中国优秀皮划艇运动员有氧能力测试分析

目的:了解目前中国优秀皮划艇运动员最大有氧能力,为制定专项有氧训练计划提供科学依据。方法:测试对象为参加2003年世锦赛的国家皮划艇队11名男运动员和9名女运动员,用BreathbyBreath法和跑台逐级递增负荷至力竭测最大摄氧量(VO2max)、通气无氧阈(VT),并采集运动后第2、4、6、10min耳血测血乳酸。结果:(1)中国优秀女子皮艇、男子皮艇和男子划艇运动员的绝对VO2max分别为3.75±0.35L/min、5.30±0.37L/min、5.15±0.11L/min;相对VO2max分别为54.8±3.38ml/kg·min、60.8±1.43ml/kg·min、61.2±4.00ml/kg·min,略低于国际优秀皮划艇运动员的平均水平。(2)中国优秀女子皮艇、男子皮艇和男子划艇运动员的通气无氧阈值分别为3.03±0.30L/min、44.2±3.00ml/kg·min;4.14±0.31L/min、47.5±1.37ml/kg·min和4.06±0.19L/min、48.2±2.27ml/kg·min。(3)多数受试者在递增负荷力竭运动后血乳酸测值较高,女子皮艇、男子皮艇、男子划艇运动员血乳酸峰值分别为10.13±1.68mmol/L(运动后第6min出现)、11.59±1.61mmol/L(运动后第4min出现)和12.99±2.75mmol/L(运动后第4min出现),而女子皮艇、男子皮艇、男子划艇运动员力竭运动后恢复10min的血乳酸分别为9.46±1.81、11.08±1.28和12.16±3.095mmol/L,总的来看恢复比较缓慢。结果表明,中国优秀皮划艇运动员VT%VO2max达到78～80%,接近优秀马拉松运动员的水平;最大摄氧量值略低于国外优秀运动员水平,血乳酸代谢清除能力不够强,提示在训练中应加强有氧训练。     

我国优秀男子现代五项运动员有氧能力特征

目的:了解我国男子优秀现代五项运动员的有氧能力特征。方法:测试对象为中国国家男子现代五项队运动员10名,测试最大摄氧量(VO2max),判定运动员的无氧阈(AT)。测试仪器采用德国产Jaeger Oxycon Pro心肺功能仪以及LE6000跑台进行测试,最大摄氧量(VO2max)测试程序是以10km/h、0.5%坡度起始,每分钟递增0.8km/h,速度达到18.0km/h时每分钟递增1%坡度。运动至力竭。结果:我国现代五项运动员的VO2max测值为4.86±0.43L/min和62.9±4.58ml·kg-1·min-1,VEmax为153.8±15.25L/min,HRmax为195.8±12.69b/min,O2/HR为24.67±2.83ml。VT-VO2为3.72±0.43L/min和48.12±3.35ml·kg-1·min-1,VT%VO2max为76.50±4.03,VT-HR为176.5±10.16b/min,VT-V为15.44±0.21km/h。结果表明:我国男子现代五项运动员的有氧能力水平低于其他相关的耐力性项目运动员,应加强有氧能力的训练,提高有氧能力。我国男子现代五项重点运动员有氧能力水平差异较大,应根据个性特征进行有针对性的个性化训练安排。     

