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Biomedical subjects

M D Feldman

Publications and source records attributed to M D Feldman.

At least 55 records · Page 3Linked to original sources
PubMed1997

Evaluation of Herbert screw fixation for the treatment of displaced scaphoid nonunions.

Ten cases of unstable scaphoid nonunions treated with Herbert screw fixation were compared to nine cases treated with Herbert screw fixation supplemented with a single Kirschner wire (K-wire) across the fracture site. Corticocancellous bone graft from the distal radius was used in all cases to reconstruct the scaphoid. The age of the patients and duration of the nonunions were similar in both groups. Postoperative radiographs demonstrated that only 5 of 10 patients with Herbert screw fixation alone healed, while 8 of 9 patients with Herbert screw and K-wire fixation healed. The time to union averaged 4.9 months in the patients supplemented with a K-wire and 7.8 months in those patients without the K-wire.

Adolescent↗
PubMed1996

Acute cardiovascular effects of OPC-18790 in patients with congestive heart failure. Time- and dose-dependence analysis based on pressure-volume relations.

BACKGROUND: OPC-18790 is a water-soluble quinolinone derivative that shares the pharmacological properties of vesnarinone and that may be useful for treating heart failure. We studied the contribution and relative dose sensitivities of the inotropic, lusitropic, and vascular effects of OPC-18790 in patients with dilated cardiomyopathy. METHODS AND RESULTS: Pressure-volume (PV) analysis was performed in 17 patients who received either 5 micrograms.kg-1.min-1 (low dose, n = 10) or 10 micrograms.kg-1.min-1 (high dose, n = 7) OPC-18790 by 1-hour IV infusion. Right heart pressures and flow and left heart PV relations (conductance catheter) were measured at baseline and every 15 minutes during infusion. Transient inferior vena caval obstruction was used to determine PV relations. Both doses produced venodilation reflected by a 10% decline in left ventricular end-diastolic volume and a 30% fall in atrial and pulmonary artery pressures. Arterial dilation was four times greater at the high dose, with an approximately 40% fall in effective arterial elastance and systemic resistance. Contractility rose by 25% to 100% (depending on PV index) with both doses. Ventricular-arterial coupling (ratio of ventricular end-systolic to arterial elastances) was approximately 0.25 at baseline and doubled (or tripled) at low (or high) dose, correlating with improved efficiency. Isovolumetric relaxation shortened, whereas the diastolic PV relation was generally unchanged. Heart rate was unaltered. CONCLUSIONS: OPC-18790 has potent venous and arterial vasodilator effects and moderate inotropic and lusitropic effects without a change in heart rate. These combined actions suggest a unique potential of OPC-18790 for heart failure treatment.

Blood Pressure↗
PubMed1996

Factitious disorder by proxy: awareness among mental health practitioners.

Factitious disorder by proxy (FDP) is a form of abuse in which a caregiver surreptitiously simulates or induces illnesses in a person for whom he or she cares. Typically, a mother is the perpetrator and at least one of her children is victimized. FDP has a high morbidity and mortality rate, and a knowledgeable health team increases the primary physician's confidence in making this difficult diagnosis. The purpose of this study was to determine the levels of awareness of FDP among mental health practitioners and their sources of information. Anonymous questionnaires were sent to 687 primary care physicians and mental health practitioners. Psychiatrists (89%) and psychologists (69%) were more aware of the disorder than were social workers (42%). Years in practice were not associated with awareness of FDP. Psychiatrists were more likely than psychologists or social workers to have had exposure through an actual case or through their professional journals. These findings were statistically significant. Awareness of FDP varies significantly among mental health professionals and may reflect the availability of information during training and in journals. Since social workers and psychologists often have earlier and broader opportunities than psychiatrists to interface with families, enhancements in training and the professional literature in these disciplines are needed if FDP is to be consistently considered and identified.

