INTRODUCTION

Recently, team physicians and primary care doctors have seen more and more articles and studies relating to risk and detection of sudden cardiac death (SCD) in athletics (^3,7,9,14,16). Much of this research centers around the ability of the electrocardiogram to find underlying cardiac pathology (^2,3,12,14,16). Each year, physicians perform millions of preparticipation sports exams (PPE) around the country. It is estimated that 30 million athletes between the ages of 10 and 18 yr will be involved in organized sports (¹), and most of these will be required to have a PPE. Most of these exams include vital signs such as resting heart rate (RHR), systolic and diastolic blood pressure (SBP/DBP), and anthropometrics including height and weight.

According to the American Heart Association (AHA), the goal of the PPE is to reduce the cardiovascular risk associated with physical activity. The American College of Cardiology states that the ultimate objective of preparticipation screening of athletes is the detection of "silent" cardiovascular abnormalities that can lead to SCD (Maron, Bethesda conference), and the PPE's primary objective is to detect potentially life-threatening or disabling conditions before undergoing specific athletic PPE (¹). To accomplish this objective, it is recommend by the AHA that preparticipation screening include eight personal and family history questions and four physical exam maneuvers (¹⁰). The fourth edition of Preparticipation Physical Evaluation, endorsed by six primary care and sports medicine societies as well as the AHA, includes these questions and many others in its recommendations. Many states have their own versions of the form, which may or may not include this history of physical exam items.

Despite the stated goal to decrease the risk of death from cardiovascular and other diseases, there are no items in the history and physical exams of younger athletes that have been associated with increased incidence of SCD. Demographic items such as being male or African-American have been associated with SCD (^3,6,8). Presence of a murmur meeting the AHA criteria (¹⁰), such as grade 3/6, diastolic, or increasing with provocative maneuvers, also has been considered significant by some experts. It remains unclear whether any of the recommended historical items or any physical exam components in the PPE are significant predictors of risk for SCD.

REVIEW OF THE LITERATURE

There are no prospectively designed articles evaluating the association of vital signs, physical findings, anthropometrics, and historical data with the risk for underlying cardiac pathology and SCD. All prospective articles are entirely descriptive (^5,13,15). Retrospective studies relating to the PPE and SCD are case-based, focusing on SCD and the associated pathology believed to be causal (^7,8).

There are studies considering which factors discovered during a preparticipation exam may be able to predict SCD, musculoskeletal injury, and other problems threatening young athletes (^2,4,5,13). In general, the studies have been inadequate at discovering the estimated 0.3% of the younger population (³) with underlying cardiac pathology. Maron et al. found that fewer than 3% of younger athletes who died of cardiac causes were diagnosed with any pathology before death (⁸).

Fuller looked at 5,615 younger athletes prospectively over a 5-yr period of time. Given the low prevalence of cardiovascular disease predisposing to sudden death, only one patient with aortic insufficiency was discovered. No patients were identified with hypertrophic cardiomyopathy (HCM), anomalous coronaries (AOCA), Marfan syndrome, or aortic stenosis. In fact, the only other significant cardiac findings in the study were 17 patients with "mild tricuspid regurgitation," 16 with "mild mitral valve prolapse (MVP)," 4 with bicuspid aortic valves, and 3 with "minimal left ventricular hypertophy." None of the athletes, except for the one with severe aortic insufficiency, were disqualified. Those with elevated blood pressure were disqualified initially to receive further evaluation, but none were shown to have significant underlying cardiac abnormalities. However, five ultimately were disqualified because of severe hypertension. The researchers did not attempt to associate any historical or physical findings with the ability to predict risk for cardiac pathology, but they did suggest that electrocardiograms significantly increased the likelihood of discovering the diagnoses described here.

Magnes et al. (⁵) looked at 10,540 consecutive PPE results, primarily to discern which conditions would limit sports participation. Their findings resulted in the disqualification of only one athlete from congenital cardiac disease and 19 others who failed to pass because of hypertension. This study was not designed to consider whether any parameters of anthropometrics or exam findings were associated with improving diagnostic detection of SCD risk, and therefore, this was not mentioned by the authors.

