While some may call it a `Christmas Coronary’ or a Hanukkah Heart Attack’ , the winter holiday season usually heralds a spike in myocardial infarctions, which may be brought on by a variety of factors. Seventeen years ago, a study looked at the rate of heart attacks in the United States, and found that Acute Myocardial Infarctions (AMIs) run as much 53% higher during the winter months than than during the summer.
Spencer FA, Goldberg RJ, Becker RC, Gore JM.
Although cold weather combined with strenuous physical activity (like clearing snow from sidewalks) has often been blamed for this increase, even in balmy Southern California, studies have shown a 33% increase in heart attacks over the holidays (see below).
A 12-Year Population-Based Analysis of More Than 220 000 Cases
Robert A. Kloner, MD, PhD; W. Kenneth Poole, PhD; Rebecca L. Perritt, MS
Non-climate related factors – like over indulgence in food and alcohol, diminished activity levels, forgetting to take prescription medicines, and combined holiday stressors like shopping, running up debt, traveling, meal preparation, and the angst that comes from dysfunctional family gatherings are likely contributors to this yearly spike.
But increasingly influenza and other respiratory infections have been linked to this seasonal increase in heart attacks as well.
Which helps to explain why we’ve seen a spate of studies – like last Augusts' UNSW: Flu Vaccine Provides Significant Protection Against Heart Attacks – linking flu vaccination to a lower risk of sudden cardiac death.
- In 2010 we saw a study in the CMAJ: Flu Vaccinations Reduce Heart Attack Risk that found that those over the age of 40 who get a seasonal flu vaccine each year may reduce their risk of a heart attack by as much as 19%. Questions were raised over the way this study was conducted (see Vaccine/Heart Attack Study Questioned), and so the results are in dispute.
- In August of 2013 (see Study: Flu Vaccine May Reduce Heart Attack Risk), we looked at study out of Australia – published in the BMJ Journal Heart, that found compelling – but not exactly conclusive – evidence that flu shots may reduce the risk of heart attacks as much as 45%.
- In October of 2013 (see JAMA: Flu Vaccine and Cardiovascular Outcomes) we looked at a meta analysis that found among patients who had previously had a heart attack, the receipt of a flu vaccine was linked to a 55% reduction in having another major cardiac event in the next few months.
Although the reputation of the flu vaccine took a major hit last winter after the late arrival of a `mismatched’ H3N2 virus (see CDC: Updated Estimated Seasonal Flu Vaccine Effectiveness), this year appears to be a better match and should provide something on the order of 40%-60% Vaccine Effectiveness (VE).
While it takes a couple of weeks for the vaccine to reach maximum effectiveness, it is not too late to get this year’s flu vaccine, as flu season is just getting started.
Regardless of the effectiveness of this year’s flu vaccine, or the severity of this year’s flu season, even on an `average day’ roughly 1,000 people suffer a Sudden Cardiac Arrest (SCA) in the United States alone. While the rate is higher in the winter than in the summer, having basic CPR skills can be a lifesaver year round.
This from the Heart Rhythm Association:
- Sudden Cardiac Arrest (SCA) is a leading cause of death in the United States, claiming more than 350,000 lives each year.
- Approximately 92% of those who experience sudden cardiac arrest do not survive.
- SCA kills more than 1,000 people a day, or one person every 90 seconds
What the people who witness these events do in the first few minutes can mean the difference between life and death for the stricken individual. Luckily, hands-only CPR (cardio-pulmonary resuscitation) is easier to do than ever before, and there are thousands of AEDs (automated external defibrillators) stationed in public venues across the nation.
With a little bit of training, you have the potential to save someone’s life.
While it won’t take the place of an actual class, you can watch how it is done on in this brief instructional video from the American Heart Association. To learn how to use an AED, you can use this online training module I wrote about in CPR Skills & AED Simulator. A CPR class only takes a few hours, can be fun, and is well worth the effort.
Of course, despite your best efforts, many SCA victims will not survive. It isn’t at all like on TV, where 75% of recipients of CPR survive. Even when cardiac arrests occur inside a hospital, the survival to discharge rate is less than 40%. Outside the hospital, the odds of seeing a good outcome are lower.
While there are no guarantee of success, early and coordinated action taken by bystanders (calling 911, starting CPR, using AED if available) can substantially improve the SCA’s chances of survival.
For more on heart attacks, and CPR, you may wish to visit some of these earlier blogs.