30例创伤性急性呼吸窘迫综合征患者的救治体会

治疗３０例创伤性急性呼吸窘迫综合征（ＡＲＤＳ）患者。结果显示，存活组与死亡组机械通气前的动脉血氧分压（ＰａＯ２）及支脉血二氧化碳分压（ＰａＣＯ２）有显著差异，后者ＰａＯ２降低更明显，ＰａＣｏ２较高。死亡者全部燕发多脏器衰竭（ＭＯＦ），未并发ＭＯＦ者均存活。ＭＯＦ一创伤早期出血性休克及创伤后期的感染性休克有关。提示救治ＡＲＤＳ的关键是及早行机械通气，迅速纠正休克，同时防治感染。     

气管内吹气对急性高碳酸血症家兔血气及呼吸力学的影响

目的　探讨气管内吹气（ Ｔ Ｇ Ｉ） 对急性高碳酸血症（ Ｈ Ｃ） 家兔二氧化碳清除的效果及其对通气效率的改善作用。方法　用自行设计的 Ｔ Ｇ Ｉ装置对常规正常机械通气（ Ｃ Ｍ Ｖ） 和低通气致 Ｈ Ｃ 家兔行 Ｔ Ｇ Ｉ,分别观察两组动物在不同吹气流量（０２ Ｌ·ｍｉｎ１ 和０４ Ｌ·ｍｉｎ１） 时呼气末二氧化碳分压（ Ｐｅｔ Ｃ Ｏ２） 、血气与呼吸力学等指标的变化。结果　（１） Ｔ Ｇ Ｉ可明显降低两组动物的动脉血二氧化碳分压（ Ｐａ Ｃ Ｏ２） 水平,并能在潮气量（ Ｖ Ｔ） 降低３０ ％ 的情况下维持 Ｐａ Ｃ Ｏ２ 在正常范围, Ｔ Ｇ Ｉ降低 Ｐａ Ｃ Ｏ２ 的作用呈流量依赖性;（２） Ｔ Ｇ Ｉ使两组动物的气道压力明显增高,但 Ｈ Ｃ 组气道峰压（ Ｐｐｅａｋ） 、平台压（ Ｐｐａｕｓｅ） 水平均显著低于 Ｃ Ｍ Ｖ 组;（３） Ｔ Ｇ Ｉ使 Ｐｅｔ Ｃ Ｏ２ 明显降低,呼气阻力（ Ｒｅ） 及呼气潮气量（ Ｖ Ｅ） 显著增高,而对肺顺应性（ Ｃｓｔ） 无明显影响;（４） Ｔ Ｇ Ｉ对平均动脉压及心率无显著影响。结论　 Ｔ Ｇ Ｉ是一种简便实用的机械通气的辅助手段,它能有效地降低 Ｐａ Ｃ Ｏ２ ,并使气道压力维持在低水平。     

慢性阻塞性肺疾病患者吸氧时通气量变化的研究

慢性阻塞性肺疾病患者吸氧时通气量变化的研究刘志于润江有作者证明可用下式表示动脉血氧饱和度（ＳａＯ２）及二氧化碳分压（ＰａＣＯ２）对每分通气量（ＶＥ）的影响，ＶＥ＝Ｖ（ＳａＯ２、ＰａＣＯ２），经微分处理得ΔＶＥ＝（ｄｖ／ｄＳａＯ２）ΔＳａＯ２＋（ｄＶ／...     

氧疗及正压通气对慢性阻塞性肺病患者夜间低氧血症的疗效

为了观察夜间氧疗及加用持续正压通气对急性加重期慢性阻塞性肺病（ＣＯＰＤ）患者夜间低氧血症的治疗效果，用脉搏氧饱和度仪对５８例患者进行监测描记，并作动脉血气分析。结果表明，白天动脉血氧分压（ＰａＯ２）、动脉血二氧化碳分压（ＰａＣＯ２）及基础脉搏氧饱和度（ＳｐＯ２）与夜间平均脉搏氧饱和度（ＭＳｐＯ２）之间有显著的正相关（ｒ＝０．７０２，ｒ＝０．６１３，ｒ＝０．６０５，Ｐ值均＜０．０１），与夜间呼吸空气时比较，３７例患者夜间氧疗效果良好，夜间平均ＳｐＯ２、平均最低ＳｐＯ２（ｍＳｐＯ２）升高（Ｐ＜０．０１），氧降累计时间百分比（ＣＴＮＯＤ％）降低（Ｐ＜０．０１）。其余２１例患者疗效不佳，改用夜间氧疗加持续正压通气（ＢｉＰＡＰ）后效果极好，夜间ＭＳｐＯ２、ｍＳｐＯ２与ＣＴＮＯＤ％三项指标均显著改善（Ｐ＜０．０１），且睡后ＰａＯ２升高（Ｐ＜０．０１），ＰａＣＯ２降低（Ｐ＜０．０１）。证实夜间氧疗能纠正多数ＣＯＰＤ患者的夜间低氧血症，对疗效不良者加用无创持续正压通气可获满意效果。     

