CHAPTER 64: THE ATHLETE AND THE CARDIOVASCULAR SYSTEM

INTRODUCTION

Evaluation and management of the athlete with cardiovascular disease and arrhythmias represents a unique challenge. Although athletes are symbols of the healthiest segment of our society, they are occasionally affected by cardiovascular conditions that come to the attention of the clinician. The physician can be faced with clinical judgments related to evaluation of symptoms, such as chest discomfort, or signs, such as a murmur, that can be either benign or a manifestation of an underlying cardiac condition. Clinical judgment commonly serves as the basis for recommendations for therapy and athletic participation. In this setting, there is the real risk of failing to detect a cardiac condition that may result in serious or even life-threatening consequences. There is also considerable risk of unnecessarily treating and restricting sports activity in an athlete misdiagnosed as having an underlying cardiac condition. The consequences of missing an important cardiac diagnosis can be life-threatening. The cardiovascular conditions that predispose to life-threatening complications with athletic activity are now known from pathologic studies^1,2 (Table 64–1). Recommendations for clinical evaluation, management, and athletic participation are also available to guide clinicians.³ This chapter will review cardiovascular disease in the athlete from multiple perspectives. These include distinguishing physiologic cardiovascular adaptations to exercise from true cardiac disease, clinical evaluation of the athlete with suspected cardiovascular disease, arrhythmias in athletes, commotio cordis, guidelines for athletic restriction, and performance-enhancing substances.

THE ATHLETE’S HEART

The athlete’s heart refers to the clinical syndrome of cardiac chamber enlargement, hypertrophy, and normal or augmented ventricular systolic function commonly accompanied by sinus arrhythmia, sinus bradycardia, and a systolic flow murmur.^4,5 The notion that the cardiovascular system differentiates physiologically, structurally, and functionally in response to athletic training was initially advanced more than a century ago.⁵ Using cardiac auscultation and percussion, Henschen described enlargement of the heart caused by athletic activity in cross-country skiers.⁵ He reported that right and left heart physiologic dilation and hypertrophy resulted from cross-country skiing and that these athletic hearts could perform more work than the heart of a nonathlete.⁵

Debate ensued about whether these adaptations to exercise are physiologic and benign or pathologic and the potential harbinger of disease and disability. The heart of the trained athlete was considered by some to be enlarged and weakened ...