Biomedical subjects

K B Schechtman

Publications and source records attributed to K B Schechtman.

At least 91 records · Page 5Linked to original sources

PubMed1989

Preoperative irradiation for rectal cancer. Improved local control and long-term survival.

Between July 1975 and July 1986, 112 patients with adenocarcinoma of the rectum were treated using preoperative irradiation followed by excisional surgery on the colorectal surgery service of Jewish Hospital at Washington University Medical Center in St. Louis. There were 68 men and 44 women in this study, with ages ranging from 19 to 94 years of age. In all cases, the rectal cancers were believed to be transmurally invasive based on initial clinical examination. Included in this group were 13 patients with poorly differentiated tumors and 51 patients with tumors fixed to surrounding tissues. Between 1975 and 1980, we used 2000 cGy preoperative irradiation followed by immediate excisional surgery to treat 22 patients. Excisional surgery for cure was divided between abdomino-perineal resection of the rectosigmoid in eleven patients, low anterior resection of the rectosigmoid in eight patients, and a low Hartmann's procedure in three patients. Five-year survival for 20 patients with potentially curable lesions (Dukes' A, B, and C), was 85%, and there was no local recurrence. Between 1980 and 1986, 90 patients were treated with 4500 cGy preoperative irradiation over a 5-week period followed by a 6-week waiting period, before excisional surgery. There were 72 patients with Dukes' A, B, and C lesions. Fifty patients underwent abdomino-perineal resection of the rectosigmoid, 33 patients underwent low anterior resection of the rectum, and seven patients underwent a low Hartmann's procedure. Five-year survival was 86%. Local recurrence was 1.8%. Tumor fixation and histologic dedifferentiation were the only factors that influenced survival. Five-year survival of patients with fixed poorly differentiated tumors was 27% as compared to 87% in patients with nonfixed well-differentiated tumors (p less than 0.0001). Tumor fixation was not a significant factor in itself. Preoperative external beam irradiation improves survival, local control, and resectability in patients with rectal cancer. This effect may be due to the treatment of the "tangential" margins and local lymph node metastases. Preoperative staging can be accomplished by determining fixation and differentiation of the tumor when preoperative irradiation is used.

Adenocarcinoma↗

PubMed1989

Favourable long term prognosis in patients with non-Q wave acute myocardial infarction not associated with specific electrocardiographic changes. Diltiazem Reinfarction Study Research Group.

Electrocardiograms obtained serially from 544 patients with non-Q wave infarction in the Diltiazem Reinfarction Study were analysed to compare the short term (less than or equal to 14 days) and long term (one year) follow up of 105 patients (19%) whose admission electrocardiogram showed no localisable repolarisation abnormalities (group 1) with the outcome in 439 patients (81%) who had ST-T wave abnormalities (group 2) localised to two or more contiguous leads within an anterior, inferior, or lateral lead group. There were no major between group differences in baseline clinical variables, concomitant medications, or treatment allocation (diltiazem v placebo). Group 2 patients, in the first year, had a higher incidence of early recurrent ischaemia (angina greater than or equal to 24 hours after myocardial infarction associated with ischaemic repolarisation changes), reinfarction, and readmission for chest pain than group 1 patients, despite comparable creatine kinase and creatine kinase MB activities in both groups. About 20% of patients with acute non-Q wave myocardial infarction did not have definable ST-T wave abnormalities. These patients had a similar clinical and enzymatic profile as patients with non-Q wave infarction with definable ST-T wave abnormalities and they were more likely to have a favourable short term and long term outcome.

Creatine Kinase↗

PubMed1989

ST segment shifts are poor predictors of subsequent Q wave evolution in acute myocardial infarction. A natural history study of early non-Q wave infarction.

