单纯右冠状动脉狭窄对左心室功能的影响

目的:探讨单纯右冠状动脉（RCA）狭窄不同狭窄程度和狭窄节段对左心室功能的影响。方法:将冠状动脉造影证实为单纯RCA狭窄的患者99例,按不同狭窄程度、不同狭窄节段和不同冠脉优势型进行分组,并与494例无冠状动脉狭窄的对照组比较,经左心室造影测定的左室射血分数（LVEF）和左室舒张末压（LVEDP）。结果:与对照组患者相比,轻度、中度和重度单纯右RCA狭窄患者的LVEF变化不显著,完全闭塞患者的LVEF显著下降（P<0.05）;右冠中段、右冠远段、后降支和侧后支病变患者的LVEF均无有意义变化,右冠近段病变患者LVEF下降有统计学意义（P<0.05）。单纯RCA狭窄患者中,右冠优势组LVEF略低于均衡优势组和左冠优势组,但差异未达显著水平。单纯RCA狭窄对LVEDP的影响并不明显。结论:单纯RCA主干近段狭窄和单纯RCA完全闭塞对左室收缩功能可产生一定程度的损害。     

右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响

目的　探讨右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响及其机制。方法　对比分析左冠状动脉狭窄患者在合并与不合并右冠状动脉病变时的左心室射血分数。结果　与相应部位单纯左冠状动脉狭窄患者相比 ,合并右冠状动脉病变患者左心室射血分数均呈不同程度地下降 ,其中在左前降支、左前降支 +左回旋支狭窄基础上合并右冠状动脉病变时左心室射血分数下降有统计学意义 (P <0 .0 5或 0 .0 1) ,左主干合并右冠状动脉狭窄患者下降幅度最大 ,但无统计学意义。结论　右冠状动脉病变可在单纯左冠状动脉狭窄的基础上使左心室收缩功能进一步恶化 ;当左冠状动脉狭窄部位为左前降支、左主干或左前降支 +左回旋支时 ,对左心室收缩功能影响更为严重     

右冠状动脉狭窄程度对左冠状动脉狭窄患者左室射血分数的影响

目的研究右冠状动脉不同程度狭窄对左冠状动脉狭窄患者左室射血分数（LVEF）的影响。方法根据左冠状动脉病变部位不同,将1 000例左冠状动脉狭窄患者分为左前降支（LAD）狭窄,左回旋支（LCX）狭窄,左主干（LM）狭窄,左前降支+左回旋支（LAD+LCX）狭窄4个系列。每个系列再根据右冠状动脉（RCA）病变程度不同分为RCA正常组（直径狭窄<50%）、RCA非闭塞组（99%>直径狭窄≥50%）和RCA闭塞组（直径狭窄≥99%）,比较分析3组间LVEF的差异。结果在LAD,LCX,LM,LAD+LCX狭窄时,与RCA正常组LVEF相比,RCA非闭塞组LVEF分别下降0.9%,0.3%,3.4%和2.8%;RCA闭塞组LVEF分别下降10.9%,3.7%,6.5%和5.2%。LAD狭窄时,RCA非闭塞组和RCA闭塞组之间LVEF有统计学差异（P<0.01）。结论右冠状动脉病变可在左冠状动脉狭窄的基础上使左室射血分数进一步下降;当左冠状动脉狭窄为闭塞性病变时,影响更为明显。     

Exercise and rest technetium-99m-tetrofosmin lung uptake: correlation with left ventricular ejection fraction in patients with coronary artery disease

Increased lung uptake of thallium-201 (Tl-201) and technetium-99m (Tc-99m) MIBI in myocardial perfusion imaging is a reliable marker of left ventricular dysfunction. The goal of our study was to establish whether the lung-to-heart (L/H) uptake ratio with a newer cardiac imaging agent, Tc-99m tetrofosmin, can also provide valuable information about left ventricular function. We studied 60 patients with recent coronary artery diseases (CAD) undergoing first-pass radionuclide ventriculography to calculate left ventricular ejection fraction (LVEF) and myocardial perfusion imaging to calculate the L/H ratio. Group A consisting of 30 CAD patients with higher LVEF (> or =40%) had a significantly lower L/H ratio than group B consisting of 30 CAD patients with abnormal LVEF (<40%) during exercise and rest. In groups A and B, the exercise and rest L/H ratios did not differ significantly. However, a statistically significant inverse correlation was found between the L/H ratio and LVEF during exercise and rest among the 60 patients. L/H ratios, measured by 99mTc-tetrofosmin imaging, provide clinically useful information with which to predict left ventricular dysfunction in CAD patients.     

