A new study has pointed out that levels of anxiety sensitivity must be considered before choosing medical treatment for patients with heart failure and atrial fibrillation (AF).
Heart and Stroke Foundation researcher and lead author Nancy Frasure-Smith, explained that anxiety sensitivity is the degree to which a person is frightened by bodily sensations and symptoms, particularly those associated with anxiety.
"For most people, sweaty palms and an increasing heart rate are simply unpleasant symptoms that occur in stressful situations, for others these same symptoms are interpreted as a sign of impending doom.
"People with high anxiety sensitivity tend to magnify the potential consequences of their anxiety symptoms, leading to an increase in anxiety and its symptoms in a spiralling increase of fear and worry," said Frasure-Smith.
While anxiety sensitivity is known to predict the occurrence of panic attacks in cardiac and non-cardiac patients, and is associated with greater symptom preoccupation and worse quality of life in patients with AF, it has not been previously studied as a predictor of cardiac outcomes.
These results are based on a sub-study from the Atrial Fibrillation and Congestive Heart Failure Trial (AF-CHF), a randomized trial of rhythm versus rate control treatment strategies whose results were presented at the Canadian Cardiovascular Congress in 2008.
Prior to randomization 933 AF-CHF study participants completed a paper and pencil measure of anxiety sensitivity.
They were then randomly placed in one of two treatment groups: a 'rhythm' group that was treated with anti-arrhythmic medication and cardioversion (an electric shock to convert an abnormal heart rhythm back to normal rhythm); and a 'rate' group that received medication to help keep people's heart rates within a certain range.
Participants were followed for an average of 37 months.
Results showed that, as in the overall AF-CHF trial, the majority of patients had as good a prognosis with the rate control strategy as with the rhythm control approach.
In contrast, patients with high anxiety sensitivity had significantly better outcomes if they were treated with the more complicated rhythm control strategy.
"Increased emotional responses to AF symptoms in people with high anxiety sensitivity may lead to increased levels of stress hormones making them more vulnerable to fatal arrhythmias and worsening heart failure," said Frasure-Smith.
The findings were discussed at the Canadian Cardiovascular Congress 2010, co-hosted by the Heart and Stroke Foundation and the Canadian Cardiovascular Society.