MR扩散加权成像在肾功能评价中的应用

目的探讨MR扩散加权成像在肾功能评价中的价值。方法健康志愿者15例作为对照组,慢性肾病(chron ic k idney d isease,CKD)患者32例(其中肌酐正常组12例,肌酐升高组20例)作为研究组。分别测量各例的表观扩散系数(apparent d iffusion coeffic ient,ADC)并与血清肌酐水平及肌酐清除率对比分析。结果15例志愿者在扩散敏感梯度系数(b值)取50、100、400 s/mm2时平均ADC值分别为(405.366±35.964)×10-5mm2/s、(339.646±23.059)×10-5mm2/s、(254.532±13.676)×10-5mm2/s。CKD组病例中肌酐正常组分别ADC值为(336.622±12.879)×10-5mm2/s、(308.142±20.998)×10-5mm2/s、(211.398±14.604)×10-5mm2/s,肌酐升高组分别为(307.717±84.930)×10-5mm2/s、(265.415±57.754)×10-5mm2/s、(201.672±26.411)×10-5mm2/s,ADC值均低于正常对照组(肌酐正常组与正常对照组比较的t值分别为9.720、5.190、11.093,P值均<0.05;肌酐升高组与正常对照组比较的t值分别为6.533、7.382、10.864,P值均<0.05)。肌酐升高组病例的平均血清肌酐水平为(828.490±699.350)μmol/L,肌酐升高组病例的ADC值与血清肌酐水平负相关,但无统计学意义(b值分别为50、100、400 s/mm2时相关系数分别为-0.272、-0.283、-0.023,P值均>0.05)。肌酐升高组病例的平均肌酐清除率为(15.405±14.541)m l/m in,该组病例的ADC值与肌酐清除率呈弱正相关(b值分别为50、100、400 s/mm2时相关系数分别为0.511、0.430、0.335,P值均<0.05,ADC值与肌酐清楚率呈正相关,但相关关系不密切)。结论对肾脏进行扩散加权成像及ADC值测量是1种有一定潜力且无创的肾功能评价的手段。     

1241例青少年运动员静息心电图特征

目的:分析青少年运动员心电图及其异常表现。方法:分析2005~2008年在北京市先农坛体校门诊部进行常规体检的1241名青少年运动员的静息心电图。受试对象年龄9~17岁,训练时间4~10年,其中男性719名,女性522名,均为国家二级及以上运动员,涉及26个运动项目。结果:(1)1241名青少年运动员中,752名存在心电图异常,占60.6%。窦性心动过缓、窦性心律不齐、左室高电压检出率分别为35.70%、35.13%和20.06%。房室交界性心律、不完全性右束支传导阻滞,II、III、avf导联ST-T改变和一度房室传导阻滞检出率分别为4.11%、1.40%、1.21%和1.13%。(2)青少年运动员平均心率为63.91±10.68次/分,其中男运动员为62.33±10.79次/分,女运动员为66.00±10.18次/分,有显著性差异(P<0.01);体能主导类项目运动员的平均心率为61.66±9.89次/分,技能主导类项目的为66.82±10.99次/分,其差异也具有统计学意义(P<0.05)。提示青少年运动员的心电图特点是长期、系统的训练所致的心脏适应性的改变。     

女子举重运动员尿肌酐的测定及其与运动成绩的相关探讨

<正> 有关正常成人和某些专项成年运动员的肌酐系数(每公斤体重24小时肌酐排泄毫克数)国内早有报导。本研究旨在通过尿肌酐的测定,探讨肌酐系数与举重系数(每公斤体重举起的重量)的相关程度,试图为力量性项目的选材和成绩预测提供参考依据。     

优秀男子水球运动员身体形态和生理机能特点分析

目的:分析优秀男子水球运动员身体形态、身体成分和身体机能特点,比较不同位置水球运动员上述三个方面的特点。方法:14名上海队男子水球运动员,其中中锋位置运动员6名,边锋和外围位置运动员8名,分别对此14名优秀运动员的身体形态、身体成分和身体机能进行测试。结果:优秀水球运动员身材高大,平均身高189.5±6.8cm,体重97.6±8.7kg,中锋队员身高和体重高于边锋,但身高差异无显著性;体脂含量14.8±4.1%,瘦体重为78.1±8.3kg,BMI指数达到27.1±1.4,中锋运动员瘦体重明显高于边锋(P<0.05),体脂%含量有差异,但差异无显著性。优秀水球运动员磷酸原代谢能力水平高,无氧糖酵解能力和有氧能力均一般,中锋和边锋的无氧能力和有氧能力无显著性差异(P>0.05)。结果显示:我国优秀水球运动员身体形态和身体成份特征与国外研究报道基本一致,而其有氧能力与国外优秀水球运动员有一定的差距。     

