Dilated left ventricle with multiple outpouchings — a severe congenital ventricu

lNTRODUCTlON

Left-dominant arrhythmogenic cardiomyopathy (LDAC) is a non-hypertrophic, non-hypertensive, and non-valvular progressive cardiomyopathy with fibrofatty myocardium infiltration that prominently occurs in the left ventricle[1]. LDAC might present with ventricular outpouching, which makes it difficult to differentiate from congenital ventricular diverticulum from the echocardiography[2]. Here,we present a case of LDAC with left chest leads low voltage, fragmented QRS (f-QRS), left ventricle (LV)dilation, LV systolic impairment, LV outpouchings, and late gadolinium enhancement of LV myocardium, which was finally diagnosed using multimodality cardiovascular imaging.

CASE PRESENTATlON

Chief complaints

A 57-year-old woman, presenting with a dilated left ventricle, reduced ejection fraction, and chronic bifascicular block, was referred to the cardiology department, West China Hospital, on December 10,2019.

History of present illness

LDAC is a relatively rare disease, which requires multimodality cardiovascular imaging for diagnosis.CMRI combined with CCTA is an excellent approach for identification of multiple types of cardiomyopathy and cardiac inner structures. From the present case, clinicians are advised to consider LDAC in patients with localized left ventricular lesions and multiple electrocardiographic abnormalities.

由2位具有多年影像诊断经验的核医学医师对所有患者的影像学资料进行背对背阅片，对受试者病灶感兴趣区（region of interest，ROI）进行勾画，并计算其最大标准摄取值（maximum standard uptake value，SUVmax）。18F-FDG PET/CT阳性的诊断标准为18F-FDG摄取的SUVmax高于周围本底水平（一般SUVmax≥2.5）或病灶同机平扫CT具有典型恶性形态学征象。

History of past illness

The patient had neither prior medical comorbidities nor addictions.

Personal and family history

Her father had a premature sudden cardiac death at the age of 40.

Physical examination

The patient showed good nutrition, active position, clear mind, fluent language, and was cooperative in examination. Examinations on her whole skin and mucous membrane revealed no yellow staining,cyanosis, and bleeding spots. She had a blood pressure and resting heart rate of 120/68 mmHg and 60 beats per min, respectively, and auscultation of both lungs was normal with neither dry nor wet rales.The apical pulse was located 0.5 cm lateral to the midclavicular line on the left side of the fifth rib, while her heart rhythm was regular. The first and second heart sounds were basically normal, without extra and splitting of the heart sound. No valvular murmurs were detected in any of the auscultation areas. In addition, she did not exhibit any physical signs of heart failure, including edema, ascites, jugular venous distention, and hepatojugular reflux.

Laboratory examinations

Results from the routine blood test and plasma biochemical examinations, including kidney and liver function, glucose, lipid, and electrolyte, were normal. Similarly, thyroid function, kappa and lambda urine free light chains as well as coagulation profile and autoimmune antibodies were also within the normal range. The plasma N-terminal fragment of the pro-brain natriuretic peptide was 325 ng/L.

Imaging examinations

The electrocardiogram (Figure 1) revealed left anterior branch block, complete right bundle branch block (RBBB), high sidewall abnormal Q wave, and left chest leads (V4-V6) low voltage with poor R wave progression. On the other hand, Holter monitoring (Figures 2 and 3) revealed sinus arrest with a 1.74 s R-R interval, multisource premature ventricular beats, non-sustained ventricular tachycardia with an RBBB pattern, and f-QRS in leads V3-V6. Transthoracic echocardiography (TTE) showed a dilated LV with a diameter of 60 mm as well as a reduced LV ejection fraction of 35% and a left ventricular apex cystic outpouching (12 mm × 13 mm) that displayed synchronous contractility (Figure 4A-C).Myocardial contrast echocardiography revealed contractile outpouching without obvious filling defects(Figure 4D). Coronary computerized tomography angiography (CCTA) revealed right dominant coronary artery circulation without obvious stenosis, LV multiple outpouchings, uneven thickness of the LV wall (Figure 5A, B, E, and F), hypodense region (CT value -90～-114 HU) at localized myocardium of LV septum (Figure 5C), and free wall (Figure 5D). These findings were consistent with profiles of fatty tissue infiltration. In addition, we used cardiac magnetic resonance imaging (CMRI) to evaluate the cardiac structure, bilateral ventricular function, segmental movement, and tissue characterization in the patient. CMRI results revealed LV dilatation, abnormal activity of the LV wall (Figure 6A and B), an outpouching at the LV apex, and a low signal in the septum myocardium midwall after contrast injection (Figure 6C). Moreover, late gadolinium enhancement in the midwall of the left ventricular septum and free wall myocardium were also evident (Figure 6D).

