Clinical features and diagnosis of congenital stenosis of the pulmonary artery and the right ventricular outflow tract

AIM: To analyse clinical manifestations of congenital pulmonary artery stenosis (CPAS) and right ventricular outlet stenosis (RVOS), development of its diagnosis depending on anatomic variants of heart disease. MATERIAL AND METHODS: The data on 539 patients examined with conventional clinical and highly informative novel techniques were studied. RESULTS: The analysis of the CPAS and RVOS clinical picture depending on the anatomic variant of the heart disease has shown that clinical symptomatology was of the same type. The data of the tests have some specific features allowing identification of some forms of the heart disease. CONCLUSION: Diagnostic and prognostic significance of the findings was determined which gave rise to an optimal examination scheme with focus on wider use of highly informative techniques.     

频发右心室流出道室性期前收缩对右心室流出道结构影响的研究

目的 探讨右心室流出道(RVOT)起源频发室性期前收缩对RVOT结构的影响.方法 选取2009～2011年行射频消融治疗的频发RVOT起源室性期前收缩患者30例,分析其心电图特征、动态心电图、心脏彩色超声结果及术中精确定位,分析室性期前收缩对RVOT结构的影响.结果 射频消融术前RVOT直径为(31.76±3.33)mm,术后6个月为(30.93±2.68)mm(P＜0.01);相关性分析显示:RVOT直径与室性期前收缩负荷呈正相关(r=0.484,P＜0.05).RVOT间隔部来源室性期前收缩QRS时限为(157.69±18.33) ms,游离壁来源室性期前收缩QRS时限为(179.23±16.05)ms(P＜0.01),QRS时限与来源部位相关(r=0.566,P＜0.01).室性期前收缩QRS时限与RVOT直径无相关性(r=0.097,P＞0.05).结论 RVOT来源室性期前收缩经射频消融治疗后,RVOT直径有减小的趋势,其与室性期前收缩负荷呈正相关,与室性期前收缩形态无相关性.     

右心室流出道起源室性期前收缩患者左心室腔流场分布模式的研究

目的 分析正常人及右室流出道(right ventricular outflow tract,RVOT)起源室性期前收缩(premature ventricular complexes,PVCs)患者左心室腔等容收缩期涡流及左心室腔不同层面时间-血流曲线分布规律,探讨RVOT起源PVCs对左心室腔流场分布模式的影响。方法 分别获取27例RVOT起源PVCs患者在窦性心搏、室性期前收缩时及25例正常人的心尖四腔观二维彩色多普勒血流图。应用血流向量标测(vector flow mapping,VFM)技术,在涡流模式下分析等容收缩期左心室腔涡流直径（横径、纵径）、速度（最大正向速度、最大负向速度）、圈数;获取左心室腔基底段至心尖段各层面时间-血流曲线,分别测量各层面收缩期负向、舒张期正向血流量。结果 与正常对照组比较,RVOT起源PVCs患者在室性期前收缩时,等容收缩期所形成涡流的涡流直径、速度、圈数均降低（P均＜0.01）,左心室腔时间-血流曲线杂乱;窦性心搏时等容收缩期涡流的速度降低,左心室流量分布规律改变。结论 RVOT起源PVCs患者在窦性心搏及室性期前收缩时均存在左心室腔流场分布模式的改变,VFM技术能够用于标测正常及异常电激动状态下左心室腔内血液流场的变化。     

Assessment of pulmonary valve and right ventricular outflow tract with real-time three-dimensional echocardiography

