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Fan, L.; Zheng, C.W.; Zhou, H.; Tang, H.; Zhang, G.; Gao, C.; Lang, F., and Gao, Y., 2020. Gust characteristic analysis of wind energy resource in the western Pacific Ocean. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 404–410. Coconut Creek (Florida), ISSN 0749-0208.As a key factor in the ocean energy development, particularly for preventing and reducing disaster, the analysis of gust characteristic is necessary. This study presents the characteristics of annual and seasonal wind speed, gust wind speed in the western Pacific region, using the CCMP wind data and ERA-interim gust data. Results show that, (1) There is a good consistency in annual variation between the averaged wind speed and averaged gust, while a great difference with the maximum gust. (2) The averaged wind speed for 35 years in the nearshore is smaller than that in the off-shore. There is a large value belt in Ryukyu Islands -- Taiwan Island -- the traditional South China Sea gale center, with two obvious large centers (about 7.5-8.0 m/s) located in the Taiwan Strait, the traditional South China Sea gale center. The large area of maximum annual mean gust (> 50 m/s) is mainly locates in the broad ocean of the east of Taiwan, (3) There is an obvious seasonal difference of the average wind speed, average gust and maximum gust. The average gust has noticeable monthly variation, the peak usually appears in November and the trough mainly appearing in summer. There is also a noticeable monthly variation for the maximum gust. In the middle and south of the South China Sea, the maximum gust is

The framework of similarity-based prognostics was presented, which takes advantage of system 's training instances' degradation trajectory and run-to-failure time to predict the remaining useful life(RUL) of test instances. Degradation models are extracted from time series data of training instances. Similarity between time series data of test instance and degradation model is calculated by likelihood function. RUL value according to the degradation model is then estimated at the best matched time stamp. RUL values weighted by similarities are fused by kernel density estimation to form the final probability density of the RUL of test instance. Results of aviation equipment simulation experiments show that the similarity-based RUL prediction performs better in accuracy and convergency.

In this paper, a dual-band high temperature superconducting (HTS) filter with 14-pole and 3 cross couplings is presented. The equivalent model, theoretical result, coupling matrix, and the simulated result of the filter are demonstrated. The desired filter is designed and fabricated using double-sided DyBa2Cu3O7 thin films on MgO wafer 2 inches in diameter and 0.5 mm in thickness. The filter has two passbands with frequencies 1920-1940 MHz and 1960-1980 MHz respectively, and insertion loss less than 0.2 dB. The measurement results show that the response of practical filters is in good agreement with that of simulated results and theoretical analysis, with the group delay variation being less than ±20 ns over 90% of the filter bandwidth for the two passbands.

To solve the problem of pattern extraction from infrared finger vein images, a new concept of small signal amplification of images based on its pattern feature is proposed. Due to transformation on images, the gradient pattern of boundaries has sparseness in transformation domain. Then the gradient pattern can be preserved and amplified at multi-level transformation domain. So the boundaries will be reconstructed and provide important information for following segmentation by inverse transformation. Secondly, an active contour segmentation model is give which based on prior shapes. At last, the concept of image's pattern feature amplification is preliminary identified by experimental result. Meanwhile the problem for gray level distortion and local convergence of segmentation curve is solved.

Gas pump thermocouple plays a major role in accurate measurement of the kiln temperature and reducing temperature measurement error. How to design and optimize hot cover structure as well as raise temperature measurement precision has become an important issue in researching and developing new temperature measuring equipment. The author uses the FLUENT6.0 software to simulate the suction of thermocouple working status. In view of the thermocouple hot cover structure, three modes are structurally optimized and simulated, namely diffuser nozzle, extended length and narrow hot cover diameter. Contrast temperature of convective data shows that optimizing heat expiation cover structure can reduce temperature measuring error, which provides numerical and theoretical reference for theoretical analysis and making of the equipment.

This paper present development rule of high-tech industry on the view of relationship of innovation feature factors and profit with statistics data from National Bureau of Statistics by Dual-density Dependent model and Density Dependence Model. It was found that the R&D investment did not generate direct promotion for profit growth, new products development investment (NPDI) also showed a weak promotion for profit increasing, R&D investment and new products development investment promote to growth each other.

