Echocardiographic assessment of tricuspid regurgitation during ventricular demand pacing

Twenty patients from our pacemaker clinic population were assessed clinically and by saline contrast echocardiography (subxiphoid view) to determine the prevalence of tricuspid regurgitation (TR) and, if TR was present, its mechanism. The patients had no known TR before lead placement, a single transvenous right ventricular pacing lead present more than 6 months (mean 52, range 7 to 138), ventricular demand pacing alternating with sinus rhythm and rate programmability. Each patient was studied in sinus rhythm and during ventricular pacing. Using the criterion of inferior vena cava (IVC) contrast reflux during ventricular systole to diagnose TR, no patient had evidence of TR in sinus rhythm, consistent with clinical examination. During ventricular demand pacing, jugular venous pulse cannon A waves developed in 10 patients, and 18 patients (including these 10) had IVC contrast reflux during ventricular systole. Analysis of the timing of IVC reflux revealed its close temporal relation to the timing of atrial systole rather than a fixed timing during ventricular systole. This reflux occurred with loss of normal atrioventricular (AV) synchrony and the underlying mechanism in all cases was shown to be right atrial contraction against a closed tricuspid valve. Two patients who did not have such a pattern with pacing maintained normal AV synchrony. These observations indicate that: TR is an uncommon accompaniment of ventricular demand pacing; the jugular venous pulse and IVC echocardiographic contrast patterns during ventricular demand pacing simulate TR when AV asynchrony [corrected] occurs; and the IVC contrast pattern of pacing induced AV asynchrony [corrected] is best termed the cannon A wave synchronous pattern.     

Mechanistic insights into functional mitral regurgitation

Effective valve repair in patients with mitral regurgitation (MR) demands an understanding of its mechanism. In patients with ischemic heart disease and functional MR, which doubles late mortality, normal leaflets are apically displaced. This reflects an altered balance of forces acting on the leaflets: increased tethering forces restricting closure, resulting from an altered geometry of leaflet attachments, and decreased ventricular forces acting to close the leaflets. Extensive evidence confirms a central and predominant role of tethering as the final common pathway inducing functional MR; left ventricular (LV) pressure dynamically modulates the orifice area. Because ischemic MR is a disease of the entire mitral complex, including the remodeling LV, reducing annular size alone is often ineffective. Undersizing rings attempts to compensate for tethering; new and potentially more effective strategies directly address tethering by infarct plication, papillary muscle repositioning with a localized patch, or basal chordal cutting to increase coaptational surface area without prolapse. A comprehensive understanding of the valve in its ventricular context, therefore, provides new opportunities for successful valve repair in patients.     

Mechanistic insights into atrial functional mitral regurgitation: Far more complicated than just left atrial remodeling

Recent studies lend credibility to the notion that lone atrial fibrillation (AF) can cause functional mitral regurgitation (MR), commonly referred to as atrial functional MR (AF‐MR). The conventional view holds that left atrial enlargement associated with AF causes annular dilatation which gradually moves the mitral valve leaflets apart resulting in inadequate coaptation and regurgitation. Recent findings, however, suggest that AF‐MR is not solely related to left atrial remodeling, but that important structural and functional abnormalities of the left ventricle also play a role in its pathogenesis.     

右心室电极相关的三尖瓣反流

右心室(RV)电极相关的三尖瓣反流(TR)是心血管植入式电子装置(CIED)术后并发症之一,其发生机制主要为电极导线对三尖瓣的机械作用和右心室起搏改变了心脏的收缩顺序。电极种类及数量、植入时间、起搏位置及心房颤动等是其危险因素。结合病史、体格检查及辅助检查可作出明确诊断,治疗包括药物治疗、电极复位、拔出及外科手术。本文对近年关于右心室电极相关三尖瓣反流的相关研究作一综述。     

