The terrorist attacks on the World Trade Center on September 11 2001 shocked the nation, causing deep and lasting psychological and physiological effects. Over the ensuing twenty years, numerous health problems have been described in the survivors of the attacks as well as the rescue workers. These effects include respiratory illnesses (chronic cough, asthma, bronchitis, sinus disease), several cancers (especially prostate and thyroid cancer, multiple myeloma, lymphoma, leukemia) and post traumatic stress disorder (PTSD). The diseases are due to two main factors: dust inhalation and stress (both acute and long term). Do these same factors affect the heart? What are the cardiac consequences of the terrorist attacks?
Immediately after the World Trade Center attack there was an increase in heart attacks and arrhythmias, in the New York City area and beyond. One hospital in Brooklyn reported a 35% increase in the rate of heart attack in the 60 days following the attacks. Another study looked at hospitals in New Jersey within a 50-mile radius of the World Trade Centers. The researchers showed a 49% increase in heart attacks within 60 days of the attack. In addition, there was an increase in severe arrhythmias (irregular heart rhythms). Patients with an automatic implantable defibrillator (AICD) routinely have their devices interrogated. At the time of interrogation, any arrhythmia that has occurred since the last interrogation can be detected and the amount and severity of arrhythmia determined. In the New York City vicinity, there was a significant increase in life-threatening arrhythmias seen in the AICD patients. The incidence of ventricular tachycardia and ventricular fibrillation (each of which can lead to cardiac arrest) doubled in the 30 days after the attack. This finding was not confined to New York City. AICD patients in Florida had a similar doubling of ventricular arrhythmias in the same time period.
Did the attacks and the aftermath have any long-term effect on heart health? The World Trade Center Health Registry has followed rescue workers and lower Manhattan residents and office workers since the attacks. In 2010, they reported an increase in hospitalization for heart disease and stroke in the enrollees. PTSD (found in 22% of the women and 15% of the men) increased the risk for heart disease. Another study followed nearly 10,000 firefighters who responded on 9/11 and helped in the recovery afterwards. Over 16 years, there was an increase in heart attack, heart stents, heart surgery and heart deaths in this cohort of firefighters. The risk increased in those who responded earlier (44% higher risk for firefighters responding on 9/11 versus those who arrived later) and those who had longer exposure to the World Trace Center dust.
There appear to be two mechanisms which increased the risk for heart disease after the terrorist attacks, exposure to dust and stress. It is well known that people exposed to air borne particulate matter are at risk for heart disease. For example, populations living in cities that have heavy air pollution are at higher risk for heart disease than those who live in cleaner air. The particulate matter from the World Trade Center dust was similar to air pollution. With more than million tons of dust, the exposure was extreme. The highest concentration was during and immediately after the collapse of the towers. This explains why firefighters with early exposure had more subsequent heart disease than others. Acute stress reactions, such as occur with natural disasters, are known triggers for heart attacks. An increase in heart attacks was reported after several earthquakes and the tsunami in Japan in 2011. The World Trade Center attacks certainly provoked acute stress reactions in many people. Acute stress will activate the sympathetic nervous system, revving up the body. This in turn can lead to a heart attack, analogous to the out of shape man running for a bus in the cold. Since the body is not used to such a severe reaction, plaque in a heart artery can rupture, blood clotting is initiated and a heart attack occurs. Chronic exposure to stress (for example, PTSD or living in chronic fear of a terrorist attack) keeps the sympathetic nervous activated, causing an elevated blood pressure and heart rate, increases inflammation, and promotes plaque formation in the heart arteries. In addition, the hormonal changes lessen the body’s ability to defend itself from a heart attack.
The World Trade Center attack was a horrible and tragic event on multiple levels. However, some good rises from the ashes. There are a couple of lessons for keeping the heart healthy that we can learn from aftermath of the attack. The first lesson is to try to avoid areas with dust or particulate matter in the air (for example in the workplace or in polluted cities). The second lesson is the importance of managing stress. There are two ways to handle stress. The first is to avoid stress, which is difficult in our modern world. The second way is to manage stress by changing the reaction to it; to change the perception of stress. There are a variety of methods to cope with stress. These include meditation, yoga, deep breathing, laughter and pet ownership. In addition, exercise is an excellent way to relieve stress. Try taking a good brisk walk. Preferably outdoors. Preferably in clean air.
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