Summary
Sudden cardiac death is not always as sudden as it seems; a German study shows that three quarters of such patients have warning symptoms or signs.
Introduction
People sometimes say, "He dropped dead, just like that!" And it seems worse when it's a relatively young person, when a serious heart event is so unexpected. But it seems that so-called sudden cardiac death may not be quite so sudden. And this has implications for cardiac prevention. A report in the medical journal Circulation describes information collected on 400 patients in Berlin with presumed cardiac arrest that occurred out of hospital. Here's a summary of the findings.
What was done
Doctors in Berlin used the city's emergency system to collect information on all cases of out-of-hospital sudden cardiac arrest over a one-year period. Either after declaration of death or restoration of circulation, the emergency physician interviewed all available witnesses, using a questionnaire that collected the patient's medical history, medication use, and any symptoms and signs occurring before the sudden event. Follow-up continued until hospital discharge or failure to resuscitate.
What the analyses showed
Out of 5831 emergency calls, 406 patients qualified for analysis, having had "unexpected cardiac arrest of presumed cardiac origin in someone over 18, occurring within 24 hours of onset of any symptoms interpreted as being of cardiac origin". Over half (58%) were men, and their average age was 71. Women in the collective were, on average, younger than men - 68 vs. 76 years.
Over 70% of the sudden cardiac deaths occurred at home - out of reach of a public defibrillator. Bystanders attempted resuscitation in a small number (14%), and about a quarter of these cases survived. Only 4% survived without bystander resuscitation.
The majority of patients had a history of heart disease (30%) or typical symptoms of coronary heart disease (36%). The remainder had risk factors for heart disease - high blood pressure, diabetes, smoking, or chronic obstructive pulmonary disease (COPD). Information on preceding symptoms was available in 80% of the patients.
In those with preceding symptoms, angina was present for an average of 2 hours in 22%, shortness of breath for 30 minutes in 15%, nausea or vomiting for 2 hours in 7%, and dizziness or faintness for up to an hour in 6%. Only 25% of patients had no complaints before "dropping dead".
Patients at home tolerated their symptoms much longer before collapsing than those in public places (an average of 71 minutes vs. 20 minutes). And, not surprisingly, there was a lower frequency of resuscitation by a witness or use of a defibrillator in those afflicted at home.
What these findings mean
First, the vast majority of victims had a history of heart disease, typical symptoms of coronary heart disease, or existing risk factors for heart disease. Only about one in five had no warning symptoms of any sort.
Second, most people had their attacks at home. Public defibrillators may therefore not be as much help as hoped. Third, there was a poor success rate for CPR - in Berlin, anyway. More general training is needed.
Most important, however, is the fact that the majority of the patients were "at risk", and three out of four had warning symptoms, often for an hour or more. At-risk patients should be instructed to get to the Emergency Room if they experience warning symptoms - angina, shortness of breath, nausea, dizziness, or faintness - without another good reason. If this was widely recognized and acted on, we might be able to reduce the number of people who appear to "just drop dead".
