Stress and cardiovascular health

The importance of a healthy lifestyle to reduce stress in order to manage risk factors associated with adverse cardiovascular outcomes is emphasised in a Review in this week's edition of The Lancet.

Dr Daniel Brotman, Johns Hopkins Hospital, Baltimore, MD, USA and colleagues studied relevant literature published between 1990 and 2006 to prepare the Review. They say: “Since antiquity, people have been intuitively aware of the connection between the heart and emotional stress.”

They examine the effect of stress on the sympathetic nervous system, stress physiology, and cardiovascular effects of stress, saying: “Acute physical stressors such as surgery, trauma, and intense physical exertion are well-known triggers of cardiovascular events. Emotional stressors are increasingly recognised as precipitants of such events.” They refer to an earthquake in Los Angeles in 1994, in which the number of cardiac deaths in the area in individuals who did not undergo direct physical trauma or increased physical exertion was two to five times the normal rate.

Also studied in the Review are subacute and chronic stressors. Major life changes are associated with psychological/emotional adjustment can increase the risk of cardiac events – eg. in the months following the death of a spouse, mortality from all causes, particularly cardiovascular ones, is increased. The authors say: “Similarly, the fear in the USA subsequent to the terrorist attacks on the World Trade Centre in New York in 2001 resulted in a rate of defibrillator firings of two to three times normal during the month after the event.”

The authors look at why individuals experience different responses to stress, and why cardiovascular events related to stress are more prevalent in the early morning than at other times – the reasons for this may include daily fluctuations in stress hormones and endothelial dysfunction.

They also comment on the lack of evidence to support the efficacy of behavioural and psychological stress reduction in the prevention of cardiac events. Such techniques are currently being studied in controlled clinical trials.

In conclusion, the authors say that stress is clearly an important – and potentially modifiable – risk factor for acute and chronic adverse cardiovascular disorders, and that effective medications are already in use. They say: “Ample evidence exists for a strong and consistent association acute and chronic psychological stress with cardiovascular risk factors….physicians should remain cognisant of the cardiovascular risk associated with chronic mental illness and psychological stressors, should take seriously patient symptoms (such as chest pain) which arise in conjunction with negative emotions, and should help their patients to alleviate unnecessary psychological strain, by advising that a healthy lifestyle should include stress reduction, anger management, and treatment of mental illness.”