolinium enhancement, deformation imaging and diffusion tensor imaging are all promising techniques to differentiate between athlete's heart and hypertrophic cardiomyopathy. Further studies are required to better determine the ability of these techniques to detect hypertrophic cardiomyopathy in athletes. Although exercise capacity as measured by stress testing does not differentiate between athlete's heart and dilated cardiomyopathy, reduced cardiac contractile reserve with exercise observed on CMR imaging may be useful in establishing a diagnosis of dilated cardiomyopathy in an athlete. Stress testingDuring exercise stress testing, heart rate remains lower than normal at submaximal stress and increases appropriately and comparably to heart rate in nonathletes at maximal stress; it rapidly recovers after exercise. Blood pressure response is normal if:
Many resting ECG changes decrease or disappear during exercise; this finding is unique to athlete's heart, distinguishing it from pathologic conditions. However, pseudonormalization of T-wave inversions could reflect myocardial ischemia and thus warrants further investigation in older athletes. Also, a normal exercise stress test result does not rule out a cardiomyopathy. Author: Robert S. McKelvie, MD, PhD, Western University If you want to learn more about Diagnosis of Heart, please visit the links below: //www.chinautech.com/ //www.chinautech.com/product-5152253249405418.html //www.chinautech.com/products/pm6800-patient-monitor.html |
Will Treating High Blood Pressure Curb Dementia Risk?
Brain Oxygen Saturation Monitor
Related Article
