The injury to tissue following ischemia can lead to structural and functional changes preventing the heart from continuing normal conduction cycles and altering heart rate. : 829 : 829

Non-atherosclerotic coronary artery abnormalities
Abnormalities of the coronary arteries not related to atherosclerosis include congenital coronary artery anomalies (most commonly anomalous origin of left coronary artery from the pulmonary artery), inflammation known as coronary arteritis, embolism, vasospasm, and mechanical abnormalities related to connective tissue diseases or trauma. These conditions account for 10-15% of cardiac arrest and sudden cardiac death. : 829 
Coronary arteritis commonly results from a pediatric febrile inflammatory condition known as Kawasaki disease. Other vasculitides can also contribute to increased risk of sudden cardiac death. Embolism, or clotting, of the coronary arteries most commonly occurs from septic emboli secondary to endocarditis with involvement of the aortic valve, tricuspid valve, or prosthetic valves. Coronary vasospasm may result in cardiac arrhythmias, altering the electrical conduction of the heart with a risk of complete cardiac arrest from severe or prolonged rhythm changes. Mechanical abnormalities with associated risk of cardiac arrest may arise from coronary artery dissection which can be attributed to Marfan Syndrome or trauma. : 829

Structural heart disease
Structural heart diseases not related to coronary artery disease account for 10% of all sudden cardiac deaths. Examples of these include:  cardiomyopathies (hypertrophic, dilated, or arrythmogenic), cardiac rhythm disturbances, myocarditis, hypertensive heart disease, and congestive heart failure. Left ventricular hypertrophy is thought to be a leading cause of sudden cardiac deaths in the adult population.
Among children rates of survival are 3 to 16% in North America. For in hospital cardiac arrest survival to discharge is around 22%. Those who survive to Return-of-Spontaneous-Circulation (ROSC) and hospital admission frequently present with Post-Cardiac Arrest Syndrome which usually presents with neurological injury that can range from mild memory problems to coma.Hypoxic ischemic brain injury is the most detrimental outcome for people suffering a cardiac arrest. Poor neurological outcomes following cardiac arrest are much more prevalent in countries that do not use withdrawal of life support (~50%) as compared to those that do (less than 10%). Most improvements in cognition occur during the first three months following cardiac arrest, with some individuals reporting improvement up to one-year post cardiac arrest. 50 – 70% of cardiac arrest survivors report fatigue as a symptom, making fatigue the most prevalent patient-reported symptom.Prognosis is typically assessed 72 hours or more after cardiac arrest. Rates of survival are better in those who someone saw collapse, got bystander CPR, or had either ventricular tachycardia or ventricular fibrillation when assessed. Survival among those with Vfib or Vtach is 15 to 23%. Women are more likely to survive cardiac arrest and leave hospital than men.A 1997 review found rates of survival to discharge of 14% although different studies varied from 0 to 28%. In those over the age of 70 who have a cardiac arrest while in hospital, survival to hospital discharge is less than 20%.