Serial myocardial imaging with technetium-99m methoxyisobutyl isonitrile (9'Tc-MIBI) has been proposed for evaluating myocardial salvage after reperfusion. To define 'mTc-MIBI uptake before and after reperfusion, 17 open-chest dogs underwent 3 hours of left anterior descending artery occlusion and 3 hours of reperfusion. 9'Tc-MIBI was injected during occlusion (group 1) or after 90 minutes of reperfusion (group 2). Myocardial 99'Tc-MIBI activity was correlated with microsphere flow during occlusion and reperfusion. Anatomic risk area and infarct area were defined by postmortem vital staining and correlated with the perfusion defects defined by analysis of 99mTc-MIBI macroautoradiographs and gamma camera images of myocardial slices. The left ventricle was divided into 96 segments for gamma well counting. Flow and '9"Tc-MIBI activity were normalized to nonischemic values. Myocardial segments were grouped, based on occlusion flow, into zones: severely ischemic (<30% nonischemic), moderately ischemic (>30%o, .60%o nonischemic), mildly ischemic (>60%o, <90%1 nonischemic), and nonischemic (>90%o, < 120% nonischemic). Among dogs injected with "'Tc-MIBI during coronary occlusion (group 1), myocardial 99'Tc-MIBI activity correlated linearly with occlusion flow for both endocardial (r=0.91) and transmural (r=0.91) segments. The risk area defined by '9mTc-MIBI autoradiography (group 1) correlated with the postmortem risk area (p=0.94) but was 29O smaller than the anatomic risk area (p=0.03), reflecting the contribution of collateral flow. Among dogs injected with "'Tc-MIBI after reperfusion (group 2), myocardial 99"Tc-MIBI did not correlate with reperfusion flow in either endocardial or transmural segments. Among group 2 dogs, myocardial 9'Tc-MIBI activity was significantly less than reperfusion flow at the time of injection in the severely ischemic (25 ±5% versus 74±24% nonischemic,p=0.002), moderately ischemic (54±12% versus 96+15% nonischemic, p=0.001), and mildly ischemic (84±6% versus 93±3% nonischemic, p=0.002) zones. The defect area defined by 'mTc-MIBI autoradiography (group 2) correlated very closely with the postmortem infarct area (p=0.98). Thus, the myocardial uptake of 99mTc-MIBI during coronary occlusion correlates with occlusion flow and reflects the "area at risk." When 99mTc-MIBI was given after 90 minutes of reperfusion following 3 hours of coronary occlusion, the myocardial activity was significantly reduced compared with reperfusion flow in both necrotic and perinecrotic regions, reflecting myocardial viability more than the degree of reperfusion. (Circulation 1990;82:1424-1437 T X ahe current management of myocardial infarcinfarction, the extent of myocardial necrosis is detertion focuses on the application of acute mined by the "area at risk," collateral flow, and the interventional reperfusion techniques to duration of coronary occlusion.2 A noninvasive imagreduce myocardial necrosis.1 During myocardial ing technique that could 1) assess the area at risk, 2)

Measures of handgrip strength can be used to conveniently assess overall muscle strength capacity. Although stand-alone measures of handgrip strength provide robust health information, the clinical meaningfulness to determine prevention and treatment options for weakness remains limited because the etiology of muscle weakness remains unclear. Moreover, clinical outcomes associated with handgrip strength are wide-ranging. Therefore, disentangling how handgrip strength is associated with health conditions that are metabolically or neurologically driven may improve our understanding of the factors linked to handgrip strength. The purpose of this topical review was to highlight and summarize evidence examining the associations of handgrip strength with certain health outcomes that are metabolically and neurologically driven. From this perusal of the literature, we posit that stand-alone handgrip strength be considered an umbrella assessment of the body systems that contribute to strength capacity, and a panoptic measurement of muscle strength that is representative of overall health status, not a specific health condition. Recommendations for future strength capacity–related research are also provided.

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Introduction The purpose of the current study was to examine if isometric peak force and rate of force development (RFD) were related to the ability to successfully perform a simulated casualty evacuation task in both unweighted and weighted conditions. Methods Eighteen male participants from Army Reserve Officers’ Training Corps (ROTC) completed a maximum isometric deadlift on a force plate (IRB#HE16227). Isometric peak force and RFD were calculated from ground reaction force. Two simulated casualty evacuation performance trials were then completed. The unweighted trial consisted of lifting and carrying a 75 kg dummy as quickly as possible for 50 m. The weighted trial was similar except 9 kg vests were added to both the simulation dummy and the participant to represent 18 kg of duty gear. Independent sample t-tests and Pearson correlations were performed to compare the characteristics of those who passed and failed the weighted trial. Results All of the participants (n = 18) completed the unweighted casualty evacuation trial, while 72% (n = 13) were able to complete the weighted casualty evacuation trial. The participants that successfully completed the weighted evacuation trial had significantly (p &lt; 0.05) greater isometric peak force (1420 ± 165 vs. 1076 ± 256 N) and lean mass (74.18 ± 3.89 vs. 65.34 ± 3.89 kg) when compared to participants (n = 5) that could not complete the weighted evacuating task trial. Additionally, greater Army Physical Fitness Test scores (288 ± 13 vs. 269 ± 16 arbitrary units) and significantly faster (30.34 ± 4.41 vs. 44.92 ± 10.62 seconds) unweighted evacuation trial times were observed in participants that could complete the weighted evacuation task. Peak force was also significantly correlated with lean mass (r = 0.51, p &lt; 0.05). There was no relationship between RFD and performance of the unweighted or weight trial. Conclusion Isometric deadlift peak force represents an important determinant for the success of a simulated casualty evacuation task and may be a useful marker to include in periodic fitness evaluations of military personnel.

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