Risk of sudden cardiac death in young athletes: which screening strategies are appropriate?

Elevated LV Mass and LV Mass Index Sign on the Athlete's ECG: Athletes' Hearts are Prone to Ventricular Arrhythmia

OBJECTIVES

Intense exercise elevates all heart chambers' dimensions, left ventricular mass (LV mass), and left ventricular mass index (LV mass index). The relationship between increased ventricular arrhythmias and sudden cardiac death with LV dilatation and elevated LV mass has been previously demonstrated. We investigated whether sports-related LV dilatation and elevated LV mass and LV mass index cause an increase in ventricular repolarization heterogeneity.

PATIENTS AND METHODS

This prospective observational study recruited 565 participants. There were 226 (female: 28) athletes and 339 (female: 45) healthy controls between 17 and 42 years of age. They were evaluated using 12-lead-electrocardiography and transthoracic echocardiography. Electrocardiograms were obtained at a rate of 50 mm/s and an amplitude of 10 mV, including at least 3 QRS complexes for each derivation. They were taken with 12 standard deviations. Transmural dispersion of repolarization indexes (TDR) (Tp-Te interval, Tp-Te/QT ratio and Tp-Te/QTc ratio, Tp-Te(d)) were measured from precordial derivations. Measurements weretakenwith a program which was generated with MATLAB codes.

RESULTS

Tp-Te interval, Tp-Te/QT ratio, Tp-Te/QTc ratio, Tp-Te(d), PW (posterior wall thickness), IVS (interventricular septal thickness), LVEDD (left ventricular end-diastolic diameter), LV mass (left ventricular mass), and LV mass index (left ventricular mass index) for the athlete group were significantly higher than for the control group. Correlation analyses revealed that TDR indexes significantly correlated with PW, IVS, LVEDD, LV mass, and LV mass index.

CONCLUSION

LV mass and LV mass index increase in well-trained athletes, and this increase leads to an increase in TDR indexes. The increased frequency of ventricular arrhythmia and sudden cardiac death may be explained with increasing ventricular repolarization heterogeneity in these individuals.

Genetics of sudden cardiac death in children and young athletes

Sudden cardiac death is a rare but socially devastating event. The most common causes of sudden cardiac death are congenital electrical disorders and structural heart diseases. The majority of these diseases have an incomplete penetrance and variable expression; therefore, patients may be unaware of their illness. In several cases, physical activity can be the trigger for sudden cardiac death as first symptom. Our purpose is to review the causes of sudden cardiac death in sportive children and young adults and its genetic background. Symptomatic individuals often receive an implantable cardioverter-defibrillator, the preventive treatment for sudden cardiac death in most of cases due to channelopathies, which can become a challenging option in young and active patients. The identification of one of these diseases in asymptomatic patients has similarly a great impact on their everyday life, especially on their ability to undertake competitive physical activities, and the requirement of prophylactic treatment. We review main causes of sudden cardiac death in relation to its genetics and diagnostic work-up

Sudden unexplained cardiac arrest in apparently healthy children: a single-center experience

This study aimed to determine the causes of sudden cardiac arrest (SCA) in apparently healthy children at a single center in the era of primary prevention (screening questionnaire [SQ]) and secondary prevention (automated external defibrillator [AED] and the automated implantable cardioverter defibrillator [AICD]). Any child 0 to 18 years of age without prior known disease, except for attention deficit disorder, who underwent out-of-the hospital cardiopulmonary resuscitation was included in the study as a SCA subject. A retrospective chart review was used to evaluate the efficacy of the SQ, electrocardiogram (ECG), chest roentgenogram (CXR), and echocardiogram. The findings showed that for 44 of 6,656 children admitted to intensive care with SCA, an AED was used for 39%, an AICD was placed in 18%,and survival to hospital discharge was 50%. The etiology for SCA was identified in 57% of the cases, mostly in those older than 1 year, and the majority of these had a cardiac etiology (50%), whereas 7% had rupture of an arteriovenous malformation. Stimulant medication use was seen in 11% of the SCA subjects. In the best-case scenario of hypothesized primary prevention, a prior SQ, CXR, ECG, or echocardiogram may have detected respectively 18, 9, 23 and 16% of the at-risk cases, and 32% of the cases may have been detected with ECG and SQ together. Based on a historical control cohort, a positive ECG was significantly higher in the children with SCA (p = 0.014). An ECG together with a screening SQ may be more effective in identifying children potentially at risk for SCA than an SQ alone.

