Systemic sclerosis (SSc) is a chronic autoimmune disorder with unknown triggering factors, and complex pathophysiologic links which lead to fibrosis of skin and internal organs, including the heart... Show moreSystemic sclerosis (SSc) is a chronic autoimmune disorder with unknown triggering factors, and complex pathophysiologic links which lead to fibrosis of skin and internal organs, including the heart, lungs, and gut. However, more than 100 years after the first description of cardiac disease in SSc, sclerodermic cardiomyopathy (SScCmp) is an underrecognized, occult disease with important adverse long-term prognosis. Laboratory tests, electrocardiography (ECG) and cardiovascular multimodality imaging techniques (transthoracic 2D and 3D echocardiography, cardiac magnetic resonance (CMR), and novel imaging techniques, including myocardial deformation analysis) provide new insights into the cardiac abnormalities in patients with SSc. This state-of-the-art review aims to stratify all the cardiac investigations needed to diagnose and follow-up the SScCmp, and discusses the epidemiology, risk factors and pathophysiology of this important cause of morbidity of the SSc patient. Show less
Waasdorp, R.; Mugge, W.; Vos, H.J.; Groot, J.H. de; Verweij, M.D.; Jong, N. de; ... ; Daeichin, V. 2021
Skeletal muscles generate force, enabling movement through a series of fast electro-mechanical activations coordinated by the central nervous system. Understanding the underlying mechanism of such... Show moreSkeletal muscles generate force, enabling movement through a series of fast electro-mechanical activations coordinated by the central nervous system. Understanding the underlying mechanism of such fast muscle dynamics is essential in neuromuscular diagnostics, rehabilitation medicine and sports biomechanics. The unique combination of electromyography (EMG) and ultrafast ultrasound imaging (UUI) provides valuable insights into both electrical and mechanical activity of muscle fibers simultaneously, the excitation-contraction (E-C) coupling. In this feasibility study we propose a novel non-invasive method to simultaneously track the propagation of both electrical and mechanical waves in muscles using high-density electromyography and ultrafast ultrasound imaging (5000 fps). Mechanical waves were extracted from the data through an axial tissue velocity estimator based on one-lag autocorrelation. The E-C coupling in electrically evoked twitch contractions of the Biceps Brachii in healthy participants could successfully be tracked. The excitation wave (i.e. action potential) had a velocity of 3.9 +/- 0.5ms(-1) and the subsequent mechanical (i.e. contraction) wave had a velocity of 3.5 +/- 0.9ms(-1). The experiment showed evidence that contracting sarcomeres that were already activated by the action potential (AP) pull on sarcomeres that were not yet reached by the AP, which was corroborated by simulated contractions of a newly developed multisegmental muscle fiber model, consisting of 500 sarcomeres in series. In conclusion, our method can track the electromechanical muscle dynamics with high spatio-temporal resolution. Ultimately, characterizing E-C coupling in patients with neuromuscular diseases (e.g. Duchenne or Becker muscular dystrophy) may assess contraction efficiency, monitor the progression of the disease, and determine the efficacy of new treatment options. Show less