Aim Assessment of pulmonary valve (PV) and right ventricular outflow tract (RVOT) using real-time 3-dimensional echocardiography (RT3DE). Methods Two-dimensional echocardiography (2DE) and RT3DE were performed in 50 patients with congenital heart disease (mean age 32 ± 9.5 years, 60% female). Measurements were obtained at parasternal views: short axis (PSAX) at aortic valve level and long axis (PLAX) with superior tilting. RT3DE visualization was evaluated by 4-point score (1: not visualized, 2: inadequate, 3: sufficient, and 4: excellent). Diameters of PV annulus (PVAD), and RVOT (RVOTD) were measured by both 2DE and RT3DE, while areas (PVAA) and (RVOTA) by RT3DE only. Results By RT3DE, PV was visualized sufficiently in 68% and RVOT excellently in 40%. PVAD and PVAA were measured in 88%. RVOTD and PVAD by 2DE at PLAX were significantly higher than PSAX (P < 0.0001) and lower than that by RT3DE (P < 0.001). Conclusion RT3DE helps in RVOT and PV assessment adding more details supplemental to 2DE.     

Potential applications of intracardiac echocardiography in the assessment of the aortic valve from the right ventricular outflow tract.

Intracardiac echocardiography (ICE) is a developing technology and a promising method for visualizing intracardiac structures. However, its applications are currently limited to guidance during mitral valvuloplasty, catheter ablation, or electrophysiologic examination. The goal of this study was to observe the aortic valve, measure the annular diameter of the valve by ICE through a right-sided approach, and compare the results by ICE with those by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). We studied 18 patients (9 men, 9 women, aged 19 to 72 years) with various heart diseases, including 15 patients with mitral or aortic valvular disease. An imaging catheter was advanced through a long sheath into the outflow tract of the right ventricle. We obtained good longitudinal views of the aortic valve in all patients. Two of the 18 patients had poor image quality by TTE. The annular diameter by ICE correlated more closely with TEE than with TTE. In conclusion, right-sided ICE is a safe, simple, and useful procedure for observing the aortic valve during cardiac catheterization without additional discomfort in the patients. Right-sided ICE is superior to TTE in observing the aortic valve and measuring the annular diameter of the valve. The annular diameter can be measured by ICE as precisely as by TEE.     

Thermal mapping of right ventricular outflow tract tachycardia

BACKGROUND: Acute and long-term success of catheter ablation of right ventricular outflow tract tachycardia (RVOT VT) may be limited by the inability to reproduce the arrhythmia at the time of activation (AM) and pace mapping (PM). We have observed early initiation of the clinical VT when subtherapeutic radiofrequency (RF) energy was applied to the target area (TA), defined as a 2-cm(2) area around a pace match. We describe a novel approach using thermal mapping (TM) to guide the ablation of RVOT VT. METHODS: Thirteen patients (10 female, mean age 46.2 +/- 13.7 years) with symptomatic VT of left bundle branch block (LBBB) inferior axis morphology and no structural heart disease underwent standard electrophysiologic evaluation with PM (n = 13), AM (n = 13), and 3D noncontact mapping (n = 4). Thermal mapping was performed after standard techniques failed to induce stable sustained VT for mapping in all 13 patients: RF was applied for 5-10 seconds in the TA to achieve a tip temperature of 45-50 degrees C. At sites where morphologically consistent with the clinical VT was induced, RF was applied at target temperature between 50 and 60 degrees C for 30-60 seconds. TM was repeated before and after intravenous Isoproterenol infusion until no further VT could be induced by low temperature application. RESULTS: Noninducibility was achieved in all 13 patients. During a mean follow-up of 29 months (9-69 months), all patients remain arrhythmia-free, off antiarrhythmic medications. CONCLUSION: Thermal mapping is a safe and effective adjunctive technique for the mapping and ablation of RVOT VT when sustained tolerated clinical VT cannot be induced.     

