BackgroundAtrial fibrillation (AF) is the most common arrhythmia in hypertrophic cardiomyopathy (HCM) and is associated with adverse outcomes in HCM patients. Although the left atrial (LA) diameter has consistently been identified as a strong predictor of AF in HCM patients, the relationship between LA dysfunction and AF still remains unclear. The aim of this study is to evaluate the LA function in patients with non-obstructive HCM (NOHCM) utilizing cardiovascular magnetic resonance feature tracking (CMR-FT).MethodsThirty-three patients with NOHCM and 28 healthy controls were studied. The global and regional LA function and left ventricular (LV) function were compared between the two groups. The following LA global functional parameters were quantitively analyzed: reservoir function (total ejection fraction [LA total EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive ejection fraction [LA passive EF], passive strain [εe], peak early-negative SR [SRe]), and booster pump function (active ejection fraction [LA active EF], active strain [εa], peak late-negative SR [SRa]). The LA wall was automatically divided into 6 segments: anterior, antero-roof, inferior, septal, septal-roof and lateral. Three LA strain parameters (εs, εe, εa) and their corresponding strain rate parameters (SRs, SRe, SRa) during the reservoir, conduit and booster pump LA phases were segmentally measured and analyzed.ResultsThe LA reservoir (LA total EF: 57.6 ± 8.2% vs. 63.9 ± 6.4%, p < 0.01; εs: 35.0 ± 12.0% vs. 41.5 ± 11.2%, p = 0.03; SRs: 1.3 ± 0.4 s− 1 vs. 1.5 ± 0.4 s− 1, p = 0.02) and conduit function (LA passive EF: 28.7 ± 9.1% vs. 37.1 ± 10.0%, p < 0.01; εe: 18.7 ± 7.9% vs. 25.9 ± 10.0%, p < 0.01; SRe: − 0.8 ± 0.3 s− 1 vs. -1.1 ± 0.4 s− 1, p < 0.01) were all impaired in patients with NOHCM when compared with healthy controls, while LA booster pump function was preserved. The LA segmental strain and strain rate analysis demonstrated that the εs, εe, SRe of inferior, SRs, SRe of septal-roof, and SRa of antero-roof walls (all p < 0.05) were all decreased in the NOHCM cohort. Correlations between LA functional parameters and LV conventional function and LA functional parameters and baseline parameters (age, body surface area and NYHA classification) were weak. The two strongest relations were between εs and LA total EF(r = 0.84, p < 0.01), εa and LA active EF (r = 0.83, p < 0.01).ConclusionsCompared with healthy controls, patients with NOHCM have LA reservoir and conduit dysfunction, and regional LA deformation before LA enlargement. CMR-FT identifies LA dysfunction and deformation at an early stage.

The objective of this study is to expound the CT features of COVID-19 patients whose throat swab samples were negative for two consecutive nucleic acid tests after treatment. We retrospectively reviewed 46 COVID-19 patients with two consecutive negative RT-PCR tests after treatment. The cases were divided into moderate group and severe/critical group according to disease severity. Clinical and CT scanning data were collected. CT signs of pulmonary lesions and the score of lung involvement were expounded. Thirty-nine moderate cases and seven severe/critical cases were included. Residual pulmonary lesions were visible in CT images. Moderate patients showed peripheral lesions while severe/critical cases exhibited both central and peripheral lesions with all lobes involvement. Mixed ground glass opacity (GGO) and pulmonary consolidation were noted. A larger proportion of severe patients showed reticular pulmonary interstitium thickening. Air bronchogram, pleural effusion, vascular enlargement, bronchial wall thickening, bronchiectasis, pleural thickening and pleural adhesion were more frequently observed in severe/critical group. The severe/critical group showed higher CT score. Pulmonary lesions persisted even after twice consecutive negative nucleic acid tests. We strongly recommended regular follow-up of CT scans after nucleic acid tests conversion. Evaluation of complete remission should base on chest CT. Coronavirus Disease-2019 (COVID-19) is an acute infectious disease mainly involving the respiratory system 1. The highly contagious disease is caused by a novel coronavirus currently termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1. So far to April 9, 2020, 1,479,748 cases of COVID-19 patients and 87,444 deaths are reported. It is a huge strike to human health and draws much attention from countries all over the world. At present, etiological examinations, including reverse transcription-polymerase chain reaction (RT-PCR) and gene sequencing of sputum, throat swab and lower respiratory tract secretion, are the gold standard for diagnosis of COVID-19 2. Nucleic acid tests are widely recognized as the primary criteria of discharge after treatment. However, it remains unclear whether damage to the lung have been completely restored when the nucleic acid tests are negative after treatment. Explanation of this issue is essential for determining the timing of treatment termination and isolation release. Chest computed tomography (CT) provides us a powerful noninvasive mean for the diagnosis and monitoring for COVID-19. Ground glass opacity (GGO) and consolidative opacity involving bilateral and peripheral lung were CT hallmarks of COVID-19 pneumonia 3-8. It has been reported that CT manifestations vary with the course of disease 8. However, post-treatment patterns of CT images after nucleic acid tests conversion have not yet been described, which are paramount for not only understanding the pathophysiology but also developing management strategies. In the present study, we assessed chest CT images...

Background The role of the dysfunction of left atrium in the occurrence and development of cardiovascular disease has been gradually recognized. We aim to compare the impact on left atrial (LA) function between patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) without LA enlargement using cardiovascular magnetic resonance feature tracking (CMR-FT), and if possible, explore the capability of LA function for providing clinical implication and predicting clinical adverse events in the early stage of cardiovascular disease. Methods Consecutive 60 HCM patients and 60 HTN patients with normal LA size among 1413 patients who underwent CMR were retrospectively analyzed as well as 60 controls. Left atrial and ventricular functions were quantified by volumetric and CMR-FT derived strain analysis from long and short left ventricular view cines. The primary endpoint was a composite of all-cause death, stroke, new-onset or worsening heart failure to hospitalization, and paroxysmal or persistent atrial fibrillation. Results Compared to the controls, both HTN and HCM participants had impaired LA reservoir function (εs) and conduit function (εe) with the different stage of LA booster pump dysfunction (εa). LA strain was more sensitive than LV longitudinal strain (GLS) for evaluate primary endpoint (εs: 33.9% ± 7.5 vs. 41.2% ± 14.3, p = 0.02; εe: 13.6% ± 6.2 vs. 17.4% ± 10.4, p = 0.03; εa: 20.2% ± 6.0 vs. 23.7% ± 8.8, p = 0.07; GLS: -19.4% ± 6.4 vs. -20.0% ± 6.8, p = 0.70, respectively). After a mean follow-up of 6.8 years, 23 patients reached primary endpoint. Cox regression analyses indicated impaired LA reservoir and booster pump strain were associated with clinical outcomes in patients at the early stage of HTN and HCM (p < 0.05). Conclusions CMR-FT-derived strain is a potential and robust tool in demonstrating impaired LA mechanics, quantifying LA dynamics and underlining the impacts on LA-LV coupling in patients with HTN and HCM without LA enlargement. The corresponding LA dysfunction is a promising metric to assess clinical implication and predict prognosis at the early stage, superior to GLS.