Biomedical subjects

C Case

Publications and source records attributed to C Case.

At least 19 recordsLinked to original sources

PubMed2005

Relation of arterial stiffness to diastolic dysfunction in hypertensive heart disease.

OBJECTIVES: To examine the relation of arterial compliance to diastolic dysfunction in hypertensive patients with suspected diastolic heart failure (HF). PATIENTS: 70 medically treated hypertensive patients with exertional dyspnoea (40 women, mean (SD) age 58 (8) years) and 15 normotensive controls. MAIN OUTCOME MEASURES: Mitral annular early diastolic velocity with tissue Doppler imaging and flow propagation velocity were used as linear measures of diastolic function. Arterial compliance was determined by the pulse pressure method. RESULTS: According to conventional Doppler echocardiography of transmitral and pulmonary venous flow, diastolic function was classified as normal in 33 patients and abnormal in 37 patients. Of those with diastolic dysfunction, 28 had mild (impaired relaxation) and nine had advanced (pseudonormal filling) dysfunction. Arterial compliance was highest in controls (mean (SD) 1.32 (0.58) ml/mm Hg) and became progressively lower in patients with hypertension and normal function (1.04 (0.37) ml/mm Hg), impaired relaxation (0.89 (0.42) ml/mm Hg), and pseudonormal filling (0.80 (0.45) ml/mm Hg, p = 0.011). In patients with diastolic dysfunction, arterial compliance was inversely related to age (p = 0.02), blood pressure (p < 0.001), and estimated filling pressures (p < 0.01) and directly related to diastolic function (p < 0.01). After adjustment for age, sex, body size, blood pressure, and ventricular hypertrophy, arterial compliance was independently predictive of diastolic dysfunction. CONCLUSIONS: In hypertensive patients with exertional dyspnoea, progressively abnormal diastolic function is associated with reduced arterial compliance. Arterial compliance is an independent predictor of diastolic dysfunction in patients with hypertensive heart disease and should be considered a potential target for intervention in diastolic HF.

Arteries↗

PubMed2005

Functional and prognostic implications of left ventricular contractile reserve in patients with asymptomatic severe mitral regurgitation.

OBJECTIVE: To evaluate contractile reserve (CR) determined by exercise echocardiography in predicting clinical outcome and left ventricular (LV) function in asymptomatic severe mitral regurgitation (MR). DESIGN: Cohort study. SETTING: Regional cardiac centre. PATIENTS AND OUTCOME MEASURES: LV volumes and ejection fraction (EF) were measured at rest and after stress in 71 patients with isolated MR. During follow up (mean (SD) 3 (1) years), EF and functional capacity were serially assessed and cardiac events (cardiac death, heart failure, and new atrial fibrillation) were documented. RESULTS: CR was present in 45 patients (CR+) and absent in 26 patients (CR-). Age, resting LV dimensions, EF, and MR severity were similar in both groups. Mitral surgery was performed in 19 of 45 (42%) CR+ patients and 22 of 26 (85%) CR- patients. In patients undergoing surgery, CR was an independent predictor of follow up EF (p = 0.006) and postoperative LV dysfunction (EF < 50%) persisted in five patients, all in the CR- group. Event-free survival was lower in surgically treated patients without CR (p = 0.03). In medically treated patients, follow up EF was preserved in those with intact CR but progressively deteriorated in patients without CR, in whom functional capacity also deteriorated. CONCLUSIONS: Evaluation of CR by exercise echocardiography may be useful for risk stratification and may help to optimise the timing of surgery in asymptomatic severe MR.

Chronic Disease↗

PubMed2003

Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice.

BACKGROUND: Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography. METHODS AND RESULTS: We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate-risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate-high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography ( in 2615/life year saved) was more cost effective than exercise electrocardiography. CONCLUSION: Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease.

Coronary Artery Disease↗

PubMed2001

Prediction of mortality by exercise echocardiography: a strategy for combination with the duke treadmill score.

