Article Text
Abstract
Purpose To evaluate the prevalence of structural cardiac lesions using echocardiography in apparently healthy boys referred for pre-participation screening (PPS).
Subjects and methods 3100 male soccer players were evaluated by echocardiography in addition to the standard PPS.
Results In 56 subjects (1.8%), a structural cardiac lesion with potential future complication was detected. Specifically, hypertrophic cardiomyopathy (HCM) was found in two boys; bicuspid aortic valve (BAV) in 24; mitral valve prolapse in 10 and atrial septal defects (ASDs) in 20. Resting physical examination (PE) failed to identify any abnormalities in the majority of the subjects. All the boys presented an uncomplicated echocardiography, except two boys with HCM, one with BAV associated with aortic dilatation and one with a large ASD.
Conclusion Asymptomatic young athletes may have a structural cardiac alteration with the potential of present or future haemodynamic and arrhythmic consequences. A majority of mild cardiac lesions are difficult to diagnose or suspect by the current screening based on medical history, PE and ECG. Transthoracic echocardiography significantly improves the diagnostic power of screening in the detection of both mild and serious cardiac conditions in the athletic population.
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Introduction
Identification of unknown cardiac alterations is the main goal of pre-participation screening (PPS) in competitive athletes since cardiac diseases represent the leading cause of death in this population.1 In Italy, PPS is mandatory by law and includes physical examination (PE) and ECG. The first screening for children entering in competitive activity is usually performed between 8 and 12 years of age.2 Over three decades of application, the Italian PPS has shown to be effective in preventing sudden cardiac death (SCD) in athletes.3,–,6 However, this screening method could not identify all the athletes with structural cardiac alterations. Most mild cardiovascular abnormalities may not be associated with detectable ECG alterations. In addition, different type and degree of these ECG abnormalities can be found in otherwise healthy trained athletes,7 and heart murmurs occur frequently in children limiting the diagnostic power of the PE in this particular population.8 9 Echocardiography is a non-invasive, readily available and relatively inexpensive diagnostic tool with the ability to detect subclinical abnormalities early in their natural history.10 Indeed, the implementation of PPS with echocardiography has been considered by several authors.11,–,14 The aim of the present study was to evaluate the usefulness of implementing standard PPS with echocardiography to detect structural cardiac abnormalities in a large population of trained asymptomatic, apparently healthy children and adolescents.
Subjects
3100 male young soccer players (age range 6–17, mean age 11 years) were evaluated. 2170 (70%) subjects were at the first sports medicine evaluation and 930 had already undergone one or more mandatory annual PPS in other institutions, and they had been declared eligible for competition.
Methods
Children underwent the conventional Italian PPS with ECG and PE. In addition, in all subjects, a complete two-dimensional and colour Doppler echocardiogram was performed with a Siemens Acuson X 300 echocardiographic equipment with a P5.1 and P8.4 MHz transducer. The examination was conducted according to the recommendations of the European Society of Echocardiography.15
PE and ECG were performed and interpreted by three sports medicine physicians, according to the Italian legislation.3 Echocardiograms were performed by three cardiologists and two sports medicine physicians (different from those who performed PPS). All examinations were recorded and finally reviewed by a cardiologist supervisor with a strong and longstanding experience in paediatric cardiology.
Results
A total of 3044 echocardiograms were found to be completely normal. In 56 boys (1.8%), a structural cardiac lesion of different type and degree was detected (figure 1).
In particular, the following cardiac abnormalities were found:
Hypertrophic cardiomyopathy (HCM): 2 cases.
Bicuspid aortic valve (BAV): 24 cases.
Mitral valve prolapse (MVP): 10 cases.
Atrial septal defect (ASD): 20 cases. Specifically, 12 type ostium secundum small ASDs, 1 large ASD associated with anomalous pulmonary venous return and 7 atrial septum aneurysm (ASA).
In addition, 29 boys showed a patent foramen ovale but were not included in the 'pathologic' group.
