mBio: Biofilms, Stress Hormones & Heart Attacks

Diseased Carotid Arteries - Credit: David Davies, University of Binghamton

 

 

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A couple of months ago, in Post-Disaster Stress Cardiomyopathy: A Broken-Hearted Malady, we looked at a study that found a significant increase in a very rare type of heart problem called Takotsubo cardiomyopathy – also known as broken heart syndrome – following high impact natural disasters.

 

This stress related syndrome causes acute ballooning of the heart ventricles, and is a well-recognized cause of acute heart failure and dangerous cardiac arrhythmias.  

 

Johns Hopkins Medicine has a Frequently Asked Questions about Broken Heart Syndrome, that describes the condition:

1. What is “stress cardiomyopathy?”

Stress cardiomyopathy, also referred to as the “broken heart syndrome,” is a condition in which intense emotional or physical stress can cause rapid and severe heart muscle weakness (cardiomyopathy). This condition can occur following a variety of emotional stressors such as grief (e.g. death of a loved one), fear, extreme anger, and surprise. It can also occur following numerous physical stressors to the body such as stroke, seizure, difficulty breathing (such as a flare of asthma or emphysema), or significant bleeding.

 

We’ve looked at other post-disaster (likely stress related) cardiac problems, including earlier last March in Tulane University: Post-Katrina Heart Attack Rates – Revisited, where an ongoing study finds that heart attack rates remain elevated by 300% in New Orleans six years after that hurricane struck.

 

While there is plenty of anecdotal evidence showing that stress, fear, grief, or other emotional stressors can cause sudden heart attacks thus far we haven’t had a good model as to how that might happen.

 

Yesterday the open access journal mBio published a fascinating bit of work that attempts to show how a sudden release of the right stress hormone (norepinephrine) can dissolve bacteria laden biofilm deposits in the carotid artery, potentially initiating a heart attack or stroke.

 

Bacteria Present in Carotid Arterial Plaques Are Found as Biofilm Deposits Which May Contribute to Enhanced Risk of Plaque Rupture

Bernard B. Lanter, Karin Sauer, David G. Davies

IMPORTANCE The association of bacteria with atherosclerosis has been only superficially studied, with little attention focused on the potential of bacteria to form biofilms within arterial plaques.

In the current work, we show that bacteria form biofilm deposits within carotid arterial plaques, and we demonstrate that one species we have identified in plaques can be stimulated in vitro to undergo a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of transferrin. Biofilm dispersion is characterized by the release of bacterial enzymes into the surroundings of biofilm microcolonies, allowing bacteria to escape the biofilm matrix.

We believe these enzymes may have the potential to damage surrounding tissues and facilitate plaque rupture if norepinephrine is able to stimulate biofilm dispersion in vivo. This research, therefore, suggests a potential mechanistic link between hormonal state and the potential for heart attack and stroke.

(Continue . . . )

 

The American Society for Microbiology has a press release that explains in layman’s terms the mechanism this study believes it has discovered.

 

Bacteria help explain why stress, fear trigger heart attacks

WASHINGTON, DC – June 10, 2014 - Scientists believe they have an explanation for the axiom that stress, emotional shock, or overexertion may trigger heart attacks in vulnerable people. Hormones released during these events appear to cause bacterial biofilms on arterial walls to disperse, allowing plaque deposits to rupture into the bloodstream, according to research published in published today in mBio®, the online open-access journal of the American Society for Microbiology.

"Our hypothesis fitted with the observation that heart attack and stroke often occur following an event where elevated levels of catecholamine hormones are released into the blood and tissues, such as occurs during sudden emotional shock or stress, sudden exertion or over-exertion" said David Davies of Binghamton University, Binghamton, New York, an author on the study.

Davies and his colleagues isolated and cultured different species of bacteria from diseased carotid arteries that had been removed from patients with atherosclerosis. Their results showed multiple bacterial species living as biofilms in the walls of every atherosclerotic (plaque-covered) carotid artery tested.

In normal conditions, biofilms are adherent microbial communities that are resistant to antibiotic treatment and clearance by the immune system. However, upon receiving a molecular signal, biofilms undergo dispersion, releasing enzymes to digest the scaffolding that maintains the bacteria within the biofilm. These enzymes have the potential to digest the nearby tissues that prevent the arterial plaque deposit from rupturing into the bloodstream.