BACKGROUND: In studies generally involving short follow-up, exercise echocardiography has been shown to predict composite end points. We sought to study the prediction of mortality with this test and to devise a strategy for combination with standard exercise testing. METHODS AND RESULTS: Clinical, exercise testing, and echocardiographic data were collected in 5375 patients (aged 54+/-14 years, 3880 men) undergoing exercise echocardiography. The Duke treadmill score was derived from the results of treadmill exercise testing. Resting left ventricular (LV) function and the presence and severity of ischemia were interpreted by expert observers. Follow-up at 10.6 years (mean 5.5+/-1.9 years) was complete in 5211 patients (97%). The Duke score classified 59% of patients as low risk, 39% as intermediate risk, and 2% as high risk. Resting LV dysfunction was present in 1445 patients (27%), and the exercise echocardiogram was abnormal in 2525 patients (47%). Death occurred in 649 patients (12%). Over the first 6 years of follow-up, those with normal exercise echocardiograms had a mortality of 1% per year. Ischemia was an independent predictor of mortality. In sequential Cox models, the predictive power of clinical data was strengthened by adding the Duke score, resting LV function, and the results of exercise echocardiography. Exercise echocardiography was able to substratify patients with intermediate-risk Duke scores into groups with a yearly mortality of 2% to 7%. CONCLUSIONS: A normal exercise echocardiogram confers a low risk of death, and positive results are an independent predictor of death; ischemia is incremental to other data. This test may be particularly useful in patients with intermediate-risk Duke treadmill scores.

Adult↗

PubMed2001

Application of tissue Doppler to interpretation of dobutamine echocardiography and comparison with quantitative coronary angiography.

The main limitation of dobutamine echocardiography (DE) is its subjective interpretation. We sought to reduce the need for expert interpretation by developing a quantitative approach to DE using myocardial Doppler velocity (MDV) in 242 patients undergoing DE. In 128 patients with a normal dobutamine echocardiogram, the normal range was designed to give a specificity of 80%. The accuracy of this range was investigated in 114 consecutive patients who underwent coronary angiography within 2 months of DE. A standard dobutamine echocardiographic protocol was used, with MDV gathered from color tissue Doppler at rest and peak stress. Wall motion at these stages was scored by experienced observers using a 16-segment model and MDV was measured off-line. Sensitivity and specificity of wall motion scoring and MDV were obtained by comparison with angiographic evidence of disease, defined as stenosis > 50% of the coronary artery diameter. The normal range in tethered segments (septum, anteroseptum, and inferior) was > or = 7 cm/s in the basal segments and > or = 5 cm/s in the midsegments. In the free wall (anterior, lateral, and posterior), the cutoff was > or = 6 cm/s in the base and > or = 4 cm/s in the midventricle. Of 114 patients undergoing angiography, 84 (75%) had significant stenoses, and the sensitivity of wall motion scoring and MDV were 88% and 83%, respectively, with specificities of 81% and 72% (p = NS). The accuracy was similar overall (86% vs 80%), as well as in each vascular territory. These data suggest that a fully quantitative interpretation of DE using site-specific normal ranges of tissue Doppler, which account for regional variations of base-apex function, is feasible and equivalent in accuracy to expert wall motion scoring.

Adult↗

PubMed2001

Prediction of mortality using dobutamine echocardiography.

OBJECTIVES: We sought to find out whether dobutamine echocardiography (DbE) could provide independent prediction of total and cardiac mortality, incremental to clinical and angiographic variables. BACKGROUND: Existing outcome studies with DbE have examined composite end points, rather than death, over a relatively short follow-up. Clinical and stress data were collected in 3,156 patients (age 63 +/- 12 years, 1,801 men) undergoing DbE. Significant stenoses (>50% diameter) were identified in 70% of 1,073 patients undergoing coronary angiography. Total and cardiac mortality were identified over nine years of follow-up (mean 3.8 +/- 1.9). Cox models were used to analyze the effect of ischemia and other variables, independent of other determinants of mortality. RESULTS: The dobutamine echocardiogram was abnormal in 1,575 patients (50%). Death occurred in 716 patients (23%), 259 of whom (8%) were thought to have died from cardiac causes. Patients with normal DbE had a total mortality of 8% per year and a cardiac mortality of 1% per year over the first four years of follow-up. Ischemia and the extent of abnormal wall motion were independent predictors of cardiac death, together with age and heart failure. In sequential Cox models, the predictive power of clinical data alone (model chi-square 115) was strengthened by adding the resting left ventricular function (model chi-square 138) and the results of DbE (model chi-square 181). In the subgroup undergoing coronary angiography, the power of the model was increased to a minor degree by the addition of coronary anatomy data. CONCLUSIONS: Dobutamine echocardiography is an independent predictor of death, incremental to other data. While a normal dobutamine echocardiogram predicts low risk of cardiac death (on the order of 1% per year), this risk increases with the extent of abnormal wall motion at rest and stress.

