THE FIRST study to document the prevalence of sudden cardiac death (SCD) in the Republic has found that 70 per cent of SCDs in rural Ireland occur in the home. Some three-quarters of sudden deaths were due to coronary artery disease, with just 6 per cent of patients surviving long enough to be admitted to hospital.
Dr Robert Byrne, Dr James Crowley and colleagues from the departments of cardiology and pathology at the National University of Ireland, Galway (NUIG) looked at all cases of out-of-hospital SCD in the west of Ireland during 2005.
Using data from both emergency department resuscitation records and autopsy reports, they found 212 cases of SCD in counties Mayo, Galway and Roscommon. The catchment area of 414,277 people is 70 per cent rural.
The results, published in the European Heart Journal, show that three-quarters of victims were men. Although SCD occurred in all age groups, it was most prevalent in those aged 60-69. There were 10 deaths in the age group 0-39 years, while 24 people aged 40-49 died from SCD.
While 72 per cent of cardiac arrests occurred in the home, some 23 per cent of SCDs were in public places, including a single case in police custody. The remainder occurred in general practice surgeries, ambulances and residential care homes.
Significantly, all 13 patients who survived until hospital admission had a heart rhythm disturbance called ventricular fibrillation. This rhythm is amenable to correction using an external defibrillator to deliver an electric shock to the heart.
Community organisations and heart charities such as Croí have been to the forefront in making portable defibrillators available in local communities.
Coronary artery disease (a blockage in the blood vessels supplying the heart) accounted for 76 per cent of SCD cases. There were 10 cases of cardiomyopathy, a disease of the heart muscle associated with SCD in younger people. And some seven cases of SCD were classified as sudden death in patients with previously diagnosed epilepsy but in whom no evidence of prolonged seizures could be found.
"Cases of SCD in the youngest age group [0-39 years] were predominantly from conditions other than atherosclerotic coronary artery disease" the authors said. They also noted that survival from cardiac arrest in the community was strongly associated with a witness to the event being present as well as finding the heart rhythm disturbance, ventricular fibrillation.
Commenting on the findings,Dr James Crowley, consultant cardiologist at NUIG, said there was a need to establish a national registry for SCD in the Republic: "As our study shows, most SCD cases are due to an acute heart attack, so we need to focus on the primary prevention of cardiovascular disease."