Acute ST segment elevation is regarded generally as the sine qua non of evolving Q wave myocardial infarction (MI) because such electrocardiographic (ECG) injury is believed to be a marker of transmural ischemia and a forerunner of transmural necrosis. Alternatively, ST segment depression with or without T wave inversion is viewed as the dominant ECG feature of non-Q wave MI. However, this hypothesis has not been assessed prospectively in an acute MI population. We analyzed 2,304 serial ECGs at study entry (admission), day 2, day 3, and predischarge (mean, 10.2 +/- 2 days) from 576 patients with creatine kinase MB confirmed acute non-Q wave MI to determine what percentage of patients with early ST segment elevation culminated in subsequent Q wave development. Of this group, 187 patients (32%) exhibited 1 mm or greater ST segment elevation in two or more contiguous entry ECG leads. Of those patients whose non-Q wave MI could be localized on the basis of diagnostic admission ST segment shifts, the prevalence of early ST segment elevation was 43% (187 of 439). The sum total mean (+/- SD) peak ST segment elevation by lead group (anterior, inferior, lateral) was 4.0 +/- 2.4, 4.5 +/- 2.4, and 2.5 +/- 0.6 mm, respectively. Despite this, only 20% of patients with ST segment elevation (37 of 187) developed Q waves. Of 252 patients who exhibited early ST segment depression or T wave inversion or both, 39 (15%) evolved subsequent Q waves. Thus, while the prevalence of early ST segment elevation in acute evolving non-Q wave MI was higher than previously reported, 80% of patients with and 85% of patients without ST segment elevation and absent Q waves on the admission ECG did not develop subsequent Q waves during a 2-week period of observation (p = NS). In addition, when patients with ST segment elevation were compared with patients with ST segment depression or T wave inversions or both, there were no between-group differences in log peak creatine kinase (404 vs. 383 IU), reinfarction (6% vs. 8%), postinfarction angina (50% vs. 42%), or early recurrent ischemia (49% vs. 45%), defined as postinfarction angina with transient ECG changes. Thus, in patients who present with initial acute non-Q wave MI, ST segment shifts on admission are unreliable predictors of subsequent Q wave evolution and do not discriminate significant differences in postinfarction outcome. In particular, ST segment elevation during the early hours of evolving infarction is not an invariable harbinger of subsequent Q wave development.

Creatine Kinase↗

PubMed1989

Risk stratification of patients with non-Q wave myocardial infarction. The critical role of ST segment depression. The Diltiazem Reinfarction Study Research Group.

One-year follow-up data on 515 patients who survived hospitalization with MB-creatine kinase-confirmed, acute non-Q wave myocardial infarction were analyzed for factors related to mortality (n = 57) and late reinfarction (n = 64). Twelve of 24 analyzed variables were significantly associated with mortality. Those factors, which were independently predictive of mortality by Cox regression analysis, were persistent ST depression (p = 0.0009), a history of congestive heart failure (CHF) (p = 0.0069), older age (p = 0.0128), and ST elevation at hospital discharge (p = 0.0173). In-hospital reinfarction achieved borderline significance (p = 0.0512). Mortality during the follow-up period was 5.5% in patients with no ST depression, 10.1% in those with ST depression at baseline or discharge, and 22.2% in patients with ST depression at baseline and discharge (i.e., "persistent" ST depression). The age-adjusted risk of mortality for patients with persistent ST depression, discharge-ST elevation, and CHF was 13.99 times as high as was the risk for patients with no ST depression, no discharge-ST elevation, and no CHF. Of the 483 patients with complete electrocardiographic data at both baseline and discharge, 203 (42%) could be stratified into a high risk population with a risk ratio for 1-year mortality more than sevenfold that of patients with no risk factors. Although persistent ST depression was significantly associated with several measures of structural left ventricular damage, the independent significance of ST depression persisted even after adjusting for these factors. The independent predictors of late reinfarction (persistent ST depression, p = 0.0058; Killip class II or III, p = 0.0106; and left ventricular hypertrophy, p = 0.0470) permitted a similar risk stratification. We conclude that 1) easily identified clinical and electrocardiographic factors permit stratification of patients with non-Q wave infarction into high-risk subsets who may benefit from aggressive therapy; 2) ST depression is a highly significant and independent predictor of poor prognosis; and 3) the powerful predictive value of persistent ST depression suggests that non-Q wave myocardial infarction patients with this depression should be viewed as potentially high-risk patients who may be candidates for additional noninvasive testing or early coronary angiography.

Diltiazem↗

PubMed1989

Quantitative relationship between plasma lipids and glycohemoglobin in type I patients. Longitudinal study of 212 patients.

Plasma cholesterol, triglycerides, glycohemoglobin, and other covariates were measured in 212 type I (insulin-dependent) diabetic subjects on entry into a longitudinal study of diabetes and again after an average interval of 3.7 yr. Changes in individual cholesterol and triglyceride values over time were significantly correlated with changes in glycohemoglobin. After adjustment for potentially confounding covariates, plasma cholesterol declined by 2.2% (0.1 mM) for each percentage-point reduction in glycohemoglobin and plasma triglycerides declined by 8% (0.08 mM) per percentage point glycohemoglobin. Increased insulin dose was independently associated with increased plasma triglycerides, after adjusting for glycohemoglobin level and other covariates. However, insulin dose diabetic metabolic control, measured as declining glycohemoglobin, is the variable most closely associated with reduced plasma lipids in a population of typical type I diabetic patients.