Sudden cardiac death in young athletes: preparticipation screening for underlying cardiovascular abnormalities and approaches to prevention

The study of sudden cardiac death (SCD) in athletes has received more interest in the medical and lay press over the past few years. Professional athletes represent ideals of fitness and health, and the sudden death of prominent athletes can come as a shock. Underlying occult cardiovascular disorders are the most common cause of SCD in athletes. Unfortunately, because these disorders rarely present clinically, their initial manifestation is often a fatal event. Due to this, much attention has turned to both primary and secondary prevention. Primary prevention includes preparticipation screening and secondary prevention includes having automatic external defibrillators available at sporting events. This article summarizes the most common causes of athletic-related cardiac arrest and evaluates the screening methods used to screen for these conditions. The general sentiment is that we need to more effectively identify athletes who are at risk for SCD, but how to do so using an efficient screening system and in a cost-effective manner have not been determined.

When the third degree is necessary: do pediatricians obtain enough information to detect patients at risk for HCM?

This study was designed to see if pediatricians are collecting sufficient data in family histories to be able to ascertain whether children are at risk for hypertrophic cardiomyopathy (HCM). Surveys were returned by 326 general pediatricians who were members of the Second Chapter of the American Academy of Pediatrics. The majority of pediatricians (98.2%) reported taking family histories; however, only 51.2% reported that this information was updated on a regular basis. Only 29.8% of the pediatricians reported including all five risk factors for HCM in a medical family history. Although almost all of the pediatricians reported including first-degree relatives in medical family histories, only 40.5% reported including all second-degree relatives. Female physicians were found to take more thorough medical family histories than male physicians, and foreign medical school graduates were found to take more thorough medical family histories than US medical school graduates. Additionally, graduates of foreign medical schools reported updating medical family histories more often than graduates of US medical schools. This study suggests that pediatricians might not be identifying risks pertinent to the identification of HCM.

Cardiovascular pre-participation screening of young competitive athletes for prevention of sudden death in China

The cardiovascular pre-participation screening proposal for young competitive athletes has the potential to save young lives. This study aimed to identify individuals at risk for potentially lethal cardiovascular diseases in athletes before competition. Between June 2005 and July 2005, 351 (170 male and 181 female) elite Chinese athletes from 21 sports were profiled. The 12-lead electrocardiogram and echocardiography were employed to evaluate cardiovascular diseases. The vast majority had no definitive evidence of cardiovascular disease. However, abnormal ECGs were identified in 16 athletes (4.5%), including 4 with distinctly abnormal and 12 with mildly abnormal patterns. Only 13 athletes (3.7%) had echocardiographic evidence of relatively mild valve regurgitation that had not been previously suspected. In three athletes with relatively mild ventricular septal hypertrophy (13-14 mm), it was not possible to discern with absolute certainty whether the wall thickening was a manifestation of hypertrophic cardiomyopathy or secondary to athletic conditioning ("athlete heart"). This screening protocol identified no athletes with definite evidence of hypertrophic cardiomyopathy, Marfan's syndrome or other cardiovascular diseases that convey a significant potential risk for sudden death or disease progression during athletic activity. This is largely due to the relative low prevalence of conditions resulting in sudden cardiac death in young athletes and high false positive/negative rates in the tests used as part of the screening process (due to a large overlap between cardiovascular changes due to pathology and those due to intense training).

Coronary anomalies: Cardiac CT evaluation of the symptomatic adult athlete

Cardiac CT has become widely available as a diagnostic test. It is noninvasive, low risk (for contrast allergies), quick, and highly sensitive for identifying the coronary origins and course. Two coronary anomalies, the left main artery from the right sinus of Valsalva, and the right coronary artery originating from the left sinus, have been associated both with myocardial ischemia and sudden cardiac death when they course between the aorta and pulmonary arteries. These anomalies can go undetected into adulthood. The yield of noninvasive exercise testing is low. In the past, the ability to demonstrate these anomalies depended on a high index of suspicion and an aggressive invasive work-up with cardiac catheterization. Now cardiac CT can demonstrate these anomalies with ease and facilitate appropriate treatment.

Medical management of the athlete: evaluation and treatment of important issues in sports medicine

Providing care to athletes involves much more than simply treating musculoskeletal injuries. Many of the illnesses and disease processes that affect the general population are also seen in competitive athletes. Medical management of these conditions, however, can be challenging. Treatment plans need to be tailored to the individual athlete and take into consideration the rigors and demands of his or her particular sport. Important conditions that all physicians who provide care for athletes should be familiar with are sudden cardiac death, hypertension, concussion, methicillin-resistant Staphylococcus aureus infections, the female athlete triad, diabetes mellitus, and asthma.