永久右心室流出道起搏临床评价

目的评价主动固定电极在右心室流出道间隔部起搏应用中的临床疗效和稳定性。方法55例有高度房室传导阻滞的缓慢心律失常患者随机分为2组,27例采用主动固定电极行右心室流出道间隔部起搏（主动固定电极组）,28例采用被动固定电极行右心室心尖部起搏（被动固定电极组）,比较2组电极植入时间和心电图QRS波宽度,电极植入时及随访起搏阚值、感知、阻抗,电极脱位及相关并发症。结果主动固定电极组的植入时间和X线曝光时间均长于被动固定电极组,（25．82±1．84）min vs （20．07±2．45）min、（15．75±1．99）min vs （8．50±1．89）min（均P〈0．05）。主动固定电极组起搏的ORS波时限较被动固定电极组短,（130．104±4．00）ms vs （152．30±10．80）ms（P〈0．05）。主动电极植入组即刻闽值比被动电极组高,（0．71±0．27）V vs （0．51±0．17）V（P〈0．01）,术后随访3个月,2组的起搏阚值、感知差异均无统计学意义,术后3个月时主动电极组阻抗要低于被动电极组,（431．00±76．90）Ω vs （588．39±160．79）Ω（P〈0．01）,未见电极脱位等并发症。结论主动固定电极在右心室流出道间隔部的起搏应用可行而稳定。     

Gore-Tex在右心室流出道重建术中的应用

目的探讨0.1 mm厚聚四氟乙烯(Gore-Tex)片制作肺动脉单瓣跨环补片重建右心室流出道的近中期临床疗效。方法76例合并肺动脉狭窄或畸形的先天性心脏病患儿,其中法洛四联症(tetralogy of Fallot,TOF)合并肺动脉狭窄55例,TOF合并Ⅰ型肺动脉闭锁7例,TOF合并肺动脉瓣缺如5例,右心室双出口合并肺动脉狭窄3例,TOF行改良Blalock-Taussig分流术后6例(左侧改良Blalock-Taussig分流术5例,右侧1例),均行矫治术,术中使用Gore-Tex片制作肺动脉单瓣跨环补片重建右心室流出道。比较术前与术中停体外循环后血氧饱和度、肺动脉干直径等差异,随访观察手术效果。结果76例均顺利完成手术,体外循环时间118(109,134)min,主动脉阻断时间86(77,102)min,术后呼吸机辅助时间88(45,99)h,ICU停留时间135(114,161)h;术后因心包压塞急诊二次手术1例,发生一过性低心排血量综合征2例、心律失常2例、肺部感染1例,均经对症治疗后恢复;1例室间隔微小残余分流(流速<2.5 m/s),术后6个月自行闭合。术中停体外循环后血氧饱和度[96.00(94.00,97.00)%]较术前[84.00(78.00,89.00)%]增高,肺动脉干直径[12.00(10.12,13.00)mm]较术前[6.60(5.80,7.50)mm]增加,肺动脉瓣压差[21.00(16.00,27.00)mm Hg]、肺动脉瓣上流速[2.31(2.00,2.70)m/s]较术前[86.00(72.00,94.75)mm Hg、4.60(4.20,5.10)m/s]降低(P<0.05)。术后随访3~48个月,超声心动图示73例肺动脉瓣瓣叶活动良好,开启闭合正常;3例轻度肺动脉瓣狭窄,随访期间未见进一步加重;5例肺动脉瓣轻度关闭不全;均无肺动脉单瓣的撕裂、黏连、增厚、钙化、血栓形成及感染等。结论右心室流出道重建中术应用Gore-Tex片制作肺动脉单瓣有较好的近中期抗反流作用,可改善右心功能。     

Echocardiographic measurements of the right ventricle: right ventricular outflow tract 1

Purpose  

The size of the ventricles of the heart is important to establish during the clinical echocardiographic examination. Due to the complex anatomy of the right ventricle, it is difficult to measure its size at times. One of the most frequently used ways is to measure the right ventricular outflow tract (RVOT1), probably due to its good reproducibility. However, in the literature different ways are described to measure RVOT1, both at different sites and using different methods such as M-mode and 2D. The first aim of the present study was to exam if there is a significant difference in the outcome of RVOT1 using different sites and methods to measure it. The second aim was to study if there is a significant difference between the usually preferred left lateral decubitus position during the echocardiographic examination and the supine decubitus position, which the echocardiographer sometimes can be compelled to use if the patient is unable to lie in the left lateral decubitus position.     