Right ventricular ejection and regional wall motion evaluated by cardiac blood pool emission computed tomography

Calculating right ventricular (RV) ejection fraction (EF) is difficult because of geometrical problems such as irregular trabeculations, a separate infundibulum, and variations in the right ventricular shape. We performed 99mTc ECG-(dual)gated cardiac blood pool emission computed tomography (ECT) in 10 patients with ischemic heart disease, three patients with dilated cardiomyopathy (DCM), and eight normal subjects as controls, and RVEF and % shortening of the RV were calculated to evaluate right ventricular function. Methods were as follows: 1) RVEF: The region of interest (ROI) of the RV was determined on reconstructed short-axial images, and then the RV counts in the ROI were summed from the apical slice to the RA-RV boundary slice. (Formula: see text) 2) % shortening of the RV: At the RV mid-portion, the contour from the short-axial image was obtained using the threshold method; the end-diastolic contour was superimposed on the end-systolic contour, and then shortenings in the RV free wall and septum respectively, were calculated. To evaluate reliability of RVEF obtained by this method, left ventricular ejection fraction (LVEF) calculated using the same method was compared with results obtained by the previously validated method: There were significant correlations with contrast cineangiography (r = 0.69) and the conventional multigated method (r = 0.90), respectively. Cases with decreased RVEF showed a variety of right ventricular abnormal findings, including positive uptake on 99mTc-PYP scintigraphy, occlusion of the right coronary artery, RV dilatation on echocardiography. The mean RV free wall shortening in the decreased RVEF group was lower than that of the normal group (p less than 0.01), whereas there was no significant difference in the decreased LVEF group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aortic pulse pressure is associated with the localization of coronary artery disease based on coronary flow lateralization

BackgroundAortic pulse pressure (APP) is related to arterial stiffness and associated with the presence and extent of coronary artery disease (CAD). Besides, the left coronary artery (LCA) has a predominantly diastolic flow while the right coronary artery (RCA) receives systolic and diastolic flow. Thus, we hypothesized that increased systolic-diastolic pressure difference had a greater atherogenic effect on the RCA than on the LCA.MethodsA random sample of 433 CAD patients (145 females, 288 males, mean age 65.0 ± 11.1 years) undergoing coronary angiography at Staten Island University Hospital between January 2005 and May 2008 was studied. Coronary lesion was defined as a ≥50% luminal stenosis. Patients were divided into three groups, with isolated LCA lesions (n = 154), isolated RCA lesions (n = 36) or mixed LCA and RCA lesions (n = 243).ResultsAPP differed significantly between groups, being highest when the RCA alone was affected (67.6 ± 20.3 mm Hg for LCA vs. 78.8 ± 22.0 for RCA vs. 72.7 ± 22.6 for mixed, P = 0.008 for analysis of variance (ANOVA)). Age and gender were not associated with CAD location. Heart rate was associated with CAD location, lowest in RCA group, and negatively correlated with APP. However, left ventricular ejection fraction (LVEF) was lower in the mixed CAD group and positively correlated with APP. The association between APP and right-sided CAD persisted in multivariate logistic regression adjusting for confounders, including heart rate, LVEF and medication use. A similar but less significant pattern was seen with brachial arterial pressures.ConclusionsAortic pulse pressure may affect CAD along with coronary flow phasic patterns.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.87.     

