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Biomedical subjects

M L Murphy

Publications and source records attributed to M L Murphy.

At least 73 records · Page 4Linked to original sources
PubMed1983

Echocardiographic detection of right ventricular hypertrophy.

M-mode echocardiographic right ventricular wall thickness (RVW) and diastolic right ventricular internal diameter (RVID), when above the accepted normal range (RVW less than or equal to 5 mm, RVID less than or equal to 26 mm), are frequently used clinically to predict the presence of right ventricular hypertrophy. RVID was compared to anatomic right ventricular mass (RVM) in 27 patients and to RVW in 13 patients to determine their accuracy for predicting right ventricular hypertrophy (RVM greater than 65 gm). When increased, both measurements were specific for right ventricular hypertrophy. The specificity for RVW above 5 mm was 100% and for RVID greater than 26 mm was 79%. Neither was a sensitive indicator of hypertrophy. Only 36% of those with anatomic right ventricular hypertrophy had an echocardiographically dilated ventricle, and 67% had a thickened free wall. Neither measurement proved to be an accurate predictor of RVM, with a correlation for RVW of 0.56 and for diastolic RVID of 0.19.

Cardiomegaly↗
PubMed1983

Left atrial abnormality as an electrocardiographic criterion for the diagnosis of left ventricular hypertrophy in the presence of right bundle branch block.

Left atrial (LA) abnormality determined from precordial lead V1 was assessed by 2 observers as a criterion of left ventricular (LV) hypertrophy in the presence of right bundle branch block (BBB) in 23 patients. The presence of LV hypertrophy was confirmed from a postmortem cardiac partition technique and defined at 2 levels of confidence: probable and definite hypertrophy. Observers reliably differentiated between the hypertrophied and normal-sized ventricle in the presence of right BBB by using LA abnormality as an electrocardiographic criterion. When defined as definite hypertrophy, observer 1 correctly identified LV hypertrophy in 78% of the cases and observer 2 in 67% of the cases. False-positive results were present in 21% of cases by observer 1 and 14% by observer 2. Comparable results were achieved when a definition of probable hypertrophy was used. Observer performance of recognition of LA abnormality in this study was satisfactory with 91% agreement between observers. Our results are comparable and in some instances superior to conventional criteria commonly recommended to diagnose LV hypertrophy on the electrocardiogram without right BBB.

Aged↗
PubMed1983

The adverse effect of systemic hypertension following myocardial reperfusion.

Transient myocardial ischemia in postoperative hypertension is relatively common with coronary artery bypass surgery. This study examines the effect of hypertension during reperfusion of transiently ischemic myocardium. The animal model was open chest pigs with myocardial ischemia induced by the occlusion of the left anterior descending coronary artery for 30 min followed by 2 hr of reperfusion. A normotensive control group was compared with animals rendered hypertensive with phenylephrine during the ischemic and reperfusion times. In the hypertensive group, systolic blood pressure was raised from 106 to 161 mm Hg and peripheral vascular resistance from normal to 3600 dyn-sec-cm-5. Regional left ventricular wall thickness, mitochondrial function, sarcoplasmic reticulum Ca2+ uptake, tissue calcium, water content, and hemorrhage were evaluated. Compared to controls the hypertensive group had (1) loss of systolic wall thickening with increased diastolic wall thickness in the reperfused zone, (2) intramyocardial hemorrhage in the area of reperfusion, (3) significant impairment of oxidative phosphorylation by mitochondria isolated from the reperfused zone, (4) a marked reduction in the rate of Ca2+ uptake by sarcoplasmic reticulum vesicles, and (5) an increase in ischemic tissue calcium. Thus, hypertension associated with revascularization of acutely ischemic myocardium may accentuate myocardial damage.

Animals↗
PubMed1983

Quantitation of fibrosis of the heart in chronic obstructive pulmonary disease with and without cor pulmonale.

