Sudden cardiac death (SCD) is an unexpected death due to cardiac causes occurring in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease in whom no previously diagnosed fatal condition is apparent. Most cases of SCD are related to cardiac arrhythmias i.e. irregular heart beat. A prior history of left ventricular impairment (ejection fraction <30-35%) is the single-greatest risk factor for sudden death. Risk factors include a family history of premature coronary artery disease (CAD), smoking, dyslipidemia (raised lipid levels in blood), hypertension, diabetes, obesity, and a sedentary lifestyle.
Prognosis of morbidity and mortality for people who have had SCD can be made using the cardiac arrest score developed by McCullough and Thompson. The preventive measures are those for CAD. Risk factors for CAD are classified as modifiable or unmodifiable. Modifiable risk factors include smoking, exposure to second-hand smoke, hypertension, hyperlipidemia; high cholesterol (total, LDL-cholesterol [LDL-C]), low high-density lipoprotein (HDL), and high triglyceride levels; diabetes; abdominal obesity; sedentary lifestyle; high homocysteine levels; and high C-reactive protein levels. Unmodifiable risk factors include age, male sex, and family history.
Ask him to get a regular cardiac check-up done and follow a healthy life-style. And please do not be so apprehensive.