肥胖通气低下综合征呼吸中枢反应性的改变与二氧化碳潴留相关作用

目的 观察肥胖通气低下综合征患者呼吸中枢反应性的改变与二氧化碳（ＣＯ２）潴留的相关作用。方法 测定了５例白天动脉血二氧化碳分压（ＰａＣＯ２）〉４５ｍｍＨｇ的睡眠呼吸暂停综合征（ＳＡＳ）患者呼吸中枢柢氧反应性（△Ｐ０．１／△ＳａＯ２ｗ、△Ｖｅ／△ＳａＯ２）及高ＣＯ２反应性（△Ｐ０．１／△ＰａＣＯ２、△Ｖｅ／△ＰａＣＯ２）,并选择５例年龄、性别、身高、体重、呼吸暂停病程及睡眠呼吸率乱指数（ＡＨＩ）相近     

冠状动脉重建术后氧输送和氧耗关系的探讨

观察３０例冠状动脉旁路移植术（ＣＡＢＧ）后氧输送指数（ＤＯ２Ｉ）、氧耗指数（ＶＯ２Ｉ）及其关系。其中单纯ＣＡＢＧ１５例，伴左室室壁瘤切除１２例，心脏瓣膜替换３例。全组架１～４支桥者分别是１０、８、８、４例。结果２９例成活，１例死亡。成活组术后即刻至３小时ＤＯ２Ｉ提高１０．６％（Ｐ＜０．０５）。ＶＯ２Ｉ增高１５．８％（Ｐ＜０．０１）．术后１４小时较６小时ＤＯ２Ｉ增加１５．８％（Ｐ＜０．０１），而ＶＯ２Ｉ降低４．４％。死亡例即刻至３小时ＤＯ２Ｉ增加６．０％，ＶＯ２Ｉ却降低２９．１％，死于多器官功能衰竭。资料表明，作为ＣＡＢＧ术后正常恢复经过，早期ＤＯ２Ｉ升高的同时ＶＯ２Ｉ也升高，此时，细胞内氧化磷酸化得到改善，氧债得到清偿。氧输送和氧耗达到平衡后ＶＯ２Ｉ不再增加。可见ＣＡＢＧ术后维持满意ＤＯ２Ｉ非常重要。     

完全性房室阻滞在急性下壁心肌梗死合并及不合并右室梗死病人的？…

目的 确定完全性房室阻滞（ＣＡＶＢ）对急性下壁心肌梗死（ＡＩＭＩ）伴有或不伴有右室梗死（ＲＶＩ）病人预后的影响。方法 分析２６５例ＡＩＭＩ病人临床资料,２２２例无合并ＲＶＩ的病人（Ｉ组）,４３例合并ＲＶＩ病人（Ⅱ组）,根据住院期间有无合并ＣＡＶＢ再将其分为两个亚组（无合并ＣＡＶＢ组（Ｉａ,Ⅱａ组）及合并ＣＡＶＢ组（Ｉｂ,Ⅱｂ组）。选择临床及实验室资料进行比较。结果 （１）ＡＩＭＩ合并ＣＡＶＢ明显增     

聚丙烯中空纤维膜式人工肺治疗Ⅱ型呼吸功能衰竭的实验研究

目的通过体外膜式人工肺达到治疗Ⅱ型呼吸功能衰竭。方法随机选择７条实验犬制成呼吸功能衰竭模型。采取动脉（Ａ）－静脉（Ｖ）转流的方式，连结国产聚丙烯中空纤维膜式人工肺治疗低氧、高碳酸血症。分别于转流３０、６０、９０分钟采取血标本进行血气分析。结果动脉血氧饱和度（ＳａＯ２）达到９０％以上，动脉血氧分压（ＰａＯ２）由转流前７．６±１．３ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）上升为１３．６±１．８ｋＰａ，动脉血二氧化碳分压（ＰａＣＯ２）由转流前１１．６±０．６ｋＰａ下降为７．２±０．５ｋＰａ。结论实验证明该装置对Ⅱ型呼吸功能衰竭的抢救提供了一种新的治疗方法。     