The patient in the present case revealed various ECG abnormalities, including sinus node dysfunction, chronic bifascicular block, abnormal Q wave, left chest leads low voltage (V4-6), poor R wave progression in leads V4-V6, and f-QRS in leads V3-V6. These were all indicative of left ventricular myocardial abnormality and extensive conduction system disorder. f-QRS, which has been defined as the presence of additional R’ waves or a notch in the R or S wave in two contiguous leads[3], indicates myocardial scarring and represents distortion of signal conduction as well as depolarization processes within ventricles[4]. Previous studies have shown that f-QRS is an independent predictor for cardiac events, ventricular arrhythmias, and sudden cardiac death[5]. Notably, it has been detected in patients with various structural heart or primary electrical diseases, such as Brugada syndrome, arrhythmogenic right ventricular dysplasia, and acquired long QT syndrome[6]. Therefore, careful differential diagnosis for cardiomyopathy was imperative for the patient in the present case. Furthermore, there is a need to consider multimodality cardiovascular imaging.

内分泌功能检查多表现为正常。可完善血清肿瘤标记物甲胎蛋白的检测，但如甲胎蛋白位于正常范围，不能除外HCC的可能(如本组病例2)。

Genetic testing

These findings highly pointed to LDAC.

FlNAL DlAGNOSlS

High-throughput sequencing revealed no genetic variation with high clinical phenotype correlation and sufficient evidence of pathogenicity.

结合中国种子植物属的地理成分分布格局、中国热带植物区系、中国有分布的典型热带科、中国植被区划和植物区系分区，我们提出北纬22°30′是中国南部和东南部的生物地理热带北界, 但在云南西部热带北界可达到北纬24°30′, 在西藏南部的深切河谷可达到北纬29°(图2)。

TREATMENT

After comprehensive evaluation of the patient, we prescribed sacubitril valsartan sodium tablets (50 mg bid) and spironolactone (20 mg qd). We did not administer a beta-blocker in this case, owing to multiple atrioventricular conduction abnormalities. In addition, she was given low-dose thiazide diuretics when needed to relieve edema and congestion symptoms. Three months later, her left ventricular size and systolic function had not changed compared to baseline. Consequently, she was subjected to an implantable cardioverter-defibrillator after full discussion in our department.

OUTCOME AND FOLLOW-UP

Two years later, we re-evaluated her symptoms and clinical indexes and found that the symptoms improved after taking standard oral medication for ejection fraction reduced heart failure. The pacemaker program did not record sustained ventricular tachycardia or ventricular fibrillation. Echocardiography revealed that left ventricular size and systolic function were almost similar to 2 years prior to treatment.

曲港高速公路连接线路基拓宽土工格栅布设优化分析……………………………………………………… 王向平（10-68）

DlSCUSSlON

This case affirms the need for clinicians to be aware of LDAC in patients with localized left ventricular lesions and multiple electrocardiographic abnormalities. Notably, multimodality cardiovascular imaging and electrocardiogram (ECG) should be considered in this situation.