~(99m)Tc-DTPA快速测定婴儿肾小球滤过率

婴儿肾小球滤过率(GFR)的测定因尿标本收集困难,故测定难度较大。实验利用~(99m)Tc-DTPA对21名婴儿成功地进行了GFR测定,并与Schwartz′c法进行比较。病例:21名受试婴儿,平均体重6.45±3.3kg,年龄157±37天(3～348天),男婴占62％,身高61±12cm(42～80cm)。平均血肌酐值0.36±0.27     

需氧运动降低女长跑运动员的孕酮水平

<正> 对8名业余长跑女运动员(平均每周跑12.5±0.08英里)和9名不参加锻炼的对照人员测定了唾液孕酮和黄体期的孕酮水平。女长跑者与对照人员在月经周期的长短上未见差别,可是女运动员在黄体期孕酮水平降低。女长跑者孕酮高峰水平是443±58pmoL/L,大大低于对照组(655±45pmoL/L)。女长跑者与对照组相比,表示黄体     

我国优秀射击运动员大脑机能状态研究

目的:分析我国优秀射击运动员大赛前训练时的大脑神经机能状态。方法:2006年7月~2008年7月备战北京奥运会期间,利用的脑电图和脑地形图技术对中国国家射击集训队手枪班和步枪班73名运动员进行了9次大脑机能评价和训练监测。结果:在9批次测试中,男运动员106人次的大脑唤醒水平值为26.90±4.81(%),大脑功率谱能量比值为2.41±0.45;92人次的女运动员上述2值分别为25.68±4.21(%)和2.27±0.52。中枢神经机能综合评定,多数运动员处于良好以上状态,男女运动员分别为87和59人次。有60(男)和67(女)人次的运动员的运动应激能力为好或较好。射击运动员发挥欠佳时表现出多种问题,如注意力过度集中、睡眠问题、视觉紧张、听觉敏感、时间空间判断失误、心理紧张等。结论:(1)男女运动员之间大脑唤醒水平与能量比值无明显差异,不同级别运动员之间无明显差异。(2)北京奥运会前1个月时,受试的参赛运动员大脑兴奋性达到较高水平,大脑承受的运动负荷也较高。     

男子赛艇运动员有氧代谢能力与心率变异性分析

目的:探讨男子赛艇运动员有氧代谢能力与心脏自主神经调节功能的相关关系以及心率变异性(HRV)作为评定赛艇运动员机能状态指标的可能性。方法:对12名男子赛艇运动员进行VO2max、VEmax、HR、O2-pluse等指标和HRV的测定。结果:男子赛艇运动员VO2max为5·18±0·42L/min;HRmax为191·30±8·26b/min。TV·rri为5360·1±3883;LF·rri为1330·9±1382;HF·rri为2215·6±2454;LF/HF为0·838±0·46。VO2max与TV.rri呈显著性正相关(P<0·01),VO2max与LF·rri呈中度正相关(P<0·05)。结果显示:赛艇运动员安静时HRV表现为交感神经兴奋性较弱、迷走神经兴奋性较强的特点,可能是长期训练适应的结果。运动员HRV与VO2max呈显著相关,表明HRV与有氧代谢能力关系密切,其机制有待进一步研究。     

