Longitudinal Strain Patterns in Stress (Takotsubo) Cardiomyopathy: Evidence of Global Myocardial Injury and Incomplete Recovery

Abstract

BackgroundStress cardiomyopathy develops after abrupt sympathetic stimulation, likely from catecholamine-induced myocardial toxicity. The evolution of myocardial strain during and following an episode have not been previously characterized. We aimed to determine whether pre-existing contractile abnormalities may explain the observed regional dysfunction during an acute episode, and to investigate the persistence of strain abnormalities after clinical recovery. MethodsWe identified patients who were diagnosed with stress cardiomyopathy and had an echocardiogram performed prior to their episode, during their episode, and within 1 year after. Diagnosis was confirmed based on the absence of obstructive coronary lesions. Left ventricular (LV) longitudinal strain was calculated using speckle-tracking software and compared between baseline, episode, and follow-up echocardiograms. ResultsLV strain analysis was performed on 23 patients. LV ejection fraction was 64±8.7% at baseline, 45±12% during the episode, and 59±10% after a median follow-up of 46 days. LV global longitudinal strain was 24±4.7% at baseline, 11±4.9% during the episode, and 19±4.6% after follow-up. Mean ejection fraction (p<0.01) and global longitudinal strain (p<0.001) remained below baseline levels at follow-up. Longitudinal strain was reduced (<18%) in 80±23% of myocardial segments during an episode and 41±21% of myocardial segments at follow-up. During the acute episode, 35±6% of the abnormal segments were in the base, outside of the region of ballooning. ConclusionsOur findings suggests that stress cardiomyopathy is associated with global rather than regional myocardial injury, and that contractile abnormalities persist after clinical improvement. These findings challenge prior understanding of stress cardiomyopathy and may guide future pathophysiologic understanding of this complex disease.