**2. The epidemiology of SCD in sports**

It is not easy to determine the accurate epidemiology of SCD in sports. Much depends on the selected inclusion criteria for the analysis, the age of the athletes, the level of athletic achievement, sporting experience, type of sports, and other factors. Therefore, studies carried out in different countries show an unequal SCD incidence rate in athletes. Between 1980 and 2011, the Sudden Death in Young Athletes Registry in the USA, which was developed based on mass media information, recorded 2406 cases of sudden death, which were observed in 29 divers sports [6]. In this paper 80% SD occurred in high school/middle school or collegiate student athletes, and 20% were engaged in organized youth, postgraduate.

SCD incidence rate determined in the USA was 7.47 and 1.33 per 1,000,000 exercising male and female school-age athletes, respectively [10]. The statistical data can however vary greatly in some areas. According to Corrado et al. [3], the SCD incidence rate in Italy was 2.6 cases in men and 1.1 in women per 100,000 individuals per year who are involved in active competitive sports. In recent years, with screening of athletes before active exercise, this figure decreased to 0.87 cases per 100,000 per year. In the USA, in children and adolescent athletes, SCD is registered in 0.66 cases per 100,000 exercising male school students and 1.45 per 100,000 male college students and 0.12 per 100,000 female school students and 0.28 per 100,000 female college students (Van Camp et al., [10]). In Ireland [11] the SCD incidence rate in sports was 1 case per 600,000, while in a French study [12], it was 0.26 per 100,000 per year. In a study conducted on Rhoda Island [13], the rate was 0.36 per 100,000 per year in individuals aged up to 30 years and 4.46 and 0.05 per 100,000 per year in men and women older than 30, respectively. The European Heart Rhythm Association (EHRA) position paper concluded that as an overall estimate, 1–2 out of 100,000 athletes between the ages of 12 and 35 years old die suddenly each year [8].

#### **3. SCD and types of sports**

The data on sports-associated SCD cases as well as those on epidemiology are quite varied, depending on national sporting traditions, age, gender, and group inclusion criteria (professional sports, school sports, general fitness activity). Most SCD causes in the USA [6], most SCD cases in young athletes in active competitive sports occurred in basketball and football, which accounted for 35 and 30%, respectively; soccer, cross-country/track, and baseball accounted for 8, 7, and 6% of the cases respectively; such sports as wrestling, boxing, swimming, ice hockey, and marathon running accounted for between 1 and 5%; and rugby, triathlon, martial arts, tennis, volleyball, gymnastics, figure skating, golf, and others accounted for less than 1%.

By another study from the USA (Harmon et al. [5]), the highest incidence rates of SCD per athletes were 1 in 8978 in men's basketball, 1 in 23,689 in men's soccer, and 1 in 35,951 in men's football. In women its rates were 1 in 57,611 in swimming and 1 in 77,061 in basketball.

SCDs not associated with commotio cordis (see below) were reported most frequently in children and adolescents involved in ice hockey, football, and basketball [14]. In Spain SCD was observed most often in cyclists (34.4%), soccer players (21.3% in the general group and 33.3% in athletes younger than 35 years), and gymnasts (8%). Fewer deaths occurred in basketball, rowing, marathon running, jogging, and mountain climbing [15]. In Italy [3] the highest number of SCD cases was registered in soccer (40%); 9% of the cases in swimming and rugby; 7% in

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*Sudden Cardiac Death in Young Athletes DOI: http://dx.doi.org/10.5772/intechopen.90627*

**4. Сommotio cordis**

cycle racing, running, and volleyball; and 3% of cases in judo, tennis, and gymnastics. It is clear that this rating of dangerous sports is based on a specific regional and temporal sample of published sports-related SCD cases and does not fully reflect all types of sports for which SCD were recorded. SCD cases associated with many other sports periodically come to public attention through the media. The studies by Quigley and Ragosta cited above most frequently recorded SCD when playing golf (31.3 and 23.4%, respectively), cricket (21.5%), and jogging and less often during basketball (10.2%), swimming (8%), and cycling races (6%). In a major study conducted in France [16], SCD was most frequently observed during cycling (30.6%), jogging (21.3%), and soccer (13.05%); in individuals of all ages playing sports and

exercising regularly, SCD in other sports did not exceed 5% in this list.

cause of 2 [5] to 20% [6, 7, 14] of SCD cases in young athletes.

or who have retired from professional and competitive sports [6].

**6. Circumstances of SCD and prodromal symptoms**

**5. Gender and age of the victims**

The SCD cases associated with a blunt blow to the heart area and classified as death caused by heart contusion (contusion cordis) or concussion (commotio cordis) constitute a special group [14, 17–19]. Occurring in the vulnerable phase of the cardiac cycle (the beginning of T wave on ECG), this blow initiates fatal arrhythmias, ventricular fibrillation, or at once asystole. Under normal heart rate (60–80 bpm), this vulnerable period takes up approximately 2–3% of the time or up to 20% if the heart rate increases to 120 bpm or more. Therefore, athletes are more vulnerable to this grave complication during exercise. Young American athletes most frequently experience SCD in lacrosse, then hockey and basketball [14]. There have been reports of SCD occurring from a punch to the heart in martial arts, due to being struck with a hockey puck, or other circumstances. Сommotio сordis is the

According to the US Registry, the age of inclusion in the analysis of SCD and cardiac arrest in athletes was limited to 39 years; 2153 deaths from all causes (89%) occurred in males and 253 deaths (11%) were in females (4). In mortality rate among the 842 athletes with autopsy-confirmed cardiovascular diagnoses, the incidence in males exceeded that in females by 6.5-fold, P < .001 ([6], 1172). An analysis of 61 cases of SCD that occurred during exercise in Spain in 1995–2001 revealed that the age of the athletes and those involved in sports reached 65 years (mean age 31.9 ± 14.2 years). In 59 cases vs. 2, the victims were male [15]. Among 60 squash players who died suddenly at the age of 22–66 years (46 ± 10.3), 59 individuals (98.3%) were also male [20]. However, women may dominate in some sports characterized by a relatively small number of SCDs or cardiac arrests, e.g., 90% in volleyball and 73% in softball [6]. The number of arrhythmias and SCD risk increases with age. However, this applies primarily to those who are not engaged in

When analyzing the circumstances of SCD in young athletes, it was observed that in 83% of cases, SCD occurred during or immediately after exercise, and only 17% was not associated with any physical activity [6]. In some cases, it was possible to obtain the medical histories of the victims or data on the presence of some

#### *Sudden Cardiac Death in Young Athletes DOI: http://dx.doi.org/10.5772/intechopen.90627*

cycle racing, running, and volleyball; and 3% of cases in judo, tennis, and gymnastics. It is clear that this rating of dangerous sports is based on a specific regional and temporal sample of published sports-related SCD cases and does not fully reflect all types of sports for which SCD were recorded. SCD cases associated with many other sports periodically come to public attention through the media. The studies by Quigley and Ragosta cited above most frequently recorded SCD when playing golf (31.3 and 23.4%, respectively), cricket (21.5%), and jogging and less often during basketball (10.2%), swimming (8%), and cycling races (6%). In a major study conducted in France [16], SCD was most frequently observed during cycling (30.6%), jogging (21.3%), and soccer (13.05%); in individuals of all ages playing sports and exercising regularly, SCD in other sports did not exceed 5% in this list.
