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Biomedical subjects

D Schechter

Publications and source records attributed to D Schechter.

At least 37 records · Page 2Linked to original sources
PubMed1994

A measurement of pulmonary blood volume increase during systole in humans.

Pulmonary blood volume increase during systole was measured in patients by analysing chest images obtained during ECG gated radionuclide angiography examination. The difference in the total radiation counts between systole and diastole in regions of interest, which included the lungs and the left ventricle, was measured and the relative pulmonary systolic blood volume increase (SBVI)-the ratio between the pulmonary SBVI and the cardiac stroke volume-was calculated. The relative pulmonary SBVI, which is a measure for the compliance of the pulmonary blood vessels, was found to be 0.26-0.85, and the average value was 0.57 +/- 0.15. The relative pulmonary SBVI was inversely correlated with the patient age (r = 0.27, p < 0.05) and with the left ventricular ejection fraction and stroke volume (r = 0.36, p < 0.01) due to decreased arterial compliance for older patients and for increased pulmonary blood volume respectively. The correlation coefficients were not high, indicating that the compliance of the patients is determined mainly by other individual factors. Radionuclide plethysmography enables qualitative assessment of pulmonary arterial compliance.

Aging↗
PubMed1994

Breast artifact in planar cardiac imaging: a comparison of 201T1 to sestamibi-99mTc.

Breast artifact occurrence during 201T1 myocardial image interpretation is a significant problem. We serially evaluated 3 female patients utilizing exercise treadmill perfusion studies in order to assess the potential role of 99mTc-Sestamibi (MIBI) imaging in the setting of documented 201T1 breast artifact. Both visual and quantitative analyses revealed no superiority of 99mTc-MIBI over 201T1 imaging in reference to avoidance of breast artifact. The variation in artifactual cardiac imaging defects in the 3 patients most probably reflected variations in breast positioning. Finally, the ability to assess ventricular wall motion via gated 99mTc-MIBI imaging may help to confirm an artifactual versus an actual myocardial perfusion abnormality.

Aged↗
PubMed1994

Value of dobutamine/nitrate radionuclide angiography in predicting revascularization effects on ventricular function.

OBJECTIVE: Dobutamine and Nitrate Radionuclide Angiography (RNA) may help to distinguish viable from nonviable myocardium and to predict revascularization effects on LV function. SETTING: Ambulatory. EXPERIMENTAL DESIGN: Prospective. PATIENTS AND METHODS: We studied 12 patients (11 male, 1 female; mean age 56 +/- 10 years) with three-vessel disease, severe LV dysfunction, and prior MI for a mean follow-up time of 10 +/- 3.4 months. Thallium-201 scintigraphy favored potential viability in all patients: inducible ischemia with satisfactory perfusion in more than one coronary arterial territory. Global and regional LVEF's were calculated from preoperative RNA (baseline rest study and with continuous dobutamine infusion with gradual rate increase plus oral nitrates) and postoperative RNA at 1 and 6 months. RESULTS: There was no operative mortality, but two late deaths occurred. Symptomatically, most patients showed improvement. Global LVEF increased during dobutamine and nitrates preoperatively (p < 0.01), but not at 1 and 6 months postoperatively (without pharmacological intervention). Mean LVED volume was not significantly changed postoperatively. Regional EF improvement was found in 4 out of 9 LV wall segments under dobutamine and nitrates, and this increase persisted postoperatively at 1 and 6 months. CONCLUSIONS: Mild but significant increase in global LVEF during dobutamine and nitrates administration is not predictive of postoperative LVEF improvement. However, regional EF improvement appears to be predictive of post-revascularization LV functional improvement.

Administration, Sublingual↗
PubMed1994

Transient neurological events during dipyridamole stress test: an arterial steal phenomenon?

Dipyridamole-associated adverse neurological side effects have not been extensively described. We present two cases of dipyridamole-associated transient motor neurological events with no evidence of residual neurological deficits detected clinically or by head CT. The patients showed no evidence of significant extracranial (internal carotid) artery disease. We propose the presence of a regional cerebral perfusion disturbance due to an intracranial vascular steal phenomenon as the mechanism for the above side effects of dipyridamole.

Aged↗
PubMed1994

Underlying coronary artery disease and successful bone marrow transplantation: a case report.

The cardiovascular risk of concurrent coronary artery disease in patients undergoing bone marrow transplantation (BMT) is not well known. We present a case of a 32-year-old male Hodgkin's disease patient with prior chemotherapy and radiotherapy, who underwent autologous BMT. His underlying single vessel coronary artery disease was well documented and he suffered no post-autologous BMT cardiotoxicity.

Adult↗
PubMed1993

Importance of long-duration postoperative ST-segment depression in cardiac morbidity after vascular surgery.

Major vascular surgery is associated with a high incidence of cardiac ischaemic complications. By means of continuous perioperative electrocardiographic recording, we studied 151 consecutive patients undergoing major vascular surgery to find out the characteristics of any myocardial ischaemia and the relation to outcome. 13 (8.6%) patients had postoperative cardiac events (6 myocardial infarctions, 2 unstable angina, and 5 congestive heart failure). There were 342 perioperative ischaemic episodes shown by ST-segment depression; 164 (48%) occurred postoperatively. Postoperative ischaemic episodes were significantly longer than episodes before or during operations (3.2 vs 1.7 and 1.5 min per h monitored, respectively, p < 0.001). Both Detsky's cardiac risk index and long-duration (> 2 h) preoperative ischaemia were predictive of postoperative cardiac complications (odds ratios in univariate analysis 3.3, p = 0.03, and 7.2, p = 0.009, respectively). However, long-duration (> 2 h) postoperative ischaemia was the only factor significantly associated with cardiac morbidity in multivariate logistic regression analysis (odds ratio 21.7, p = 0.001). Long-duration ST-segment depression preceded most (84.6%) postoperative cardiac events, including myocardial infarctions, and no cardiac event was preceded by ST-segment elevation. 5 of the 6 postoperative myocardial infarctions were non-Q-wave infarctions. We conclude that long-duration subendocardial ischaemia, rather than acute coronary artery occlusion, may bring about postoperative myocardial injury and complications.