According to Davies, this could provide a scientific explanation for the long-held belief that heart attacks can be triggered by a stress, a sudden shock, or overexertion

(Continue . . .)

 

All of this is a very simplistic summation of a complex, and fascinating paper, one that many will want to read in its entirety. While far from settled science, it proffers a very interesting avenue for further investigation. 

Of note, while some heart attacks and Takotsubo cardiomyopathy are thought to be induced by similar cascades of stress-related hormones, their actual physical effects appears to be quite different.  Johns Hopkins describes the theories behind the cause of stress-cardiomyopathy below:

 

The precise way in which adrenaline affects the heart is unknown. It may cause narrowing of the arteries that supply the heart with blood, causing a temporary decrease in blood flow to the heart. Alternatively, the adrenaline may bind to the heart cells directly causing large amounts of calcium to enter the cells which renders them temporarily dysfunctional.

 

The bottom line, I suppose, is that by whatever mechanism, overwhelming stress can take a heavy toll on our physical and mental health.

And in ways that we are only just now beginning to unravel.

Post-Disaster Stress Cardiomyopathy: A Broken-Hearted Malady

Credit Wikipedia

 

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Although once thought to be the figment of a poet’s imagination, doctors now know it is possible to die from a `broken heart’ – from a condition known as Takotsubo cardiomyopathy – or stress induced cardiomyopathy.  Also known as broken heart syndrome, this acute ballooning of the heart ventricles is a well-recognized cause of acute heart failure and dangerous cardiac arrhythmias.

 

Johns Hopkins Medicine has a Frequently Asked Questions about Broken Heart Syndrome, that describes the condition:

 

1. What is “stress cardiomyopathy?”

Stress cardiomyopathy, also referred to as the “broken heart syndrome,” is a condition in which intense emotional or physical stress can cause rapid and severe heart muscle weakness (cardiomyopathy). This condition can occur following a variety of emotional stressors such as grief (e.g. death of a loved one), fear, extreme anger, and surprise. It can also occur following numerous physical stressors to the body such as stroke, seizure, difficulty breathing (such as a flare of asthma or emphysema), or significant bleeding.

2. What are the symptoms of stress cardiomyopathy?

Patients with stress cardiomyopathy can have similar symptoms to patients with a heart attack including chest pain, shortness of breath, congestive heart failure, and low blood pressure. Typically these symptoms begin just minutes to hours after the person has been exposed to a severe, and usually unexpected, stress.

3. Is stress cardiomyopathy dangerous?

Stress cardiomyopathy can definitely be life threatening in some cases. Because the syndrome involves severe heart muscle weakness, patients can have congestive heart failure, low blood pressure, shock, and potentially life-threatening heart rhythm abnormalities. The good news is that this condition improves very quickly, so if patients are under the care of physicians familiar with this syndrome, even the most critically ill tend to make a quick and complete recovery.

 

Since this condition is normally associated with the sudden loss of a loved one, or some other form of severe stress, it shouldn’t come as a complete surprise research finds an increased incidence of this syndrome in stress filled post-disaster scenarios. 

 

First a press release from the American College of Cardiology, after which I’ll return with a bit more.

 

 

Clusters of 'broken hearts' may be linked to massive natural disasters

Analysis of US Takotsubo cardiomyopathy cases shows pattern to cue emergency responders

WASHINGTON (March 27, 2014) — Dramatic spikes in cases of Takotsubo cardiomyopathy, also called broken heart syndrome, were found in two states after major natural disasters, suggesting the stress of disasters as a likely trigger, according to research to be presented at the American College of Cardiology's 63rd Annual Scientific Session. Authors call for greater awareness among emergency department physicians and other first responders.

Takotsubo cardiomyopathy, or broken heart syndrome, is a disorder characterized by a temporary enlargement and weakening of the heart muscle, which is often triggered by extreme physical or emotional stress – for example, being in a car accident or losing a child or spouse. Previous international studies have also linked broken heart syndrome to natural disasters, including the 2004 earthquake in Japan. This is the first U.S. study to examine the geographic distribution of the condition in relation to such catastrophes.