Alabama↗
PubMed1995

Mechanism of adenosine-induced elevation of pulmonary capillary wedge pressure in humans.

BACKGROUND: Continuous intravenous administration of adenosine to humans often results in a paradoxical rise in pulmonary capillary wedge pressure (PCWP), whereas arterial resistance is lowered and cardiac output and heart rate increase. This is believed to be due to diastolic stiffening of the ventricle or to a negative inotropic effect. In the present study, we tested these and other mechanisms by using pressure-volume (PV) analysis and echocardiography. METHODS AND RESULTS: Fifteen patients with normal rest left ventricular function underwent cardiac catheterization and received adenosine at a rate of 140 micrograms/kg per minute IV for 6 to 10 minutes. PV relations were measured in 9 patients (without coronary artery disease) using the conductance catheter method. In 6 additional patients with coronary artery disease, echocardiograms were used to assess wall thickness and function, and aortic and coronary sinus blood, lactate, oxygen, and adenosine levels were measured. Adenosine increased PCWP by 19% (+2.6 mm Hg) in both patient groups while lowering arterial load by 30% and increasing cardiac output by 45% (all P < .001). There was no significant effect of adenosine on mean linear chamber compliance or monoexponential elastic stiffness, as the diastolic PV relation was unchanged in most patients. Diastolic wall thickness also was unaltered. Thus, the PCWP rise did not appear to be due to diastolic stiffening. Adenosine induced a rightward shift of the end-systolic PV relation (ESPVR) (+12.7 +/- 3.7 mL) without a slope change. This shift likely reflected effects of afterload reduction, as other indexes (stroke work-end-diastolic volume relation and dP/dtmax at matched preload) were either unchanged or increased. Furthermore, this modest shift in ESPVR was more than compensated for by vasodilation and tachycardia, so reduced systolic function could not explain the increase in PCWP. There also was no net lactate production to suggest ischemia. Rather than arising from direct myocardial effects, PCWP elevation was most easily explained by a change in vascular loading, as both left ventricular end-diastolic volume and right atrial pressure increased (P < .05). This suggests that adenosine induced a redistribution of blood volume toward the central thorax. CONCLUSIONS: PCWP elevation in response to adenosine primarily results from changes in vascular loading rather than from direct effects on cardiac diastolic or systolic function.

Adenosine↗
PubMed1995

Tangled in the web: countertransference in the therapy of factitious disorders.

OBJECTIVE: Patients who simulate or actually self-induce illnesses to assume the "sick role" present a number of imposing psychotherapeutic challenges. The purpose of this article is to discuss the countertransferential reactions that are mobilized in therapy with these patients. METHODS: Literature searches of the MEDLINE and HEALTH databases were performed using the term "factitious disorder." The resulting citations were examined for descriptions of the potential and actual countertransference responses in therapy with such patients. The few citations with relevant material were supplemented with other clinical literature on countertransference as well as observations from cases in which the authors have served as therapists or consultants. RESULTS: Once the medical dissimulation has been exposed, the most conspicuous difficulty is in persuading the patient to agree to therapy. When therapy does take place, both the patient's overt behaviors, such as actual bodily damage, and his or her underlying emotional issues can mobilize particularly intense reactions in the therapist. CONCLUSIONS: Recognition and management of the countertransference reactions likely to emerge in therapy with factitious disorder patients are particularly important if the therapy is to be maximally effective.

Countertransference↗
PubMed1994

Hemodynamic and metabolic correlates of dipyridamole-induced myocardial thallium-201 perfusion abnormalities in multivessel coronary artery disease.