右心室流出道高位间隔部起搏的应用及护理

目的 探讨主动固定电极行右心室流出道高位间隔部起搏的可行性及护理对策.方法 40例需起搏器植入的患者,采用VVI起搏模式,将其随机分为右心室流出道高位间隔部起搏组（RVOTHS组）和右心室心尖部起搏组（RVA组）各20例,观察两组在术中及术后的各项参数以及护理对策.结果 两组患者均顺利完成手术,两组各1例术后发生电极脱位.全部手术无严重并发症出现.RVOTHS组手术曝光时间明显延长,两组比较差异有统计学意义（t=4.036,P＜0.01）.术中两组患者心室的起搏阈值、感知阈值和电极阻抗比较差异均无统计学意义（P＞0.05）,RVOTHS组起搏心电图QRS波宽度较RVA组变窄,但差异无统计学意义（t=1.613,P＞0.05）.结论 右心室流出道高位间隔部起搏是安全和可行的,术后护理重视心电监测及个性化护理,可使并发症的发生率大大降低.     

The right ventricular outflow tract: the road to septal pacing

BACKGROUND: Pacing from the right ventricular apex is associated with long-term adverse effects on left ventricular function. This has fuelled interest in alternative pacing sites, especially the septal aspect of the right ventricular outflow tract (RVOT). However, it is a common perception that septal RVOT pacing is difficult to achieve. METHODS AND RESULTS: In this article, we will review the anatomy of the RVOT and discuss the importance of standard radiographic views and the 12-lead electrocardiogram in aiding lead placement. We will also describe a method utilizing a novel stylet shape, whereby a conventional active-fixation, stylet-driven lead can be easily and reliably deployed onto the RVOT septum.     

Differential diagnosis of intracavitary tumors obstructing the right ventricular outflow tract.

Three cases of right ventricular outflow tract obstruction caused by 3 distinct tumors-myxoma, sarcoma, and presumed metastatic tumor-diagnosed by transthoracic and transesophageal echocardiography are presented. The differences among these 3 types of tumors with similar clinical and echocardiographic findings are highlighted, and a review of the pertinent literature is discussed. By applying the approximate frequencies of cardiac tumors categorized by type and site, statistically, an intracavitary right ventricular outflow tract tumor is 70 to 140 times more likely to be malignant than benign; furthermore, if it is a primary cardiac tumor, it is approximately 2 times more likely to be a sarcoma than a myxoma.     

应用PTFE人工单叶肺动脉瓣实施右心室流出道重建术的护理配合

目的总结应用PTFE人工单叶肺动脉瓣实施右心室流出道重建矫治先天性心脏病的手术配合。方法用经修剪的PTFE片缝制人工单叶肺动脉瓣及自体心包片行右心室及主肺动脉补片扩大。结果21例中死亡1例,病死率4.76％,余20例术后恢复良好,除第1例患儿存在中度肺动脉返流外,其余患者均无返流;全部患儿均无肺动脉或右心室流出道梗阻。结论在行跨肺动脉瓣右心室流出道补片扩大术中,应用PTFE人工单叶肺动脉瓣可以有效地避免术后肺动脉瓣返流,改善右心室功能。     