心房颤动导管射频消融术逆转功能性三尖瓣反流的超声研究

目的 研究导管射频消融术对非瓣膜病性房颤患者中重度功能性三尖瓣反流的影响及逆转右心重构的作用.方法 采用前瞻性的研究方法,连续入选2010年12月至2012年6月632例非瓣膜病性房颤首次行导管射频消融手术的患者,于手术前（72 h内）进行二维超声心动检查,将伴有中重度功能性三尖瓣反流的患者作为研究对象（12例）,于手术后3个月及6个月复查二维超声心动图,对比分析手术前后超声心动图数据,从而评判导管射频消融术后维持窦性心律对功能性三尖瓣反流的影响及逆转右心重构的作用.结果 导管射频消融术后3个月和6个月右心房上下径[（54.13±6.06）mm比（49.72±5.96）mm,P=0.001;（54.13±6.06）mm比（48.37±5.53）mm,P=0.001]、右心房左右径[（39.29±6.38）mm比（35.09±3.15）mm,P=-0.023;（39.29±6.38）mm比（33.86±2.97）mm,P=0.014]、右心室基底部横径[（34.65±4.51）mm比（32.58±3.93）mm,P=0.033;（34.65±4.51）mm比（31.40±3.59）mm,P=0.043]、三尖瓣反流面积[（7.30±1.37）mm^2比（3.18±2.10）mm^2,P=0.001;（7.30±1.37）mm^2比（1.52±1.92）mm^2,P=0.001]均有所减少,差异有统计学意义.结论 导管射频消融术可以改善非瓣膜病性房颤患者功能性三尖瓣反流的程度,逆转右心重构,疗效确切.     

Atrial functional tricuspid regurgitation: An underappreciated cause of secondary tricuspid regurgitation

Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR.     

经导管封堵治疗成人房间隔缺损合并功能性三尖瓣返流

目的 探讨经导管封堵成人房间隔缺损（atrial septal defect, ASD）后能否改善其合并的功能性三尖瓣返流（tricuspid regurgitation, TR）。方法 连续纳入自2019年1月1日～2020年12月31日在空军军医大学西京医院心血管内科经导管封堵的ASD合并功能性TR患者,根据术前超声心动图评估TR严重程度并进行分级,术后6个月进行超声心动图随访,评估功能性TR的改善程度。结果 与合并轻度TR组相比,合并中/重度TR组患者年龄较大（P<0.01）,ASD直径较大,RV直径较大（均P<0.05）,与合并中度TR组相比,合并重度TR组患者年龄较大（P<0.01）,RV直径较大（P<0.05）。封堵前,11例患者合并重度TR,18例患者合并中度TR, 71例患者合并轻度TR;封堵术后6个月,10例患者（91%）由重度TR降至轻度,12例患者（67%）由中度TR降至轻度。所有患者中无轻度TR患者的返流量增加至中度或重度。单变量分析显示,持续性TR与肺动脉直径、右房直径、右室直径、左房直径、左室直径及ASD大小相关。经过多变量分析,以上...     

Right atrial pressure-volume relationships in tricuspid regurgitation

Pressure-volume relationships in the right atrium were examined before and after the creation of acute experimental tricuspid regurgitation in pigs. A 1.3 kHz multielectrode impedance catheter with a measuring current of 4 mA was used to determine instantaneous right atrial pressure and relative blood volume; right atrial dimension was assessed simultaneously with ultrasonic crystals attached to the atrial walls. Impedance volume waveforms and ultrasonic crystal dimensions closely paralleled each other at baseline and after the induction of tricuspid regurgitation. The normal right atrial pressure-volume plot exhibited a figure-of-eight configuration, with an "a-loop" and a "v-loop" corresponding to the a-wave and v-wave of the right atrial pressure tracing. With severe tricuspid regurgitation, atrial pump function was abolished, and the pressure-volume plot exhibited a single clockwise loop, consistent with complete ventricularization of the right atrium. Intermediate degrees of tricuspid regurgitation preserved the figure-of-eight loop, but the size of both the a-loop and the v-loop were increased, consistent with a Starling-type load imposed on the atrium by the regurgitant blood volume. Increased right ventricular afterload mediated by constriction of the pulmonary artery and infusion of methoxamine reversibly converted the right atrial pressure-volume loop from that of mild to that of severe tricuspid regurgitation. Alternatively, constriction of the inferior vena cava and infusion of nitroprusside changed the right atrial pressure-volume loop from that of a severe pattern of tricuspid regurgitation to a less severe type of pattern. Infusion of dobutamine increased the size of the a-loop relative to the v-loop both at baseline and after induction of tricuspid regurgitation. We conclude that tricuspid regurgitation induces changes in right atrial mechanics that can be detected and quantified with an impedance catheter.     

