Eight hundred twelve men with presumed acute myocardial infarction and left ventricular filling pressure of at least 12 mm Hg participated in a randomized double-blind placebo-controlled trial to assess the efficacy of a 48-hour infusion of sodium nitroprusside. The mortality rates at 21 days (10.4 per cent in the placebo group and 11.5 per cent in the nitroprusside group) and at 13 weeks (19.0 per cent and 17.0 per cent, respectively) were not significantly affected by treatment. The efficacy of nitroprusside was related to the time of treatment: the drug had a deleterious effect in patients whose infusions were started within nine hours of the onset of pain (mortality at 13 weeks, 24.2 per cent vs. 12.7 per cent; P = 0.025) and a beneficial effect in those whose infusions were begun later (mortality at 13 weeks, 14.4 per cent vs. 22.3 per cent; P = 0.04). Nitroprusside should probably not be used routinely in patients with high left ventricular filling pressures after acute myocardial infarction. However, the results in the patients given late treatment suggest that those with persistent pump failure might receive sustained benefit from short-term nitroprusside therapy.

SUMMARY We studied 14 patients with cardiac tamponade and pulsus paradoxus; 11 were studied after relief of tamponade by pericardiocentesis. Right ventricular diastolic diameter increased during inspiration in each of 12 patients; left ventricular diastolic diameter decreased during inspiration in each of 13. Mitral valve DE amplitude decreased with inspiration in 13 of 14 patients. Mitral valve E-F slope could be measured in eight patients, and was rounded and not measurable in six. Six of the eight showed inspiratory FEIGENBAUM DEMONSTRATED that echocardiography is a sensitive tool for the recognition of pericardial effusion.' More recently, D'Cruz et al. 2 and Vignola et al.3 published echocardiographic studies of three and four patients, respectively, who had pericardial effusion with cardiac tamponade. The echocardiograms of these patients showed changes in mitral valve E-F slope and mitral valve diastolic excursion thought to be characteristic of tamponade. In addition, D'Cruz et al.' identified respiratory changes in ventricular dimensions which are important in understanding the physiology of cardiac tamponade.The purposes of this study are the following: 1) to study the echocardiogram in a larger series of patients with tamponade in order to determine the prevalence of the described echocardiographic pattern and to look for other changes not previously described; and 2) to examine the echocardiogram in patients with chronic obstructive airway disease and pulsus paradoxus in order to learn more about the disturbed physiology in that disorder in comparison with cardiac tamponade.The following study presents the echocardiographic evaluation of 14 patients with cardiac tamponade and two patients with chronic obstructive airway disease. Each of the 16 patients had a paradoxical arterial pulse, defined as an inspiratory decrease of 10 mm Hg or more in systolic arterial pressure. Eleven of the 14 patients with tamponade were studied both before and after relief of tamponade by pericardiocentesis. In addition, we studied 20 patients with large pericardial effusions but without tamponade in order to evaluate the specificity of the echocardiographic pattern. MHz transducer focused at 7.5 or 10 cm with a repetition rate of 1000 per second was used. The patients were examined in the supine or semierect position. The transducer was positioned in the fourth intercostal space adjacent to the left sternal border and standard sweeps from the aorta to the left ventricle were obtained. MethodsAn electrocardiographic lead was recorded in all patients. Instantaneous respiratory waveforms were recorded simultaneously with a tungsten wire respirometer4 in those patients studied with the Electronics for Medicine recorder: 10 patients with cardiac tamponade. Inspiration was indicated in the records of the remaining: patients with a hand marker.Measurements were made during both inspiration and expiration of the following: right and left ventricular internal diastolic diameter, right and left ventricular internal systolic diam...

In nine subjects with chronic obstructive pulmonary disease (COPD) and pulsus paradoxus, M-mode echocardiograms showed inspiratory augmentation of right ventricular dimensions and inspiratory decrease of left ventricular diastolic dimensions. In five subjects in whom the echocardiographic transistor was in the subxiphoid position, mean right ventricular dimensions increased during inspiration from 1.4 +/- 0.20 to 2.96 +/- 0.38 cm (p < 0.01). With inspiration, mean left ventricular diastolic dimensions decreased from 4.8 +/- 0.61 to 3.7 +/- 0.63 cm (p < 0.01) in these five subjects. Two-dimensional echocardiograms, performed in three subjects, confirmed inspiratory augmentation of right ventricular cross-sectional area. Similar changes were produced in two normal volunteers by artificial obstruction to breathing. Left ventricular ejection time measurements demonstrated an inspiratory decline in left ventricular stroke volume. Inspiratory filling of the right ventricle is not hampered, but rather is exaggerated in patients with COPD and pulsus paradoxus, and left ventricular stroke volume is reduced during inspiration. Exaggerated variations in intrathoracic pressure alone did not explain pulsus paradoxus. Increased right ventricular filling and stroke volume during inspiration probably play a part.

Summary. In order to explore effects of ehlorothiazide (CTZ) and diazoxide (DZX) on rat adipose tissue, as being possibly related to previously reported hyperglyeaemia in man, intact rats fed ad lib were given dailyilinjections of CTZ (200 mg/kg), DZX (50 mg/kg), or both for 14 days. They were then killed and their fat pads were incubated in buffer with and without insulin (250 ~ lmits/ml). DZX (but not CTZ) and the combination significantly decreased baseline glucose oxidation and incorporation into lipids; response to insulin was significantly impaired by either drug alone and especially by the CTZ-DZX combination. An unexpected effecg of the drug combination was severe renal disease with azotaemia and death as early as the fourth day. Histologically, the primary change seemed to be epithelial hyperplasia in the collecting tubules suggestive of the effect of potassium depletion. This in turn produced tubular obstruction with proximal dilatation and focal, acute, interstitial inflammation in both cortex and medulla. E ff ets toxiques d'une association ch[orothiazide-diazoxide sur le tissu adipeux et les reins de rats intaets_Rdsumg. Afin d'explorer les effets du chlorothiazide (CTZ) et du diazoxide (DZX) sur le tissu adipeux du rat, comme 6rant en relation possible avec l'hyperglyc6mie prdc6demment constatde chez l'homme, on a administr6 des rats intacts, nourris ad libitum, des injections quotidiennes de CTZ (200 mg/kg), de DZX (50 mg/kg) ou des deux ~ la lois pendant 14 jours. Ils 6taient alors tuds et leur tissu adipeux trait ineub@ dans un tampon avec et sans insuline (250 9 unit6s/ml). DZX (reals non CTZ) ainsi que l'association des deux substances diminuaient significativement l'oxydation basale du glucose et l'incorporation dans les lipides; la r6ponse ~ l'insuline 6tait diminu6e significativement par l'une ou l'autre drogue seule, et sp6cialement par l'association CTZ-DZX. L'association des deux drogues provoqua un effet inattendu, savoir tree atteinte r6nale sdv@re avec azotgmie et mort d~s le quatri@me jour. Histologiquement la modification primaire semble 6tre une hyperplasie dpith61iale dans les tubules collecteurs, sugg6rant l'effet d'une ddpl6tion de potassium. Ceci provoqua ~ son tour une obstruction tubulaire avec dilatation proximale et inflammation interstitielle focale aigu6 dans le cortex et la moelle.

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