Thompson et al. (¹⁵) reported on the evaluation of 2,670 young athletes during PPE. All the disqualifications for cardiac reasons (31 out of 2,670) were related to heart murmurs, and these were referred for further evaluation. A total of 30 out of 31 eventually were cleared to compete. The remaining patient required surgery for severe MVP and was disqualified. No discussion of vital signs, anthropometrics, or ethnic issues was made in the article.

Smith and Laskowski (¹³) reported on 2,739 consecutive PPE results conducted in a station format. They divided the cases of cardiac abnormalities into two groups: the "cleared with follow-up" group (CFU) and the "not cleared" group (NC). The NC group consisted of 14 athletes with hypertension, 6 with dizziness or near syncope, 5 with murmurs, and 1 with heart surgery and syncope. There was no mention as to echocardiographic findings, and the five with murmurs only were evaluated with provocative measures. Again, no prospective assessment of physical parameters and diagnoses was mentioned.

Baggish et al. (²) reported on 510 college athletes comparing evaluation with and without echocardiogram (EKG). Of note is that their population revealed three potentially lethal diagnoses, with only one with moderate pulmonic stenosis discovered on the standard PPE. A total of 9 out of 510 had chest pain, syncope, or near syncope, but none of these had demonstrated abnormalities.

Sofi et al. (¹⁴) evaluated 30,065 athletes, most of whom were adults, in Italy. There was no specific mention of the number who had murmurs, chest pain, or other symptoms consistent with AHA guidelines. However, by evaluating disqualification factors separately, only 6 out of 159 athletes disqualified would have been discovered by the standard PPE.

Wilson et al. (¹⁷) evaluated the personal family history and physical exams conducted on 1,074 junior international athletes and 1,646 school-aged individuals felt to be physically active but not elite athletes (N = 2,720). They found 9 out of 2,720 with diseases associated with sudden death. The PPE alone did not reveal a single individual with one of the nine lethal diagnoses.

Therefore, studies suggest there is extremely limited value in history and the physical in detecting athletes at risk for SCD.

SUMMARIZATION OF OUR DATA

In our research, we have questioned the benefit of some of the most basic elements of the PPE. Our data are based on 2,401 PPE results, given over 5 yr, which revealed some interesting findings. A total of 14 of the 2,401 athletes in the 10- to 18-yr-old group (with a ratio of 65% male and 35% female athletes) were found to have diagnoses consistent with significant cardiac pathology (Table). Six of these 14 were diagnoses that have been associated with SCD in athletes as described in the 36th Bethesda guidelines (¹¹). This incidence of 6 out of 2,401 (0.25%) is consistent with other demographic estimates (^7,8). Six of the diagnoses were made from murmurs discovered on exam. A total of 3 out of 14 had a history of chest pain and a murmur on exam. Again, 3 out of 14 had chest pain as their only symptom, and the last 2 had positive family histories with 1 having a murmur as well as the family history (Table). Male gender was highly associated with underlying cardiac pathology, as all 14 athletes who tested positive were male. Elevated SBP was associated highly with cardiac pathology, but this was determined to be related entirely to the fact that the males also had significantly higher SBP than the females (Fig.). We did not address the issue of ethnic origin as the PPE form we used did not inquire about ethnicity. Retrospectively, we believe this would have been valuable as there is a well-known association with race and SCD, primarily through the contribution of HCM to SCD (⁶). Indeed, the two athletes we found to have HCM were both African-American people.

We found no association of age or weight with underlying cardiac pathology. We did confirm the decline in heart rate relative to age, but did not see the anticipated decline in RHR relative to weight. As mentioned above, SBP and DBP were significantly higher in males than females in most age groups.

Our data can be summarized by saying that only the male gender proved to be helpful in finding the elusive athlete with underlying cardiac pathology, and none of the anthropometric or vital sign parameters were of significant value in this quest.

CONCLUSION

Prospective studies specifically looking at the association of height, weight, SBP, DBP, age, RHR, and gender with underlying cardiac pathology and SCD do not exist. Studies looking at the sensitivity of the history and physical exam recommended for PPE screening show that it is ineffective at predicting SCD or cardiac pathology. Male gender is associated with SCD, but the specificity of this finding is low. Likewise, vital signs do not appear to be helpful in predicting SCD; thus the heights, weights, ages, blood pressure, and pulse rates collected at nearly 10 million PPE annually are unlikely to help distinguish the athlete at risk for SCD.