功能性三尖瓣反流的临床研究进展

功能性三尖瓣反流(FTR)是指在无明显的心肌及三尖瓣器质性病变的情况下,由于其他继发因素引起的三尖瓣反流。它普遍存在于健康人群和器质性心脏病患者中。由于FTR在很长的一段时间内无明显症状,常继发左心瓣膜病或左心功能不全等,且少量的三尖瓣反流常被误认为是正常的生理现象,并未引起足够的重视。近年来的研究指出,即使是微量和轻度的三尖瓣反流,也对原发疾病的远期预后有着重要的影响,因此本文对FTR的临床研究进展进行综述,以期为功能性三尖瓣反流的临床研究提供些许参考。     

Wallstent migration into the right ventricle causing severe tricuspid regurgitation and right ventricular perforation

Endovascular stents are being used with increasing frequency for various problems of the venous system, but they have been associated with numerous complications. We report the case of an 88-year-old woman who presented with persistent, progressive dyspnea. Imaging revealed a migrated stent lodged in the tricuspid valve and extending into the right ventricle, causing severe tricuspid regurgitation. After a failed attempt at endovascular retrieval, emergent surgical removal was successful. During surgery, the stent was found to be embedded in the tricuspid leaflets, and part of the stent had also perforated the right ventricle. Review of the patient's records revealed that 2 WALLSTENT venous endoprostheses had been placed 6 months earlier to treat stenosis of the left brachiocephalic vein and, further, that the migrated stent had been visible on outpatient chest radiography performed 4 months after the stent placement. This case emphasizes the need to consider the possibility of stent migration in patients who present with unusual symptoms.     

Determinants of the severity of functional tricuspid regurgitation

We performed a prospective study of patients with chronic right ventricular (RV) dilation to determine the factors associated with the degree of functional tricuspid regurgitation (FTR). We prospectively enrolled 64 patients with chronic RV dilation and measured right atrial (RA) area, RV area and its fractional area change (RVFAC), tricuspid annular diameter and contraction, tricuspid valve (TV) tethering area, and systolic pulmonary artery pressure. We also measured the RV eccentricity index and the RV sphericity index for simple presentation of RV geometry. Regurgitant orifice area of FTR was obtained for the quantification of FTR. End-systolic RV eccentricity index (r=0.73), end-diastolic RV eccentricity index (r=0.56), RA area (r=0.49), TV tethering area (r=0.37), age (r=0.31), end-systolic (r=0.42) and end-diastolic (r=0.30) tricuspid annular diameters, and left ventricular ejection fraction (r=-0.37) were significantly related to the regurgitant orifice area of FTR in univariate analysis. However, RV area, RVFAC, and systolic pulmonary artery pressure were not. In multivariate analysis, the end-systolic RV eccentricity index (p<0.001), TV tethering area (p=0.003), and end-diastolic tricuspid annulus diameter (p=0.007) showed the independent associations with regurgitant orifice area of FTR. The sensitivities and specificities for predicting more than mild FTR were found to be 79% and 82% with an end-systolic RV eccentricity index>2.0, 69% and 73% with an end-systolic tethering area>1.0 cm2, and 64% and 59% for an end-systolic tricuspid annulus diameter>3.9 cm, respectively. FTR severity was found to show the best correlation with the end-systolic RV eccentricity index. In conclusion, these findings underscore the importance of eccentric RV dilation for determining FTR severity and should lead to the development of more rational surgical approaches to FTR beyond TV annuloplasty.     

功能性三尖瓣关闭不全外科治疗的改进

功能性三尖瓣关闭不全主要是左心瓣膜病变引起的肺动脉高压和右心室扩大所致,三尖瓣瓣叶本身及瓣下结构没有器质性病变.目前多数学者主张在行左心瓣膜置换术的同时行三尖瓣成形术,手术方式从二瓣化成形术发展到DeVega成形术,人造瓣环成形术从二维瓣环发展到三维瓣环.本文就外科治疗功能性三尖瓣关闭不全的进展作一综述.     

房间隔缺损合并三尖瓣反流的研究进展

房间隔缺损(ASD)患者常合并三尖瓣反流(TR)。严重TR会增加心血管疾病发病率和死亡率。随着心导管技术的发展,ASD介入封堵术已成为代替外科手术的一种有效治疗方法,三尖瓣的介入治疗也有了新的尝试。但目前对于ASD合并TR患者的研究较少,对于ASD合并TR的患者在ASD闭合后三尖瓣的变化情况以及严重TR的治疗策略仍存在争议。本文就ASD合并TR的机制、诊断以及治疗进行阐述。