Comparison of myocardial perfusion imaging by thallium-201 single-photon emission computed tomography with SUNY4001 (adenosine) and exercise--crossover clinical trial at multi-center

We compared the ischemic diagnosis ability and adverse events of 201Tl myocardial perfusion imaging with SUNY4001 (adenosine) stress to that with exercise (ergometer) stress both on random crossover trial. Thirty one known or suspected chronic stable angina patients who are able to exercise and 10 healthy volunteers were enrolled for the trial. The early and delayed images were obtained by SPECT imaging. The concordance of diagnoses [ischemia vs. no ischemia] between the two types of stresses was 97.3% (36/37) [Kappa: 0.9068]. The sensitivity and specificity based on the exercise test were 100% (6/6) and 96.8% (30/31) respectively. The incidence of adverse events caused by SUNY4001 and the exercise were 44.7% (17/38) and 52.6% (20/38), respectively. Major adverse events caused by SUNY4001 were BP decrease, flushing and headache. And those by exercise were ST decrease, dyspnea and chest pain. None of the adverse events required the intervention or caused life-threatening complication in the trial. The trial showed that the ischemic diagnosis ability and safety of 201Tl scintigraphy with SUNY4001 stress are almost equal to those of the exercise stress that is considered as the standard stress method. We concluded that 201Tl imaging with SUNY4001 is safe and useful for detecting ischemic heart disease, especially for patients unable to exercise adequately.     

Early glycemic control reduces large-for-gestational-age infants in 250 Japanese gestational diabetes pregnancies

Our objective was to test if tight glycemic control versus loose glycemic control in gestational diabetic patients and a gestational age of < 32 weeks influence fetal growth, fetal distress, and neonatal complication. We performed a retrospective study with 250 gestational diabetes mellitus in Japanese women. Two groups were categorized according to the timing at which good maternal glycemic control was attained at < 32 weeks and kept so until delivery (group 1) and > 32 weeks or never until delivery (group 2). In these two groups, neonatal growth (large-for-gestational age: LGA; appropriate- : AGA; and small- : SGA), neonatal complications (hypoglycemia, jaundice, polycythemia, and cumulative incidence), and incidence of fetal distress were compared. The chi2 test, unpaired t test, one-way analysis of variance (ANOVA) and multiple logistic regression analyses were used for statistical analyses. Maternal age, height, prepregnancy body mass index (BMI), gestational age at delivery were not different between the groups. In group 2 (> 32 weeks), LGA, macrosomia (> 4 kg), neonatal hypoglycemia was significantly increased compared with those in group 1. Incidence of SGA, fetal distress, and neonatal jaundice were not different between the groups. Multiple logistic regression analysis for LGA showed significant relation to timing of maternal glycemic control. We concluded that good glycemic control should be attained at < 32 weeks and maintained until delivery to reduce LGA infants and neonatal hypoglycemia in gestational diabetes mellitus. This management did not appear to decrease SGA infants or fetal distress.     

Theoretical analysis of T-wave polarity based on a model of cardiac electrical activity

The effect of the gradient of transmembrane action potential duration through the ventricular wall on T-wave polarity and QRS-T angle was investigated using a mathematical model of the electrical activity of the heart which incorporates the characteristic electrophysiological properties of the left ventricular wall. Two models, a rectangular solid model and a concave model, were constructed to simulate a part of the left ventricular wall. The ventricular gradient was defined as a linear decrease (beta msec/cm) of the action potential duration from the endocardium to epicardium. The theoretically-obtained relationship between the QRS-T angle and the ventricular gradient revealed that the transmural gradient (beta) was 10--40 msec/cm when the QRS-T angle was within the normal range. The positive T wave was obtained at the observation point which would correspond to the precordial lead when the transmural gradient was more than 30 msec/cm. The amplitude of the simulated T-wave increased with the ventricular gradient. Thus, our mathematical models can provide the quantitative relationship between the transmural ventricular gradient and T-wave polarity and are compatible with further simulation study for various pathological conditions.     

Availability, fermentability, and energy value of resistant maltodextrin: modeling of short-term indirect calorimetric measurements in healthy adults

BACKGROUND: Determination of the metabolizable (ME) and net metabolizable (NME) energy of total carbohydrate requires estimation of its available (AC) and fermentable (FC) carbohydrate content. Modeling of indirect calorimetric observations (respiratory gas exchange) and breath hydrogen would appear to make it possible to estimate noninvasively these nutritional quantities and the approximate time-course of availability. OBJECTIVE: We assessed the time-course of metabolism and energy availability from resistant maltodextrin (RMD) by modeling of respiratory gases after a single oral dose. DESIGN: Seventeen healthy adults (13 M, 4 F; aged 25-46 y) were randomly assigned to treatments (water, maltodextrin, or RMD) in a multiple-crossover, single-blinded trial with > or = 7 d washout. We monitored 8-h nitrogen-corrected oxygen and carbon dioxide exchanges and breath hydrogen. All treatment groups took low-carbohydrate meals at 3 and 6 h. RESULTS: Indirect calorimetry alone provided only qualitative information about the nutritional values of carbohydrate. In contrast, modeling of gaseous exchanges along with the use of central assumptions showed that 17 +/- 2% of RMD was AC and 40 +/- 4% was FC. As compared with 17 kJ gross energy/g RMD, mean (+/- SE) energy values were 7.3 +/- 0.6 kJ ME/g and 6.3 +/- 0.5 kJ NME/g. The fiber fraction of RMD provided 5.2 +/- 0.7 kJ ME/g and 4.1 +/- 0.6 kJ NME/g. CONCLUSIONS: Modeling with the use of this noninvasive and widely available respiratory gas-monitoring technique yields nutritional values for carbohydrate that are supported by enzymatic, microbial, and animal studies and human fecal collection studies. Improvement in this approach is likely and testable across laboratories.     