Researchers at the University of Arkansas identified 21,748 patients diagnosed with primary cases of broken heart syndrome in 2011 using a nationwide hospital discharge database. After mapping the cases by state, Vermont and Missouri emerged as having the highest rate of cases, with 380 cases per million residents in Vermont and 169 per million in Missouri. Most states had fewer than 150 cases per million residents. New Hampshire and Hawaii had the lowest rate of the disease that year.

The rate of broken heart cases in Vermont in 2011 was more than double most other states. This was the same year that Tropical Storm Irene pummeled the state with heavy rain and wind, causing the most devastation Vermont has experienced since the Great Flood of 1927. Similarly, researchers found broken heart syndrome at a rate of 169 cases per million in Missouri in 2011, the same year a massive tornado ripped through Joplin, Mo., demolishing neighborhoods and killing at least 158 people.

"Despite the seemingly increasing number of natural disasters we have, there is limited data about how it might affect the heart," said Sadip Pant, M.D., internist at the University of Arkansas for Medical Sciences, and lead investigator of the study. "Our findings suggest two disasters, one in Vermont and one in Missouri, might have been possible triggers for the clustering of Takotsubo cardiomyopathy cases in these regions."

(Continue . . .)

 

We’ve looked at the post-disaster (often stress related) effects on human health previously, including earlier this month in Tulane University: Post-Katrina Heart Attack Rates – Revisited, where heart attack rates remain elevated by 300% in New Orleans six years after that hurricane struck.

 

And just last month, in The Long Term Effects Of A Major Disaster, we looked at the post-tsunami deaths due to stress and displacement that exceeded – at least in one prefecture – those experienced during the initial earthquake and tsunami. And last fall - in Sandy 1 Year Later: Coping With The Aftermath - we looked at the lingering psychological effects of New England’s brush with that late season super storm of 2012.

 

While often hidden from view, the psychological impact of a disaster can be enormous and ongoing. Last year in Post Disaster Stress & Suicide Rates we looked at the impact of disaster-related PTSD (Post Traumatic Stress Disorder). This has been recognized as such a pressing problem that last  August the World Health Organization released a comprehensive Guidelines For Post-Trauma Mental Health Care book on the treatment of PTSD, acute stress, and bereavement:

 

While the psychological impact of a major disaster cannot be completely mitigated, encouraging individual, family, and business preparedness can go a long ways towards reducing the impact of any disaster.

 

Which is why FEMA, Ready.gov, along with organizations like the American Red Cross, spend so much time trying to convince individuals, families, businesses and communities of the value of preparing for a wide variety of emergencies and disasters.The bottom line is that those who follow the advice to Have A Plan, Make A Kit, and Be informed  will be not only be better able to deal with a disaster, they will be better prepared to weather the rigors of a long recovery as well.

 

And that, in turn, could help reduce the risks of a variety of post-disaster health issues.

 

For more on all of this, a few of my (many) blogs on disaster preparedness include:

 

In An Emergency, Who Has Your Back?

When 72 Hours Isn’t Enough

When Evacuation Is The Better Part Of Valor

Tulane University: Post-Katrina Heart Attack Rates - Revisited

Hurricane Katrina Approaching New Orleans August 2005

 

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In March of 2009, in a study led by Dr. Anand Irimpen (Associate Professor of clinical medicine at Tulane), it was disclosed that residents of New Orleans saw a 300% increase in heart attacks in the first 2 years after hurricane Katrina.

 

The Tulane University news NEW WAVE carried this report in 2009.

Post-Katrina Stress, Heart Problems Linked

March 30, 2009

(Excerpt)

There were 246 admissions for heart attacks, out of a total census of 11,282 patients, post-Katrina compared with 150 admissions out of a total 21,229 patients in the two years before the storm. In addition to a three-fold increase in heart attacks and a 120 percent increase in coronary interventions, the post-Katrina group had significantly higher prevalence of unemployment, lack of medical insurance, medication noncompliance, smoking, substance abuse, first-time hospitalization and people living in temporary housing. There were no significant differences in the racial, gender or age distribution of the two groups.