The mechanisms responsible for the development of reversible thallium-201 (TI-201) defects with dipyridamole stress in patients with coronary artery disease (CAD) is not well understood. Previous experimental animal studies have demonstrated coronary steal characterized by an absolute decrease in subendocardial flow distal to a stenosis in response to dipyridamole infusion. Accordingly, the purpose of this study was to determine if reversible TI-201 defects in response to dipyridamole infusion are reflective of myocardial ischemia or secondary to regional differences in flow reserve. Dipyridamole (0.56 mg/kg) TI-201 imaging was performed in 23 patients in whom serial electrocardiographic, hemodynamic, aortic and coronary sinus lactate, and coronary sinus adenosine measurements were obtained. All patients with CAD had TI-201 redistribution (3.8 +/- 2.0 defects/patient), and all patients without CAD had normal scans. Mean aortic pressure was similar in both groups and did not change in response to dipyridamole (non-CAD 103 +/- 11 vs CAD 99 +/- 15 mm Hg, p = NS). Pulmonary capillary wedge pressure was similar at baseline (non-CAD 11 +/- 4 vs CAD 13 +/- 5 mm Hg, p = NS) and did not change in response to the drug (non-CAD 14 +/- 3 vs CAD 15 +/- 7 mm Hg, p = NS). Lactate extraction fraction was similar at baseline (non-CAD 0.22 +/- 0.09 vs CAD 0.17 +/- 0.14, p = NS) and decreased similarly in both groups (non-CAD 0.08 +/- 0.06 vs CAD 0.05 +/- 0.12, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1994

Liejacking.

Explore the source record for details and available documents.

Adolescent↗
PubMed1994

Deceiving others/deceiving oneself: four cases of factitious rape.

Although patients with factitious disorders typically seek the "patient" role through illness portrayals, some instead portray themselves falsely as "victims." We discuss the cases of four women who claimed to have been victims of rape; the allegations ultimately were disproved. Factitious rape may be prompted by a search for nurturance; by dissociation, leading individuals to believe that trauma earlier in life is ongoing; by a need to be rescued from real, current abuse; and by projection of anger onto specific male targets. Although dramatic, factitious rape is rare, we advocate thorough investigation of rape claims even when patients have known histories of deceptive behavior.

Adult↗
PubMed1994

Ventricular systolic assessment in patients with dilated cardiomyopathy by preload-adjusted maximal power. Validation and noninvasive application.

BACKGROUND: Noninvasive cardiac-specific analysis of contractile function in patients with dilated heart failure remains problematic. This study tests whether maximal power divided by the square of end-diastolic volume (PWRmx/EDV2, or preload-adjusted PWRmx) can provide such assessment. METHODS AND RESULTS: To validate the load insensitivity of the PWRmx index and determine its response to contractile change, 24 subjects with chronic dilated cardiomyopathy underwent invasive pressure-volume catheterization study using the conductance catheter technique. Preload was transiently reduced by 30% using balloon occlusion of the inferior vena cava, and afterload impedance was lowered by 50%, induced by a bolus injection of nitroglycerin. Contractile state was varied by intravenous dobutamine, verapamil, or esmolol. PWRmx was calculated from the simultaneous product of ventricular pressure and rate of volume change (dV/dt), the latter derived from the volume catheter signal. PWRmx varied directly with preload but was minimally influenced by afterload. However, PWRmx/EDV2 was not significantly altered by either loading change. PWRmx/EDV2 did vary with contractility, correlating closely with changes in the end-systolic pressure-volume relation (r = .91, P < .001). To test the noninvasive application of this index, 12 additional patients were studied, with PWRmx/EDV2 derived from nuclear ventriculography combined with a novel method to measure central arterial pressures. Subjects received intravenous nitroprusside or dobutamine in random order. Ejection fraction increased similarly with both agents (+42.9 +/- 8.9% for dobutamine and +29.4 +/- 5.3% for nitroprusside, both P < .01). In contrast, PWRmx/EDV2 did not significantly change with nitroprusside but increased by 126 +/- 16.1% with dobutamine (P < .01). CONCLUSIONS: Preload-adjusted PWRmx is a steady-state index of ventricular systolic function that is sensitive to inotropic state and minimally influenced by physiological changes in afterload impedance or volume load. It appears useful for noninvasive cardiac-specific analysis of acute drug effects.