ECG-G-MRI三维立体法评价心功能的观察

采用ECG-G-MRI Simpson法评价了50例正常人和早期高血压21例,Ⅲ期高血压13例,扩张性心肌病8例,冠心病18例的心功能,与正常组比较,早期(Ⅰ～Ⅱ期)高血压组主要表现为左心室向心性肥厚,心肌重量增加,而LVEF正常,但RVEF轻度降低,Ⅲ期高血压组除心肌肥厚、重量增加更明显外,还出现了左心室腔明显扩大,PSWT、LVEF明显降低,ESWS显著升高.扩张性心肌病组LVEDV、LVESV、RVEDV、RVESV、D、ES Ac/Aw、LVM和ESWS等指标不仅显著超过正常组,而且明显超过其余各心血管病组,而LVEF、RVEF、ASWT和PSWT则显著低于正常组和各心血管病组,提示扩张性心肌病患者左、右心室明显扩大,心功能均极差,预后不良.冠心病组亦有心肌肥厚,左心室扩大,心肌收缩功能降低的表现.     

急性ST段抬高性前壁心肌梗死患者的右心室功能分析

目的:评价急性前壁ST段抬高性心肌梗死直接经皮冠状动脉成形术(PCI)患者的右心室收缩和舒张功能变化。方法:分析46例急性前壁ST段抬高性心肌梗死患者[前降支近端完全闭塞者24例(前降支近端闭塞组),前降支远端急性闭塞者22例(前降支远端闭塞组)]直接PCI和35例冠状动脉造影"正常"患者(对照组)的临床、冠状动脉造影和心电图资料。采用二维心脏超声分别测定入选患者的右心室舒张末期容积(RVEDV),右心室收缩末期容积(RVESV),右心室射血分数(RVEF),平均肺动脉压(MPAP),左心室舒张末期容积(LVEDV),左心室收缩末期容积(LVESV),左心室射血分数(LVEF)和心脏指数(CI)。结果:与对照组相比,前降支远端闭塞组的平均肺动脉压无显著性差异(P>0.05),而右心室舒张末期容积和收缩末期容积增大,右心室射血分数降低;左心室舒张末期容积和收缩末期容积增加,左心室射血分数、心脏指数减低(P均<0.01)。与前降支远端闭塞组比较,前降支近端闭塞组的左心室舒张末期容积和收缩末期容积增加(P<0.01),心脏指数和左心室射血分数减少(P<0.01),右心室舒张末期容积收缩末期容积和平均肺动脉压增加(P<0.05～0.01),右心室射血分数降低(P<0.01)。多元线性回归分析表明前降支近端闭塞与右心室射血分数降低(R2=0.38,P<0.01)、右心室舒张末期容积增加(R2=0.410,P<0.01)有较好的相关性。2周后,前降支近端和远端闭塞组的右心室舒张末期容积、右心室收缩末期容积、平均肺动脉压和右心室射血分数无明显差异,而前降支近端闭塞患者的左心室舒张末期容积和收缩末期容积增大,左心室射血分数和心脏指数较低(P均<0.01)。结论:提示前降支近端闭塞可能伴右心室前壁部分心肌梗死导致右心室收缩和舒张功能障碍。     

Major increase in brain natriuretic peptide indicates right ventricular systolic dysfunction in patients with heart failure

This study sought to investigate whether the presence of right ventricular systolic dysfunction with pre-existing left ventricular systolic dysfunction is associated with higher plasma brain natriuretic peptide (BNP) levels, compared with patients with isolated left ventricular dysfunction. Eighty-five patients referred for evaluation of isotopic ventricular function were prospectively included in the study. Left (LVEF) and right (RVEF) ventricular ejection fractions were evaluated by gated blood pool scintigraphy and compared with plasma BNP levels. BNP correlated negatively with LVEF, except in patients with ischaemic heart disease (P=0.09) and in patients with LVEF<40% (P=0.11). In contrast, BNP levels correlated negatively with RVEF for all subgroups. Among patients with RVEF<40%, no significant BNP difference was found between patients with or without additional left ventricular systolic dysfunction (P=0.51). Among patients with LVEF<40%, plasma BNP levels were significantly higher in patients with RVEF<40% than in patients with RVEF>/=40% (P=0.004) whereas age, renal function, clinical findings, ventricular volumes, LVEF or medication were not significantly different. In conclusion, an important increase in BNP levels in patients with left ventricular systolic dysfunction should be considered by cardiologists as an indication of high risk of right ventricular dysfunction and should justify further investigation.     

