Oxygen metabolism of the hypertrophic right ventricle in open chest dogs.

STUDY OBJECTIVE--The aim was to investigate oxygen metabolism of the hypertrophic right ventricle in anaesthetised open chest dogs. DESIGN--Right ventricular hypertrophy was induced by right ventricular pressure overload with banding the pulmonary artery for six months. Coronary blood flow and myocardial oxygen metabolism of the hypertrophic right ventricle were determined during control and after increasing right ventricular oxygen consumption, and compared with those of the normal right and left ventricles. SUBJECTS--Seven mongrel dogs with right ventricular hypertrophy and 21 normal dogs were used. All were anaesthetised with pentobarbitone sodium. MEASUREMENTS AND MAIN RESULTS--Oxygen extraction [(A-V)O2] of the hypertrophic right ventricular myocardium was greater than that of normal right ventricle in controls and almost identical to the (A-V)O2 of the normal left ventricle. It showed no increase when coronary blood flow and right ventricular oxygen consumption were raised in response to a further elevation of the right ventricular pressure and isoprenaline infusion. However, the right ventricular interventions which increased right ventricular oxygen consumption produced an elevation of (A-V)O2 of the right ventricle with an increase in right coronary blood flow. CONCLUSIONS--Higher oxygen extraction during control and no response of oxygen extraction of the hypertrophied right ventricle in response to stimuli which increase right ventricular oxygen consumption indicate that oxygen supply to the hypertrophic right ventricle is different from that of the normal right ventricle, and is more like that of the left ventricle.     

Estimation of right ventricular volume with two dimensional echocardiography

To evaluate the applicability of two dimensional echocardiography to right ventricular volume determination, a study was made of 33 consecutive patients separated into three groups (control, right ventricular volume overload and right ventricular pressure overload). Biplane two dimensional echocardiograms that were perpendicular to each other were obtained from the apical approach. The echocardiographic right ventricular volume, calculated by applying Simpson's rule, was considered to be right ventricular body volume without right ventricular outflow tract volume. The echocardiographic dimensions of the right ventricular long, short and maximal short axes were also measured in each view. These volumes and dimensions were compared with both the angiographic right ventricular body volumes calculated by applying Simpson's rule and with the values in each group. Correlation between the echocardiographic and the angiographic right ventricular body volumes (r = 0.94 at end-diastole, r = 0.84 at end-systole) was good and much better than that between echocardiographic right ventricular dimensions and angiographic right ventricular body volumes. Echocardiographic calculation of right ventricular body volume was useful in distinguishing the control group from the group with right ventricular volume overload (p < 0.005).

The correlation between the echocardiographic dimensions of the right ventricular long axis and angiographic right ventricular volumes was poor, whereas that between the echocardiographic dimensions of the right ventricular short or maximal short axis and the angiographic right ventricular volumes was fairly good. It was therefore suspected that during right ventricular enlargement, the increase in size is more extensive in the direction of the short than in the direction of the long axis. It is concluded that estimation of right ventricular volume and morphology with two dimensional echocardiography may be of value in clinical practice.     

超声心动图对先天性心脏病右心室功能的评价

目的以右心室造影为对照,使用超声心动图常规的四腔心切面和全新的右心室全显示切面定量评价右心室射血分数（right ventricular ejection fraction,RVEF）,探讨右心室全显示切面在右心功能评价中的应用价值。方法2011年4月至2011年11月通过临床和超声心动图检查选择伴有右心室形态或血流动力学改变的先天性心脏病患者22例（男13例,女9例,年龄16～67岁）为研究对象。除对人选患者行常规的超声心动图检查外,还使用四腔心切面和右心室全显示切面测量RVEF。在心导管实验室使用右心室造影测量RVEF。将四腔心和右心室全显示切面RVEF与右心室造影RVEF行随机区组设计方差分析及Pearson相关性分析,右心室全显示切面RVEF与其余右心功能指标行Pearson相关分析,并采用Bland—Ahman法评价右心室全显示切面与右心室造影的一致性。结果3种方法测得的RVEF分别为右心室全显示切面48．O％±11．3％、四腔心切面49．5％±13．1％、右心室造影48．7％±12．1％。3种方法测量结果比较,差异无统计学意义（F=0．327,P=0．723）。右心室全显示切面RVEF与右心室造影RVEF呈高度相关（r=0．908,P〈0．001）,四腔心切面RVEF与右心室造影RVEF呈中度相关（r=0．659,P=0．001）。右心室全显示切面RVEF与肺动脉收缩压及主肺动脉宽度负相关（P〈0．05）,与右心室每搏输出量正相关（P〈0．05）,与其他右心功能评价指标则无明显相关性。结论与常规的四腔心测量方法相比。超声心动图右心室全显示切面测量的RVEF与右心室造影的相关性更好,可能是一种准确和可靠的评价右心室收缩功能的方法。     