In precision agriculture technology system, cropland data acquisition acts as the foundation as well as the weakness of our country’s research on this field. In this dissertation, according to the present actual demands, an embedded cropland data acquisition and processing system is designed. The system is supposed to achieve many tasks such as agricultural sensors data acquisition, GPS information acquisition and navigation. During the process of design, factors such as performance, cost, and expansibility are all taken into account. The hardware is based on a 32-bit Embedded microprocessor with high performance but low power consumption--Intel Xscale PXA270, while the real-time operating system is Windows CE 5.0. This design has very important practical significance to speed up the process of agricultural modernization in China.

With the popularity of mobile phone, the function of the mobile phone has extended from communication tool to other areas, such as amusement, game, Web browsing, and so on. Most of the mobile manufactures have provided some toolkits in their products for developing such kinds of tools. However, different toolkits provided by different mobile phone manufacturers are quite different, mainly on screen size, screen color, way of key-press responsing and unicode character displaying, etc. One must develop the software for particular kind of mobile phones, and it is not easy to transplant the software from one kind of mobile phones to another kind, which bothers the developers quite well. To solve above problems, we have developed a wireless component library, RichUI. By using RichUI, developers can only concentrate on the development of business function without considering the details of different toolkit implementations, and the software developed based on RichUI can be used in different kinds of mobile phones.

To determine alterations in myocardial metabolism and and hemodynamics that occur within the first 30 minutes after coronary arterial occlusion, before the onset of ventricular fibrillation, measurements were compared in two series of dogs. Series A, 90 dogs that did not manifest ventricular fibrillation after coronary occlusion, were considered a control group. Series B consisted of 28 dogs that had ventricular fibrillation within 30 minutes after occlusion. All had similar comprehensive measurements completed preceding the onset of ventricular fibrillation. The animals in series B (subseuqnt fibrillation) had significantly higher heart rates before and after coronary occlusion. In this series cardiac metabolism of the occluded segment judged by transmyocardial lactate extraction, potassium balance, sodium/potassium ratio and blood pH because grossly more abnormal after coronary occlusion than in series A. In 5 animals whose measurements were obtained within 5 minutes of the onset of ventricular fibrillation, a sudden massive lactate production, potassium loss and increased acidosis of the occluded portion supervened minutes before the onset of the fatal arrhythmia. Animals with ventricular fibrillation had higher intracoronary S-T segment elevation that persisted until the onset of ventricular fibrillation. Measurements of abnormal hemodynamic function (left ventricular end-diastolic pressure, peak systolic pressure and first derivative of left ventricular pressure [DP/dt]) were not associated with an increased incidence of ventricular fibrillation. The study indicates that animals that manifest ventricular fibrillation within 30 minutes after coronary occlusion have higher preocclusion heart rates, a more severe metabolic disorder of the coronary occluded segment and more persistent intracoronary S-T segment elevation compared with animals that do not manifest ventricular fibrillation.

The consequences of sublingual and intravenous nitroglycerin treatment after acute coronary occlusion were studied in 18 closed chest dogs. Intravenous (0.1 mg/min) or sublingual (0.4 mg/15 min) nitroglycerin therapy was instituted 1 hour after occlusion and the effects were observed over a period of 2 hours. Hemodynamics and global and regional cardiac function were measured in both the coronary occluded and nonoccluded segments of the left ventricle before and during coronary occlusion, and after administration of nitroglycerin. A similar nine dog control series was used to establish the significance of the measured effects of nitroglycerin. Intravenous nitroglycerin therapy after 1 hour of occlusion resulted in a marked increase in heart rate (37 ± 12 [mean ± standard error of the mean] percent), reduction of systolic blood pressure (9 ± 3 percent), decrease in left ventricular end-diastolic and end-systolic volumes (32 ± 5 percent and 34 ± 5 percent), increase in coronary sinus flow (64 ± 24 percent) and decrease in left ventricular stroke work (29 ± 8 percent). Sublingually administered nitroglycerin produced similar trends but much less pronounced effects. However, intravenous or sublingual administration of nitroglycerin provided no improvement or caused further deterioration in ischemic region lactate extraction and potassium loss. The left ventricular ejection fraction, which was severely depressed after 1 hour of occlusion, changed minimally after administration of nitroglycerin, and there was no evidence of any correction of regional left ventricular akinesia or dyskinesia. Whereas mean systemic vascular resistance changed minimally as a result of nitroglycerin therapy, it increased 19 ± 8 percent during a corresponding period of an untreated coronary occlusion series suggesting that nitroglycerin prevented an anticipated increase. Postocclusion S-T segment elevation in the electrocardiogram persisted after treatment. Our data corroborated that nitroglycerin reduced left ventricular volumes and increased coronary sinus flow; however, these improvements were accompanied by persisting metabolic and mechanical derangements in the ischemic region.

