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Biomedical subjects

H B Hechtman

Publications and source records attributed to H B Hechtman.

At least 235 records · Page 13Linked to original sources
PubMed1977

Assessment of myocardial performance and optimal volume loading during elective abdominal aortic aneurysm resection.

Myocardial depression has been suggested as a cause of declamping hypotension. To investigate and manage this problem, thermal dilution catheters were placed in 22 elderly, high-risk patients (mean age 71 years) who underwent elective abdominal aortic aneurysm resection. There were no deaths. Myocardial performance curves (MPC) were determined preoperatively, following induction of anesthesia, during aortic clamping, following declamping, and 12 to 48 hours postoperatively. The slope of this curve was taken as an index of myocardial performance. Preoperative cardiac index at a pulmonary artery wedge pressure of 10 mm Hg (CI10) decreased significantly following induction of anesthesia (P less than .002) and persisted during aortic cross-clamping. Following declamping, CI10 rose to preoperative levels. The slope of the MPC followed this same pattern. There was no significant change in blood pressure with the aorta clamped or following declamping. Myocardial performance is depressed following induction of anesthesia but declamping hypotension can be minimized or prevented by optimum volume loading as guided by Starling's myocardial performance curves.

Aged↗
PubMed1977

Myocardial depression during sepsis.

The cardiac response to volume loading was evaluated in fifty severely septic patients. After a rapid infusion of albumin or whole blood the cardiac index (CI) and left ventricular stroke work index (LVSWI) were recorded as the pulmonary arterial wedge pressure (PAWP) increased. Initial values of PAWP, CI, and LVSWI were similar in both the nineteen surviving and thirty-one nonsurviving patients. Surviving patients, however, demonstrated greater increases in CI and LVSWI as PAWP rose. Nearly half of both patient groups developed decreases in CI and LVSWI as the PAWP continued to increase. These downslopes occurred at relatively low PAWP and are taken as evidence of an abnormality of myocardial function in both survivors and nonsurvivors. The lower upslope of the performance curves in nonsurvivors indicates myocardial depression or a negative inotropic effect. Cardiac ischemia, acute respiratory failure, and high affinity red cells were found to diminish the cardiac response to volume loading, whereas hepatic and renal failure were associated with a good CI and LVSWI response.

Blood Pressure↗
PubMed1976

Cardiac output measurement by thermodilution during cardiac operations.

Measurement of cardiac output by the thermodilution (COTD) technique through a flow-advanced pulmonary artery catheter is simple, reliable, and practical at the bedside. Rapid repeat determinations are possible, facilitating dynamic description of myocardial performance through construction of ventricular function curves. Replicate determinations of cardiac output indicate that the thermodilution method is more accurate than the indocyanine green technique. Examples of the clinical application of COTD in cardiac surgical patients are provided.

Animals↗
PubMed1975

Clinical applications of thermodilution cardiac output determinations.

The pulmonary arterial catheter was shown to be safe and easily positioned in a group of 200 patients. Thermodilution cardiac output measurement was shown to be simple, rapid, and safe. The technic was as accurate as the simultaneously measured indocyanine green cardiac output, and more reproducible, particularly at high and low flows. The construction of myocardial performance curves during a fluid challenge is described. The value of these curves is guiding fluid, drug, and respirator therapy is illustrated by case presentations.

Aged↗
PubMed1975

Nutrient myocardial blood flow in experimental myocardial ischemia. Effects of intraaortic balloon counterpulsation and coronary reperfusion.

This experimental study was designed to evaluate the effect of intraaortic balloon pumping (IABP) upon nutrient myocardial blood flow (NMBF) following acute myocardial ischemia in dogs, but also to determine whether IABP improves NMBF following revascularization. Localized myocardial ischemia was produced by ligation of one or two small branches of the circumflex coronary artery combined with a three hour snare occlusion of the left anterior descending coronary artery distal to the first septal branch. NMBF was measured by NaI131 washout at three points corresponding to the peripheral, intermediate, and central zones of the infarct. Occlusion of the coronary arteries reduced NMBF. Release of occlusion after three hours, or the equivalent of coronary artery revascularization, increased NMBF but did not restore it to control levels. The increase in flow was more marked in the peripheral zones of ischemia. IABP increased NMBF significantly both during and after release of occlusion. The effect was sustained after cessation of IABP only when the latter was maintained during the period of reperfusion. The results indicate that NMBF, defined by washout of a locally injected tracer, was improved by both IABP and reperfusion. The beneficial effect was maximal when the two techniques were combined.

Animals↗
PubMed1975

Improved myocardial performance following high 2-3 diphosphoglycerate red cell transfusions.

Twenty-two matched coronary bypass surgery (CABS) patients were randomly divided into two groups; 11 patients in the control group received CPD-stored or fresh blood (mean age, 5.5 days) containing 70 percent of normal 2-3 diphosphoglycerate (2-3 DPG) and 11 patients received 2-3 DPG-enriched previously frozen, washed, concentrated red cells (2-3 DPG 150 percent of normal). Coming off cardiopulmonary bypass, when given a volume load, the high 2-3 DPG patients had a significant increase in cardiac index (2.95 L. per minute vs. 2.18 L. per minute, p smaller than 0.001) at similar filling pressures. At this time body oxygen consumption, in vivo P50, red cell 2-3 DPG, and arterial-venous oxygen content difference were all increased, but P minus vo2 was normal. Improved oxygen delivery occurred without decreasing mixed venous oxygen tension. The results suggest that, with volume loading, function in the heart with coronary artery disease is limited in part by available oxygen. By decreasing oxygen affinity for hemoglobin by altering red blood cells biochemically, myocardial performance can be improved safely.

Blood Transfusion↗