Biomarkers↗

PubMed1989

Plasma lipids in patients with type I diabetes mellitus. Influence of race, gender, and plasma glucose control: lipids do not correlate with glucose control in black women.

Plasma lipids and hemoglobin A1 were measured in 544 type I diabetic patients. Hemoglobin A1 was positively correlated with the levels of total plasma cholesterol, total triglycerides, and low-density lipoprotein cholesterol and negatively correlated with the level of high-density lipoprotein cholesterol in the entire biracial group. These relationships between plasma lipids and hemoglobin A1 were not present in black women. In the white diabetic population a reduction in hemoglobin A1 of one percentage point was statistically associated with a decrease of 0.16 to 0.17 mmol/L in total plasma cholesterol, a decrease of 0.10 to 0.13 mmol/L in low-density lipoprotein cholesterol, and a reduction of 0.12 to 0.14 mmol/L in triglycerides. These findings suggest that race and gender are important determinants of the response of plasma lipids to glucose control in type I diabetes mellitus.

Adolescent↗

PubMed1988

Clinical significance and prognostic importance of left ventricular hypertrophy in non-Q-wave acute myocardial infarction.

Left ventricular (LV) hypertrophy is known to be an independent risk factor for cardiac death, but its significance in non-Q-wave acute myocardial infarction (AMI) has not been assessed previously. In a randomized diltiazem-placebo-controlled therapeutic trial of non-Q-wave AMI confirmed by creatine kinase-MB (CK-MB), 126 of 544 patients (23%) exhibited LV hypertrophy using standard voltage criteria. Compared to patients without LV hypertrophy, patients with LV hypertrophy were significantly older (65 vs 60 years, p less than 0.0001) and had smaller peak adjusted CK levels (490 +/- 376 vs 666 +/- 726 IU/liter, p less than 0.001) than patients without LV hypertrophy. Patients with and without LV hypertrophy did not differ significantly in acute mortality during hospitalization, progression to Q waves, reinfarction by CK-MB criteria or angina associated with transient electrocardiographic changes. Compared with patients without LV hypertrophy, those patients with non-Q-wave AMI and LV hypertrophy had a 2-fold higher incidence of reinfarction (24 vs 12%, p less than 0.005) and death (19 vs 9%, p = 0.044) during the first year of follow-up. Multivariate regression analysis revealed that the relative risk of death and reinfarction during the initial year after AMI was increased by a factor of 1.7 and 2.1 among patients with LV hypertrophy, respectively. It was therefore concluded that, although patients with LV hypertrophy and non-Q-wave AMI have smaller enzymatic infarcts and the same short-term prognosis as do patients without LV hypertrophy, their reinfarction and mortality rates are significantly increased during the first year of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1988

Improved differentiation of patients with and without ventricular tachycardia by frequency analysis of multiple electrocardiographic leads.

Previously, these investigators have analyzed fast Fourier transforms of signal-averaged electrocardiograms (ECGs) to distinguish patients with from those without sustained ventricular tachycardia (VT). In these studies, analysis was performed on X, Y and Z ECG signals and patient to patient comparisons were based on an average of the X, Y and Z results. The purpose of this study was to determine the extent to which fast Fourier transform analysis of individual ECG leads and of the vector magnitude contribute to the differentiation of patient groups. Studies were performed in 28 normal subjects (group I), 38 patients with prior myocardial infarction but without VT (group II), 38 patients with anterior infarction and sustained VT (group III) and 29 patients with inferior infarction and sustained VT (group IV). Results in group I were used to define normal values for the area and peak magnitude ratios for the individual X, Y and Z leads and for the vector magnitude and to define normal values for the mean XYZ area and peak magnitude ratios. Spectra of the X, Y and Z leads, the vector magnitude and the mean XYZ results were significantly different in patients with VT compared with normal subjects and patients without VT (p less than 0.001). Results were abnormal in multiple leads from 71% of patients with VT and from only 5% of normal subjects (p less than 0.0001). In many patients with VT, abnormalities were identified in 2 of the 3 leads indicating a selective spatial distribution of altered ECG signals that elicit abnormal frequency components.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

Morbidity and mortality of coronary bypass surgery in patients 75 years of age or older.