有限内固定结合外固定支架治疗复杂胫骨平台骨折的疗效分析

目的探讨有限内固定结合外固定支架治疗复杂胫骨平台骨折的临床效果。方法选择2010年1月~2013年6月在新疆维吾尔自治区人民医院米东医院外科收治的复杂胫骨平台骨折患者92例(SchatzkerⅣ型41例,Ⅴ型25例,Ⅵ型26例),男性61例,女性31例;年龄31~77岁,平均54.2岁。所有患者均为开放性骨折(Gustilo分型:Ⅰ型38例,Ⅱ型26例,Ⅲ28例),按照随机数字表法分为观察组和对照组,各46例。观察组采用有限内固定结合外固定支架治疗,对照组采用单纯钢板内固定传统手术治疗。对比两组手术情况、术后骨折愈合情况以及关节炎发生率,并对伤膝关节功能进行评估。结果观察组手术时间、术中出血量、术后愈合时间以及微动移位分别为(183.09±26.47)min、(304.75±51.47)mL、(0.57±0.11)周、(0.14±0.03)mm,均显著低于对照组的(213.47±34.23)min、(361.37±56.83)mL、(0.74±0.15)周、(0.31±0.07)mm;观察组术后膝关节评定优良率以及术后愈合率分别为97.83%(45/46)和93.48%(43/46),均显著高于对照组82.61%(38/46)和78.26%(36/46),而术后关节炎发生率观察组2.17%(1/46)低于对照组13.04%(6/46),上述差异均有统计学意义(P0.05)。结论有限内固定结合外固定支架治疗复杂胫骨平台骨折对患者造成的创伤小,术后恢复快,并且愈合程度高、关节炎发生率低,适合临床推广应用。     

The Role of N-Acetylcysteine in the Prevention of Contrast-Induced Nephrotoxicity

Purpose To determine the role of prophylactic N-acetylcysteine in the prevention of contrast-induced nephrotoxicity. Methods One hundred and sixteen patients undergoing noncoronary angiography, with or without pre-existing renal impairment, were randomly assigned to receive prophylactic oral N-acetylcysteine or no treatment. Serum creatinine (sCr) was measured prior to angiography and 48 hr after the procedure. Urine samples were collected before and after the examination for measurement of malondialdehyde (MDA) concentration. Contrast-induced nephrotoxicity (CIN) was defined as a rise in serum creatinine of 0.5 mg/dl (44 mmol/l) at 48 hr. Results Complete data were available on 106 patients, 53 of whom had received N-acetylcysteine. There were no significant differences between the two groups in baseline characteristics, type of angiogram, or volume and concentration of contrast used. Three patients (2.8%), all of whom had received N-acetylcysteine, developed CIN. In the N-acetylcysteine group, the mean serum creatinine in patients with renal impairment was 151.0 ± 44.2 μmol/l prior to the procedure and 155.6 ± 48.6 μmol/l (p = 0.49) after the procedure. Respective values for those without renal impairment were 79.6 ± 15.1 μmol/l and 81.2 ± 20.0 μmol/l (p = 0.65). In the group that had not received N-acetylcysteine, the mean serum creatinine levels before and after the procedure were 150.0 ± 58.1 and 141.4 ± 48.0 μmol/l (p = 0.17) in patients with renal impairment and 79.7 ± 14.2 and 81.4 ± 15.4 μmol/l (p = 0.34) in those without renal impairment. In both groups, no significant change in urinary MDA concentration was observed. Conclusion There is no benefit to the prophylactic administration of N-acetylcysteine in patients undergoing peripheral angiography using current contrast media.     

Hypocalcaemia after treatment with [177Lu-DOTA0,Tyr3]octreotate

Purpose

The aim of this study was to explore the possible mechanisms involved in an observed decline in serum calcium levels in patients with a neuroendocrine tumour (NET) treated with [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate (¹⁷⁷Lu-octreotate).

Methods

In 47 patients with NET who were normocalcaemic at baseline, serum calcium, albumin, creatinine, alkaline phosphatase, gamma glutamyl transpeptidase, magnesium, phosphate and 25-hydroxyvitamin D were prospectively analysed at baseline and up to 6 months after treatment. Parathyroid hormone (PTH), 1,25-dihydroxyvitamin D₃, type 1 aminoterminal propeptide of procollagen, bone-specific alkaline phosphatase, carboxyterminal crosslinking telopeptide of bone collagen, collagen type I crosslinked N-telopeptide, and creatinine and calcium in 24-h urine samples, were evaluated at baseline and at 3 and 6 months. Another 153 patients with NET were included in a retrospective study to estimate the occurrence of hypocalcaemia in a larger patient group.