Revascularization of the right coronary artery: Influence thermodilution right ventricular ejection fraction

This study was designed in order to evaluate the influence of right coronary artery (RCA) disease and its revascularization on right heart performance monitored by measuring thermodilution right ventricular ejection fraction (RVEF). Forty patients undergoing elective aortocoronary bypass surgery were divided into two groups: group 1, with RCA revascularization, n = 20; and group 2, without RCA disease or revascularization, n = 20. RVEF was measured using a pulmonary arterial catheter mounted with a fast-response thermistor and a bedside microprocessor ejection fraction computer. The major finding of the study was that myocardial revascularization with extracorporeal circulation was followed by a decrease in RVEF which was significantly more pronounced in group 1 (−13.1%) in comparison to group 2 (−5.0%). RVEF gradually increased after bypass, but did not reach baseline values. By the first postoperative day, RVEF had reached baseline values again in group 1 and had increased beyond baseline values in group 2. Traditionally measured hemodynamic parameters could not be correlated with the course of RVEF, except for cardiac index. The present study further suggests that right-sided events may have clinical effects on left-sided function. Inadequate protection of the right heart, especially in patients with RCA stenosis, may result in depression of right ventricular myocardial performance, which can be monitored serially by measuring RVEF.     

Independent effects of both right and left ventricular function on plasma brain natriuretic peptide

BACKGROUND: Brain natriuretic peptide (BNP) is increased in heart failure; however, the relative contribution of the right and left ventricles is largely unknown. AIM: To investigate if right ventricular function has an independent influence on plasma BNP concentration. METHODS: Right (RVEF), left ventricular ejection fraction (LVEF), and left ventricular end-diastolic volume index (LVEDVI) were determined in 105 consecutive patients by first-pass radionuclide ventriculography (FP-RNV) and multiple ECG-gated equilibrium radionuclide ventriculography (ERNV), respectively. BNP was analyzed by immunoassay. RESULTS: Mean LVEF was 0.51 (range 0.10-0.83) with 36% having a reduced LVEF (<0.50). Mean RVEF was 0.50 (range 0.26-0.78) with 43% having a reduced RVEF (<0.50). The mean LVEDVI was 92 ml/m2 with 22% above the upper normal limit (117 ml/m2). Mean BNP was 239 pg/ml range (0.63-2523). In univariate linear regression analysis LVEF, LVEDVI and RVEF all correlated significantly with log BNP (p<0.0001). In a multivariate analysis only RVEF and LVEF remained significant. The parameter estimates of the final adjusted model indicated that RVEF and LVEF influence on log BNP were of the same magnitude. CONCLUSION: BNP, which is a strong prognostic marker in heart failure, independently depends on both left and right ventricular systolic function. This might, at least in part, explain why BNP holds stronger prognostic value than LVEF alone.     

Right and left ventricular dysfunction in patients with chronic obstructive lung disease: Assessment by first-pass radionuclide angiography