The effects of methylprednisolone treatment on acute myocardial ischemia were studied in nine closed chest dogs. After 1 hour of proximal occlusion of the left anterior descending coronary artery, an intravenous bolus injection (50 mg/kg body weight) of methylprednisolone was administered and its effects studied during an additional 2 hours of occlusion. After 2 hours of treatment the following significant mean alterations from levels after 1 hour of occlusion were noted: an increase of 16.7 percent in heart rate and decreases of 23 percent in left ventricular end-diastolic pressure, 32 percent in stroke volume, 14 percent in cardiac output and 37 percent in stroke work. Peak systolic pressure, maximal rate of rise of left ventricular pressure (dP/dt), left ventricular end-diastolic volume, systemic vascular resistance and coronary sinus blood flow changed less than 10 percent. Ejection fraction and regional cardiac wall motion were not improved. Metabolic dysfunction of the coronary-occluded myocardium, revealed by regional lactate as well as potassium derangements, persisted throughout the 2 hour treatment period. Comparison of these results with equivalent data from an untreated series of nine dogs with 3 hours of occlusion demonstrated no improvement in the treated series. Methylprednisolone failed to restore regional cardiac metabolic and mechanical function, and treatment was associated with a further rise in S-T segment elevations. Administration of methylprednisolone after 1 hour of proximal left anterior descending coronary occlusion apparently does not reverse cardiac dysfunction in the first 2 hours of treatment.

Hemodynamic and regional metabolic measurements were obtained in seven closed chest dogs during a control period, 3 hours of coronary occlusion and 5 hours of reperfusion. Reperfusion resulted in intermittent ectopic arrhythmias in five dogs and severe shock in two. It usually caused increases in heart rate, coronary sinus flow and maximal isovolumetric rate of rise in left ventricular pressure (dP/dt), which were associated with a decrease in systemic pressure, left ventricular end-diastolic pressure, systemic vascular resistance and stroke work. A transitory increase in cardiac output occurred. Global myocardial oxygen consumption, which was reduced during occlusion, increased with reperfusion. Reperfusion induced abnormal lactate metabolism and myocardial potassium loss in the previously occluded area and often in the nonoccluded segment as well. Histopathologic changes of accelerated necrosis, reactive hyperemia and hemorrhage were often noted after reperfusion. These studies indicate that reperfusion after 3 hours of occlusion caused serious abnormalities in hemodynamic states, metabolic function and morphologic features of the heart.

A new closed chest animal technique permits selective intracoronary balloon occlusion and measurement of hemodynamic and regional metabolic function before and during occlusion and reperfusion. The distal end of the double lumen balloon catheter provides information about the nature and extent of flow distal to the occlusion and permits blood sampling or administration of pharmacologic agents directly into the ischemic zone. Independent blood sampling from the great cardiac vein by means of a specially designed balloon catheter and from the coronary sinus by cannula allows simultaneous biochemical and regional blood flow measurements from the occluded and nonoccluded segments of the heart. Simultaneous intracoronary epicardial electrocardiograms permit electrophysiologic correlation with regional hemodynamic and metabolic events. The administration of oxygen by tracheal airway can increase partial oxygen tension in the circulation distal to coronary occlusion. When intracoronary pressures distal to occlusion are markedly reduced, the frequency of ventricular fibrillation is much greater.