水稻种质资源耐旱性鉴定与评价………… 王宝祥，余剑锋，徐 波，刘 艳，邢运高，孙治广，迟 铭，石时来，边建民，徐大勇（1）

CMRI combined with CCTA is effective in identification of multiple types of cardiomyopathy and cardiac inner structures. Initially, we considered the left ventricular apex outpouching with a thick wall,narrow communication, and synchronous contractility to be a diverticulum based on evidence from echocardiography and myocardial contrast echocardiography. However, CCTA and CMRI generated more details for differential diagnosis. Previous studies have shown that CCTA, a noninvasive approach, can effectively distinguish outpouchings caused by myocardial infarction and ischemic cardiomyopathy related to occlusion (or lack thereof) of the coronary arteries[7,8]. Furthermore, CMRI has a unique advantage in identifying cardiomyopathy. Black blood with T1 and T2 sequences as well as dynamic bring blood were used to evaluate the cardiac structure, tissue characterization, bilateral ventricular function, and segmental movement. In addition, delayed enhancement imaging following administration of gadolinium can result in more information on fibrosis, scarring, and fat infiltration in the local myocardium[9]. In the present case, CCTA and CMRI results revealed LV septum and free wall local myocardium replaced by fatty tissue as well as LV midwall late gadolinium enhancement,multiple LV outpouchings, and uneven thickness of the LV wall, without stenosis of coronary arteries.These abnormalities were accompanied by non-sustained ventricular tachycardia with an RBBB pattern and f-QRS in the left chest leads. Consequently, we considered that this patient had arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy refers to a category of non-hypertrophic, non-hypertensive, and non-valvular progressive cardiomyopathy with fibrofatty myocardium infiltration[10]. Previous studies have classified arrhythmogenic cardiomyopathy into classical arrhythmogenic right ventricular cardiomyopathy, LDAC, and biventricular involvement categories[11]. The patient in the present study was eventually diagnosed with LDAC. LDAC, which was first described by Sen-Chowdhry[1] in 2008, has been easily overlooked or misdiagnosed as myocardial infarction, myocarditis, and dilated cardiomyopathy in clinical practice. Notably, LDAC is a relatively rare disease. For example, it accounted for less than 0.15% of 35845 consecutive patients who were referred for CMRI examinations in Fuwai Hospital (Beijing, China), National Center for Cardiovascular Diseases[12].

Clinically, LDAC patients mainly manifest palpitations, presyncope, exertional dyspnea, and chest pain with normal coronary angiography, with only a handful of cases found to be asymptomatic[12,13].Patients with LDAC have poor prognosis. For example, Feliu[13] found that 32.4% of all LDAC patients studied manifested major adverse cardiovascular events, which were mainly accompanied by sudden cardiac death and ventricular arrhythmias, during a mean follow-up of 3.74 years.

新型干法水泥窑协同处置就是利用水泥回转窑设备在焚烧处理废弃物的同时产生熟料。在继承传统垃圾焚烧炉的优点时，有机地将自身高温、循环等优势发挥出来。既能充分利用废物中的有机成分的热值实现节能，又能完全利用废物中的无机成分作为原料生产熟料；既能使废弃物中的有毒有害有机物在新型干法回转窑的高温环境中完全焚毁，又能使废物中的有毒有害重金属固定到熟料中。同时还可以处理垃圾处理过程中产生的臭气和污水浓缩液，能有效防止二次污染。以热盘炉预焚烧为例的焚烧系统工艺流程如图1所示。

At present, no specific diagnostic criteria exist for LDAC. In 2008, Dr. Chowdhry established the following initial diagnostic features of LDAC: (1) Arrhythmia: sustained or non-sustained ventricular tachycardia; (2) Imaging: (a) LV aneurysms; and (b) mild LV dilation and/or systolic impairment; (3)Biopsy/CMRI: (a) cardiomyocyte loss with fibrofatty replacement on histology; and (b) extensive late gadolinium enhancement of LV myocardium (with subepicardial/midmyocardial distribution); and (4)Unexplained T-wave inversion in V5, V6 ± V4, I, and AVL[1]. Recently, Corrado[11] suggested that the following elements should be considered as LDAC: (1) ECG changes, such as low QRS voltages in limb leads and inverted T waves in the inferolateral leads; (2) Ventricular arrhythmias with an RBBB pattern; and (3) Structural and functional imaging features consistent with ‘hypokinetic and fibrotic LV.’Interestingly, the ultrasonographer initially misdiagnosed the patient in the present study as congenital ventricular diverticulum (CVD), according to the left ventricular apex cystic outpouching displaying synchronous contractility with the corresponding cardiac chamber.

Although myocardial biopsy is the gold standard diagnostic criterion, this patient refused this invasive examination. After comprehensively analyzing a combination of the medical history and positive clues on auxiliary examinations, including ECG, TTE, CCTA, and CMRI, the specialists in our department unanimously diagnosed the patient with LDAC. She was subsequently administered with standard oral therapy for heart failure with reduced ejection fraction and implantable cardioverterdefibrillator. The patient was very satisfied with the process of diagnosis, treatment, and follow-up.