To evaluate the relationship between right and left ventricular function in patients with obstructive lung disease, we studied 10 normal subjects (group 1) and 37 patients with chronic obstructive pulmonary disease by first pass radionuclide angiography. These 37 patients were divided into three groups: nine with mild chronic obstructive pulmonary disease (group 2), 20 with severe chronic obstructive pulmonary disease (group 3) and eight with severe chronic obstructive pulmonary disease and primary left ventricular disease (group 4). In each subject right ventricular ejection fraction (RVEF), left ventricular ejection fraction (LVEF) and ejection fraction during first third of systole (first third LVEF) were calculated. LVEF RVEF First-Third LVEF Group 1 0.60 ± 0.05 0.52 ± 0.03 0.29 ± 0.04 Group 2 0.61 ± 0.08 0.52 ± 0.03 0.29 ± 0.02 Group 3 0.58 ± 0.09 0.46 ± 0.091 0.24 ± 0.061 Group 4 0.51 ± 0.061 0.44 ± 0.091 0.20 ± 0.031 1 p < 0.05 versus 1. All subjects in group 2 had normal left ventricular and right ventricular function. In group 3,11 of 10 (55 per cent) had a low RVEF and three of 20 (15 per cent) a low LVEF. However eight of 20 in this group (40 per cent) had a depressed first-third LVEF. The correlation between decline in RVEF and first-third LVEF was good r = 0.73. We conclude that (1) certain indices of early systolic left ventricular ejection are abnormal in many patients with chronic obstructive pulmonary disease and correlate with the decline in right ventricular function; (2) this is not seen in patients with mild chronic obstructive pulmonary disease and is worse in patients with underlying left-sided heart disease.     

Influence of acute preoperative hemodilution on right ventricular function

In a randomized study, the effects of acute, preoperative hemodilution (HD) (12 mL/kg) on right ventricular function were investigated in coronary artery surgery patients with reduced left ventricular function (ejection fraction < 50%) and significant stenosis of the right coronary artery (RCA). Blood was replaced either by hydroxyethyl starch (HES) solution (ratio 1:1; HD-HES; n = 15) or by Ringer's lactate, (RL) (ratio 2.5:1; HD-RL; n = 15). Fifteen comparable patients without HD served as a control group. Besides commonly measured pressure parameters, right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and right ventricular ejection fraction (RVEF) were measured using a computerized thermodilution technique before and after HD, as well as after extracorporeal circulation (ECC). Right ventricular systolic function, expressed as RVEF, was not changed significantly by HD in any group. Furthermore, right ventricular function of the hemodiluted patients was not impaired by the subsequent ECC procedure. None of the traditionally measured parameters could be correlated significantly to the right ventricular thermodilution variables. It is concluded that moderate HD does not change right ventricular function even when the RCA is significantly stenosed.     

Correlation of abnormal response of left ventricular ejection fraction after exercise and left ventricular cavity-to-myocardium count ratio of technetium-99m-tetrofosmin single photon emission computed tomography in patients with coronary artery disease

The aim of this study was to assess the value of the left ventricular cavity-to-myocardium count ratio (C/M ratio) of technetium-99m (Tc-99m) tetrofosmin single photon emission computed tomography (SPECT) to identify abnormal left ventricular ejection fraction (LVEF) responses after exercise in patients with coronary artery diseases (CAD). We studied 50 patients with recent CAD undergoing rest and exercise first-pass ventriculography to calculate LVEF and rest and exercise Tc-99m tetrofosmin myocardial perfusion SPECT to calculate left ventricular C/M ratios. Group A, consisting of 25 CAD patients with normal responses (increased LVEF> or =5% after exercise), had significantly higher rest and exercise C/M ratios than those of the group B, consisting of 25 CAD patients with abnormal responses (increased LVEF <5% after exercise) after exercise. However, the C/M ratios between exercise and rest did not differ significantly between groups A and B. In addition, there was significant correlation between LVEF and C/M ratios in all of the patients. C/M ratios of Tc-99m tetrofosmin myocardial perfusion SPECT are useful parameters for identifying patients with abnormal LVEF responses among patients with CAD.     

Clinical significance of the right ventricular free wall appearance on stress Tl-201 myocardial images in ischemic heart disease