 

In 2011, we looked at an update to this Tulane study (see Post-Katrina Heart Attack Rates) that found – four years after the disaster – that heart attack rates remained 300% higher than pre-Katrina levels in the City, and that:

 

While psychiatric conditions such as clinical depression, a history of coronary artery disease and marital status did not appear to contribute to heart attacks in the two-year analysis, these factors seem to play a significant role as time has progressed.

Irimpen suggests there is a lag phase between the onset of psychiatric illness and its manifestation in the form of a heart attack. 

Today, Tulane University has announced a 6-year follow up to this study, and once again the impact of Katrina on cardiac health remains pronounced.  First some details on the study, after which I’ll return with more:

 

Rise in Heart Attacks After Hurricane Katrina Persisted Six Years Later

Researchers also find a lasting disruption in the timing of heart attacks after the disaster.

Released: 3/18/2014 10:00 AM EDT
Source Newsroom: Tulane University

Mayo Clinic Proceedings

Newswise — Lingering stress from major disasters can damage health years later, according to a new Tulane University study that found a three-fold spike in heart attacks continued in New Orleans six years after Hurricane Katrina.

Researchers also found a lasting disruption in the timing of heart attacks in the six years after the storm with significantly more incidents occurring on nights and weekends, which are typically times hospitals see fewer admissions for heart attacks.

The research, which will be published in the journal Mayo Clinic Proceedings, is an update of an ongoing study tracking the increases in admissions for heart attacks at Tulane Medical Center in downtown New Orleans after Hurricane Katrina. The new study confirmed the increase persisted even six years later.

“Prior to Hurricane Katrina, about 0.7 percent of the patients we were treating in our medical center were suffering from myocardial infarctions (heart attacks),” said lead author Dr. Matthew Peters, internal medicine resident at Tulane University School of Medicine. “This increased to about 2 percent in first three years after Katrina and continued to increase to almost 3 percent in years four through six after the storm.”

The hospital had 1,177 heart attack cases during the six years after the storm, representing 2.4 percent of patient admissions; only 0.7 percent of its patients were admitted for heart attacks two years before Katrina.

Researchers attribute the increase to several factors, most notably chronic stress, higher unemployment and greater risk factors for heart disease, such as increased rates of smoking, substance abuse, psychiatric disorders and noncompliance in taking prescribed medications.

“We found more patients without insurance, who were unemployed and more who had a previous history of coronary artery disease, showing us that the milieu of patients was a sicker population,” said senior author Dr. Anand Irimpen, an associate professor of medicine for the Tulane Heart and Vascular Institute and chief, cardiology section, Southeast Louisiana Veterans Health Care System.

Video interviews with both researchers are available online:

Dr. Matthew Peters – http://youtu.be/2oPOUZZLOmE

Dr. Anand Irimpen - http://youtu.be/nWANLTsSnzY

 

We’ve looked at other post-disaster health impacts in the past, such as in Post Disaster Stress & Suicide Rates. One disaster discussed was a 1999 7.3 earthquake that struck in Chi-Chi, Nantou county in central Taiwan killing more than 2,300 people.

 

A study that subsequently appeared in the Taiwan Journal of Medicine (Disease-specific Mortality Associated with Earthquake in Taiwan Hsien-Wen Kuo, Shu-Jen Wu, Ming-Chu Chiu) found `a considerable increase in the number of suicides after the earthquake’.

 

A little over a year ago, in Disaster’s Hidden Toll, we looked at the long-term, largely unseen, effect on nursing home patients who were forced to evacuate to temporary facilities after Japan’s Great Earthquake & Tsunami of 2011.

 

A study showed a 2.4 fold increase in deaths during the 8 months following the earthquake.  Deaths not caused by the quake, tsunami, or radiation release itself – but likely brought on by the stress of having to live in make-shift emergency shelters.

 

And just last month, in The Long Term Effects Of A Major Disaster, we looked at the post-tsunami deaths due to stress and displacement that exceeded – at least in one prefecture – those experienced during the initial earthquake and tsunami.

 

Closer to home, last fall in Sandy 1 Year Later: Coping With The Aftermath, we looked at the lingering psychological effects of New England’s brush with that late season super storm of 2012.

