To determine the usefulness of contrast echocardiography in the diagnosis of aortic dissection (AD) and in the assessment of findings necessary for adequate patient management. Conventional and contrast-enhanced transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) were performed in 128 consecutive patients with clinically suspected acute AD. Results were validated independently against intraoperative findings in 45 patients and computed tomography information in 83. Sensitivity and specificity of conventional TTE increased after contrast enhancement from 73.7 to 86.8% (P< 0.005) and 71.2 to 90.4% (P < 0.05), respectively. Sensitivity and specificity of enhanced TTE were similar to conventional TOE in ascending aorta (93.3 vs. 95.6% and 97.6 vs. 96.4%, respectively) and in the arch (88.4 vs. 93.0% and 95.3 vs. 98.82%, respectively). Contrast-enhanced TOE permitted the location of non-visualized entry tear in seven cases (10.6%), helped to correctly identify the true lumen in six (9.1%), and diagnosed retrograde dissection in nine (13.6%). Contrast enhancement substantially improves TTE in the diagnosis of AD and should be considered as the initial imaging modality in the emergency setting. Contrast enhancement also has significant value for obtaining critical morphological and haemokinetic information by TOE useful for adequate patient management.

Electromechanical characterization during atrial fibrillation (AF) remains a significant gap in the understanding of AF-related atrial myopathy. This study reports mechanistic insights into the electromechanical remodeling process associated with AF progression and further demonstrates its prognostic value in the clinic. In pigs, sequential electromechanical assessment during AF progression shows a progressive decrease in mechanical activity and early dissociation from its electrical counterpart. Atrial tissue samples from animals with AF reveal an abnormal increase in cardiomyocytes death and alterations in calcium handling proteins. High-throughput quantitative proteomics and immunoblotting analyses at different stages of AF progression identify downregulation of contractile proteins and progressive increase in atrial fibrosis. Moreover, advanced optical mapping techniques, applied to whole heart preparations during AF, demonstrate that AF-related remodeling decreases the frequency threshold for dissociation between transmembrane voltage signals and intracellular calcium transients compared to healthy controls. Single cell simulations of human atrial cardiomyocytes also confirm the experimental results. In patients, non-invasive assessment of the atrial electromechanical relationship further demonstrate that atrial electromechanical dissociation is an early prognostic indicator for acute and long-term rhythm control.