A quantitative histopathological study of right bundle branch block complicating acute anteroseptal myocardial infarction

The aim of the present study was to evaluate whether necrosis of the right bundle branch is responsible for development of right bundle branch block in acute myocardial infarction. Twenty patients with acute anteroseptal myocardial infarction were studied--10 with right bundle branch block (group A) and 10 without (group B)--to evaluate by serial sectioning the pathological extent of myocardial infarction surrounding the right bundle branch and also that of right bundle branch necrosis. Myocardial infarction reached the right bundle branch more than 8 mm above the moderator band in all of group A, whereas myocardial infarction reached the right bundle branch less than 3 mm above the moderator band in only three patients in group B. Nine hearts in group A showed significant necrosis of the right bundle branch. In group B and in one case with transient right bundle branch block no necrosis was found. The occurrence of right bundle branch block was almost entirely explained by necrosis of the right bundle branch, but transient right bundle branch block did develop without necrosis of the right bundle branch.     

A quantitative histopathological study of right bundle branch block complicating acute anteroseptal myocardial infarction.

The aim of the present study was to evaluate whether necrosis of the right bundle branch is responsible for development of right bundle branch block in acute myocardial infarction. Twenty patients with acute anteroseptal myocardial infarction were studied--10 with right bundle branch block (group A) and 10 without (group B)--to evaluate by serial sectioning the pathological extent of myocardial infarction surrounding the right bundle branch and also that of right bundle branch necrosis. Myocardial infarction reached the right bundle branch more than 8 mm above the moderator band in all of group A, whereas myocardial infarction reached the right bundle branch less than 3 mm above the moderator band in only three patients in group B. Nine hearts in group A showed significant necrosis of the right bundle branch. In group B and in one case with transient right bundle branch block no necrosis was found. The occurrence of right bundle branch block was almost entirely explained by necrosis of the right bundle branch, but transient right bundle branch block did develop without necrosis of the right bundle branch.     

Right bundle branch block in complete transposition

Two of 26 infants with complete transposition presented with complete right bundle branch block in the first year of life, and 10 showed incomplete right bundle branch block. In no instance was the right ventricular conduction anomaly related to surgery or cardiac catheterization and it was not present at birth. The two cases with complete right bundle branch block had prolonged and severe hypoxemia and markedly dilated right ventricles. One had depressed right ventricular function and died after a Mustard procedure from low output syndrome. Whereas incomplete right bundle branch block may reflect right ventricular hypertrophy, it is suggested that complete right bundle branch block in complete transposition may signify right ventricular dysfunction and possibly irreversible changes of the right ventricular myocardium. It may be a sequel of long-term hypoxemia and pressure overload. Once observed, it is perhaps an indication for an alternative surgical approach other than an intra-atrial repair procedure.     

Analysis of right atrium function in patients with chronic pressure overload of the right ventricle

Right atrial function was evaluated in 16 patients with and without chronic right ventricular pressure overload. A simultaneous right atrial pressure recording using a catheter-tip-micromanometer and right atrial volume determination using cross-sectional echocardiography were performed. The pressure-volume curve of the right atrium was composed of an a-loop and a v-loop. The ratio of active atrial emptying to right ventricular stroke volume in patients with right ventricular pressure overload was significantly larger than in the control group (36 +/- 6% vs. 23 +/- 5%, p less than 0.04). The right atrial work was also significantly greater in patients with right ventricular pressure overload (6.2 +/- 2.0 mWs) than in normal subjects (4.2 +/- 2.0 mWs, p less than 0.04). The ratio of active atrial emptying to ventricular stroke volume and right atrial work were significantly related in both control group and patients with right ventricular pressure overload (r = 0.83). Right atrial work also showed a significant linear correlation with right atrial work before active atrial emptying (r = 0.92). We conclude that in patients with right ventricular pressure overload the right atrium shows more pronounced active emptying and contributes to better diastolic filling of the right ventricle.     