Cardiac Catheterization↗
PubMed1994

Intracoronary angiotensin-converting enzyme inhibition improves diastolic function in patients with hypertensive left ventricular hypertrophy.

BACKGROUND: There is increasing recognition of myocardial angiotensin-converting enzyme, which is induced with the development of left ventricular hypertrophy (LVH). The potential physiological significance of subsequent increased angiotensin I to II conversion in the presence of LVH is unclear but has been postulated to cause abnormal Ca2+ handling and secondary diastolic dysfunction. Accordingly, we hypothesized that acute angiotensin-converting enzyme inhibition would result in decreased production of angiotensin II and improved active (Ca(2+)-dependent) relaxation in patients with hypertensive LVH. METHODS AND RESULTS: Intracoronary (IC) enalaprilat was administered to 25 patients with and without LVH secondary to essential hypertension. Indexes of diastolic and systolic LV function were determined from pressure (micromanometer)-volume (conductance) analysis at steady state and with occlusion of the inferior vena cava. Patients were divided into those receiving high- (5.0 mg, n = 15) and low-dose (1.5 mg, n = 10) IC enalaprilat during a 30-minute infusion at 1 mL/min. The high-dose patients were further divided along the median normalized LV wall thickness of 0.671 cm/m2. The time constant of isovolumic relaxation (TauL) was prolonged at baseline in patients receiving high-dose enalaprilat with wall thickness > 0.671 cm/m2 (TauL, 56 +/- 2 versus 44 +/- 2 and 45 +/- 2 milliseconds, respectively, P < .01 by ANOVA) and shortened only in this patient group (TauL, 49 +/- 3 versus 46 +/- 2 and 43 +/- 2 milliseconds, respectively, P < .01 versus baseline and other groups by ANOVA). The improvement in TauL was directly proportional to the degree of LVH (r = .92, P < .001). Although there was a decrease in LV end-diastolic pressure (23 +/- 2 to 15 +/- 1 mm Hg, P < .01) and volume (86 +/- 8 to 67 +/- 9 mL/m2, P < .05) in those patients with a reduction in TauL, this is due to movement down a similar diastolic pressure-volume relation with no change in chamber elastic stiffness (0.023 +/- 0.002 to 0.025 +/- 0.004 mL-1, P = NS). CONCLUSIONS: Intracoronary enalaprilat resulted in an improvement in active (Ca(2+)-dependent) relaxation in those patients with more severe hypertensive LVH. The improvement in active relaxation was directly proportional to the severity of LVH. These results support the hypothesis that the cardiac renin-angiotensin system is an important determinant of active diastolic function in hypertensive LVH.

Adult↗
PubMed1994

Denial in Munchausen syndrome by proxy: the consulting psychiatrist's dilemma.

OBJECTIVE: The purpose of this review, which also includes the report of a new case, is to discuss the pervasive denial of responsibility among individuals who have engaged in Munchausen syndrome by proxy (MSBP) behavior. In MSBP, a caretaker (almost always the mother) fabricates or induces illness in her child; she then presents the child for medical treatment, disclaiming knowledge of the etiology of the illness. METHOD: Literature searches of several computer databases were performed, and ninety-two citations dealing with MSBP, culled from medical, legal, and lay publications, were examined for descriptions of caretakers' responses to being confronted with the allegation of MSBP. Thirty-four citations contained relevant material, which was combined with observations from cases in which the author has served as a consultant. RESULTS: Caretakers engaging in MSBP consistently deny any role in the dissimulation, even when confronted with compelling evidence. This denial complicates management, though intervention must focus on ensuring the safety of the child regardless of the caregiver's response. CONCLUSIONS: Techniques sometimes advocated in factitious disorders in general may be useful in stopping the abusive behavior; however, no consistently effective strategy for overcoming denial in MSBP has yet been described.

Adult↗