A randomised controlled trial of stress in stress cardiomyopathy patients
By Paul Bridgman 23 March 2022
It has been long debated whether the cause for stress cardiomyopathy is in the brain, the heart, or even perhaps in the connection between the two. A cardinal feature of the cardiomyopathy is QT prolongation, onset shortly after the precipitating event and then worsening over an average of three days before resolving. Published this week in PLOS One, a randomised control trial seeks to establish whether women who have recovered from stress cardiomyopathy show any increased susceptibility to QT prolongation with repeated exposure to emotional stress.
The trial included 12 women with a history of the condition and 12 controls without major cardiovascular disease. On two separate occasions, these women had 24-hour ECGs recorded with a holter monitor and were either subjected to a stress-inducing hyperventilation exercise or a calming diaphragmatic breathing exercise.
The trial showed that heart rate increases, and that QTc prolongs in response to the stress. The QT prolongation persisted for 20 minutes. As a secondary purely emotional stressor unheralded phone calls were made to the participants during the trial with similar results, there was no difference in response between cases and controls. While the trial showed that the QT interval is labile and strongly affected by emotion, there is nothing intrinsically different in response between the patients and the controls. Reassuringly, there was no evidence that the cases carried a background alteration in QT sensitivity.
Authors: Watson GM, Sutherland J, Lacey C, Bridgman PG (2022)