不同部位组合起搏对充血性心力衰竭患者急性血流动力学影响的研究

观察右房左室起搏对充血性心力衰竭 (CHF)患者急性血流动力学的影响。 8例心功能II～IV级CHF患者 ,分别置入右房、右室和左室电极 (经冠状静脉窦 ) ,行不同部位组合起搏的急性血流动力学研究 ,其中 6例获得成功。使用Bitronic公司生产的双腔起搏分析仪 (ERA30 0 )分别行单纯右室心尖部 (RVA)、右房右室 (RA +RV)、右房左室 (RA +LV)、右房双室 (RA +BiV)起搏 ,同时用二维超声心动图测定上述四种起搏状况下的血流动力学参数 ,并进行比较。结果 :右房左室起搏和右房双室起搏血流动力学参数两者间无显著差异 ,但比单纯右室心尖部起搏和右房右室起搏有所改善。结论 :右房左室起搏似可使更多的CHF患者在得益于起搏治疗的同时明显降低医疗费用。     

Enhanced detection of proximal right coronary artery stenosis with the additional analysis of right ventricular thallium-201 uptake in stress scintigrams

The value of right ventricular thallium-201 analysis in detecting proximal right coronary artery stenosis in exercise myocardial scintigraphy was analyzed in 52 patients, 27 with and 25 without proximal right coronary artery stenosis. For the detection of proximal right coronary artery stenosis, the sensitivity and specificity of thallium scintigraphic analysis were 59 and 88% for a right ventricular abnormality, 67 and 68% for a left ventricular inferior wall abnormality, and 93 and 56% for an abnormality of either. When both right and left ventricular thallium images were abnormal, all 9 patients had proximal right coronary artery stenoses, and when both were normal, 26 of 28 patients had a normal proximal right coronary artery. The sensitivity and specificity of blood pool scintigraphic variables during exercise (right ventricular ejection fraction and left ventricular inferior wall motion) were not significantly different for detection of proximal right coronary artery stenosis.Thus, the additional analysis of the right ventricle on thallium-201 stress scintigrams can improve the detection of proximal right coronary artery stenosis. When both right ventricular and left ventricular thallium scintigrams are abnormal (or normal), the ability to predict the presence (or absence) of proximal right coronary artery stenosis is very high.     

Right ventricular dysfunction after acute pulmonary embolism: Pathophysiologic factors, detection, and therapeutic implications

Acute PE may lead to right ventricular dilatation and failure. Through ventricular interdependence and decreased left ventricular filling, cardiac output and systemic circulation also may be compromised. The associated decrease in coronary perfusion pressure to the acutely overload right ventricle may produce ischemia and worsening right heart failure. This downward cycle of right ventricular failure and ischemia may ultimately progress to right ventricular infarction, circulatory arrest, and death. Certain clinical findings, hemodynamic values, and, particularly, echocardiographic signs can identify right ventricular dysfunction after PE. Detection of right ventricular hypokinesis helps to stratify patients' risk, because right ventricular dysfunction confers a worse prognosis than does normal right ventricular function after PE. The concept of “hemodynamic instability’ after PE should be expanded to include right ventricular dilatation and wall motion abnormalities, even among normotensive patients. Aggressive intervention with thrombolytic therapy, vasoactive agents, or mechanical embolectomy may improve right ventricular function and clinical outcome.     

房间隔缺损封堵术后右心形态和功能的变化

目的 :评价继发孔房间隔缺损 (房缺 )封堵术后及随访中右心形态及右心室功能的变化。方法 :全组患者 36例 ,男性 11例 ,女性 2 5例 ,年龄 5～ 5 6 ( 2 7 2± 14 6 )岁。均用Amplatzer封堵器治疗。于封堵术前 1天、术后 2天、术后 3个月分别行超声心动图检查 ,右心室容积采用面积长度法计算。结果 :房缺封堵术后 2天及 3个月随访 ,右心房上下径、左右径 ,舒张末期右心室前后径、左右径均进行性改善 ,与术前比较 ,有显著差异 (P <0 0 5～ 0 0 1)。术后 2天 ,右心室的舒张末期容积 ,每搏输出量、射血分数均较术前明显改善 ,有显著性差异 (P <0 0 5 )。术后 3个月右心室的舒张末期容积、收缩末期容积、每搏输出量、射血分数较术前进一步改善 ,均有显著差异 (P <0 0 1)。结论 :房缺封堵术后及短期随访中 ,右心形态进行性改善 ,主要表现在右心房上下径、左右径及右心室舒张末期前后径、左右径进行性缩小 ;右心室的高动力循环状态术后虽明显减轻 ,但随访中右心功能无明显改变 ,保持了正常的右心功能     

