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A Sheikh

Publications and source records attributed to A Sheikh.

99 records · Page 6Linked to original sources

Effect of dichloroacetate in the treatment of anoxic lactic acidosis in dogs.

Lactic acidosis is seen frequently after severe anoxia and circulatory failure. Because dichloroacetate (DCA) has been shown to be effective in the treatment of lactic acidosis, we studied its effect on lactate levels and pH in arterial and sagittal sinus blood specimens in a pediatric canine model of anoxic cardiac arrest followed by CPR. Lactate levels rose steadily in all puppies receiving DCA alone (group 1), DCA plus bicarbonate (group 2), bicarbonate alone (group 3), or neither drug (group 4). Arterial and sagittal-sinus lactate levels were in the range of 2 mmol/L during the baseline period, 6 mmol/L after anoxic arrest, and 10 mmol/L after 20 min of CPR. Bicarbonate, but not DCA, significantly raised arterial pH. Neither drug reversed the progression of acidosis in the sagittal sinus; mean pH ranged from 6.85 to 6.92 among the four groups after 20 min of CPR. We speculate that DCA did not decrease lactate levels or raise the pH in either the peripheral circulation or the CNS (sagittal sinus) because of poor perfusion achieved during closed-chest cardiac compression.

Acetates↗

Comparative study of meptazinol and pethidine for the relief of pain in labour.

A double-blind comparison of pethidine and meptazinol in the relief of pain during labour was undertaken in 205 healthy women. The protocol allowed 100 mg of the test drug to be repeated at intervals of 2 h to a maximum of three doses. It was noteworthy that only 29 mothers were given a second dose of narcotic. Every woman receiving one injection of meptazinol complained of moderate to severe pain after 2 h; 97% of those receiving one injection of pethidine were complaining of moderate to severe pain after 2 h. There was no difference between the two drugs with regard to pain relief or in side-effects both in mother and baby.

Adult↗

Chronic recurrent right ventricular tachycardia in patients without ischemic heart disease: clinical, hemodynamic, and angiographic findings.

Surgical cure of right ventricular tachycardia (RVT) has been recently described in patients with "arrhythmogenic right ventricular dysplasia," a disease characterized by abnormal electrical activation of the right ventricle and localized or generalized angiographic right ventricular (RV) wall motion abnormalities (WMA). In search of a selective RV cardiomyopathy complicated by chronic recurrent RVT, 38 consecutive patients (mean age 30.5 +/- 12 years) with RVT and no ischemic heart disease were studied clinically, noninvasively, and by cardiac catheterization including left and right ventriculography. RV volumes were as follow: end-systolic volume ranged from 23 to 103 (mean +/- SD, 45.8 +/- 20) cc/m2 and was abnormal in 14 patients (37%); end-diastolic volume ranged from 57 to 138 (90.5 +/- 26) cc/m2 and was abnormal in 15 patients (39%); ejection fraction (EF) ranged from 0.18 to 0.64 and was decreased in five patients (13%). Seventeen patients (45%) had abnormal RV volume, EF, and/or pressures (RVD), five (13%) of whom had abnormal LV volume, EF, and/or pressures (LVD), and 12 (32%) patients with RVD had no LVD. Twenty-one patients (55%) had no RVD, two of whom had LVD. Only two of the 17 patients had RV regional WMA, one with and one without LVD. Most patients with LVD five of seven (71%) also had RVD while 12 of 31 patients (39%) with no LVD had RVD. In conclusion, less than one half of patients with RVT had selective RV cardiomyopathy and more than one half of patients with RVT had normal RV hemodynamics and angiography.

Adolescent↗

Determination of left ventricular ejection fraction by visual estimation during real-time two-dimensional echocardiography.

