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Biomedical subjects

G Hollander

Publications and source records attributed to G Hollander.

At least 55 records · Page 3Linked to original sources
PubMed1989

Pericardial effusion early in acute myocardial infarction.

The incidence and significance of pericardial effusions early in acute myocardial infarction remain unclear. Using two-dimensional echocardiography, 172 patients with an acute myocardial infarction were evaluated within 72 h of presentation. Thirty patients (17%) had a pericardial effusion (29 small, 1 moderate) while 142 (83%) did not. No patient developed cardiac tamponade or required pericardiocentesis. Patients with pericardial effusions had higher peak creatine kinase as compared to patients without effusions (2036 +/- 1466 vs. 1483 +/- 1241, p less than 0.05) and a greater number of aneurysms (20% vs. 6%, p less than 0.05). In-hospital mortality was higher in the patients with pericardial effusions (10% vs. 2%, p less than 0.05). In conclusion, pericardial effusions are common in the early AMI period but are generally small and hemodynamically insignificant. They are associated with larger infarcts and greater mortality.

Aged↗
PubMed1989

Anticipation of bypass surgery: can it induce silent myocardial ischemia?

Psychological stress has been demonstrated to induce myocardial ischemia. To determine whether stressful events before a coronary artery bypass grafting procedure precipitate myocardial ischemia, silent or symptomatic, and whether this can have an effect on the prognosis, 26 patients were evaluated before a bypass operation with continuous Holter monitor recording. Specific events monitored were signing surgical consent, receiving preoperative medications, shaving and preparing, and transfer to the operating room. A positive Holter result was defined as an ST segment depression of 1 mm or more lasting one minute or longer. Six patients (23%) were found to have one or more episodes of substantial ST segment depression, with a total of ten episodes lasting 208 minutes recorded. All episodes were silent and not associated with an increase in mean heart rate. The majority of episodes occurred randomly, although three episodes did occur between 5 and 6 AM at the time of transport to the operating room. This appeared to be related more to the circadian rhythm than to the stress of transport. No perioperative or postoperative myocardial infarctions occurred, and all patients were alive at 30 days. In conclusion, silent myocardial ischemia present in the immediate preoperative period does not appear to be related to specific preoperative events. Frequency of early morning ischemia may warrant changes in the medication schedule to provide additional protection during these hours.

Aged↗
PubMed1989

Cigarette smoking renders LDL susceptible to peroxidative modification and enhanced metabolism by macrophages.

The effect of cigarette smoking on peroxidation of plasma low density lipoprotein (LDL) was studied in 16 smokers aged 23-56 years; 12 nonsmokers of similar age served as controls. The smokers were asked to refrain from smoking 24-40 h prior to testing. Peroxidation was assessed by determination of thiobarbituric acid reactive substances (TBARS) in fresh plasma and LDL and by an increase in 125I-LDL metabolism by peritoneal macrophages. There was no difference in TBARS in freshly prepared plasma or LDL of smokers and nonsmokers. However, LDL of smokers, conditioned by incubation with bovine aortic smooth muscle cells (SMC), had 2-fold or higher TBARS values when compared to SMC conditioned LDL of nonsmokers. 2-4-fold higher TBARS values were seen also in SMC conditioned LDL when the comparison was made between LDL isolated from plasma before smoking of 6-7 cigarettes (time 0), and LDL of the same individual isolated from plasma 90 min thereafter. The metabolism of SMC conditioned 125I-LDL by peritoneal macrophages was examined; LDL isolated from plasma of smokers at time 0 was metabolized twice as avidly as LDL of nonsmokers and a further increase was seen with LDL isolated 90 min after acute smoking. The present results indicate that cigarette smoking renders plasma LDL more susceptible to subsequent peroxidative modification by cellular elements.

Adult↗
PubMed1989

Full dose subcutaneous heparin therapy.

Anticoagulation is used extensively for the treatment and prevention of thromboembolic disease. Full dose anticoagulation with heparin is usually administered intravenously via continuous 24-hour infusion to avoid complications with intermittent intravenous administration. Continuous intravenous therapy is costly and cumbersome for nurses and patients. Subcutaneous administration of heparin in full dosage offers an attractive therapeutic alternative. This study examines the safety, efficacy, and cost considerations of this form of therapy. Fifteen patients admitted to the hospital for myocardial infarction were evaluated. After the patients were transferred from the cardiac intensive care unit, intravenous heparin was discontinued, while therapeutic anticoagulation was maintained via the subcutaneous route. Complications were limited to local hematoma formation. A cost comparison revealed substantial savings with subcutaneous administration.