This study examined whether an occlusive thrombus within a coronary artery can be lysed by streptokinase retroperfusion into the associated regional coronary vein. Experimental coronary artery thrombosis was induced in 15 closed chest dogs by placing a small copper coil at a proximal site of the left anterior descending coronary artery. Total thrombotic obstruction of this artery was verified within 10 to 60 minutes (38.0 +/- 15.8, mean +/- standard deviation) and streptokinase was administered within 94.0 +/- 17.4 minutes from coil insertion at an average rate of 42 IU/kg per minute by one of three modes: 1) intermittent 10 minute direct coronary venous retroinfusion (five dogs); 2) continuous infusion into the pumping circuit of synchronized phased retroperfusion of the great cardiac vein with arterial blood (five dogs); and 3) for comparison, streptokinase administered intravenously (five dogs). The intracoronary thrombus was fully lysed and anterograde reperfusion established within 51.0 +/- 18.7 minutes by intermittent streptokinase retroinfusion, and in 50.0 +/- 6.1 minutes by streptokinase supplemented synchronized retroperfusion (50.5 +/- 13.2 minutes for pooled retrograde coronary venous delivery). Lysis was also induced by systemic streptokinase, but the time to lysis was significantly longer and more variable (131.6 +/- 60.6 minutes) than with retrograde administration (p less than 0.01). The retroperfusion modality appears the preferable technique because it provides early thrombolysis and, at the same time, improves cardiac function and maintains myocardial viability of the jeopardized ischemic zone pending achievement of full reflow. Thus, streptokinase retroperfusion, if promptly instituted, may be a useful complemental nonsurgical treatment of evolving acute myocardial infarction after thrombotic coronary artery occlusion.

Two dimensional echocardiography was applied experimentally in the closed chest dog to quantitate left ventricular function during and immediately after single premature ventricular contractions induced through threshold stimulation at the apex. Coupling intervals were varied over a range from 35 to 85 percent of the R-R interval during normal sinus rhythm (920 to 980 ms). The quality of tomographic echocardiographic images during premature as well as postextrasystolic beats was found to be satisfactory for quantitating short axis section areas at end-diastole and end-systole. A systolic fractional area change was computed from two dimensional echocardiographic measurements to characterize mid ventricular cardiac function, which correlated significantly with peak left ventricular pressure and maximal first derivative of left ventricular pressure (dP/dt). Marked shortening of coupling intervals reduced fractional shortening during premature systole and enhanced the degree of potentiation during the postextrasystolic beat. By contrast, premature beats with relatively long coupling intervals caused less reduction in contraction and only minor postextrasystolic potentiation. Systolic shortening of left ventricular length as well as transverse diameters were studied in a two dimensional echocardiographic long axis cross section. During long coupling intervals contraction was normal except for distinct regional systolic outward “bulging” in the apical region. In contrast, short coupling intervals were associated with a more significant generalized derangement of ventricular wall motion during systole. It is concluded that the two dimensional echocardiographic method can be used to portray and quantitate global as well as regional left ventricular function during disturbances of cardiac rhythm.

1. 1. Experiments using radioactive spherules demonstrate that the coronary interarterial collateral circulation is not functional in the normal dog's heart. Hypoxemia can activate some coronary interarterial anastomosis. 2. 2. Three weeks after coronary occlusion the interarterial anastomosis is at least 35 μ in diameter, and at 12 weeks is even more extensive.

l -dopa was administered to 20 dogs in cardiogenic shock. Beneficial effects were noted three to five minutes after infusion began, but more significant effects were observed within 15 minutes, reaching a maximum 45 to 60 minutes after infusion. The principal changes observed were: (1) a significant increase in coronary flow, (2) a significant rise in left ventricular dp dt max , and (3) a decrease in total peripheral vascular resistance. Aortic and mesenteric flows increased significantly. Renal flow did not improve throughout the l -dopa infusion. l -dopa benefits were probably due to a stimulation of the beta-receptors.

Sixty per cent of a control series of the dogs died from a standard toxic dose of digitalis. In a series rendered toxic by a similar dose of digitalis, only 10 per cent died when they were treated with the combination of sodium-potassium citrate salts. A combination of sodium and potassium citrate salts administered intravenously is effective for the treatment of digitalis-induced arrhythmias.