Aged↗

PubMed2001

Does renal failure cause an atherosclerotic milieu in patients with end-stage renal disease?

PURPOSE: Atherosclerotic vascular disease is the main cause of morbidity and mortality in patients with end-stage renal disease, but the independent contribution of renal failure rather than associated risk factors is unclear. We sought to examine the relative contribution of these factors to the severity of atherosclerosis by measuring intima-medial thickness and brachial artery reactivity in uremic patients and controls. SUBJECTS AND METHODS: Cardiovascular risk factors, including lipid and homocysteine levels, were evaluated in 213 patients (69 on hemodialysis, 60 on peritoneal dialysis, and 82 nonuremic controls). High-resolution B-mode ultrasonography with automated off-line analysis was used to measure the intima-medial thickness in the common carotid artery and to measure the lumen diameter of the brachial artery at rest, during reactive hyperemia, and after sublingual nitroglycerine. The correlations of risk factors with intima-medial thickness and brachial reactivity were examined using a general linear regression model. RESULTS: Patients with renal failure had a greater mean (+/- SEM) maximum intima-medial thickness than controls (0.83 +/- 0.02 mm versus 0.70 +/- 0.02 mm, P < 0.05), but the brachial artery response to reactive hyperemia was not significantly different between the renal failure patients and the control group (4.7% +/- 6.1% versus 6.1% +/- 8.6% dilatation, P > 0.05). The uremic state was an independent predictor of intima-medial thickness (r2 = 0.16, P < 0.001) but not of brachial artery reactivity (P = 0.99). CONCLUSION: The atherosclerotic burden in patients with renal failure, as indicated by an increased intima-medial thickness, may reflect effects of uremia that are independent of cardiovascular risk factors.

Adult↗

PubMed2001

Automated edge-detection technique for measurement of brachial artery reactivity: a comparison of concordance with manual measurements.

Concerns have been raised about the reproducibility of brachial artery reactivity (BAR), because subjective decisions regarding the location of interfaces may influence the measurement of very small changes in lumen diameter. We studied 120 consecutive patients with BAR to address if an automated technique could be applied, and if experience influenced reproducibility between two observers, one experienced and one inexperienced. Digital cineloops were measured automatically, using software that measures the leading edge of the endothelium and tracks this in sequential frames and also manually, where a set of three point-to-point measurements were averaged. There was a high correlation between automated and manual techniques for both observers, although less variability was present with expert readers. The limits of agreement overall for interobserver concordance were 0.13 +/- 0.65 mm for the manual and 0.03 +/- 0.74 mm for the automated measurement. For intraobserver concordance, the limits of agreement were - 0.07 +/- 0.38 mm for observer 1 and - 0.16 +/- 0.55 mm for observer 2. We concluded that BAR measurements were highly concordant between observers, although more concordant using the automated method, and that experience does affect concordance. Care must be taken to ensure that the same segments are measured between observers and serially.

Automation↗

PubMed2001

Effect of power Doppler and digital subtraction techniques on the comparison of myocardial contrast echocardiography with SPECT.

OBJECTIVE: To compare the accuracy and feasibility of harmonic power Doppler and digitally subtracted colour coded grey scale imaging for the assessment of perfusion defect severity by single photon emission computed tomography (SPECT) in an unselected group of patients. DESIGN: Cohort study. SETTING: Regional cardiothoracic unit. PATIENTS: 49 patients (mean (SD) age 61 (11) years; 27 women, 22 men) with known or suspected coronary artery disease were studied with simultaneous myocardial contrast echo (MCE) and SPECT after standard dipyridamole stress. MAIN OUTCOME MEASURES: Regional myocardial perfusion by SPECT, performed with (99m)Tc tetrafosmin, scored qualitatively and also quantitated as per cent maximum activity. RESULTS: Normal perfusion was identified by SPECT in 225 of 270 segments (83%). Contrast echo images were interpretable in 92% of patients. The proportion of normal MCE by grey scale, subtracted, and power Doppler techniques were respectively 76%, 74%, and 88% (p < 0.05) at > 80% of maximum counts, compared with 65%, 69%, and 61% at < 60% of maximum counts. For each technique, specificity was lowest in the lateral wall, although power Doppler was the least affected. Grey scale and subtraction techniques were least accurate in the septal wall, but power Doppler showed particular problems in the apex. On a per patient analysis, the sensitivity was 67%, 75%, and 83% for detection of coronary artery disease using grey scale, colour coded, and power Doppler, respectively, with a significant difference between power Doppler and grey scale only (p < 0.05). Specificity was also the highest for power Doppler, at 55%, but not significantly different from subtracted colour coded images. CONCLUSIONS: Myocardial contrast echo using harmonic power Doppler has greater accuracy than with grey scale imaging and digital subtraction. However, power Doppler appears to be less sensitive for mild perfusion defects.