一氧化氮供体对离体大鼠心脏心肌缺血再灌注损伤不同时间的作用

目的：探讨在心肌缺血再灌注过程的不同时期补充一氧化氮（ＮＯ）对心肌损伤的影响。方法：以离体灌流大鼠心脏作为缺血（３０分钟）再灌注（６０分钟）模型。４８只心脏分为４组：Ａ组（ｎ＝１１）仅于再灌注期初２０分钟内给予硝酸甘油（ＮＯ供体）；Ｂ组（ｎ＝１２）于低流量缺血期及再灌注期初２０分钟内均给予硝酸甘油；Ｃ组（ｎ＝１４）为缺血再灌注对照组；Ｄ组（ｎ＝１１）仅于低流量缺血期给予硝酸甘油。测定心功能及肌酸激酶漏出量，同时测定心脏ＮＯ释放量。结果：Ｂ组及Ｄ组缺血后心功能的恢复明显低于Ｃ组和（或）Ａ组。Ｂ组缺血后冠状动脉流量的恢复显著低于Ａ组。Ｂ组及Ｄ组缺血再灌注期肌酸激酶漏出量明显大于Ｃ组及Ａ组。结论：Ｂ组对心肌组织的损伤最重；Ｄ组可损伤心肌细胞；Ａ组对心肌组织无损害。     

不同术前药的冠心病病人术中冠脉搭桥术入液量对血流动力学的 …

将８０例冠脉搭桥病人随机双盲分为：Ａ组（对照组,ｎ＝４０）;Ｂ组（试验组,ｎ＝４０）。Ａ组术前１ｈ口服安定１０ｍｇ、术前３０ｍｉｎ肌注吗啡０．１５～０．２ｍｇ／ｋｇ和东莨菪碱０．３ｍｇ。Ｂ组术前药增加口服氨酰心安６．２５～１２．５ｍｇ及硫氮唑酮３０ｍｇ。分别观察体外循环（ＣＰＢ）前２组病人在不同入液量下的各项血流动力学指标。Ａ组与Ｂ组病人诱导后静脉入液量分别为６５２．５ｍｌ及６５７．５;开胸前分别     

Exercise performance of the high risk acute myocardial infarction patient after cardiac rehabilitation

Sixty-five subjects with a recent acute myocardial infarction (AMI), 50 men and 15 women aged 39 to 79 years (mean 62 +/- 9), were entered into a 12-week phase II cardiac rehabilitation program. Group I subjects were those with an ejection fraction greater than 40% (mean 56) and group II subjects were those with an ejection fraction less than 40% (mean 28). Subjects were further classified into those with or without myocardial ischemia (Ia, IIa and Ib, IIb, respectively) based on a treadmill stress test before entry. Work performance during the training sessions was similar for all subgroups, although group IIb had the lowest values for work rate and time of exercise for each individual activity. Subgroup analysis, as determined by a pre- and postprogram treadmill stress test, showed there was no significant difference in time of exercise, peak oxygen consumption and change in submaximal heart rate (decrease) for groups Ia, Ib or IIa. However, group IIb had poor performance in time of exercise (delta = 2 +/- 2 minutes), peak oxygen consumption (delta = 3 +/- 5 ml/min) and submaximal heart rate (delta = 0.4 +/- 17 beats/min) compared with the 3 other subgroups. These subjects also did not demonstrate an improvement of these values in the posttraining period. Patients who have had AMI and have both significant left ventricular dysfunction and myocardial ischemia did not have an adequate training response after 12 weeks of a formal phase II cardiac rehabilitation program.(ABSTRACT TRUNCATED AT 250 WORDS)     

Differences in Myocardial Velocity Gradient Measured Throughout the Cardiac Cycle in Patients With Hypertrophic Cardiomyopathy,Athletes and Patients With Left Ventricular Hypertrophy Due to Hypertension

