sudden cardiac death ( scd ) is described as an event that is non - traumatic , non - violent , unexpected and resulting from sudden cardiac arrest within six hours of previously witnessed normal health .
it is a rare but tragic condition usually precipitated by physical activity which occurs not only in athletes , but in all people .  
the growth of long distance running races has been accompanied by studies documenting that prolonged exercise can trigger unheralded ventricular arrhythmias and cardiac arrest in individuals without overt heart disease .  
an accurate determination of the incidence of the phenomenon is very difficult to achieve , because of the extreme differences in age , sex , race , athletes and non - athletes .
literature data report that in apparently healthy long - distance runners the incidence of sudden cardiac arrest ranges from 1:15000 to 1:150000 per years , while the estimated incidence of sudden deaths in marathon runners is 0.63:100000 .
scd is more frequent in male and black athletes , and increases significantly with age .  
the most common cardiovascular conditions predisposing to ventricular tachyarrhythmias , leading to sudden cardiac arrest in athletes , include manifest or latent primary electrical disease and latent structural causes ( table 1 ) .
the most common cause of death by sudden cardiac arrest in italy is arrhytmogenic right ventricular cardiomiopathy , while in uk and in usa   is hypertrophic cardiomiopathy .  
the diagnosis is very difficult to make as many athletes remain asymptomatic until a cardiac dysfunction takes place .  
moreover , even when each of the known causes of cardiac arrest without overt heart disease has been excluded , the diagnosis remains unexplained in almost half of these patients .
at the finishing line of a marathon ( 42 km and 195 m ) , a 37 y runner with no history of disease collapsed due to a cardiac arrest after 236 minutes of running .
the cardiac arrest was witnessed by an advanced cardiac life support ( acls ) team that immediately started advanced cardiopulmonary resuscitation ( first return of spontaneous circulation achieved in 18 ) .
central venous blood gas analysis with manual ventilation was : ph 7,01 , pao2 23 mmhg , paco2 52 mmhg , na 145 meq , k 5.1 meq , ca 1.23 mmol / l , glucose 62 mg / dl , lactate 10.5 mmol / l , hco 13.1 meq / l , be -17.9 , svo2 17% . during the treatment of the refractory cardiac arrest the patient developed an impressive pulmonary edema ,
the patient was admitted to the nearest emergency department and then , taken into consideration the indication to veno - arterial extracorporeal membrane oxygenation ( ecmo ) , he was immediately transferred to a tertiary centre ( irccs san raffaele of milan ) to start the extracorporeal life support ( ecls ) .   thanks to this procedure , it was possible to perform controlled cooling of the patient till 32c in consideration of the multi - organ damage to the heat stroke .
further testing strategy included a coronary angiography that excluded coronary spasm , occlusion and anatomic anomalies , intra - aortic balloon pump positioning , transtoracic ecocardiography revealing normal kinesis .
after five days on veno arterial ecmo , brain death diagnosis was established and multi - organ donation was allowed ( kidneys , bones , liver , femoral artery , cardiac valves , corneas ) .
autopsy revealed a diffuse cerebral edema , acute pulmonary stasis , a focal undermucosal colic hemorrhage and no definite cause of scd .
nowadays it is evident that scd is a rare but dreadful event within both athletes and non - athletes .  
the outcome of patients victims of sudden cardiac arrest can be largely different depending on different variables including etiology , rapidity of cardiopulmonary resuscitation and defibrillation and age
. the outcome can be : survival with recovery ( 14.6% )   as well as organ donation , heart transplantation or ventricular assist device implantation .
today , these results can be attained with ecls treatment , by now codified in referral tertiary care hospitals .
clinicians can use different strategies to prevent scd : pre - participation screening as accurate anamnesis , medical examination , electrocardiography and echocardiogram can be life - saving and cost effective , even if contrasting results have been demonstrated ; making progress in research to allow early diagnosis of potentially lethal clinically silent cardiovascular abnormalities causing scd and detect its risk factors;guarantee an on - the - field cardiopulmonary resuscitation and early defibrillation by trained personnel ; predispose an ecmo assistance on - site in those long - distance races in which the risk of scd is increased , to provide an immediate and aggressive treatment of cardiac arrest and controlled cooling to ameliorate outcomes .
pre - participation screening as accurate anamnesis , medical examination , electrocardiography and echocardiogram can be life - saving and cost effective , even if contrasting results have been demonstrated ; making progress in research to allow early diagnosis of potentially lethal clinically silent cardiovascular abnormalities causing scd and detect its risk factors ; guarantee an on - the - field cardiopulmonary resuscitation and early defibrillation by trained personnel ; predispose an ecmo assistance on - site in those long - distance races in which the risk of scd is increased , to provide an immediate and aggressive treatment of cardiac arrest and controlled cooling to ameliorate outcomes .
deaths between athletes can be minimized if these conditions will be guaranteed : race organizers plan for comprehensive and advanced emergency cardiac care;the public and the participants are aware of the problem and trained in basic life support;an accurate screening of athletes is performed to detect who meets the criteria for disqualification ; ecls should be considered without delay in refractory cardiac arrest;ecls fast - track should be planned not only for large events involving thousands athletes , but also for ordinary management of refractory cardiac arrest in patient who meet criteria for enrollment to extracorporeal treatment ( actually , waiting for a consensus conference guidelines , represented by patients characterized by
 brain too good to die  , receiving high quality   cardiopulmonary resuscitation ( cpr ) and with a short  road - to - pump  time .
race organizers plan for comprehensive and advanced emergency cardiac care ; the public and the participants are aware of the problem and trained in basic life support ; an accurate screening of athletes is performed to detect who meets the criteria for disqualification ; ecls should be considered without delay in refractory cardiac arrest ; ecls fast - track should be planned not only for large events involving thousands athletes , but also for ordinary management of refractory cardiac arrest in patient who meet criteria for enrollment to extracorporeal treatment ( actually , waiting for a consensus conference guidelines , represented by patients characterized by 
brain too good to die  , receiving high quality   cardiopulmonary resuscitation ( cpr ) and with a short  road - to - pump  time .
 sudden cardiac death is a rare condition resulting from undetected cardiac abnormalities in athletes and non - athletes . 
 participant screening , immediate and advanced medical management can probably reduce mortality and ameliorate outcomes . in recent years 
 , extracorporeal membrane oxygenation has emerged as a valuable therapeutic option in patients experiencing refractory cardiac arrest as a bridge to different types of outcome , including recovery , heart transplantation or ventricular assist device and organ donations . in this report 
 we describe a case of a sudden cardiac arrest in a marathon runner treated with extracorporeal membrane oxygenation . 
Introduction
Case Report
Discussion
Conclusions