In order to evaluate the clinical significance of thallium (Tl)-201 myocardial imaging for diagnosing the right ventricular (RV) ischemia, we studied the relationship of right ventricular free wall (RVFW) appearance on myocardial images to coronary arteriographic findings. Patients were divided into 3 groups as follows: 1) normal control (NC) group (19 cases) without angiographically documented coronary artery disease; 2) non-RCA group (18 cases) with significant coronary artery lesion restricted to the left coronary artery (LCA); and 3) RCA group (36 cases) with significant right coronary artery (RCA) stenosis regardless of underlying LCA disease. After the patients had exercised up to 80-85% of the predicted maximal heart rate, immediate and 3-4 hour delayed myocardial images were obtained. As for presence or absence of the RV ischemia on images, the RVFW appearance in 30 degrees and 60 degrees left anterior oblique (LAO) views were assessed carefully. On the immediate images, all patients except one in the NC group and all except 3 in the non-RCA group demonstrated 'continuous visualization' of the RVFW in both views. In the RCA group, 6 showed 'non-visualization' and 11 'defective visualization' of the RVFW in 30 degrees LAO view. In 60 degrees LAO view, 6 presented 'non-visualization' and other 6 'defective visualization' of the RVFW. On the delayed images, although none of the patients in the groups NC and non-RCA demonstrated redistribution phenomenon of the RVFW, 4 patients in the RCA group showed redistribution of Tl-201 into the RVFW. Non- and defective visualization of the RVFW on the immediate images were related to the proximally located RCA lesion, previous history of inferior myocardial infarction and high grade RCA stenosis. Collateral vessels seemed to protect the RVFW against the development of exercise induced ischemia and affect the occurrence of redistribution of Tl-201 into the RVFW. In conclusion, stress Tl-201 myocardial imaging enables us to estimate the myocardial blood flow of the RV and is a useful non-invasive method in the evaluation of RV ischemia.     

Simultaneous analysis of myocardial perfusion and ventricular function. Normal values in the Mexican population

Myocardial perfusion imaging is an useful procedure in the evaluation of patients with coronary artery disease, Gated SPECT technique evaluates simultaneously perfusion and ventricular function, left ventricular ejection fraction (LVEF), ventricular volumes and the transient ischemic dilatation of the left ventricle. OBJECTIVE: To evaluate the normal ventricle volumes and the ejection fraction of the LV obtained automatically with the Gated SPECT in Mexican population. METHODS: 100 patients were studied with low likelihood for CAD. All of them were studied with Tc-99m Sestamibi Gated SPECT. We obtained automatically the LVEF, and the end diastolic and systolic left ventricular volumes. RESULTS: Myocardial perfusion, regional motion and systolic thickening were normal in all patients. We obtained the mean values of EF and end diastolic and systolic volumes. These values were lower in female. CONCLUSION: Tc-99m Sestamibi myocardial perfusion SPECT is an useful procedure, with high accuracy for the simultaneous evaluation of myocardial perfusion and ventricular function.     

Effect of bisoprolol on right ventricular function and brain natriuretic peptide in patients with heart failure

Beta-blocker use improves left ventricular ejection fraction (LVEF) in patients with heart failure. A similar effect of b blockers on right ventricular function has been proposed, although the effect of bisoprolol, a highly selective b-1 blocker, on right ventricular function has not been assessed. This study investigated the short-term effect of bisoprolol on right ventricular function in chronic heart failure patients. A cohort of 30 heart failure patients who were not taking b blockers at baseline was studied prospectively. Right ventricular ejection fraction (RVEF) and LVEF were measured at both baseline and 4 months by radionuclide angiography. Bisoprolol was up-titrated during four monthly visits by a preestablished protocol to a target dose of 10 mg/d. The dose of vasodilators was not changed. Quality of life and brain natriuretic peptide level were assessed. Mean age was 62.7+/-14.3 years. Baseline RVEF was 30.7%+/-6.3% and baseline LVEF was 21.7%+/-9.4%. Mean bisoprolol dose reached was 5.3+/-3.9 mg daily. At 4 months, RVEF significantly increased by 7.1% (95% confidence interval, 3.9-10.2; p=0.0001) and LVEF also increased significantly by 7.9% (95% confidence interval, 4.0%-11.9%; p=0.0003). Quality-of-life score improved from 42.8 to 30.8 (p=0.047). No correlation was found between brain natriuretic peptide levels and RVEF. Bisoprolol treatment for 4 months resulted in a significant improvement of RVEF, which paralleled the improvement of LVEF.     