Results

In the prospectively included patients, the mean serum calcium level decreased significantly after treatment (2.31?±?0.01 to 2.26?±?0.02 mmol/l, p?=?0.02). Eight patients (17 %) showed a marked decrease in serum calcium levels with a nadir of ≤2.10 mmol/l. In five patients (11 %), calcium substitution therapy was prescribed. PTH increased significantly (5.9?±?0.6 to 6.7?±?0.8 pmol/l, p?=?0.02), presumably in response to the decreasing serum calcium levels. 25-Hydroxyvitamin D remained stable after treatment. Creatinine levels increased significantly (73?±?3 to 77?±?3 μmol/l, p?=?0.01), but not enough to explain the hypocalcaemia. Phosphate levels remained unaffected. In the retrospectively analysed patients, the mean serum calcium level decreased significantly from 2.33?±?0.01 at baseline to a nadir of 2.24?±?0.01 mmol/l at 18 months after treatment (p?<?0.001). Of the 153 patients, 33 (22 %) showed a serum calcium nadir of ≤2.10 mmol/l, and 11 (7 %) received calcium substitution therapy.

Conclusion

The mean serum calcium level decreased significantly after treatment with ¹⁷⁷Lu-octreotate, resulting in mild hypocalcaemia in about 20 % of patients. We excluded several potential causes of this hypocalcaemia, so the cause remains unknown. Serum calcium levels should be monitored after peptide receptor radionuclide therapy, and calcium substitution therapy should be initiated if appropriate.     

Nephrotoxicity of high-dose gadolinium compared with iodinated contrast

To determine if high-dose gadolinium chelates are less nephrotoxic than iodinated contrast. Records of 342 patients who had received high-dose gadolinium (.2 to .4 mmol/kg) for magnetic resonance imaging were reviewed to identify patients who had also received iodinated contrast for radiographic examinations. Their clinical course and laboratory data were reviewed to identify changes in serum creatinine attributable to the contrast agents. In 64 patients, serum creatinine data were available pre and post both gadolinium and iodinated contrast. The mean change in serum creatinine after gadolinium in these 64 patients was ?.07 mg/dL (?6 μmol/L). By comparison, the mean change in serum creatinine in the same patients after iodinated contrast was .35 mg/dL (+31 μmol/L) from 2.0 ± 1.4 to 2.3 ± 1.8 (P=.002). Eleven of the 64 patients had iodinated contrast-induced renal failure (.5 mg/dL or greater rise in serum creatinine); none had gadolinium contrast-induced renal failure despite the high gadolinium dose and high prevalence of underlying renal insufficiency. High-dose gadolinium chelates are significantly less nephrotoxic than iodinated contrast.     

早期低剂量腹膜透析对改善尿毒症患者生活质量的价值

目的探讨早期低剂量腹膜透析治疗尿毒症患者的疗效。方法选择2007年3月-2010年2月慢性肾功能不全患者38例,分为两组:腹透组(n=19):接受常规药物治疗,并予间歇性腹膜透析,每日4000～6000ml,每周4～5d;对照组(n=19):接受常规药物治疗。随访24周。所有患者在治疗前、后采用症状频率和严重指数、SF-36生活质量量表对临床症状、生活质量进行评价,并监测血常规、肝肾功能、血糖、电解质及尿量。结果腹透组血红蛋白、血肌酐均较对照组明显改善。腹透组患者临床症状评分治疗前为11.80±5.41,治疗后第8周和第12周时分别降低至7.15±3.15(P<0.05)和5.94±3.70(P<0.01),对照组在治疗前、治疗后第8周和第12周时评分分别为11.23±5.35、9.80±4.02和10.11±4.48。两组间的差异持续至随访期结束。腹透组患者生活质量明显改善。结论早期低剂量腹膜透析可有效改善尿毒症患者临床症状和生活质量。     