Aged↗
PubMed1988

Septal rupture: effect of oxygen administration.

A patient with interventricular septal rupture as a complication of myocardial infarction was studied to determine whether varying the concentration of inspired oxygen would alter the magnitude of intracardiac shunt. A significant correlation was found showing that high concentration of inspired oxygen results in increased left to right shunting probably due to systemic vasoconstriction and pulmonary vasodilatation.

Combined Modality Therapy↗
PubMed1988

Relationship between location of chest pain and site of coronary artery occlusion.

Chest pain characteristics and site of coronary artery occlusion were evaluated in 148 patients having single-vessel coronary angioplasty and in 95 patients having double-vessel angioplasty. The locations of chest pain included substernal and left precordium, right precordium and epigastric. The possible sites of pain radiation were limited to neck/jaw, left arm, right arm, and interscapular. The patient described whether or not the pain was typical of previous angina, and the presence of ST segment deviation was noted to be certain that ischemia was present. The analysis showed that the occluded artery could not be reliably identified. However, it was possible to say which artery was most likely not diseased. Patients presenting with substernal or left chest pain with radiation to the left arm had a less than 10% chance of having right coronary artery disease. A patient presenting with epigastric pain radiating to the neck or jaw had a less than 13% chance of having left anterior descending disease. It is concluded that in patients with single- and double-vessel coronary disease, there is some relationship between chest pain pattern and disease location.

Angina Pectoris↗
PubMed1986

Etiology and clinical significance of new fascicular conduction defects following coronary bypass surgery.

Two hundred consecutive patients undergoing only coronary bypass surgery were studied. Forty-five patients (group A) developed new fascicular conduction blocks and 155 patients (group B) did not. The 45 patients in group A developed the following fascicular conduction blocks: right bundle branch block 47%, right bundle branch block and left anterior hemiblock 8%, right bundle branch block and first-degree atrioventricular block 2%, left anterior hemiblock 11%, left bundle branch block 18%, right bundle branch block-left anterior hemiblock and first-degree atrioventricular block 5%. There were no significant differences in sex, incidence of diabetes, number of grafts performed, ejection fraction (less than 55%), and perioperative infarction. Group A patients were older (p less than 0.01). Hypertension was found frequently in group A (27 vs 45 patients; p less than 0.01) and was present for a mean of 12.4 years in group A and 4.9 years in group B (p less than 0.01). Preoperative use of digitalis was found in 14 (31%) patients in group A and in 18 (12%) patients in group B (p less than 0.01). Twenty-one (47%) patients in group A had significant disease (greater than 70%) of the left main coronary artery as compared to 17 (10.9%) in group B (p less than 0.001). There was no difference in the recurrence of angina or the survival rate at 14 months. In conclusion, the incidence of new fascicular conduction block after bypass surgery is 22.5%. Long-standing hypertension, left main coronary disease, and the preoperative use of digitalis appear to be predisposing factors. New fascicular conduction block does not affect prognosis.

Age Factors↗
PubMed1984

Metabolism of liposomes prepared from a labelled ether analog of 1,2-dioleoyl-sn-glycero-3-phosphocholine in the rat.

To synthesize the ether analog of 1,2-diacyl-sn-glycero-3-phosphocholine (PC), 1-O-cis-9'- octadecenyl -2-O-cis-9'-[9',10'(n)-3H] ocatadecenyl -sn-glycero-3- phosphocholine, we have adapted available methodology and have obtained a product of high specific activity and purity. The labelled dioleyl ether phosphatidylcholine ( DOEPC ) was used to prepare 250-350 A unilamellar liposomes, which contained also PC and free cholesterol. Following intravenous injection into rats, labelled PC was cleared from the plasma at a faster rate than DOEPC . The uptake of both labelled compounds by the liver increased up to 3 h, at which time there was about 40% of injected PC and 60% of DOEPC . The PC disappeared more rapidly than the DOEPC , so that 17 and 48% of injected label were present in the liver 24 h after injection of PC and DOEPC , respectively. Ten days after injection of DOEPC , about 10% of the label was still present in the liver. During the first 5 days after injection of DOEPC , 10% of radioactivity was found in the gastrointestinal tract and about 20% in the carcass; no increase in carcass radioactivity occurred during the loss of label from the liver. 24 and 48 h after injection of DOEPC , 40% of liver radioactivity was present in a neutral lipid, which on TLC comigrated with triacylglycerol. Since after alkaline hydrolysis this compound comigrated with diacylglycerol, it appears that the ether bond of DOEPC was not hydrolyzed, but after removal of phosphocholine, presumably by phospholipase C, the diether glycerol was reacylated . In experiments in vitro, the rate of exchange of labelled PC with red blood cell phospholipids exceeded that of DOEPC . Incubation of cultured hepatocytes with liposomes containing PC and/or DOEPC resulted in uptake of both phospholipids and metabolism of DOEPC to neutral lipids. The present findings indicate that DOEPC undergoes slow metabolism and can be eliminated from the body. These properties could prove advantageous for the use of DOEPC as a carrier of drugs and possibly as a carrier of free cholesterol in reverse cholesterol transport.