 

While the psychological impact of a major disaster cannot be fully prevented, individual, family, and business preparedness can go a long ways towards reducing the impact of any disaster.

 

FEMA, Ready.gov, along with organizations like the American Red Cross (and indeed, this blog), spend a great deal of time trying to convince individuals, families, businesses and communities of the value of preparing for a wide variety of emergencies and disasters.

 

Having a modest supply of food, water, and medicine – and a workable family or business disaster plan – can go a long ways toward reducing both stress and hardship during and after a disaster. The standard advice is that everyone needs to be prepared to deal with a disaster for at least 3 days (meaning having a first aid kit, emergency supplies, and a plan) before help arrives.

 

Sure . . .  they’d like you to be prepared for longer . . .  but 72 hours is a reasonable start. I personally advocate having 2 week’s worth of supplies, but then I live in the heart of hurricane country, and have a fondness for eating regularly (see NPM11: Living The Prepared Life). 

 

Although a good disaster plan and emergency kit are imperative to get you through the opening hours, days, or even weeks of a disaster, knowing how to help friends, family, and neighbors deal with the psychological effects of a disaster can be equally important.

 

While often hidden from view, the psychological impact of a disaster can be enormous and ongoing. Last year in Post Disaster Stress & Suicide Rates we looked at the impact of disaster-related PTSD (Post Traumatic Stress Disorder). Luckily, there are things that can be done - even by the layperson - to help reduce the psychological impact of a disaster. 

 

A few resources you may wish to revisit:

 

In Psychological First Aid: The WHO Guide For Field Workers we looked a simple guidebook anyone can use to help others in emotional distress.

 

The CDC also provides a website which contains a number of resources devoted to coping with disasters.

 

Coping With a Disaster or Traumatic Event

Trauma and Disaster Mental Health Resources

The effects of a disaster, terrorist attack, or other public health emergency can be long-lasting, and the resulting trauma can reverberate even with those not directly affected by the disaster. This page provides general strategies for promoting mental health and resilience. These strategies were developed by various organizations based on experiences in prior disasters.

 

Last August the World Health Organization released a comprehensive Guidelines For Post-Trauma Mental Health Care book on the treatment of PTSD, acute stress, and bereavement:

The bottom line is that those who follow FEMA’s, and Ready.gov’s advice to Have A Plan, Make A Kit, and Be informed  will be not only be better able to deal with a disaster, they will be better prepared to weather the rigors of a long recovery as well.

 

And that, in turn, could help reduce the risks of post-disaster health issues, such as has plagued New Orleans since Katrina.

 

A few of my (many) blogs on disaster preparedness include:

In An Emergency, Who Has Your Back?

When 72 Hours Isn’t Enough

When Evacuation Is The Better Part Of Valor

The Long Term Effects Of A Major Disaster

+

Credit NHK News – Fukushima evacuation zone March 2011

 

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We are approaching the third anniversary of the Great East Japan Earthquake and Tsunami of 2011, and despite massive recovery operations, living conditions remain difficult for many in the hardest hit prefectures. As we’ve seen before with other major disasters, the emotional and physical challenges during the recovery phase can often equal or even exceed those experienced during the actual event.

 

Adding to the already enormous stress levels from this disaster are the almost daily reports of radiation readings in and around the damaged Fukushima power plant, and concerns over the safety of food, water, and even the air they breathe. Concerns that are likely to persist for years to come.

 

Today it is being widely reported that the number of post-tsunami deaths due to stress and displacement have exceeded – at least in one prefecture – those experienced during the initial earthquake and tsunami.  This from the Japan Times:

 

Fukushima stress deaths top 3/11 toll

Uncertainties amid nuclear crisis acutely felt by elderly

Kyodo

Feb 20, 2014

FUKUSHIMA – Stress and other illnesses related to the 2011 quake and tsunami had killed 1,656 people in Fukushima Prefecture as of Wednesday, outnumbering the 1,607 whose deaths were directly tied to disaster-caused injuries, according to data compiled by the prefecture and local police.

A prefectural official said many people “have undergone drastic changes in their lives and are still unable to map out their future plans, such as homecoming, causing increased stress on them.”