Sudden cardiac death in athletes: the Lausanne Recommendations

OBJECTIVES

This study reports on sudden cardiac death (SCD) in sport in the literature and aims at achieving a generally acceptable preparticipation screening protocol (PPSP) endorsed by the consensus meeting of the International Olympic Committee (IOC).

BACKGROUND

The sudden death of athletes under 35 years engaged in competitive sports is a well-known occurrence; the incidence is higher in athletes (approximately 2/100,000 per year) than in non-athletes (2.5 : 1), and the cause is cardiovascular in over 90%.

METHODS

A systematic review of the literature identified causes of SCD, sex, age, underlying cardiac disease and the type of sport and PPSP in use. Methods necessary to detect pre-existing cardiac abnormalities are discussed to formulate a PPSP for the Medical Commission of the IOC.

RESULTS

SCD occurred in 1101 (1966-2004) reported cases in athletes under 35 years, 50% had congenital anatomical heart disease and cardiomyopathies and 10% had early-onset atherosclerotic heart disease. Forty percent occurred in athletes under 18 years, 33% under 16 years; the female/male ratio was 1/9. SCD was reported in almost all sports; most frequently involved were soccer (30%), basketball (25%) and running (15%). The PPSP were of varying quality and content. The IOC consensus meeting accepted the proposed Lausanne Recommendations based on this research and expert opinions (http://multimedia.olympic.org/pdf/en_report_886.pdf).

CONCLUSION

SCD occurs more frequently in young athletes, even those under the age of 18 years, than expected and is predominantly caused by pre-existing congenital cardiac abnormalities. Premature atherosclerotic disease forms another important cause in these young adults. A generally acceptable PPSP has been achieved by the IOC's acceptance of the Lausanne Recommendations.

Cardiac issues in the young athlete

Young athletes are disproportionately plagued with congenital cardiac disease. Many of these diseases predispose to sudden cardiac death (SCD), a dramatic and tragic outcome for any young athlete. In many cases, conditions that predispose to SCD do not cause symptoms or show signs on examination, making diagnosis of cardiac disease and prevention of SCD difficult. Clinicians should be familiar with common causes of SCD and their symptoms, perform careful evaluations, refer athletes in whom there are concerns, and make sure any concerning findings receive thorough evaluation. Clinicians should also be familiar with and follow recent guidelines on return to play. Unfortunately, most preparticipation examinations are inadequate, due in part to use of inadequate forms. Better forms are available and should replace inadequate ones.

Use of multislice computed tomographic coronary angiography for the diagnosis of anomalous coronary arteries

The accurate diagnosis of anomalous coronary arteries by invasive angiography is limited by the inability to define the anatomic course in relation to surrounding structures. Computed tomographic coronary angiography has recently emerged as a noninvasive method to visualize the coronary arteries. Multislice computed tomography with up to 64 detector arrays, along with 3-dimensional rendering, has further improved the temporal and spatial resolution of noninvasive coronary imaging. In this series of cases, the investigators describe their institution's experience with computed tomographic coronary angiography as a complement to invasive coronary angiography in determining the origin and course of different anomalous coronary arteries in 16 patients. With the aid of 3-dimensional volume rendering, 6 anomalous right coronary arteries, 4 anomalous left circumflex coronary arteries, 4 single coronary arteries, and 2 anomalous left main coronary arteries were all clearly defined with regard to their origin and course. It is proposed that computed tomographic coronary angiography is the diagnostic test of choice in the evaluation of such anomalies.

Evaluating cardiac symptoms in the athlete: is it safe to play?

OBJECTIVE

Concern regarding the risk of sudden unexpected cardiac death has fueled interest in athletes who experience chest pain, syncope, or palpitations during training and competition. This review examines the etiology and evaluation of these symptoms in young athletes.

DATA SOURCES/SYNTHESIS

Previously published reports that have provided a base of expert opinion were examined to define the optimal means of assessment before returning athletes to play.

RESULTS

A well-defined differential diagnosis must be considered to rule out heart disease and define noncardiac causes of these symptoms.

CONCLUSIONS

Athletes who experience symptoms such as chest pain, syncope, and palpitations during competition and training can be safely returned to play only after the evaluation is completed.

Evaluating cardiovascular presentations: what does an electrocardiogram have to offer?

The general pediatrician remains the key to the timely recognition and treatment of cardiovascular disorders, particularly those that present acutely and may require immediate attention. In the evaluation of these cardiovascular urgencies, ancillary studies such as the electrocardiogram continue to be important, readily available tools that can aide in the diagnostic process. It is thus incumbent on the general practitioner to foster the skill necessary to employ such tools reliably, particularly in the setting of urgent evaluations. At the same time, recognition of the limitations of such testing will help both in the acute setting and in the understanding of their application in population settings.