Objectives. We sought to compare the myocardial velocity gradient (MVG) measured across the left ventricular (LV) posterior wall during the cardiac cycle between patients with hypertrophic cardiomyopathy (HCM), athletes and patients with LV hypertrophy due to systemic hypertension and to determine whether it might be used to discriminate these groups.Background. The MVG is a new ultrasound variable, based on the color Doppler technique, that quantifies the spatial distribution of transmyocardial velocities.Methods. A cohort of 158 subjects was subdivided by age into two groups: Group I (mean [±SD] 30 ± 7 years) and Group II (58 ± 8 years). Within each group there were three categories of subjects: Group Ia consisted of patients with HCM (n = 25), Group Ib consisted of athletes (n = 21), and Group Ic consisted of normal subjects; Group IIa consisted of patients with HCM (n = 19), Group IIb consisted of hypertensive patients (n = 27), and Group IIc consisted of normal subjects (n = 33).Results. The MVG (mean [±SD] s⁻¹) measured in systole was lower (p < 0.01) in patients with HCM (Group Ia 3.2 ± 1.1; Group IIa 2.9 ± 1.2) compared with athletes (Group Ib 4.6 ± 1.1), hypertensive patients (Group IIb 4.2 ± 1.8) and normal subjects (Group Ic 4.4 ± 0.8; Group IIc 4.8 ± 0.8). In early diastole, the MVG was lower (p < 0.05) in patients with HCM (Group Ia 3.7 ± 1.5; Group IIa 2.6 ± 0.9) than in athletes (Group Ib 9.9 ± 1.9) and normal subjects (Group Ic 9.2 ± 2.0; Group IIc 3.6 ± 1.5), but not hypertensive patients (Group IIb 3.3 ± 1.3). In late diastole, the MVG in patients with HCM (Group Ia 1.3 ± 0.8; Group IIa 1.4 ± 0.8) was lower (p < 0.01) than that in hypertensive patients (Group IIb 4.3 ± 1.7) and normal subjects (Group IIc 3.8 ± 0.9). An MVG ≤7 s⁻¹, as a single diagnostic approach, differentiated accurately (0.96 positive and 0.94 negative predictive value) between patients with HCM and athletes when the measurements were taken during early diastole.Conclusions. In both age groups, the MVG was lower in both systole and diastole in patients with HCM than in athletes, hypertensive patients or normal subjects. The MVG measured in early diastole in a group of subjects 18 to 45 years old would appear to be an accurate variable used to discriminate between HCM and hypertrophy in athletes.     

Surgical revascularization of the myocardium in patients with chronic coronary disease and depressed left ventricular function: 1-year observation

Many reports confirm the importance and benefit of the surgical revascularization (CABG) in patients with ischemic heart disease and severely depressed left ventricular (LV) systolic function. This mode of treatment is better than medical therapy in patients with very low LV ejection fraction (LVEF) and can prolong the life. However, the effect of CABG on LV hemodynamics is still unclear. The aim of the study was: 1) to assess the effect of CABG on LV hemodynamics in patients with low LVEF and 2) to examine the influence of two types of cardioplegia-crystalloid (CC) and blood (BC) cardioplegia--on LV function during 1 year follow-up. 122 patients with stable angina pectoris qualified for CABG were included in the study. Patients were divided into two groups: group I-47 pts with LVEF < or = 40% and group II--75 pts with LVEF > 40% and then patients were randomized for two types of antegrade-retrograde cardioplegia (CC--subgroups Ia, IIa and BC--subgroups Ib, IIb). Before operation and 4 times after CABG (after 2-6 weeks, 3 months, 6 months and 1 year) echocardiographic examination was performed. Diameters of left atrium and ventricle, LVEF and wall motion score index (WMSI) were calculated. During 1 year 8 patients died (5 of them during perioperative period and 3 patients during follow-up). Patients in group I before operation were in higher NYHA and CCS class and had more often myocardial infarction. During each of the five echocardiographic examination the values of LVEF and WMSI did not differ between subgroups Ia vs Ib and IIa vs IIb. In group I, especially in patients with very low LVEF < or = 30%, the values of LVEF and WMSI improved significantly (p < 0.001) during 1 year of follow-up. But in group II a transient deterioration of LVEF (p < 0.05) 2-6 weeks after CABG was noted. We conclude that surgical revascularization in patients with severe depressed hemodynamics improves LV systolic function during 1 year follow-up. The use of CC or BC did not seem to make any difference to the early and long-term hemodynamic effect of the revascularization.     