Effects of occlusion of the left anterior descending coronary artery during angioplasty on right-sided cardiac pressures and electrocardiographic changes

Controversy persists regarding the presence and extent of right ventricular involvement with acute anterior injury. Also unclear are the incidence and significance of ST elevations in the right-sided leads in acute left anterior descending artery occlusion. Baseline and coronary occlusion hemodynamics and 15-lead electrocardiograms (addition of RV3 through RV5) were recorded in 42 patients during 32 left anterior descending and 13 right coronary artery angioplasties. The right coronary and left anterior descending artery angioplasties had similar baseline right and left ventricular hemodynamics, as well as identical right atrial to pulmonary wedge pressure ratios (0.51 right coronary vs 0.51 left anterior descending). Whereas the right coronary and left anterior descending occlusions produced similar elevations in right ventricular filling pressures, the left anterior descending occlusions produced greater elevations in left ventricular filling pressures. The right atrial to pulmonary wedge ratio increased with right coronary occlusions, but was unchanged with left anterior descending occlusions (0.79 right vs 0.46 left, p less than or equal to 0.0001). Presence of right-lead ST elevations in 10 left anterior descending occlusions did not con-note increased right ventricular filling pressures, but did suggest increased left ventricular ischemia and dysfunction. In conclusion, right ventricular dysfunction, as manifested by increased filling pressures, is seen with both right coronary and left anterior descending occlusions. Although it is the predominant abnormality in right coronary occlusions, in left anterior descending occlusions it is proportional to left ventricular dysfunction. ST elevations in a right lead with left anterior descending occlusions do not constitute a marker for increased right ventricular dysfunction.     

Using functional magnetic resonance imaging to explore the possible mechanism of the action of acupuncture at Dazhong (KI 4) on the functional cerebral regions of healthy volunteers

Acupuncture at right Dazhong (KI 4) mostly affects functional magnetic resonance imaging signal in the right inferior frontal gyrus, right insular lobe, right thalamus, right middle frontal gyrus and right orbitofrontal cortex, which are associated with governing executive functions, emotional activities and social behaviour.     

右心室流入道间隔部起搏血流动力学研究

目的本文旨在对右心室流入道间隔部起搏的血流动力学进行分析,以确立右心室流入道间隔部起搏的临床地位。方法本研究通过射频消融房室结建立Ⅲ°房室传导阻滞模型,结合影像学及心电图定位方法于右心室流入道间隔部置入螺旋电极导线,并分别比较右心室心尖部、右心室流出道及右心室流入道间隔部起搏后急性血流动力学指标变化,并随访右心室流入道间隔部起搏2周后的血流动力学指标。结果即刻血流动力学研究结果显示,右心室流入道间隔部较心尖部和右心室流出道起搏心排血量高(P<0.05),左心室舒张末期压力较低(P<0.05),而右心室流入道间隔部起搏前后各项血流动力学无显著变化。结论右心室流入道间隔部起搏具有良好的血流动力学效应,可作为右心室心尖部起搏的替代起搏部位。     

Double Aortic Arch with Dominant Left Arch and Right Ligamentum Arteriosum

This case report describes a rare example of double aortic arch with a dominant left aortic arch, patent minor right aortic arch, left descending aorta, and right ligamentum arteriosum causing tracheobronchial compression in a twin baby girl with DiGeorge syndrome. She also had large right subclavian artery arising from right‐sided diverticulum of Kommerell, aplastic thymus, T cell lymphopenia with normal immunoglobulin, hypocalcemia, and hypomagnesemia. The diverticulum of Kommerell was resected and minor right aortic arch, right ligamentum arteriosum, and right subclavian artery were divided through right posterolateral thoracotomy. Aortopexy was performed under bronchoscopic guidance to relieve the airway compression. We strongly suggest a right‐sided approach in this type of vascular arrangement for easy access and better outcome.     

