A forgotten essential chamber that may be involved in the cardiac complications of COVID-19 The right ventricle seems to have been forgotten among heart chambers , although some studies have shown its crucial role in coronavirus disease 2019 (COVID-19) Interestingly, both its size and function are believed to be associated with cardiac complications and mortality in COVID-19 COVID-19 is caused by severe acute respiratory syndrome corona-virus 2 (SARS-CoV-2) which spread globally after the first case was observed in Wuhan at the end of 2019 1 Recent studies suggested that COVID-19 may be accompanied by cardiac complications, including acute coronary syndrome, cardiac arrhythmia, myocarditis, pericardi-tis, and heart failure in nearly 20% of patients, which are ssociated with an increased risk of mortality 2 Laboratory data such as cardiac tropo-nin as well as echocardiography parameters can be effective means of cardiac assessment in these patients Transthoracic echocardiography (TTE) is the optimum method of cardiac imaging used in COVID-19 patients which is able to diagnose different cardiac abnormalities including haemodynamic dysfunction Also, it is useful for the prediction of future cardiac morbidity in these patients 3 Reduced right ventricular (RV) activity is a good predictor for heart failure and cardiac mortality 4 The effect of COVID-19 on the right ventricle activity is in the main unknown It seems that the pathophysiological pathways of COVID-19 including increased after-load after acute respiratory distress syndrome, pulmonary embolism, cytokine-negative inotropic effects, and renin-angiotensin system dys-function are possible mechanisms for RV dysfunction in COVID-19 patients 5 A summary of some studies which have been conducted to assess RV function in COVID-19 patients is presented in Table 1 Li et al performed an echocardiographic investigation in 120 cases of COVID-19 They assessed RV fractional area change, tricuspid annu-lar plane systolic excursion, and Doppler tricuspid tissue annular velocity In their study, RV function was categorized by right ventricular longitudinal strain (RVLS) It was concluded that patients with the lowest RVLS tertile were more susceptible to cardiac injury, and a higher mortality rate was observed in this group In addition, patients' mortality was associated with RVLS, RV fractional area change, and tricuspid annular plane systolic excursion 6 In the study of Szekely et al , the most common cardiac pathology in COVID-19 was RV dilatation (39%) which was more than both left ventricular (LV) diastolic dysfunction (16%) and LV systolic dysfunction (10%) In fact, it was concluded that LV systolic function is preserved in these patients, although LV diastolic function and RV function are impaired 2 In a retrospective study by Argulian et al , echocardiography parameters of 105 cases of COVID-19 were studied RV dilation was observed in 32 patients (31%) Furthermore, RV hypokinesis and moderate to severe tricuspid regurgitation were more common in patients with RV dilation Interestingly, there were no differences in LV size and function in patients with RV dilation in comparison with normal patients 7

中文翻译：

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重新思考清洁空气：空气质量法和 COVID-19

可能与 COVID-19 心脏并发症有关的被遗忘的基本心室 右心室似乎已被遗忘在心室中，尽管一些研究表明其在 2019 年冠状病毒病 (COVID-19) 中的关键作用 有趣的是，它的大小和功能被认为与 COVID-19 的心脏并发症和死亡率有关 COVID-19 是由严重急性呼吸系统综合症冠状病毒 2（SARS-CoV-2）引起的，该病毒在武汉发现第一例病例后在全球传播2019 年底 1 最近的研究表明，在近 20% 的患者中，COVID-19 可能伴有心脏并发症，包括急性冠状动脉综合征、心律失常、心肌炎、心包炎和心力衰竭，与死亡风险增加相关 2 实验室数据，如心肌肌钙蛋白以及超声心动图参数可以成为这些患者心脏评估的有效手段 经胸超声心动图 (TTE) 是 COVID-19 中使用的最佳心脏成像方法能够诊断包括血流动力学功能障碍在内的不同心脏异常的患者 此外，它有助于预测这些患者未来的心脏发病率 3 右心室 (RV) 活动减少是心力衰竭和心脏死亡率的良好预测指标 4 COVID 的影响-19 右心室活动主要未知似乎 COVID-19 的病理生理途径包括急性呼吸窘迫综合征后后负荷增加、肺栓塞、细胞因子负性肌力作用、和肾素-血管紧张素系统功能障碍是 COVID-19 患者 RV 功能障碍的可能机制 5 表 1 总结了一些评估 COVID-19 患者 RV 功能的研究 Li 等人进行了一项超声心动图调查在 120 例 COVID-19 患者中，他们评估了 RV 面积变化、三尖瓣环平面收缩偏移和多普勒三尖瓣组织环速度 在他们的研究中，RV 功能按右心室纵向应变 (RVLS) 进行分类。得出的结论是，患有RVLS 最低的三分位数更容易发生心脏损伤，在该组中观察到更高的死亡率 此外，患者的死亡率与 RVLS、RV 面积分数变化和三尖瓣环平面收缩期偏移 6 在 Szekely 等的研究中,COVID-19 中最常见的心脏病理是 RV 扩张 (39%)，这比左心室 (LV) 舒张功能障碍 (16%) 和 LV 收缩功能障碍 (10%) 都多。事实上，得出的结论是 LV 收缩功能尽管 LV 舒张功能和 RV 功能受损 2 在 Argulian 等人的一项回顾性研究中，对 105 例 COVID-19 的超声心动图参数进行了研究，但在这些患者中观察到了 32 名患者（31%）的 RV 扩张。 RV 扩张患者的运动功能减退和中度至重度三尖瓣关闭不全更常见 有趣的是，与正常患者相比，RV 扩张患者的 LV 大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7尽管 LV 舒张功能和 RV 功能受损 2 在 Argulian 等人的一项回顾性研究中，研究了 105 例 COVID-19 的超声心动图参数 32 名患者 (31%) 观察到 RV 扩张 此外，RV 运动减退和中度至重度三尖瓣RV 扩张患者的反流更常见 有趣的是，与正常患者相比，RV 扩张患者的 LV 大小和功能没有差异 7尽管 LV 舒张功能和 RV 功能受损 2 在 Argulian 等人的一项回顾性研究中，研究了 105 例 COVID-19 的超声心动图参数 32 名患者 (31%) 观察到 RV 扩张 此外，RV 运动减退和中度至重度三尖瓣RV 扩张患者的反流更常见 有趣的是，与正常患者相比，RV 扩张患者的 LV 大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7与正常患者相比，右室扩张患者的左室大小和功能没有差异 7