Prognostic significance of complete atrioventricular block in patients with acute inferior myocardial infarction with and without right ventricular involvement

Data were obtained and analyzed in 243 patients with acute inferior myocardial infarction who were admitted to the coronary care unit during the years 1987 and 1988. One hundred and ninety-eight patients had no signs of right ventricular involvement (group I), whereas 45 patients had inferior myocardial infarction with right ventricular infarction (group II). Patients were divided into groups depending on the presence or absence of complete atrioventricular block during hospital stay (groups Ia and IIa without block and groups Ib and IIb with block). Selected clinical and laboratory variables were compared for each group. We found that patients with inferior myocardial infarction and complete atrioventricular block had significantly higher mortality rates only in the presence of right ventricular infarction: 41% mortality rate in group IIb versus 11% mortality rate in group Ib (p less than 0.05). Patients with right ventricular infarction but without complete atrioventricular block (group IIa) had a mortality rate similar to that found in patients with inferior myocardial infarction and no atrioventricular block (group Ia): 14% versus 11% (p = NS). In patients with inferior myocardial infarction without right ventricular involvement (group I), complete atrioventricular block did not influence survival: 14% mortality rate in group Ib versus 11% mortality rate in group Ia (p = NS). The excessively high mortality rate in patients who have inferior myocardial infarction with right ventricular involvement and complete atrioventricular block could be the consequence of greater infarct size, but the synergistic influence of right ventricular infarction and complete atrioventricular block could be the other factor that influences outcome.     

Modern differential-therapeutic aspects of the drug therapy of chronic gout

The present paper adopts a definite attitude to the differentiated therapy of the disturbances of the uric acid metabolism. This demands an exacter subdivision of the kind of the metabolic disturbance (types Ia, Ib, IIa, IIb, and III). On the basis of this classification in types an individually adapted therapy is possible. It might form the prerequisite of a still more effective meeting of the nephrogenic complications of the gout and of the reduction of the side effects of the necessary permanent therapy.     

An experimental study in etiologic effect of pancreas divisum on chronic pancreatitis and its pathogenesis

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｐａｔｉｅｎｔｓｗｉｔｈｐａｎｃｒｅａｓｄｉｖｉｓｕｍ（ＰＤ）ｗｅｒｅｃｏｎｓｉｄｅｒｅｄｔｏｈａｖｅａｈｉｇｈｅｒｒｉｓｋｆｏｒｃｈｒｏｎｉｃｒｅｃｕｒｅｎｔｐａｎｃｒｅａｔｉｔｉｓ．Ｂｕｔｔｈｅｅｔｉｏｌｏｇｙａｎｄ...     

Endoscopic biopsy study for staging of reflux esophagitis

Endoscopy reveals that the lesions of reflux esophagitis are red and white spots and streaks. The red lesions are thought to reflect local inflammatory alterations with or without partial necrosis of the squamous epithelium, while white lesions represent complete necroses of the squamous epithelium with fibrin deposits. Fifty-nine patients with reflux esophagitis and red lesions (n = 23) or white lesions (n = 36) underwent endoscopically controlled biopsy of selected particles. Histologic analysis confirmed the hypothesis that white lesions are nearly always necroses involving all layers of the squamous epithelium with fibrin deposits (and rarely epithelial hyperplasia), while red lesions are caused by local granulocytic inflammation or granulation tissue with partial reepithelialization. These results suggest that reflux esophagitis Savary Stages I and II can be rationally subclassified into reflux esophagitis with red spots (Stage Ia), white spots (Stage Ib), red streaks (Stage IIa), and white streaks (Stage IIb).     

Intraperitoneal hyperthermic perfusion may induce bacterial translocation

BACKGROUND/AIMS: Intraperitoneal hyperthermic perfusion (IPHP) has been used widely in oncologic practice. Hyperthermia is known to decrease the interstitial pressure. Also intraperitoneal hyperthermia may alter the intestinal mucosal barrier and the intestinal bacterial flora. These changes may lead to bacterial translocation (BT). To the best of our knowledge, there is no data about the possible role of IPHP on BT. METHODOLOGY: Fifty-one rats were divided into two groups. Group I (n=36) received IPHP by heated isotonic salt solution at a temperature of of 43.0 degrees C and group II (n=15) received intraperitoneal normothermic lavage by isotonic salt solution at 37.0 degrees C. Each group was divided into three subgroups which were sacrificed at 1st (Ia, IIa), 3rd (Ib, IIb) and 7th (Ic, IIc) days. Mesenteric lymph nodes (MLN), spleen and liver were sampled and cecal aspirates were obtained. The presence of viable bacteria in samples was noted. Cecal bacterial population levels (CBPL) were reported as colony forming units (CFU). Groups were compared in terms of BT and CBPL. RESULTS: BT was not detected in the Ia (IPHP, 1st day) and IIa,b,c (all control groups). However, statistically significant BT was observed in group Ib and Ic (83.3% and 66.6%, respectively) in comparison to control group (p<0.01). Also there was positive correlation between CBPL and BT. CONCLUSIONS: Intraperitoneal hyperthermia causes remarkable BT. This may explain septic complications after IPHP. Further studies are necessary to better understand the effects of IPHP on the pathophysiology of BT.     