Aged↗

PubMed2001

Do anaesthetized patients recover better after Bispectral Index Monitoring?

Could Bispectral Index (BIS) monitoring during anaesthesia improve the recovery characteristics of patients? Previous studies have shown conflicting results. To eliminate bias, a control group of 75 cases anaesthetized by the authors was compared to a reference group of 141 cases anaesthetized by other anaesthetists. A study group of 71 cases was then anaesthetized by the authors titrating to BIS 40-50 and this was compared with the control group. Recovery characteristics were assessed using a Modified Aldrete score. BIS monitored cases had improvements in blood pressure stability (P = 0.023) and respiratory score (P = 0.016) throughout the study period. Activity and consciousness levels were higher on arrival in PACU in the BIS monitored group (P = 0.015 and P = 0.017) but were not maintained. There was no significant difference in mean oxygen saturation scores. The improved recovery characteristics in BIS monitored patients may have positive implications for safety, nursing workload, staffing, and cost savings in the PACU.

Anesthesia Recovery Period↗

PubMed2001

Assessment of regional long-axis function during dobutamine echocardiography.

Echocardiographic analysis of regional left ventricular function is based upon the assessment of radial motion. Long-axis motion is an important contributor to overall function, but has been difficult to evaluate clinically until the recent development of tissue Doppler techniques. We sought to compare the standard visual assessment of radial motion with quantitative tissue Doppler measurement of peak systolic velocity, timing and strain rate (SRI) in 104 patients with known or suspected coronary artery disease undergoing dobutamine stress echocardiography (DbE). A standard DbE protocol was used with colour tissue Doppler images acquired in digital ciné-loop format. Peak systolic velocity (PSV), time to peak velocity (TPV) and SRI were assessed off-line by an independent operator. Wall motion was assessed by an experienced reader. Mean PSV, TPV and SRI values were compared with wall motion and the presence of coronary artery disease by angiography. A further analysis included assessing the extent of jeopardized myocardium by comparing average values of PSV, TPV and SRI against the previously validated angiographic score. Segments identified as having normal and abnormal radial wall motion showed significant differences in mean PSV (7.9 +/- 3.8 and 5.9 +/- 3.3 cm/s respectively; P < 0.001), TPV (84 +/- 40 and 95 +/- 48 ms respectively; P = 0.005) and SRI (-1.45 +/- 0.5 and -1.1 +/- 0.9 s(-1) respectively; P < 0.001). The presence of a stenosed subtending coronary artery was also associated with significant differences from normally perfused segments for mean PSV (8.1+/-3.4 compared with 5.7+/-3.7 cm/s; P < 0.001), TPV (78 +/- 50 compared with 92 +/- 45 ms; P < 0.001) and SRI (-1.35 +/- 0.5 compared with -1.20 +/- 0.4 s(-1); P = 0.05). PSV, TPV and SRI also varied significantly according to the extent of jeopardized myocardium within a vascular territory. These results suggest that peak systolic velocity, timing of contraction and SRI reflect the underlying physiological characteristics of the regional myocardium during DbE, and may potentially allow objective analysis of wall motion.

Adrenergic beta-Agonists↗

PubMed2001

Outpatient mastectomy: clinical, payer, and geographic influences.