To determine factors associated with an increased risk of postoperative complications in elderly patients, 60 consecutive patients 75 years of age or older undergoing isolated coronary artery bypass grafting (CABG) were evaluated. Thirty-nine patients (65.0%) had at least one major postoperative complication, including 2 deaths (3.3%). Low body weight was the only univariate predictor (p less than 0.05) of an increased likelihood of complications overall. Prior cardiac operation, low serum cholesterol value, and prolonged cardiopulmonary bypass time were associated with increased bleeding. Electrocardiographic evidence of left ventricular hypertrophy was associated with prolonged postoperative confusion. Age of 80 years or more and increased cross-clamp time were predictive of pulmonary dysfunction. Low cardiac output occurred more frequently in patients with nonsinus rhythm, prior cardiac operation, recent congestive heart failure, or elevated level of blood urea nitrogen. Identification of risk factors for specific complications should prompt further studies to define ways of reducing morbidity and the resultant high cost associated with CABG in elderly patients.

Aged↗

PubMed1988

Identification of patients with sustained ventricular tachycardia by frequency analysis of signal-averaged electrocardiograms despite the presence of bundle branch block.

Previously, we have demonstrated distinguishing features in the fast Fourier transform (FFT) of signal-averaged electrocardiograms (ECGs) obtained during sinus rhythm in the absence of bundle branch block that differentiate patients with from those without sustained ventricular tachycardia (VT). The ECGs during sinus rhythm from many patients with sustained VT, however, exhibit intraventricular conduction abnormalities. Accordingly, this study was performed to determine whether the presence of bundle branch block during sinus rhythm precluded accurate identification of patients with sustained VT. Studies were performed in 28 normal subjects (group I) and 141 patients with organic heart disease grouped according to clinical characteristics. Group II comprised 40 patients without VT in whom the QRS duration during sinus rhythm was less than 120 msec. Group III included 21 patients without VT in whom the QRS duration during sinus rhythm was 120 msec or greater. Group IV comprised 43 patients with sustained VT having ECGs during sinus rhythm with QRS durations less than 120 msec. Group V included 37 patients with sustained VT in whom the QRS duration during sinus rhythm was 120 msec or greater. FFTs of the terminal QRS and ST segment of signal-averaged X, Y, and Z ECGs were computed. Transformed data were expressed as an FFT magnitude and the relative contribution and peak magnitudes of 20 to 50 Hz frequencies determined after first demonstrating that this FFT method was more appropriate, when compared with the energy spectrum, for analyzing ECG signals having a broad range of ST segment durations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Electrocardiographic evolution of posterior acute myocardial infarction: importance of early precordial ST-segment depression.

Precordial ST-segment depression is typically observed in anterior non-Q-wave acute myocardial infarction (AMI), and is generally not regarded as an indication for acute thrombolytic therapy. Of 544 patients with creatine kinase (CK)-MB-confirmed non-Q-wave AMI randomized to the prospective multicenter Diltiazem Reinfarction Study, 50 patients (9.2%) had isolated precordial ST-segment depression of 1 mm or more in 2 or more contiguous precordial electrocardiographic leads (V1-V4). Serial electrocardiograms recorded at study entry (mean 50.5 hours after onset of chest pain), on study day 2, study day 3 and at predischarge showed that in 23 of 50 patients (40%) electrocardiographic evidence of posterior AMI evolved, defined as an R wave of 0.04 second or more in lead V1 and an R:S greater than or equal to 1 in lead V2. In 18 of these 23 patients (78%), posterior AMI had evolved by study day 3, and none had an abnormal reelevation of CK-MB (every 12-hour sampling) for up to 14 days of hospitalization. Compared with the remaining 27 patients who had electrocardiographic features of anterior non-Q-wave AMI only, the 23 with initial precordial ST segment depression in whom posterior AMI developed had significantly higher mean peak CK values (1,051 +/- 172 vs 663 +/- 89 IU, p less than 0.009) and greater mean precordial ST-segment depression in lead V1 (0.28 vs + 0.19 mm, p = 0.01), in lead V2 (1.3 vs 0.26 mm, p = 0.003) and in lead V3 (2.0 vs 0.93 mm, p = 0.0004).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗

PubMed1987

Exercise training reduces depression and increases the performance of pleasant activities in hemodialysis patients.