Around 136,000 people are still displaced in the prefecture, which has had to cope with the devastating effects of the natural disasters and meltdowns at the Fukushima No. 1 nuclear station.

(Continue . . . )

 

According to this report, roughly 90% of those killed by indirect causes were 66 years of age or older.  A little over a year ago, in Disaster’s Hidden Toll, we looked at the long-term, largely unseen, effect on nursing home patients who were forced to evacuate to temporary facilities.

 

A study showed a 2.4 fold increase in deaths during the 8 months following the earthquake.  Deaths not caused by the quake, tsunami, or radiation release itself – but likely brought on by the stress of having to live in make-shift emergency shelters.

 

A unusually large number of these excess deaths were due to pneumonia or bronchitis, which many attribute to insufficient emergency shelters provided for the elderly and frail.

 

We’ve looked at other post-disaster health impacts in the past, such as in Post Disaster Stress & Suicide Rates. One disaster discussed was a 1999 7.3 earthquake that struck in Chi-Chi, Nantou county in central Taiwan killing more than 2,300 people.

 

A study that subsequently appeared in the Taiwan Journal of Medicine (Disease-specific Mortality Associated with Earthquake in Taiwan Hsien-Wen Kuo, Shu-Jen Wu, Ming-Chu Chiu) found `a considerable increase in the number of suicides after the earthquake’.

PTSD (Post Traumatic Stress Disorder) can often occur in the wake of a disaster or traumatic experience. Symptoms may include anxiety, depression, suicide and PTSD may even lead to drug and alcohol-related disorders.

 

Victims of personal violence, rescue and medical workers, victims of disasters, terrorism, physical or psychological trauma, and/or a combat zone are all at risk of suffering some level of PTSD.

 

I’ve written about post-disaster psychological first aid (PFA) several times in the past, including in Post Disaster Stress & Suicide Rates, PTSD Awareness Day, and Promising Practices: Psychological First Aid.  Last August the World Health Organization released a comprehensive Guidelines For Post-Trauma Mental Health Care book on the treatment of PTSD, acute stress, and bereavement:

Credit WHO

Publication details

Number of pages: 273
Publication date: 2013
Languages: English
ISBN: 978 92 4 150540 6

Downloads

• English

Overview

These WHO mhGAP guidelines were developed to provide recommended management strategies for conditions specifically related to stress, including symptoms of acute stress, post-traumatic stress disorder and bereavement.

The guidelines were developed by an independent Guidelines Development Group and inform a new mhGAP module on the Assessment and Management of Conditions Specifically Related to Stress.

 

While there is much variability in the levels of stress created by different disasters (exacerbated by both the severity and duration), cultural attitudes towards suicide, and in the effectiveness of individual coping skills, there seems little doubt that major disasters can cause both temporary and long-term mental health problems.

 

The CDC’s website contains a number of resources devoted to coping with disasters.

 

Coping With a Disaster or Traumatic Event

Trauma and Disaster Mental Health Resources

The effects of a disaster, terrorist attack, or other public health emergency can be long-lasting, and the resulting trauma can reverberate even with those not directly affected by the disaster. This page provides general strategies for promoting mental health and resilience. These strategies were developed by various organizations based on experiences in prior disasters.

(Continue . . .)

 

And from the National Center For PTSD, you’ll find abundant resources - including videos - on how to provide Psychological First Aid.

Lastly, while the psychological impact of a major disaster cannot be fully prevented, individual, family, and business preparedness can go a long ways towards reducing both the physical and emotional impact of any disaster.

 

Having a modest supply of food, water, and medicine – and a workable family or business disaster plan – can go a long ways toward reducing both stress and hardship.

Basic Preps: Emergency Weather Radio, First Aid Kit, Battery Lantern, Water storage

 

Those that follow FEMA’s, and Ready.gov’s advice to Have A Plan, Make A Kit, and Be informed  will be better equipped to deal with any eventuality.  Which is why I promote basic preparedness at every opportunity in this blog.

 

A few of my (many) blogs on that subject include:

 

In An Emergency, Who Has Your Back?

When 72 Hours Isn’t Enough

When Evacuation Is The Better Part Of Valor

NPM13: Pandemic Planning Assumptions