OBJECTIVE: To determine (1) the use of outpatient services for all surgical breast procedures for breast cancer and (2) the influence of payer and state on the use of outpatient services for complete mastectomy in light of state and federal length-of-stay managed care legislation. DATA SOURCES: Healthcare Cost and Utilization Project representing all discharges from hospitals and ambulatory surgery centers for five states (Colorado, Connecticut, Maryland, New Jersey, and New York) and seven years (1990-96). STUDY DESIGN: Longitudinal, cross-sectional analyses of all women undergoing inpatient and outpatient complete mastectomy (CMAS), subtotal mastectomy (STMAS), and lumpectomy (LUMP) for cancer were employed. Total age-adjusted rates and percentage of outpatient CMAS, STMAS, and LUMP were compared. Independent influence of state and HMO payer on likelihood of receiving an outpatient CMAS was determined from multivariate models, adjusting for clinical characteristics (age < 50 years, comorbidity, metastases, simple mastectomy, breast reconstruction) and hospital characteristics (teaching, ownership, urban). PRINCIPAL FINDINGS: In 1993, 1 to 2 percent of CMASs were outpatient in all states. By 1996, 8 percent of CMASs were outpatient in Connecticut, 13 percent were outpatient in Maryland, and 22 percent were outpatient in Colorado. In comparison, LUMPs were 78 to 88 percent outpatient, and by 1996, 43 to 72 percent of STMASs were outpatient. In 1996, women were 30 percent more likely to receive an outpatient CMAS in New York, 2.5 times more likely in Connecticut, 4.7 times more likely in Maryland, and 8.6 times more likely in Colorado compared to New Jersey. In addition, women with Medicare, Medicaid, or private commercial insurance were less likely to receive an outpatient CMAS compared to women with an HMO payer. CONCLUSIONS: LUMP is an outpatient procedure, and STMAS is becoming primarily outpatient. CMAS, while still primarily inpatient, is increasingly outpatient in some states. Although clinical characteristics remain important, the state in which a woman receives care and whether she has an HMO payer are strong determinants of whether she receives an outpatient CMAS.

Adult↗

PubMed2000

Exercise echocardiography predicts development of left ventricular dysfunction in medically and surgically treated patients with asymptomatic severe aortic regurgitation.

OBJECTIVE: To assess resting and exercise echocardiography for prediction of left ventricular dysfunction in patients with significant asymptomatic aortic regurgitation. DESIGN: Cohort study of patients with aortic regurgitation. SETTING: Tertiary referral centre specialising in valvar surgery. PATIENTS: 61 patients (38 men, 23 women; mean (SD) age 53 (14) years) with asymptomatic or minimally symptomatic aortic regurgitation and no known coronary artery disease; 35 were treated medically and 26 had aortic valve replacement. INTERVENTIONS: Exercise echocardiography was used to evaluate ejection fraction, which was measured on the resting and post-stress images using the modified Simpson method. Patients with an increment of ejection fraction after exercise were denoted as having contractile reserve (CR+); those without an increment were labelled CR-. MAIN OUTCOME MEASURES: Standard univariate and multivariate methods and receiver operating characteristic analyses were used to assess the ability of contractile reserve to predict follow up ejection fraction. RESULTS: In the 35 medically treated patients, 13 of 21 (62%) with CR+ (mean (SD) ejection fraction increment 7 (3)%) had preserved ejection fraction on follow up. In the 14 patients with CR- (ejection fraction decrement 8 (4)%), 13 (93%) had a decrement of ejection fraction on follow up from 60 (5)% at baseline to 54 (3)% on follow up (p = 0.005). Age, resting left ventricular dimensions, medical treatment, aortic regurgitation severity, exercise capacity, and rate-pressure product were similar in both CR+ and CR- groups. Among the 26 surgical patients, 13 showed CR+ (ejection fraction increase 9 (5)%), all of whom had an increase in ejection fraction on follow up (from 49% to 59%). Of 13 surgical patients with CR- (ejection fraction decrease 7 (5)%), 10 (77%) showed the same or worse ejection fraction on postoperative follow up. CONCLUSIONS: Contractile reserve on exercise echocardiography is a better predictor of left ventricular decompensation than resting indices in asymptomatic patients with aortic regurgitation. In patients undergoing aortic valve replacement, contractile reserve had a better correlation with resting ejection fraction on postoperative follow up. Measurement of contractile reserve may be useful to monitor the early development of myocardial dysfunction in asymptomatic patients with aortic regurgitation, and may help to optimise the timing of surgery.

Adult↗

PubMed2000

Allied health outcomes research using a collaborative distance approach.

As part of an activity sponsored by the Coalition for Allied Health Leadership, individuals representing various allied health disciples formed a team to develop a presentation and bibliography on outcomes research in allied health. Team members worked with each other while geographically separated, and concluded that several factors contributed to the difficulty the team encountered in working together in a truly collaborative manner. However, the team's efforts did result in a viable presentation on outcomes research in allied health to include definition and parameters, a discussion of the multidimensional nature of treatment and its effects, suggested schema, and comparisons of several outcome-assessment instruments. In addition, a bibliography on outcomes research in allied health was produced.