A promising new procedure: laparoscopic devascularization for hepatocellular carcinoma with extra-hepatic feeding arteries

We have developed a new therapeutic modality: laparoscopic devascularization (LDEV) for hepatocellular carcinoma (HCC). Thirteen patients with HCC were treated with LDEV from March 1998 to March 2002. All LDEV procedures were performed under laparoscopic surgery using laparoscopic coagulating shears (LCS), endo-clip and endo-GIA. To prevent recanalization of extra-hepatic feeding arteries, we always add local ablation therapy (LAT) intraoperatively. The results are as follows. 1. The right gastroepiploic artery in 11 patients, right gastric artery in 1 and right inferior phrenic artery in 2 were devascularized. 2. The amount of intraoperative bleeding ranged 5-150 g and the operating time for devasculalization ranged 5-50 min, with an average of 30 min. 3. LAT was also performed in all cases. 4. No complications occurred. 5. A recurrent feeding artery developed in only one case (8%). 6. Nine patients are living (6-52, average 27 months) and 4 have died (5-28, average 16 months).     

Effect of left ventricular hypertrophy secondary to systemic hypertension on left coronary artery flow dynamics.

STUDY OBJECTIVE--The aim was to clarify the characteristics of the phasic blood velocity pattern and their possible causes in left ventricular hypertrophy secondary to systemic hypertension. DESIGN--Measurements of blood velocities in the left anterior descending coronary artery were made with a 20 MHz Doppler catheter with a top mounted annular crystal. All patients had normal coronary arteriograms. PATIENTS--23 hypertensive patients [systolic/diastolic pressure: 181(SD 15)/100(4) mm Hg)] with left ventricular hypertrophy, and 13 atypical chest pain patients without left ventricular hypertrophy or any abnormal haemodynamic findings (normal controls) entered the study. MEASUREMENTS AND MAIN RESULTS--The left anterior descending coronary artery blood velocity waveform in pressure overloaded left ventricular hypertrophy was characterised by delayed early diastolic inflow. The diastolic rise time of coronary flow (TDR), ie, the time from the beginning of diastole to peak velocity, was higher in patients with hypertensive left ventricular hypertrophy than in normal controls, at 145(56) v 66(15) ms, p less than 0.001. In patients with hypertensive left ventricular hypertrophy, TDR correlated well with the degree of hypertrophy (r = 0.83, p less than 0.01) and also with peak left ventricular systolic pressure (r = 0.62, p less than 0.01). The coronary flow reserve, calculated from the ratio of the diastolic mean velocity after intracoronary injection of papaverine to the resting flow velocity, decreased with prolongation of TDR (r = 0.58, p less than 0.02). CONCLUSIONS--(1) Impairment of early diastolic coronary arterial inflow is the most remarkable characteristic in pressure overloaded left ventricular hypertrophy; (2) preceding systolic vascular compression and impaired left ventricular relaxation correlate with the delayed early diastolic inflow; (3) the delayed inflow is an important possible cause of the decreased coronary flow reserve in the hypertensive left ventricular hypertrophy.     

Effect of packed cell volume on diastolic coronary artery pressure-flow relations in the dog

To elucidate the role of the haemorheological properties of the perfusate in the coronary circulation, the diastolic pressure-flow relation was studied in nine open chest heart blocked dogs with minimal vasomotor tone when blood with various packed cell volumes (12-67%) was used as perfusate. An electrical analogue model with proximal resistance R1, capacitance C, distal resistance R2, and the zero flow pressure intercept Pint was derived from the observation of the pressure-flow relation to support the data analysis. The diastolic pressure decay was then determined after the perfusion line had been clamped to calculate stop flow coronary artery pressure (Psf). The stop flow coronary artery pressure decreased in relation to packed cell volume (r = 0.45, p less than 0.01), and the value for the lowest packed cell volume (10-29%) was slightly higher than the great cardiac vein pressure (about 3 mmHg). The zero flow pressure intercept of the steady state pressure-flow relation showed a close correlation with the stop flow coronary artery pressure (r = 0.87, p less than 0.001). The value of R1 + R2, which reflects the inverse of the steady state pressure-flow slope, decreased simultaneously with the packed cell volume (r = 0.62, p less than 0.001). The resistance ratio R2/(R1 + R2) by our model prediction decreased in relation to packed cell volume (r = 0.5, p less than 0.001). The values of stop flow coronary artery pressure, zero flow pressure intercept, and R1 + R2 for the highest packed cell volume (50-69%) were 17.8(1.1) mmHg, 25.1(1.3) mmHg, and 0.48(0.05) mmHg.ml-1.min.100 g-1 respectively, whereas those for the lowest packed cell volume (10-29%) were 13.4(0.8) mmHg, 19.7(1.0) mmHg, and 0.24(0.02) mmHg.ml-1.min.100 g-1. The pressure difference between the stop flow coronary artery pressure and the zero flow pressure intercept may be due to the non-linearity in the pressure-flow relation at a low perfusion pressure. The left ventricular end diastolic pressure and great cardiac vein pressure did not change in relation to the packed cell volume of the coronary perfusate. Thus it is concluded that packed cell volume is one factor determining the high zero flow pressure.