It has been shown that the measured reduction in the cross-sectional area of the left ventricle (LV), as viewed in the short axis, closely approximates its ejection fraction (EF). We assessed the reliability of using two-dimensional echocardiography (2DE) to visually estimate the EF during real-time viewing, without the need of digitizers, planimetry, or calculations. Twenty-five adult hospitalized patients with either suspected or known cardiac disease were evaluated prospectively. Each patient also had gated nuclear angiography during the same admission, and 14 had cardiac catheterization with left ventriculography. The EF was determined by 2DE using a visual estimate of the percent area reduction of the LV cavity in the short-axis view at the level of the papillary muscles. All 2 DE studies were read by two or more blinded reviewers, with a value for the EF to the nearest 2.5% determined by consensus. These values correlated closely to the values determined in all 25 patients with gated nuclear angiography (r = 0.927) and the 14 patients who had left ventriculography (r = 0.935). We believe that this method of visually estimating the LVEF will enable echocardiographers to easily use 2 DE for a reliable and instantaneous assessment of ventricular function, without the need of sophisticated analytical equipment.

Adult↗

Radionuclide regurgitant index: value and limitations.

The radionuclide regurgitant index, defined as left ventricular/right ventricular stroke counts obtained from gated equilibrium studies, has been reported to predict the presence and severity of left-sided valve regurgitation. This study evaluated the radionuclide regurgitant index in 100 patients in whom left-sided valve regurgitation was angiographically graded (0 to 4+) with regard to most severe mitral or aortic regurgitation. Regurgitation was graded 0 in 44 of the 100 patients, 1+ in 22, 2+ in 8, 3+ in 6 and 4+ in 20. The radionuclide regurgitant index was 0.9 to 1.5 in 51 patients, 1.6 to 2.4 in 23 and 2.5 to 12.0 in 26. The mean radionuclide regurgitant index was 1.34 in the group with no regurgitation and 1.60 in those with 1+, 2.01 in those with 2+, 2.80 in those with 3+ and 3.85 in those with 4+ regurgitation. There was a significant difference (p less than 0.05) in the radionuclide regurgitant index between patients with no regurgitation and each group with regurgitation and between groups with regurgitation separated by two or more grades of angiographic regurgitation. Twelve patients had a discordant radionuclide regurgitant index; their index either predicted clinically significant or severe regurgitation when they had no or trivial regurgitation, or predicted no or trivial regurgitation when they had clinically significant regurgitation. Eight of 10 patients with a left ventricular ejection fraction of less than 0.30 had a discordant index (p less than 0.0005). All three patients with mitral valve prolapse associated with frequent ventricular extrasystoles had a discordant index (p less than 0.0005).

Adolescent↗

Transplacental pharmacokinetics of flecainide in the gravid baboon and fetus.

The objective of this study was to characterize the transfer of flecainide across the placenta and determine the fetal: maternal ratio of flecainide in the gravid baboon. Flecainide acetate has been especially successful for the treatment of fetal supraventricular tachycardia associated with hydrops fetalis. However, the degree of transplacental transmission remains unknown. In this study, all animals were placed under general anesthesia. Flecainide 2.5 mg/kg was administered intravenously. Percutaneous umbilical blood sampling was performed simultaneously with maternal sampling. Flecainide levels were measured using high-performance liquid chromatography with ultraviolet detection. A total of six gravid baboons were studied at an average gestational age of 132 days. The mean maternal volume of distribution at steady state was 5.1 +/- 1.8 L/kg. The mean combined elimination constant (k(el)) was 0.79 +/- 0.19 hr(-1) [95% confidence interval (CI), 0.64-0.93]. There was a linear relationship between maternal and fetal concentrations, with a ratio of fetal-to-maternal serum levels of 0.49 +/- 0.05 (95% CI, 0.39-0.59). At steady state, fetal flecainide levels are approximately 50% of maternal flecainide levels. Flecainide is rapidly distributed in the mother and fetus following a single intravenous dose with a maternal volume of distribution similar to that reported in normal healthy human adults. Since fetal levels correlate closely with maternal levels, we propose that it is possible to estimate fetal levels by monitoring maternal levels.

Animals↗