Effects of oral mexiletine on left and right ventricular function

Malignant ventricular arrhythmias often occur in patients with left ventricular (LV) dysfunction. Antiarrhythmic drugs may further impair LV function in these patients. Mexiletine, a lidocaine congener, is an effective antiarrhythmic drug, but when administered orally, its effect on LV and right ventricular (RV) function is unknown. To determine the hemodynamic effects of mexiletine, LV and RV ejection fraction (EF) were measured by radionuclide ventriculography in 10 patients with LV dysfunction (LVEF less than 50%). Symptom-limited exercise tests were also performed. Patients were studied before and during therapy with oral mexiletine. There was no significant change in LVEF (28% vs 27%) or RVEF (46% vs 41%). Also, heart rate at rest, exercise duration and peak heart rate during exercise were unchanged. Thus, in patients with LV dysfunction, oral mexiletine does not significantly affect LV or RV function.     

Effect of beta-blockade on right ventricular performance in patients with and without right ventricular dysfunction due to coronary artery disease

To assess the effects of beta-blockade on right ventricular performance in patients with and without right ventricular dysfunction due to coronary artery disease, we performed radionuclide ventriculography on eight patients with normal right ventricular ejection fraction (RVEF greater than or equal to 35%) and 14 patients with mild to moderate right ventricular dysfunction (RVEF less than 35%) at rest. All patients had chronic stable angina pectoris, and nine patients had prior myocardial infarction. Radionuclide ventriculography was performed on placebo and during clinical beta-blockade (heart rate, 50 to 60 beats per minute and less than or equal to 20% increase in heart rate over baseline during stage I treadmill exercise, Bruce protocol) with the oral, cardioselective beta-blocking agent, betaxolol. The resting RVEF (mean +/- 1 SD) was 33% +/- 7% on placebo and 34% +/- 7% during clinical beta-blockade. Mean exercise RVEF was 40% +/- 8% on placebo and 39% +/- 8% during clinical beta-blockade. These differences were not statistically significant. Resting left ventricular ejection fraction ranged from 22% to 60% (mean, 42% +/- 8%). On placebo, one of eight patients with a resting RVEF greater than or equal to 35% had a normal exercise RVEF response (greater than or equal to 5% increment) whereas nine of 14 patients with resting RVEF less than 35% had normal exercise response. The discordant relationship between baseline RVEF and exercise response on placebo became less marked during clinical beta-blockade. We conclude that beta-blockade does not produce significant deterioration of right ventricular systolic function or right ventricular reserve either in patients with normal or in those with mild to moderately impaired resting right ventricular systolic function.     

Endomyocardial biopsy findings in pediatric patients with post myocarditic state

Endomyocardial biopsy was performed on eight children 5 to 12 years old, who were in post myocarditic state. They were evaluated within 2 to 25 months (mean lyr and 1 m) after the onset of the symptoms. Two of the patients developed heart failure and six patients developed other cardiac manifestations such as syncope, palpitation or ECG abnormalities at onset. Definite elevation of viral antibody titer was observed in four patients. Radionuclide angiography was also performed in all eight patients. An abnormal perfusion area was observed in six patients as a focal hypoperfusion area by T1-201 myocardial imaging. Ejection fraction was examined by Tc-99m-HSA gated equilibrium ventriculography. LVEF was reduced in 3 patients and RVEF was reduced in 2 patients. Judging from the histopathological findings, these patients were divided into three categories: chronic or smoldering myocarditis (3 patients); healing or healed myocarditis (4 patients); and post myocarditic hypertrophy (1 patient). Measurement of left ventricular function was obtained by cardiac catheterization and left ventriculography (LVG), which revealed some abnormal findings such as increased left ventricular mass index, increased left ventricular end diastolic volume index (LVEDVI) and reduced left ventricular ejection fraction (LVEF). Therefore, endomyocardial biopsy findings of pediatric patients in a post myocarditic state reveal certain histopathological abnormalities even in the long-term follow-up period in the absence of cardiac dysfunction.