Angiographic findings in arrhythmogenic dysplasia of the right ventricle

Arrhythmogenic right ventricular dysplasia is characterized by fibrous and adipose replacement of the right ventricular myocardium and recurrent ventricular arrhythmias of left bundle branch block morphologic pattern. Sometimes the diagnosis is difficult because not all the clinical and instrumental findings are present and the separation between arrhythmogenic right ventricular dysplasia and other right ventricular cardiopathies is uncertain. In such cases the angiographic appearance of the right ventricle has been considered the "gold standard". To assess the diagnostic value of right ventricular morphology in identifying arrhythmogenic right ventricular dysplasia, we compared the angiographic findings of 8 patients with arrhythmogenic right ventricular dysplasia, 10 with biventricular dilated cardiomyopathy and 10 with Ebstein's anomaly. The following aspects were considered: deep fissuring of the anterior or inferior wall, outflow tract enlargement, contrast persistence in the right ventricle during the levophase, regional wall motion abnormalities including aneurysmal formations and tricuspid regurgitation. Aneurysmal formations of the right ventricle were found only in arrhythmogenic right ventricular dysplasia whereas the other angiographic findings were common to all the above mentioned diseases. Right ventricular angiography is an important adjunct to the clinical and instrumental diagnosis of arrhythmogenic right ventricular dysplasia, but most of its angiographic features are common to other diseases which cause right ventricular dilatation.     

Negative right ventricular diastolic pressure after operation for pulmonary valve stenosis: the phenomenon and its relation to volume load and conal contraction

The phenomenon of negative right ventricular diastolic pressure immediately after operation for relief of isolated pulmonary valve stenosis was investigated in 11 patients. Pressures in the right ventricle and pulmonary artery were measured with a catheter tip micromanometer. One patient had a negative right ventricular diastolic pressure before operation. At the end of operation right ventricular diastolic pressure was negative in all 11 patients. The greater the right ventricular hypertrophy, the lower were these diastolic pressures. Negative right ventricular diastolic pressure is thus common in patients after pulmonary valvotomy, but fluid administration may eliminate it. Negative right ventricular diastolic pressure may be the result of hypercontraction and reduced volume of the hypertrophied right ventricle after relief of right ventricular outflow tract obstruction.     

Negative right ventricular diastolic pressure after operation for pulmonary valve stenosis: the phenomenon and its relation to volume load and conal contraction.

The phenomenon of negative right ventricular diastolic pressure immediately after operation for relief of isolated pulmonary valve stenosis was investigated in 11 patients. Pressures in the right ventricle and pulmonary artery were measured with a catheter tip micromanometer. One patient had a negative right ventricular diastolic pressure before operation. At the end of operation right ventricular diastolic pressure was negative in all 11 patients. The greater the right ventricular hypertrophy, the lower were these diastolic pressures. Negative right ventricular diastolic pressure is thus common in patients after pulmonary valvotomy, but fluid administration may eliminate it. Negative right ventricular diastolic pressure may be the result of hypercontraction and reduced volume of the hypertrophied right ventricle after relief of right ventricular outflow tract obstruction.     

多普勒超声心动图评价右室负荷状态的右室舒张功能

本文应用三尖瓣多普勒频谱方法,研究各种右室负荷状态的先心病右室舒张功能的变化。观察到右室压力负荷过重患者舒张早期与晚期右室充盈指标均有显著改变,右室容量负荷过重者以舒张晚期功能异常为主,而右室尚未出现负荷过重的先心病也存在右室舒张功能异常现象。     

Effect of opening the pericardium on right ventricular hemodynamics during cardiac surgery

The impact of the pericardium on right ventricular performance in the presence of normal filling pressures was evaluated using a rapid response RVEF thermodilution pulmonary artery catheter and TEE. In eight patients with normal right coronary arteries undergoing coronary artery bypass surgery, hemodynamic measurements revealed increased right ventricular end-diastolic and end-systolic volumes with diminished RVEF after opening the pericardium. In eight additional patients with right coronary artery disease, directionally similar changes in right ventricular volume were seen. Ejection fraction, however, was unchanged possibly due to altered right ventricular compliance. Echocardiogram evaluation of right ventricular area changes in patients with compromised right coronary systems corresponded to ejection fraction determinations obtained with thermodilution technique.