This study compares the effects of a structured exercise training program to the therapeutic benefits of a 'support' group on the depressed mood and reduced performance of pleasant activities by hemodialysis patients. After 6 months of an aerobic exercise training program, the 10 exercisers showed a significant increase in maximal aerobic capacity (VO2max) and a significant decrease in dysphoric mood when compared to 7 patients attending the support group. Support group participants reported a significant decrease in pleasant activities while there was no change in the exercisers. Eighteen months after the exercise training program, the exercisers reported continued low levels of depressed mood, and were performing significantly more pleasant activities than they reported prior to the exercise program. The results of this study suggest an exercise training program may be useful in the psychosocial rehabilitation of some hemodialysis patients.

Activities of Daily Living↗

PubMed1986

Improved selection of patients for programmed ventricular stimulation by frequency analysis of signal-averaged electrocardiograms.

Improved selection of patients with suspected sustained ventricular tachycardia (VT) for programmed ventricular stimulation is needed. To determine if frequency analysis detects patients in whom sustained VT might be induced, we first obtained fast-Fourier transforms (FFT) of signal-averaged electrocardiograms (ECGs) from 20 patients with spontaneous sustained VT (group 1) and compared them with the results of programmed ventricular stimulation with single and double extrastimuli during two cycle lengths and burst pacing from two right ventricular sites. The FFT data were expressed as an area ratio that quantified the relative contributions of 20 to 50 Hz frequencies in the terminal QRS and ST segment. A logistic regression with inducibility as the dependent variable was used to help define area ratio values greater than 20 as abnormal. Sustained monomorphic VT was induced in 18 patients, each with an area ratio value greater than 20. Sustained VT was not induced in two patients, each with an area ratio value less than 20. FFT data were then compared prospectively with the results of programmed stimulation in 38 patients (group II) with nonsustained VT (12 patients) or syncope (26 patients) referred for electrophysiologic study. In none of the 26 patients in group II with normal FFT values was VT inducible. Sustained monomorphic VT was induced in five of 12 patients with abnormal FFT values. Thus, the results of FFT analysis correctly predicted the results of programmed ventricular stimulation in 88% of patients studied and in 82% of patients in group II with syncope or nonsustained VT. Moreover, all five patients in group II in whom sustained VT was induced were identified correctly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1986

Plasma apoproteins and the severity of coronary artery disease.

Plasma levels of lipids, lipoproteins, and apoproteins in 281 patients undergoing cardiac catheterization were correlated with the incidence and severity of coronary artery disease (CAD) to determine if measurements of apoprotein levels are more predictive of the presence and severity of CAD than the corresponding levels of lipoprotein lipids. In 156 men with CAD among 194 men in the study the only variable other than age that correlated with the severity of CAD, defined by the number of lesions and percent stenosis, was the ratio of apoprotein AI to apoprotein B (r = .1908, p less than .03). The ratio of apoprotein AI to apoprotein B was a more accurate predictor of the severity of CAD than was the ratio of the corresponding high-density to low-density lipoprotein levels (coefficients of partial determination of .07 and .035; p less than .001 and p less than .07, respectively). Multivariate analysis confirmed the independent effect of the ratio of apoprotein AI to apoprotein B on the severity of CAD even after adjustments were made for lipid levels, age, presence of hypertension or diabetes, and therapy with beta-blockers or diuretics. Among men with total occlusion of a coronary artery apoprotein E and apoprotein B levels were significantly higher than in control subjects with a similar extent of CAD (p less than .03). The lipid profiles of the 37 women with CAD were very different from those of the men.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1986

Flecainide in the treatment of nonsustained ventricular tachycardia.

Thirty-two patients received flecainide acetate for nonsustained ventricular tachycardia after having had unsuccessful treatment with a mean of four antiarrhythmic drugs. The mean left ventricular ejection fraction was 41% in 27. Thirty-one patients had organic heart disease, and 22 patients had arrhythmia-related symptoms. Total suppression of ventricular tachycardia occurred in 22 patients. Thirty patients were discharged from the hospital receiving flecainide at a mean (+/- SD) dosage of 315 +/- 76 mg/d and 26 of these patients attained a mean trough plasma drug level of 567 +/- 254 ng/mL. One patient had proarrhythmia and 3 had worsening of heart failure. Twenty-two patients remained in the trial for a mean follow-up of 13 +/- 7 months. Five patients died (1 suddenly) during the follow-up period. Our data indicate that flecainide suppresses refractory nonsustained ventricular tachycardia in 69% of patients who have organic heart disease. Serious adverse effects were minimized by initiation of treatment in the hospital and careful surveillance of electrocardiograms and plasma drug levels.

Adult↗

PubMed1985

Factor associated with diabetic control and utilization patterns in a low-income, older adult population.