Allied Health Occupations↗

PubMed1998

Novel antineoplastic agents with efficacy against multidrug resistant tumor cells.

A novel series of pentafluorobenzenesulfonamides has been shown to inhibit the growth of a variety of human tumor cell lines. Among the cell types against which these agents were evaluated were the multidrug resistant (MDR) cell lines MCF-7/ADR and P388/ADR. The cytotoxic activity of members of this series of compounds was not affected by the multidrug resistant pump in MCF-7/ADR or P388/ADR cells.

Antineoplastic Agents↗

PubMed1998

H2 histaminergic control of inhibition of eating induced by intragastric NaCl in rats.

A role for endogenous histamine and histamine receptor subtypes in mediating the inhibition of eating induced by intragastric (i.g.) hypertonic NaCl was examined in adult male Sprague-Dawley rats surgically equipped with a chronic gastric catheter. The i.g. infusion of 2 mL 900 or 1,800 mOsm/kg of NaCl inhibited: 1) ingestion of pellets in rats eating after 24-h food deprivation; and 2) ingestion of cookies in rats eating without prior deprivation. The H1 receptor antagonists dexbrompheniramine (DXB; 1 mg/kg) and pyrilamine (PYR; 4 mg/kg) did not attenuate the inhibitory effects of i.g. 900 or 1,800 mOsm/kg of NaCl for rats eating pellets and for rats eating cookies. The H2 antagonists cimetidine (CIM; 16 mg/kg) and metiamide (MET; 16 mg/kg) attenuated the inhibitory effects of i.g. 1,800 mOsm/kg of NaCl upon ingestion of cookies, but intracerebroventricular (i.c.v.) infusion (through a chronic indwelling cannula) of 100 microg of CIM did not mimic this effect of intraperitoneal (i.p.) CIM. The i.p. CIM failed to attenuate the inhibition of eating cookies produced by i.p. octapeptide of cholecystokinin (CCK-8; 3 microg/kg). The H3 antagonist thioperamide (TH; 10 mg/kg i.p.) and the H3 agonist R-alpha-methylhistamine (RAM; 3 mg/kg i.p.) did not alter the inhibitory effect of i.g. 1,800 mOsm/kg of NaCl for rats eating cookies. Combined treatments of systemic DXB plus CIM, and DXB plus CIM plus thioperamide (TH) did not reverse the inhibitory effects of i.g. 1,800 mOsm/kg of NaCl upon ingestion of cookies. Finally, i.p. DXB, but not CIM, attenuated the ability of i.g. 900 mOsm/kg of NaCl to increase water intake; conversely, i.p. CIM, but not DXB, attenuated the ability of i.g. 900 mOsm/kg of NaCl to inhibit eating of cookies. These findings demonstrate a double dissociation of effects upon ingestive behavior: H1, but not H2, antagonism attenuates the effect of i.g. hypertonic NaCl on water intake, whereas H2, but not H1, antagonism attenuates the inhibition of eating produced by i.g. hypertonic NaCl. These results demonstrate that different subtypes of peripheral and/or central histamine receptors contribute to different behavioral consequences of postprandial gastrointestinal osmotic loads in rats.

Animals↗

PubMed1998

Early results of AV sequential pacing on left ventricular outflow obstruction after Senning procedure.

Dual chamber pacing was shown to decrease left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy 30 years ago. We report early results of AV sequential pacing from the LV apex in a patient with transposition of the great arteries who is post-Senning procedure. LVOT obstruction resulted from septal deviation and systolic anterior motion of the mitral valve. Pacing was indicated for sinus node dysfunction. AV sequential pacing with a short optimal AV interval of 60 ms demonstrated a 45% reduction in the degree of LVOT obstruction. This article suggests that LVOT obstruction after the Senning procedure can be palliated by asynchronous septal contraction induced by AV sequential pacing, even if the activation is from LV apex, and avoid or postpone surgery in selected situations.

Adolescent↗

PubMed1997

Pediatric ECMO for severe quinidine cardiotoxicity.

We report the use of extracorporeal membrane oxygenation (ECMO) to establish and maintain cardiovascular stability in a 16 month old with refractory bradydysrrhythmias and hypotension after an acute overdose of quinidine. He underwent an 11-day course of ECMO and was discharged with normal neurologic function. This case illustrates the role ECMO can play in the treatment of profound cardiovascular collapse caused by toxic ingestions. To be optimally effective, management of such patients must be anticipatory.

Anti-Arrhythmia Agents↗