Animals↗
PubMed1984

Methemoglobin levels produced by organic nitrates in patients with coronary artery disease.

To determine if ordinary doses of nitrates produce a significant increase in methemoglobin, methemoglobin levels were measured in 59 randomly selected patients with coronary artery disease and unstable angina pectoris who were receiving organic nitrate therapy. Patients were taking isosorbide dinitrate, 2% nitroglycerin ointment, or a combination of the two. Patients were subdivided according to whether they were using one (group A) or more than one (group B) organic nitrate preparations. These results were compared with 17 control patients. Mean methemoglobin levels in group B were 1.78 +/- 1.29%, and this differed significantly (P less than 0.05) from both group A mean methemoglobin, 1.13 +/- 0.92%, and controls, 0.99 +/- 0.55%. The proportion of patients with elevated methemoglobin concentration increased from the control to group A to group B. It is concluded that commonly used dosages of nitrates are capable of causing elevations of methemoglobin which are probably not of routine clinical significance. However, these elevations may be of import in certain patient populations such as those with coronary insufficiency or anemia.

Aged↗
PubMed1984

High mortality early reinfarction with first nontransmural myocardial infarction.

Thirty-eight patients with first nontransmural myocardial infarction were studied to determine prognosis and clinical markers of a high-risk subgroup. We found a high incidence of reinfarction (18%) at a median time of 16 days post nontransmural infarction (seven patients). Reinfarction was uniformly associated with death within 24 hours. A total of 14 patients (37%) either died (eight patients) or required urgent revascularization (six patients). Predominant ST segment depression with presenting nontransmural infarction and a history of prior angina were associated with increased mortality (p less than 0.05 and p = 0.05, respectively). We conclude that patients with nontransmural infarction are at high risk for early recurrent infarction. Patients with history of prior angina and predominant ST segment depression may be at particularly high risk. Reinfarction in these patients is frequently extensive. We recommend that these patients be considered for early coronary angiography.

Aged↗
PubMed1984

Dilated cardiomyopathy in identical twins.

Identical twins had dilated cardiomyopathy and evidence of an autoimmune process involving both the heart and thyroid gland. An inherited abnormality of immune regulation is suggested as a possible basis for these unusual findings.

Adult↗
PubMed1983

Metabolism of HDL-cholesteryl ester in the rat, studied with a nonhydrolyzable analog, cholesteryl linoleyl ether.

Intralipid was sonicated with [3H]cholesteryl linoleyl ether (a nonhydrolyzable analog of cholesteryl linoleate) and incubated with rat HDL and d greater than 1.21 fraction of rabbit serum at a ratio of 0.012 mg triacylglycerol to 1 mg HDL protein. 25% of [3H]cholesteryl linoleyl ether was transferred to HDL. The labeled HDL was injected into donor rats and was screened for 4 h. [125I]HDL was subjected to the same protocol as the 3H-labeled HDL, including screening. The screened, labeled sera were injected into acceptor rats and the disappearance of radioactivity from the circulation was compared. The t1/2 in the circulation of [125I]HDL was about 10.5 h, while that of [3H]cholesteryl linoleyl ether-HDL was about 8 h. The liver and carcass were the major sites of uptake of [3H]cholesteryl linoleyl ether-HDL and accounted for 29-41% (liver) and 30% (carcass) of the injected label. Maximal recovery of [3H]cholesteryl linoleyl ether in the liver was seen 48 h after injection, and thereafter there was a progressive decline of radioactivity, which reached 7.8% after 28 days. The maximal recovery of [125I]HDL in the liver was about 9%. Pretreatment of the acceptor rats with estradiol for 5 days resulted in a 20% increase in the hepatic uptake of [3H]cholesteryl linoleyl ether-HDL and a 5-fold increase in adrenal uptake. The present findings indicate that in the rat the liver is the major site of uptake of HDL cholesteryl ester and that part of the HDL cholesteryl ester may be cleared from the circulation separately from the protein moiety. On the basis of our previous findings (Stein, Y., Kleinman Y, Halperin, G., and Stein, O. (1983) Biochim. Biophys. Acta 750, 300-305) the loss of the [3H]cholesteryl linoleyl ether from the liver after 14-28 days was interpreted to indicate that the labeled [3H]cholesteryl linoleyl ether had been taken up by hepatocytes.