The effect of glyceryl trinitrate (nitroglycerin) on systemic and coronary hemodynamics was studied in normal dogs by means of electromagnetic flowmeters and integrator computers. When given intravenously, glyceryl trinitrate produced changes in the hemodynamics which can be of benefit to the patient with angina pectoris. The drug first increased the coronary blood flow and cardiac index and reduced peripheral vascular resistance for about 20 seconds. This was followed by normal coronary flow with reduced peripheral and coronary vascular resistance, for about 60 seconds; at the same time cardiac work was markedly reduced. These results confirm that the beneficial effects of nitroglycerine are due to its action on the coronary as well as the systemic circulation.

The effects of venoarterial pulsatile partial bypass upon the coronary, mesenteric and renal circulations were studied in cardiogenic shock. Circulatory assist corrected the shock state in 9 of the 10 animals as exhibited by return of systemic pressure to normotensive levels. The most uniform effect was the increase in coronary flow with lowering of coronary resistance associated with other objective signs of improved myocardial nutrition—that is, less cardiac irritability and correction of S-T elevations. Mesenteric flow was irregularly improved by pumping. Renal flow was not corrected; it remained at the same low levels that occurred during shock because of an increased renal vascular resistance.

Venoarterial pulsatile partial bypass and intraaortic balloon counterpulse techniques produce (1) diastolic augmentation of aortic pressure which improves perfusion of the myocardium, and (2) a sink in presystolic and systolic pressures which lowers the workload of the left ventricle. Both techniques are effective in reversing the shock state in dogs and in man. Regional hemodynamic studies performed before, during and after counterpulsation explain benefits and drawbacks of each technique.

This paper investigates the features of embodied energy flow network between Chinese industries to show the relationships between industries in the perspective of energy. Firstly we calculated embodied energy flow between each couple of industries based on ecological input-output table. Then we build 5 networks in the year of 1987, 1992, 1997, 2002 and 2007. After that, the features of these networks are analyzed based on complex network theory. The network scale, network density, weighted degree and betweenness centrality are utilized as indicators. Our result shows: The basic network features change little during research period. Industries that have most embodied energy flows changes from oil related industries to coal related industries. Two kinds of industries have the power to control other industries: industries with most weighted embodied flows and industries have close relationship with people's daily life.

Hypothermic synchronized retroperfusion (HSRP) was applied in closed-chest dogs after acute coronary occlusion to determine whether this intervention can significantly retard the otherwise rapidly developing irreversible ischemic injury. The left anterior descending coronary artery (LAD) was occluded for 3 hours in 22 dogs and for 6 hours in 16 dogs. Starting 30 minutes after occlusion, HSRP was applied during maintained coronary occlusion in 21 dogs. The remaining dogs served as untreated controls. Arterial blood was cooled to 20 degrees C and retroperfused in diastole into the regional coronary veins. Hemodynamics, contrast cineangiography and two-dimensional echocardiography were measured sequentially. Glycogen-depleted ischemic areas and necrotic zones were delineated in transverse slices of the left ventricle. Untreated controls dogs further deteriorated; in contrast, HSRP between 30 minutes and 3- and 6-hour LAD occlusion significantly reduced the rate-pressure product (21.3 +/- 4.0% or 26.8 +/- 8.2%) and left ventricular end-diastolic pressure (39.5 +/- 9.5% or 51.4 +/- 7.7%) and increased ejection fraction (28 +/- 17% and 33 +/- 2.0%). HSRP caused no arrhythmias and led to much less necrosis of ischemic myocardium in the treated 3- or 6-hour occlusion series (7.4 +/- 2.7% or 28.9 +/- 12.6%) than in respective untreated controls (47.1 +/- 8.9% and 72.3 +/- 5.9%). Moderately hypothermic closed-chest phased retroperfusion appears to protect reversibly injured ischemic myocardium and improve cardiac function. Such treatment may be particularly suitable in the earliest stages of evolving myocardial infarction, when maintenance of myocardial viability is essential for preservation of jeopardized myocardium while awaiting coronary bypass revascularization or nonsurgical thrombolytic reperfusion.