A non-obstructive HCM was diagnosed in two boys aged 12 and 13, who were both evaluated for the first time. Both of them presented with the 'classic' asymmetric pattern of septal hypertrophy, involving the anterior segment (interventricular septum thickness: 16 and 15 mm, with posterior wall thickness of 9 and 8 mm, respectively) associated with small cavity dimensions (left ventricular end diastolic diameter: 42 and 44mm, respectively). Medical history and PE failed to reveal any abnormalities. On the contrary, ECG presented the typical HCM abnormalities: Q waves and negative T waves in the inferior leads and deep, negative/diphasic T waves in V2-V6 leads (figure 2). These children were withdrawn from training and competition16 and they were referred to a paediatric cardiologic centre. BAV was found in 24 children; 19 of them previously underwent PPS and were declared normal.
Of these children, only three had a systolic click. Four had 1–2/6 systolic or diastolic murmurs audible on the aortic area. PE was normal in the other children. ECG was within normal limits in all of them, except in one boy (who presented with aortic root dilatation) with left axial deviation, negative T waves in V1-V3 and premature ventricular and supra-ventricular beats. MVP was diagnosed in 10 children. A systolic click was audible in one boy while the others had a completely normal PE. ECG was normal in all children. ASA was found in seven children and in three subjects it was associated with a left-to-right mild shunt not haemodynamically significant. A light systolic murmur (1–2/6) was audible in four children, although the ECG was normal. An isolated small ASD type ostium secundum with a minimum left-to-right shunt was detected in 12 boys. PE and ECG were normal. A large ASD type ostium primum with severe left-to-right shunt, anomalous pulmonary venous return, right ventricular dilatation and initial pulmonary hypertension was found in a 16-year-old boy who required surgical correction. The boy was asymptomatic. PE revealed an ample and non-persistent split of the second heart sound and a 2/6 murmur was audible on the whole cardiac area. The ECG showed an incomplete right bundle branch block with RSR pattern in V1 and V2 of <0.12 s in duration. This subject had been playing competitive soccer since the age of 8 years. He underwent periodical PPS, and he was always judged 'healthy' and eligible for competition.
Discussion
The results of the present study appear noteworthy when considering that even if only four boys were found to have clinically significant conditions, the other 52 presented mild abnormalities at risk for future arrhythmic or haemodynamic complications. The preventive role of PPS includes the identification of young athletes with cardiac lesions requiring long-term follow-up in order to guarantee a safe sports participation and an early identification of the progression of diseases. The Italian PPS has proved to be effective in preventing SCD in the athletes.4 However, the use of only ECG as an instrumental test may represent a diagnostic limitation, particularly in athletes. ECG has shown to have relatively low specificity in this population mainly because of the high frequency of ECG alterations associated with the normal physiological adaptations of the trained athlete's heart.7 This study confirmed the high sensitivity of PE and ECG in raising clinical suspicions of severe cardiac alterations predisposing to SCD, however, it also highlighted that apparently healthy children engaged in competitive sports may have hidden mild structural cardiac alterations not detectable by standard PPS but easily recognisable by echocardiography. A cost-effective use of echocardiography in athletes has been widely discussed. Wyman et al13 suggested the routine use of a 5-min two-dimensional echocardiogram as a useful and feasible screening modality. Other authors17 18 recommend the limited use of echocardiography for screening athletes involved in the selected sport. Considering that the cardiac lesions recognisable in young athletes are basically congenital conditions, we suggest the introduction of echocardiography only at the first sports medicine evaluation in order to increase the otherwise proved effectiveness of the Italian PPS. Moreover, if the echocardiogram is carried out by the same sports medicine physician who performs the medical evaluation, the cost, as well as the duration of the screening would not be significantly increased (approximately 20% at the first PPS only).
What is already know on this topic
Italian pre-participation screening (PPS), including ECG, beyond medical history and physical examination is effective in preventing sudden cardiac death in athletes.
What this study adds
Some minor congenital cardiac lesions requiring long-term follow-up in athletes are not detectable with standard PPS and are easily recognisable by echocardiography. This study suggests the introduction of echocardiography only at the first sports medicine evaluation to increase the otherwise proved effectiveness of the Italian PPS.
References
Footnotes
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Competing interests None.
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Provenance and peer review Not commissioned; externally peer reviewed.