全容积三维超声定量评价右室流出道的可行性

目的 评价从全容积三维超声心动图(FV3DE)数据库中截取的感兴趣区切面观测量右室流出道的可行性.方法 18例法洛四联症患儿纳入研究,年龄(3.2±4.5)岁.采用二维超声心动图(2DE)、FV3DE和心血管造影同时测量右室流出道.FV3DE采用漏斗部、肺动脉瓣环、肺动脉主干、左肺动脉或右肺动脉的横截面切面观进行测量.结果 漏斗部前后径的FV3DE和2DE测值差异无统计学意义(t=-0.865,P=0.399).FV3DE显示漏斗部的前后径小于左右径(t=-13.968,P=0.000),提示法洛四联症漏斗部的横截面类似于椭圆形.肺动脉瓣环直径的FV3DE、2DE与心血管造影测值差异无统计学意义(P>0.05),且均与心血管造影测值良好相关(r=0.899和r=0.839).左、右肺动脉直径的FV3DE、2DE与心血管造影测值差异无统计学意义(P>0.05),且均与心血管造影测值良好相关(左肺动脉:r=0.947和r=0.797;右肺动脉:r=0.987和r=0.831).从FV3DE数据库中截取的切面观还可测量漏斗部、肺动脉瓣环、肺动脉主干以及左、右肺动脉的横截面积,分别为(61.9±33.0)mm2、(64.9±32.5)mm2、(65.4±25.9)mm2、(34.9±17.1)mm2和(40.2±21.0)mm2.由FV3DE得到的肺动脉直径指数(PDI)和肺动脉截面积指数(PAI)与心血管造影的McGoon指数和Nakata指数均良好相关(r=0.877和r=0.983).结论 从FV3DE数据库中截取的切面观测量右室流出道的比传统2DE切面观的测值更准确.由FV3DE得到的PDI和PAI是反映肺动脉发育状况的可信指标.     

右心室流出道起搏电极部位的放射影像及心电图形态的相关性研究

目的 探讨采用主动电极行右心室流出道(RVOT)起搏时,电极部位与其放射影像、心电图形态之间的相关性研究.方法 回顾分析安装体内埋藏式起搏器的110例患者,行RVOT起搏术.行后前位,左前斜45°,右前斜30°放射照片.后前位及左前斜位区分室间隔或游离壁,右前斜位区分流出道上部或下部.术后行12导联心电图.结果 110例患者中有18例电极位于流出道以下,92例(83.6%)位于流出道上部或下部.92例流出道患者中有58例(63.0%)位于间隔部,34例位于游离壁(37.0%);25例(27.2%)位于高位流出道,67例(72.8%)位于低位流出道.间隔部起搏患者与游离壁起搏患者比较,QRS时间短(134±18)ms vs(142±21)ms,P<0.05.游离壁起搏中,Ⅲ导联切迹多见(P<0.01).结论 RVOT起搏的电极X线表现及心电图形态对确定起搏部位有很大的帮助.     

Cardiac magnetic resonance-derived right ventricular outflow tract systolic flow acceleration: a novel index of right ventricular function and prognosis in patients with pulmonary arterial hypertension

To validate the right ventricular outflow tract systolic flow acceleration (RVOT_ACC; peak flow velocity/time-to-peak velocity) measured by phase-contrast (PC)—cardiovascular magnetic resonance (CMR) as a novel index of right ventricular (RV) function, and to investigate its clinical implications in patients with pulmonary arterial hypertension (PAH). Thirty (38 % male, 43 ± 15 years old) out of 55 consecutive patients who were initially diagnosed with PAH at the referral center were prospectively enrolled between March 2009 and July 2010 and were followed for PAH-related cardiovascular events for 2 years. The invasively measured maximum dP/dt (dP/dt_max) was used as an index of RV contractility. The PC-CMR-derived RVOT_ACC was compared with well-known prognostic parameters. The PC-CMR-derived RVOT_ACC correlated strongly with the dP/dt_max and estimated RV function more accurately than the CMR-derived RV ejection fraction. The CMR-derived RVOT_ACC level (HR = 0.87, 95 % CI 0.78–0.98, p = 0.038) could be another powerful prognostic index compared with the functional capacity (hazard ratio [HR] = 0.88, 95 % confidence interval [CI] 0.78–0.97, p = 0.035) and REVEAL Registry risk score (HR = 0.83, CI 0.56–0.95, p = 0.012). Furthermore, receiver-operating characteristic analysis identified ≥0.4 m/s² as the optimal RVOT_ACC cut-off for predicting subsequent cardiovascular events. PC-CMR-derived RVOT_ACC is a promising non-invasively measured index of RV function and prognosis in patients with PAH.