Hemodynamic and regional metabolic function was assessed simultaneously in 34 closed chest dogs during a preocclusion control period and 3 hours of intracoronary balloon occlusion of the proximal left anterior descending artery. The data indicate immediate alteration in hemodynamic measurements with many fluctuations in the 3 hour occlusion period. No specific hemodynamic pattern was evident. When the mean data were analyzed, occlusion was found to cause early increases in left ventricular end-diastolic pressure (43 percent) and systemic vascular resistance (21 percent), and decreases in peak systolic pressure (5 percent), maximal rate of rise of left ventricular pressure (dP/dt) (20 percent), cardiac output (19 percent), stroke work (26 percent) and coronary sinus blood flow (19 percent). Regional metabolic measurements showed significantly different metabolic function in the occluded and nonoccluded zones of the left ventricle. Lactate balance decreased to near production levels, and a substantial potassium loss occurred in the occluded zone shortly after occlusion; lactate and potassium balances later fluctuated, but usually remained depressed. Abnormal lactate metabolism and potassium efflux were often observed in the nonoccluded zone. A 6 to 8 percent increase in oxygen extraction was noted in both segments. Progressive alterations in hemodynamic and metabolic function of the heart after coronary occlusion are not uniform and exhibit dynamic fluctuations. Although a direct relation was noted between the degree of metabolic dysfunction and hemodynamic change, individual experiments often revealed a distinct metabolic-mechanical dissociation.

A retroperfusion system was developed that augments retrograde delivery of arterial blood into an acutely ischemic myocardial region during diastole and facilitates coronary venous drainage in systole. An electrocardiogram-synchronized, gas-actuated bladder pump propels retroperfusate through an autoinflatable balloon catheter whose tip is placed within the regional coronary vein that drains the ischemic myocardium. Experiments were performed in 26 closed chest dogs with 4 hour intracoronary balloon occlusion of the proximal left anterior descending coronary artery. An untreated control series consisted of 13 dogs; the remaining 13 dogs were treated with retroperfusion, which was initiated after the first hour of acute coronary occlusion. Synchronized retroperfusion resulted in a significant 37 +/- 10 per cent (mean +/- standard error of the mean) decrease in left ventricular end-diastolic pressure from 11 +/- 2 to 5 +/- 21 mm Hg, a 20 +/- 4 percent decrease in peak systolic pressure (140 +/- 7 to 110 +/- 6 mm Hg) and a 25 +/- 6 percent reduction in systemic vascular resistance (3,880 +/- 340 to 2,380 +/- 300 dynes sec cm-5). Ischemic region intracoronary S-T segment elevation decreased 40 +/- 15 percent, and potassium loss was reduced 92 +/- 22 percent. Partial pressure of oxygen measured distal to the coronary occlusion decreased 36 +/- 2 percent, suggesting oxygen delivery to and extraction by the jeopardized ischemic myocardium. Ventriculography in four dogs revealed an increase in left ventricular ejection fraction and reversal of ischemic segment dyskinesia by synchronized retroperfusion. A nitro-blue tetrazolium study of 10 excised hearts indicated that 3 hours of synchronized retroperfusion significantly reduced the size of ischemic injury to 3.3 +/- 2 percent of the left ventricle (versus 16.2 +/- 5 percent in the untreated control group). In addition, retroperfusion appeared to correct ischemic arrhythmias. The experimental data suggest that this treatment is capable of improving cardiac function and salvaging jeopardized myocardium. Clinical application is envisioned as a prompt temporary emergency support for acute and profound ischemic dysfunction not readily treatable by other interventions.