综上所述，本文先是分析了在针对小微企业的税收优惠政策的执行上存在哪些问题，主要有：税收优惠政策存在局限性、税收征收管理不够完善、小微企业的管理有所欠缺。对此本文提出一些建议，需要提高优惠政策合理性，增加对技术创新层面的优惠，完善税务管理模式，更需要小微企业重视自身管理。

CVD has the atypical and nonspecific clinical manifestations at an early stage, namely arrhythmias,cardiac rupture, heart failure, and embolism[18,19], which make it easily confused with LDAC.However, some of these features can be adopted during the differential diagnosis between CVD and LDAC. First, most CVD are single and located at the cardiac apex[20,21]. Second, the left ventricular wall exhibits neither signal alterations nor signs of necrosis or fibrous tissue in CVD cases[22]. Third,CVD patients exhibit more frequent extracardiac anomalies than those with LDAC[19]. Fourth, the size of CVD does not change over time, suggesting a benign course[23]. However, the patient in the present study not only manifested multiple left ventricular outpouchings but also exhibited uneven-thickness left ventricular wall with multiple flaky fatty infiltrations. This interesting case indicates that clinicians should not ignore LDAC upon detecting left ventricle outpouching on TTE.

烤鸡翅经调味、烧烤后具有外焦里嫩的口感而备受青睐。但直接用烧烤模式进行烧烤时，食物表面容易烤焦、汁液流失，口感柴、难咀嚼。然而利用真空低温烹饪不仅可以实现水分和重量最小程度的损失，还能更好的保留食物的原味和色泽，烹制的菜肴营养美味又健康[3，4]。

CVD, first described in 1816, was often asymptomatic and incidentally detected during a regular physical check-up. Generally, the left ventricular diverticulum was in a thick wall, comprising endocardium, myocardium, and pericardium, with a narrow communication between the cavity and ventricular and displayed synchronous contractility with the LV[14]. This was likened to an appendix originating from the ventricle. The left ventricular diverticulum has an average size that varies from 0.5 cm to as large as 8.0-9.0 cm[15]. Notably, the left ventricular diverticulum not only has low prevalence,as evidenced by 0.4%-2.2% across different studies[16], but has also been associated with occurrence of other congenital abnormalities, including septal defects, dextrocardia, and pulmonary stenosis.Generally, CVD combined with midline thoraco-abdominal congenital abnormalities, diaphragmatic and sternal defects, and partial absence of diaphragmatic pericardium is referred to as Cantrell’s syndrome[17].

CONCLUSlON

She occasionally experienced mild chest pain and paroxysmal palpitation during activity in the past 2 years. Her exercise capacity was also mildly reduced. She did not manifest symptoms of fatigue,dizziness, syncope, peripheral edema, and abdominal distention.

ACKNOWLEDGEMENTS

The authors thank the radiology department of West China Hospital, Sichuan University for technical support. Second, we thank Dr. Jerry, PhD from the Home for researchers editorial team for editing the language of this manuscript.

FOOTNOTES

Chengdu Science and Technology Bureau, China, No. 2020-YF05-00290-SN.

Zhang X and Ye RY contributed equally to this article; Zhang X and Ye RY were the patient’s cardiologists, reviewed the literature, and contributed to manuscript drafting; Chen XP was responsible for the revision of the manuscript for important intellectual content; All authors issued final approval for the version to be submitted.

Written informed consent was obtained from the patient for the publication of this case report and the accompanying images.

The authors declare that they have no competing interests to declare.

无线通信用电信息采集系统适合应用在用户密度低、电表安装分散、对数据实时性要求不高的情况。特别是农村、城市边缘、乡镇等地区的用户分布情况和无线信道情况都非常适合使用无线通信采集系统。

The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).

新型耐用材料 iglidur J200 已登陆 igus 产品目录册和在线商店。在线商店的优势在于可以通过丝杠配置器在线配置大螺距螺纹丝杠、梯形螺纹丝杠和公制螺纹丝杠，并在线预测螺母的使用寿命。除了三种常见的丝杠材料外，设计工程师们还可以根据应用需求从九种不同的免润滑且免维护的螺母材料中进行选择。其中包括具有超高耐磨性的新型高性能工程塑料 iglidur J200。

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is noncommercial. See: https://creativecommons.org/Licenses/by-nc/4.0/

China

Xin Zhang 0000-0003-3305-3144; Run-Yu Ye 0000-0001-8245-0774; Xiao-Ping Chen 0000-0001-7172-8216.

Gong ZM

Filipodia

Gong ZM