MACULAR HAEMORRHAGE IN ADULT ACUTE LEUKAEMIA PATIENTS AT PRESENTATION AND THE RISK OF SUBSEQUENT INTRACRANIAL HAEMORRHAGE

Glycoprotein (GP)-specific platelet-associated IgG (PA-IgG) may be demonstrable in autoimmune-mediated thrombocytopenia. We studied 159 consecutive patients with histories of thrombocytopenia by a modified direct monoclonal antibody-specific immobilization of platelet antigens (direct MAIPA) assay, which immobilizes GP IIb/IIIa, GP Ib/IX and GP Ia/IIa simultaneously. This modification requires smaller quantities of platelets than standard measurements performed separately. PA-IgG was present in 84/159 (53%) patients, as shown by the direct platelet immunofluorescence test (PIFT) with flow cytometry as a reference. PA-IgG against GP IIb/IIIa and/or GP Ib/IX and/or GP Ia/IIa was noted in 46 patients (29%), of whom 93% (43/46) were also PA-IgG positive. The amount of PA-IgG detected by PIFT correlated directly with that detected by direct MAIPA ( r =0.71; P <0.0001). Only three patients 12548 with negative direct PIFT had GP-specific PA-IgG. GPV-specific PA-IgG was detected in 13 (10%) of the 125 patients, in whom further studies could be performed. In the subgroup of patients with GP-specific PA-IgG, the median fluorescence intensities of direct PIFT were higher than in patients with no GP-specific PA-IgG ( P <0.001). Direct PIFT and direct MAIPA divided the patients into asymmetric subgroups. However, the relative roles of these tests in the diagnosis of autoimmune-mediated thrombocytopenia await further studies.     

Myocardial thallium-201 kinetics during coronary occlusion and reperfusion: influence of method of reflow and timing of thallium-201 administration

Thallium-201 (201Tl) uptake and redistribution kinetics were examined in an open-chest canine preparation of occlusion and reperfusion. Seven dogs (group I) underwent 3 hr of sustained occlusion and received 1.5 mCi of 201Tl after 40 min of occlusion of the left anterior descending coronary artery (LAD). Group II (n = 18) underwent 60 min of LAD occlusion followed by sudden and total release of the ligature. Group IIa (n = 8) received intravenous 201Tl during occlusion of the LAD, whereas group IIb (n = 10) received intravenous 201Tl at the time of peak reflow. Group III dogs (n = 26) also underwent 60 min of LAD occlusion that was followed by gradual reflow through a residual critical stenosis. Animals in this group also received 201Tl either before (IIIa; n = 16) or after reflow was established (IIIb; n = 10). In group I, the relative 201Tl gradient (nonischemic minus ischemic activity) decreased from 88 +/- 8% (mean +/- SEM) to 59 +/- 6% during 3 hr of coronary occlusion (p = .034). After rapid and total reperfusion (group IIa), this gradient decreased from 71 +/- 6% during occlusion to 26 +/- 5% after reflow (p less than .001). After slow reperfusion through a residual stenosis (group IIIa), the gradient decreased from 81 +/- 5% to 31 +/- 5% (p less than .001) (p = .56 compared with group IIa). In rapidly reperfused dogs receiving intravenous thallium during peak reflow (IIb), initial 201Tl activity in the ischemic zone was 155 +/- 20% of initial normal activity and fell to 93 +/- 13% of normal after 2 hr of reperfusion. Similarly, in dogs reperfused slowly through a critical stenosis (IIIb), which received 201Tl during reflow, 201Tl activity soon after reflow was 94 +/- 4% of initial normal and decreased to 80 +/- 6% at 2 hr of reperfusion (p = .10). Histochemical evidence of necrosis was present in the biopsy region in 80% of the 20 dogs subjected to triphenyl tetrazolium chloride (TTC) staining. Microsphere-determined transmural blood flow was similar in all groups during LAD occlusion and final flows after 2 hr were comparable in all subgroups undergoing reflow. Ischemic zone flow (% normal) was significantly higher at the time of 201Tl administration in groups IIb (192 +/- 25%) and IIIb (110 +/- 5%), which received 201Tl during reflow, than in groups IIa (31 +/- 9%) and IIIa (22 +/- 5%), which received 201Tl during occlusion.(ABSTRACT TRUNCATED AT 400 WORDS)