Two experimental series of closed chest dogs were compared: Group A (five dogs with 7 days of continuous occlusion of the proximal left anterior descending coronary artery); and Group B (six dogs with 7 days of reperfusion after 3 hours of acute occlusion of the same artery). Hemodynamic measurements, ventricular wall motion, coronary sinus blood flow and regional metabolism in both coronary occluded and nonoccluded segments of the left ventricle were measured sequentially. The infarct size was characterized by detailed histopathologic analysis. In the control dogs (Group A), mechanical and metabolic function remained severely depressed after 7 days of occlusion, and mean infarct size was 31.6 percent. In Group B, significant mechanical and metabolic dysfunction developed during 3 hours of occlusion and did not improve during the 1st hour of reperfusion. However, after 7 days of reperfusion, function returned to near preocclusion level. Mean infarct size was 14.2 percent, but in two of the six dogs infarct size was 43 percent and 23 percent, respectively. The study confirmed the unstable character of the early phase of reperfusion, attributed to cell swelling, edema and hemorrhages that resulted in inadequate coronary reflow, arrhythmias and functional derangements. Prolonged reperfusion for 7 days reduced mean infarct size and improved cardiac function.

Focal necrosis (microinfarcts) and regional lactate derangements were observed in closed chest dogs in the nonoccluded (remote) posterior segments of the left and right ventricles after acute occlusion of the proximal left anterior descending coronary artery. Focal infarcts in the remote areas were observed in five of the six dogs with 7 days of occlusion of the left anterior descending artery and in six of seven dogs with 7 days of reperfusion after 3 hours of occlusion. There was a good correlation between the finding of microinfarcts and myocardial lactate derangements in the corresponding remote myocardium. No significant lactate derangements or microinfarcts were found in sham experiments. These findings suggest that ischemia of the remote myocardium frequently accompanies an acute coronary occlusion and may result in irreversible focal lesions.

Because of the controversy concerning techniques of cardiac resuscitation, it was decided to return to the laboratory to evaluate the hemodynamic benefits of these techniques under more controlled conditions. The experimental design revealed closed-chest massage to be an effective technique when compared to open-chest resuscitation. Closed-chest massage is proposed as a scientifically valid interim resuscitative measure which, if applied within the crucial four-minute limit, will maintain life until definitive diagnostic and therapeutic procedures can be instituted.

A considerable net myocardial potassium loss was demonstrated in the dog during rapid ventricular tachycardias. This net potassium loss was associated with some serious arrhythmias which invariably induced resistant ventricular fibrillation. The myocardial potassium loss was associated with an increased myocardial oxygen consumption and lactic acid production. These studies suggest that restoration of the myocardial potassium balance may provide a more proper rationale for the treatment of cardiac arrhythmias.

Ninety-six percent successful resuscitation was achieved after circulatory support in 25 dogs with resistant ventricular fibrillation; in 17 of these the fibrillation was induced by coronary occlusion. When arterial-coronary sinus lactate differences were studied, a negative balance of lactate was found during ventricular fibrillation. Circulatory assist was able to provide a positive lactate balance, suggesting improvement of altered metabolic pathways in the myocardium. Since cardiac arrest secondary to myocardial infarction induces hemodynamic and metabolic disturbances similar to those presented in this experimental model, this study provides evidence of the value of circulatory assist to enhance defibrillation when refractory cardiac arrest is present.

Ajmalin is an effective drug for the treatment of serious digitalis-toxic cardiac arrhythmias. The mortality rate in the ajmalin-treated animals was 10 per cent. The mortality rate in a control series was 50 per cent.

When given early vasopressor drugs can be an effective from of therapy for cardiogenic shock because they increase coronary blood flow, cardiac output and blood pressure. They vasodilate the coronary vascular bed and in 40 percent of the experiments, reduce total peripheral vascular resistance. The use of 3-hydroxytyramine and the vasopressor-vasodilator combination provide most effective coronary and regional perfusion to other vital organs. New mechanical circulatory assistance techniques applied to the treatment of irreversible cardiogenic shock promise that the high mortality rate associated with this dreaded complication will be reduced.

Ascending aorta synchronized pulsation (AASP) was found to be simple and effective method of counterpulsation directed at the root of the aorta. It provided excellent mechanical assistance for the treatment of severe cardiogenic shock following coronary artery ligation. Because the proximal site of counterpulsation requires low stroke pump volumes, only minimal hemolysis resulted. The AASP counterpulsation was performed for periods up to 90 minutes in ten dogs. After two minutes a significant increase in coronary flow and reduction in systolic pressures were observed, and after 90 minutes of continued AASP counterpulsation, pressures and flows increased from shock levels toward normotensive control levels and hemodynamic indices improved. These improvements persisted after AASP pumping was stopped in nine dogs, which proved AASP reversed the cardiogenic shock state.