Aged↗
PubMed1993

Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva as a cause of ischemia at old age.

The case of a patient with an anomalous origin of the circumflex coronary artery causing myocardial ischemia and infarction is presented. Even though the anomalous artery was not located between aorta and pulmonary artery, this anomaly, which is usually considered benign, was responsible for the ischemic symptoms. Transesophageal echocardiographic study demonstrated an acute angulation at the proximal portion of this abnormal vessel, very close to its origin from the right coronary sinus, which we believe caused the abnormality in coronary flow in this patient.

Aged↗
PubMed1993

Preoperative pulmonary hemodynamics and early mortality after orthotopic cardiac transplantation: the Pittsburgh experience.

The influence of preoperative transpulmonary pressure gradient (TPG) and pulmonary vascular resistance (PVR) on early post-transplant mortality was evaluated in 425 orthotopic transplant recipients. The overall 30-day post-transplant mortality rate was 12.5%; the majority of the deaths (52.8%) were due to primary allograft failure. The 0- to 2-day mortality rate was threefold higher in patients with severe preoperative pulmonary hypertension (TPG > or = 15 mm Hg or PVR > or = 5 Wood units), whereas the 3- to 7-day and 8- to 30-day mortality rates were similar. Early post-transplant mortality (0 to 2 days and 8 to 30 days) was also significantly higher (15.9% vs 3.9% and 9.9% vs 2.8%, respectively; p < 0.05) in women compared with men. Women with severe preoperative pulmonary hypertension had higher (p < 0.05) 0- to 2-day post-transplant mortality than comparable men. According to univariate analysis, recipients with preoperative TPG > or = 15 mm Hg had a significantly higher 30-day postoperative mortality rate, irrespective of their level of PVR. Furthermore, patients with severe preoperative pulmonary hypertension who underwent transplantation between 1980 and 1987 had a higher 0- to 2-day post-transplant mortality rate compared with patients operated on after that time. Multiple logistic regression analysis identified female recipient sex and preoperative TPG but not preoperative PVR, era of transplantation, or recipient age as significant (p < 0.001 and p < 0.01, respectively) independent predictors of early post-transplant mortality.

Adolescent↗
PubMed1992

Recombinant interleukin-2 and interferon alpha immunotherapy following autologous bone marrow transplantation. A case report of cardiovascular toxicity with serial echocardiographic evaluation.

The most serious side effects of recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFN alpha) immunotherapy are cardiovascular disturbances, including systemic hypotension, left-ventricular dysfunction and pulmonary edema. We present a 25-year-old female who developed reversible cardiogenic shock during intermediate dose rIL-2 and low dose rIFN alpha therapy. Rapid clinical improvement occurred after intravenous fluid and dopamine support. A serial echocardiographic evaluation, which has not been described previously in this setting, is reported.

Adult↗
PubMed1992

Efficacy of antihypertensive medication in orthotopic heart transplant recipients and its effect on renal function.

The authors looked at 77 patients following orthotopic heart transplant who received a triple immunosuppressive regimen including cyclosporine to see the effect of various antihypertensive medications on mean arterial blood pressure and renal function. There were 62 men and 15 women retrospectively classified into three groups according to the antihypertensive medications they received. Group 1 included 26 patients followed up for 10.7 +/- 2.7 months who received hydralazine therapy. Group 2 included 32 patients followed up for 9.0 +/- 3.4 months who received angiotensin-converting enzyme inhibition therapy. Group 3 included 19 patients followed up for 10.1 +/- 3.3 months who received beta-adrenergic blocking agents. Mean arterial pressure (MAP), serum blood urea nitrogen (BUN), and serum creatinine (CR) were determined for each group at the start and end of the follow-up period. The MAP at the start of the study was 107 +/- 14 in group 1, 110 +/- 13 in group 2, and 100 +/- 11 in group 3. It was not statistically significantly different in any of the groups. At the end of the follow-up period, MAP was 112 +/- 10, 111 +/- 10, and 106 +/- 12 for the three groups respectively, and it was not significantly different in any group. The serum BUN in group 3 was 25 +/- 8 mg/dL at the start of the study, and it was not significantly lower than that in group 1, 28 +/- 6, but it was significantly different from that in group 2, 34 +/- 9, P less than 0.05. At the end of the follow-up period, the difference was still maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Vascular entrapment of intra-aortic balloon after short-term balloon counterpulsation.

Prolonged, continuous intra-aortic balloon (IAB) counterpulsation for several weeks can result in balloon entrapment secondary to thrombus formation in the balloon lumen. In this report, we describe a patient who developed IAB entrapment, early (1 wk) after initiation of counterpulsation. A trace amount of blood was noted in the tubing connecting the balloon catheter to the console for 3 days prior to IAB malfunction and vascular entrapment. We suggest that the balloon catheter be removed immediately when blood is detected in the external connecting tubing even if the IAB is functioning satisfactorily.

Adult↗