超声引导下腰丛联合骶旁坐骨神经阻滞在高龄股骨颈骨折内固定术中的应用

目的探讨超声引导下腰丛联合骶旁坐骨神经阻滞在高龄患者股骨颈骨折内固定术中的应用效果。方法选取2015年1月~2016年3月在解放军空军第四五七医院接受内固定术的高龄股骨颈骨折患者80例为研究对象,并根据麻醉方式将其分为对照组和观察组各40例。对照组男性18例,女性22例;年龄75~92岁,平均85.67岁;使用传统的神经刺激仪引导行后路腰丛联合坐骨神经联合阻滞麻醉。观察组男性19例,女性21例;年龄76~93岁,平均85.72岁;使用超声引导下腰丛联合骶旁坐骨神经阻滞麻醉。观察两组患者围手术期心肺功能指标、认知功能(定向力、瞬时记忆和注意力计算力等)和术后疼痛的差异。结果麻醉穿刺前,对照组和观察组的平均动脉压(MAP)和心率(HR)分别为(92.32±10.42)、(92.35±11.27)mm Hg和(67.53±6.87)、(67.45±1.25)次/min,差异无统计学意义(P0.05);麻醉完成后10min、手术开始时和手术结束时,观察组的MAP分别为(91.03±7.85)、(88.67±8.93)、(85.45±8.12)mmHg,显著高于对照组的(86.75±8.32)、(84.01±7.65)、(80.14±7.54)mm Hg,差异有统计学意义(P0.05);上述时段观察组的HR分别为(67.92±1.89)、(68.12±1.34)、(66.97±1.26)次/min,显著高于对照组的(63.25±1.69)、(60.42±1.25)、(60.48±1.89)次/min,差异有统计学意义(P0.05)。两组患者术前定向力、瞬时记忆和注意力计算力等认知功能指标无明显差异,术后两组患者上述指标较术前降低,而两组间术后比较无明显差异;术后观察组视觉模拟评分明显低于对照组,差异具有统计学意义(P0.05)。结论超声引导下腰丛联合骶旁坐骨神经阻滞应用于股骨颈骨折手术,对患者的心肺功能无明显影响,且麻醉效果好,可明显减轻患者术后疼痛,有利于患者术后快速康复。     

Snatch lift kinematics and bar energetics in male adolescent and adult weightlifters

AIM: The aim of the present study was compare linear kinematics and energy changes of the barbell, along with the angular kinematics of the leg movement during the snatch technique, between male adolescent and adult weightlifters. METHODS: Two S-VHS cameras operating at 60 fields per second recorded the heaviest lifts of 14 male adolescent and 9 adult top-level weightlifters under competitive conditions. The spatial co-ordinates of selected points on the body and the barbell were calculated using the direct linear transformation procedure. A low pass digital filter with 4 Hz cut-off frequency was used for the smoothing of raw co-ordinate data. The 't'-test for independent samples was used for the statistical treatment of data. RESULTS: The results revealed that there were no significant differences between the adolescent and the adult weightlifters in the majority of the kinematic variables. However, adolescent weightlifters extended their knees significantly slower (t21 = 4.211, p < 0.05) during the 1st pull and their ankles during the 2nd pull (t21 = 2.440, p < 0.05) than the adult weightlifters did. Moreover, the average relative power output was significantly greater for the adult weightlifters during both the 1st (t21 = 2.303, p < 0.05) and the snd pull (t21 = 2.611, p < 0.05). CONCLUSION: These results indicate that the adolescent weightlifters were characterised from a high level of snatch technique and differentiated from the adults predominantly at the less powerful execution of the movement.     