Phantom arrhythmias and evanescent cardiac abnormalities may cause distressing symptoms, but unless the electrocardiogram is recorded during the event, the diagnosis will escape the clinician. The recent introduction of the Holter monitor for electrocardiographic monitoring for periods up to ten hours in the patient's native environment allows the clinician to detect these pathological states. Instances of neurological symptoms due to cerebrovascular insufficiency and chest pain due to coronary insufficiency detected by this monitoring system suggests that many episodes of hemodynamic crises escape detection by the clinician.

After almost 25 years of extensive experimentation there appears to be confusion about the actual clinical performance of available mechanical systems for treatment of cardiogenic shock. Because shock continues to have an 80 to 90 percent mortality rate, we consider it urgent that a multidisciplinary assessment be made of clinical benefits and drawbacks of circulatory assist techniques. The most attractive assist technique is counterpulsation, which provides,, in each cardiac cycle, left ventricular unloading and augmentation of the myocardial perfusion potentia1.l Such a dual assist concept represents an idea:l approach to the treatment of cardiac pump failure because it may reverse the vicious cycle that tends to perpetuate the shock state. Among the growing number of counterpulsation systems developed to date are: (1) femoral arterialarterial counterpulsationl; (2) venoarterial pulsatile phased bypassz; (3) intraaortic balloon pumping3T4; (4) ascending aorta synchronized pulsation5; (5) aortic root balloon pum!ping6; (6) unidirectional intraaortic balloon pumping7; (7) external pressure cardiac assists; (8) body acceleration synchronized with the heartg; and (9) implanted dynamic aortic patch for extended ae.sistance.lO Partial effects of counterpulsation, particularly unloading of the left ventricle, may be achieved with (10) transarterial closed chest left ventricular bypass,ll and (11) left atrium-to-aorta bypass.12 Although most of the physiologic data on the effectiveness of these systems were derived from animal experimentation, the ultimate test of effectiveness is its application to man. Results of 2 techniqu.es that have recently been popularized, intraaortic balloon and external pressure counterpulsation, are now available for evaluation. Clinical results of balloon counterpulsation: Recent reports of 2 major studies13y14 provided statistical data on this technique in patients with

Digitalis toxicity must be considered a serious cardiac emergency when it causes ectopic arrhythmias, conduction defects, and suppression of sinus pacemaking function. It has been estimated that 6% to 20% of patients receiving the glycosides develop digitalis toxicity1,2because of the narrow range that exists between the therapeutic and toxic dose. The therapeutic dose is approximately 60% of the toxic dose.3 There are a number of factors which precipitate digitalis toxicity: (1) overdose, (2) individual idiosyncracy, (3) electrolyte imbalance following potassium loss due to diarrhea or gastric intubation, etc, and (4) calcium administration to the digitalized patient causing a sudden potassium exodus from cardiac muscle.4,5At present, a common precipitating cause of digitalis toxicity is hypokalemia resulting from the use of saluretic drugs in conjunction with digitalis.3,6-9 There is no specific arrhythmia due to digitalis toxicity. When the glycosides are used in excess, or if there is an associated loss

Sixty symptomatic patients, with recurrent cardiac arrhythmias resistant to conventional antiarrhythmic therapy, were treated with orally administered sodium diphenylhydantoin to assess the antiarrhythmic efficacy of the drug. The arrhythmias seen were (1) premature ventricular contractions, (2) paroxysmal atrial tachycardia, (3) paroxysmal atrial fibrillation, (4) premature atrial systoles, (5) premature nodal systoles, and (6) chronic atrial flutter. On an initial regimen of 100 mg three times daily, 37 of the 60 patients had an excellent response in that they have maintained regular sinus rhythm over an average of 16.8 months to date. A moderate response was obtained in six additional patients in whom there was a marked reduction in the frequency of the arrhythmia and the severity of symptoms. Six other patients failed to respond to the medication, and 11 were forced to discontinue taking the drug because of the development of side effects. No blood dyscrasias were seen.