The importance to health educators of identification of factors associated with diabetic control is underscored by the prevalence of the disease and its physical, psychological and economic impacts, all of which appear greatest for the poor. An investigation of social, attitudinal, and physical characteristics of 161 low income, predominantly black and female diabetic clinic patients was conducted. Results indicate that the factors associated with poor control (higher mean fasting blood glucose) include being older, lack of belief in control over health, lack of belief in the efficacy of treatment, a belief that diabetes is less serious than three curable illnesses, reported lack of social support in a crisis with diabetes, reported low satisfaction with the clinic, and finally, higher levels of reported problems with the self-care regimen, particularly diet. Moreover, poor control was also significantly associated with an increase in the number of emergency room visits and clinic visits. Increased clinic visits were also significantly associated with younger age, a higher number of prescribed medications and the requirement for insulin therapy, higher knowledge scores, and two health beliefs, the belief that diabetes is more serious than curable illnesses, and the belief that the treatment is likely to help. More frequent emergency room visits were also associated with being white, a higher number of complications of the disease, and more reported problems with self care. A higher number of days hospitalized was significantly associated with more complications, lower satisfaction with the clinic, and lack of belief in control over health. The results suggest the potential usefulness of a number of activities by health educators to positively influence diabetes control and decrease negative utilization patterns, such as hospitalizations. These include education aimed at refocusing health beliefs to emphasize the individual's control outcomes as well as the efficacy of treatment, and behavioral training to increase practical dietary skills. Finally, altering structural characteristics of clinics to better meet patient needs, such as decreasing waiting times, may encourage patient efforts towards diabetic control.

Attitude to Health↗

PubMed1983

Racial differences in plasma high-density lipoproteins in patients receiving hemodialysis. A possible mechanism for accelerated atherosclerosis in white men.

Among 346 nondiabetic patients receiving long-term hemodialysis, cardiovascular mortality was higher in white than in black men (P less than 0.02) but was similar between black and white women, despite the higher incidence of nephrosclerosis in black men and women (59 and 58 per cent vs. 8 and 10 per cent, respectively; P less than 0.0001). There were significant racial differences in plasma lipid and apoprotein levels in a subset of 100 of these patients. The white men had higher levels of plasma triglyceride and lower levels of high-density-lipoprotein (HDL) cholesterol, apoprotein A-I, and apoprotein A-II than black men; concentrations of HDL, apoprotein A-I, and apoprotein A-II were also lower in white than in black women. The distribution of the HDL subfractions HDL2, HDL3, and HDL3D, as determined by zonal ultracentrifugation, was normal in black and abnormal in white men receiving hemodialysis. HDL2 concentrations were higher in black than in white men by both zonal analysis (P less than 0.05) and polyanionic precipitation of the HDL subfractions (P less than 0.01). The distributions and concentrations of HDL2 and HDL3L were similar in black and white women. Thus, there are marked racial differences in HDL in male patients receiving hemodialysis. The abnormalities in HDL and the hypertriglyceridemia in the white men may explain their high rate of cardiovascular mortality.

Adult↗

PubMed1980

The effects of intravenous nitroglycerin on hemodynamics, coronary blood flow and morphologically and enzymatically estimated infarct size in conscious dogs.

Nitroglycerin (TNG) decreases ST-segment elevation accompanying myocardial ischemia, but its effect on morphometrically and enzymatically estimated infarct size (IS) has not been defined. Accordingly, coronary occlusion was produced in 92 conscious dogs; 65 survived for 24 hours. Thirty-three received TNG (200-300 microgram/min i.v. for 8 hours) and the results were compared with those in 32 untreated dogs. Coronary blood flow (CBF) was measured with tracer microspheres (141Ce, 85Sr and 95Nb) 5 minutes after occlusion before TNG, 20 minutes after TNG and again at 8 hours. Mean blood pressure decreased from 103 to 84 mm Hg with TNG, vs 99 to 94 mm Hg in controls (p > 0.02). Nitroglycerin increased CBF in the subendocardium of ischemic areas by 45% (0.09 to 0.13 ml/min/g). The dogs were sacrificed after 24 hours and IS was estimated morphometrically (25 +/- 1% vs 27 +/- 1% of left ventricular weight) and from myocardial CK depletion (23 +/- 1% vs 24 +/- 1%) were similar for the two groups. Thus, despite increased subendocardial CBF, prolonged i.v. TNG did not decrease infarct size, although a 15% difference would have been detected with this sample size. TNG may relieve coronary spasm but does not appear to be beneficial with sustained coronary occlusion.

Animals↗