Long-term toxicity of [<Superscript>177</Superscript>Lu-DOTA<Superscript>0</Superscript>,Tyr<Superscript>3</Superscript>]octreotate in rats

Purpose and methods Studies on peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues have shown promising results with regard to tumour control. The efficacy of PRRT is limited by uptake and retention in the proximal tubules of the kidney, which might lead to radiation nephropathy. We investigated the long-term renal toxicity after different doses of [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate and the effects of dose fractionation and lysine co-injection in two tumour-bearing rat models. Results Significant renal toxicity was detected beyond 100 days after start of treatment as shown by elevated serum creatinine and proteinuria. Microscopically, tubules were strongly dilated with flat epithelium, containing protein cylinders. Creatinine levels rose significantly after 555 MBq [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate, but were significantly lower after 278 MBq (single injection) or two weekly doses of 278 MBq. Renal damage scores were maximal after 555 MBq and significantly lower in the 278 and 2×278 MBq groups. Three doses of 185 MBq [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate with intervals of a day, a week or a month significantly influenced serum creatinine (469±18, 134±70 and 65±15 μmol/l, respectively; p<0.001). Renal histological damage scores were not significantly influenced by dose fractionation. Lysine co-administration with three weekly treatments of 185 MBq significantly lowered serum creatinine and proteinuria. Conclusion Injection of high doses of [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate resulted in severe renal damage in rats as indicated by proteinuria, elevated serum creatinine and histological damage. This damage was dose dependent and became overt between 100 and 200 days after treatment. Dose fractionation had significant beneficial effects on kidney function. Also, lysine co-injection successfully prevented functional damage.     

Comparative myocardial uptake of technetium-99 m sestamibi and technetium-99m tetrofosmin one hour after stress injection

Technetium-99m sestamibi and ^99mTc-tetrofosmin are at present the preferred tracers for simultaneous assessment of myocardial perfusion and function by gated single-photon emission tomography (SPET). The aim of this work was to compare sestamibi and tetrofosmin myocardial uptake 1 h after stress injection. Consecutive unselected patients were studied either with sestamibi or with tetrofosmin on a random basis, until at least 100 patients had been enrolled for each gender and tracer. Stress was obtained by dipyridamole or exercise or combined dipyridamole + exercise; in the latter cases, exercise was sustained for at least 1.5 min after tracer injection. Injected activity was similarly adjusted to body weight. For each patient, imaging began 60–75 min after injection. All SPET projections were summed; due to the acquisition technology (”roving zoom”, i.e. a mobile zoom), the heart always appeared at the centre of the frame in all projections and in the sum image. Thus minimal lung background contamination could be assumed in an elliptic region of interest placed over the heart on the sum image. Three indexes were analysed: total myocardial counts (Sum), mean myocardial pixel (Mean) and maximum myocardial pixel (Max). Four patient groups were analysed: males with sestamibi or tetrofosmin (MS: n = 189 and MT: n = 157), females with sestamibi or tetrofosmin (FS: n = 101 and FT: n = 104). MS and MT groups were comparable for physical variables, maximum heart rate and stress type, as were the FS and FT groups. Sum, Mean and Max were significantly higher with sestamibi (P = 0.0001 by ANOVA). Comparing MS vs MT and FS vs FT, mean values ± SD were as follows: for Sum (kcounts) 750±184 vs 652±166, and 707±202 vs 594±189; for Mean (counts) 4517±1171 vs 4107±898, and 4908±1119 vs 4144±1025; and for Max (counts) 6471±1654 vs 5794±1312, and 7318±1886 vs 6152±1684. The mean gain with sestamibi was +15%, +10% and +12% in males, and +19%, +18% and +19% in females. Similar differences were found within each stress type subgroup. No gender-specific effect was found for Mean, so the overall mean gain was calculated for Mean: +13% for sestamibi vs tetrofosmin. These findings are consistent with other published smaller sample series. Possible differences between tracers with regard to residual activity in syringes were ruled out by an additional experiment. In summary, we found significantly higher myocardial counts with sestamibi than with tetrofosmin, in males as well as in females. Received 10 February and in revised form 27 July 1998