Adrenal Glands↗
PubMed1983

Single catheter technique for accurate cardiac outputs from left ventricle.

We report our experience in cardiac output measurements using a single catheter for left ventricular green dye injection with sampling from the side arm of a femoral artery introducer sheath. This technique is compared to thermal dilution (20 patients) and pulmonary artery green dye injection (20 patients). There were no significant differences between the single catheter left ventricular method and the other two accepted methods for measuring cardiac output.

Cardiac Catheterization↗
PubMed1983

Bundle branch block in acute myocardial infarction.

The management of patients with acute myocardial infarction complicated by bundle branch block is a significant clinical problem and represents 8% to 13% of patients with acute infarction. This study reviews the records of 606 patients with myocardial infarction admitted to our coronary care unit. Forty-seven (8%) had complete bundle branch block. The risk of developing high-degree AV block in these 47 patients was reviewed. There are no established therapeutic guidelines for patients with pre-existing bundle branch block and left bundle branch block in acute myocardial infarction. We found a high risk of progression in patients with pre-existing bifascicular block in the presence of anterior wall infarction (25%) as well as in patients with left bundle branch block with acute anterior wall infarction (100%). On the basis of our data and careful review of the literature, we recommend prophylactic pacemaker insertion in these high-risk groups.

Bundle-Branch Block↗
PubMed1983

Clinical significance of slow paroxysmal atrial tachycardia.

This study examines the clinical setting, characteristics, and follow-up of 173 patients who had slow paroxysmal atrial tachycardia (SPAT) (greater than 4 beats, rate less than 150 bpm) during 24-hour Holter monitoring. These episodes were classified by probable mechanism according to recognized ECG criteria and included AV nodal reentry (AVNR), sinoatrial nodal reentry (SANR), and automatic (A). There were 76 males (44%) with a mean age of 72 years and 97 females (56%) with a mean age of 73 years. The indications for Holter recording revealed that the SANR and A subgroups had a higher frequency of cerebral symptoms compared to AVNR (p less than 0.01). Chest pain was more common in the SANR group as compared to the other two groups (p less than 0.01). There was no difference in the frequency of palpitation in the three subgroups. The mean rate of SPAT for the entire group was 115.2 +/- 14 and these episodes had a mean duration of 5.58 +/- 3.07 seconds. The SANR subgroup had a significantly slower rate (107.1 +/- 9.2) as compared to the AVNR subgroup (p less than 0.01). One hundred fourteen patients were available for follow-up. The average period of follow-up was similar for all three groups. At follow-up the frequency of sick sinus syndrome as determined clinically and permanent pacemaker insertion was significantly greater in the SANR subgroup (p less than 0.01) as compared to the other subgroups which did not differ from each other.

Aged↗
PubMed1983

Efficacy of sustained-release buccal nitroglycerin in patients with angina pectoris. New and long-acting therapy demonstrated by exercise.

The antianginal efficacy of a single sustained-release buccal nitroglycerin (BNTG) tablet was assessed in 16 patients with known coronary artery disease. Patients were trained in bicycle ergometry to induce angina pectoris within three to five minutes. A hemodynamically effective dose of BNTG was identified. Patients were tested at baseline and given placebo and BNTG in a randomized, double-blind manner on consecutive days. They were tested at 0.5, 1, 3, and 5 hours after drug administration. The average increase in exercise duration with BNTG compared with placebo at 0.5 hours was 40 percent (p less than 0.01); at 1 hour was 31 percent (p less than 0.01); at 3 hours was 27 percent (p less than 0.01); at 5 hours was 15 percent (p = NS). In a subset of ten patients in whom the tablet was maintained in the buccal pouch for five or more hours before dissolving, increase in exercise duration was significant at all times tested (p less than 0.05). We conclude that BNTG is an effective modality of administering nitroglycerin for rapid and prolonged effect with reduction in angina pectoris and increase in exercise duration which may persist for at least five hours.

Adult↗