This study examined the hearts of 55 patients dying of chronic obstructive pulmonary disease, with and without cor pulmonale, quantitated histologically the degree of myocardial fibrosis in the left and right ventricle, and determined the relationship to associated disease states. Comparison has been made to a control group of 17 patients free of cardiopulmonary disease. Patients with associated and advanced ischemic heart disease, as proved by marked atherosclerosis and myocardial infarction, have significantly increased myocardial fibrosis throughout all layers of the left ventricular wall in comparison to control patients or patients with chronic obstructive pulmonary disease free of associated cardiac disease. Right ventricular fibrosis was not significantly increased; however, one case showed a marked degree of fibrosis related to myocardial infarction. Subdivision of patients with chronic obstructive pulmonary disease into groups with definite anatomic right ventricular hypertrophy, a clinical diagnosis of cor pulmonale, or with chronic hypoxemia failed to show any difference in the percentage of myocardial fibrosis of the ventricles among these groups. Increased fibrosis of the right or left ventricle in patients with chronic obstructive pulmonary disease, therefore, is not related to the degree of myocardial hypertrophy pathologically, the hypoxemic state, or clinical heart failure, but to ischemic heart disease with myocardial infarction.

Adult↗
PubMed1983

Physiologic effects of oral bronchodilators during rest and exercise in chronic obstructive pulmonary disease.

At rest and during exercise, noninvasive studies of cardiopulmonary physiology in patients with chronic obstructive pulmonary disease (COPD) were carried out to determine the objective benefits of commonly used oral bronchodilator drugs in 15 stable patients without cardiovascular disease or reversible obstruction of airflow. Theophylline, terbutaline, a combination of theophylline and terbutaline, and placebo were given for ten days each in a randomly sequenced double-blind protocol for outpatients. Spirometric values, the ratio of physiologic dead space to tidal volume (VDp/VT), and the alveolar-arterial oxygen pressure difference (P[A-a]O2) were studied at rest on each regimen. During steady-state exercise the changes in VDp/VT and P(A-a)O2, as well as the ventilatory equivalent for oxygen and oxygen pulse, were measured. When compared with placebo, no significant change was noted in the previously mentioned measurements with any regimen, with the exception of a small improvement in the forced expiratory volume in one second, which was significant for all regimens. These findings suggest that commonly used oral bronchodilator drugs in usual doses may have small effects on airflow even in "irreversible" COPD but that the objective effect of these agents on gas exchange during rest and exercise is not significant.

Administration, Oral↗
PubMed1982

Ventricular performance and biochemical alteration of regional ischemic myocardium after reperfusion in the pig.

Reperfusion of acutely ischemic myocardium may cause profound alterations in left ventricular wall performance and metabolism. This study evaluates regional left ventricular wall thickness, analyzes metabolic and biochemical alterations, and examines tissue hemorrhage during 15, 30, and 120 minutes of myocardial ischemia, each followed by 120 minutes of reperfusion. Reperfusion after 15 minutes of ischemia showed nearly normal ventricular wall thickening and motion, intact metabolic and biochemical function, and no tissue hemorrhage. However, reperfusion after 30 and 120 minutes of ischemia was associated with ventricular wall thickening and failure to resume systolic and diastolic wall motion. Furthermore, adverse metabolic and biochemical alterations and reperfusion zone hemorrhaging increased proportionally with the duration of ischemia. These findings suggest critical myocardial damage occurring between 15 and 30 minutes of ischemia in an animal model without preexisting coronary collateral circulation. The observed metabolic and biochemical changes are consistent with irreversible cell membrane defects, allowing calcium ion accumulation and thus adversely affecting diastolic relaxation and systolic thickening.

Adenosine Triphosphate↗
PubMed1982

Divalent cation-activated ATP hydrolysis by mitochondrial ATP'ase--mechanism for energy depletion in ischemic reperfused myocardium.

Recovery of high-energy compounds by ischemic myocardium is believed to be important for its return to normal functioning. While it has been previously shown that oxidative phosphorylation is markedly reduced in mitochondria isolated from ischemic myocardium in the presence of all substrates, alterations in ATPase activity have not been confirmed. This study demonstrates that, although the rate of ATP hydrolysis produced by mitochondria isolated from 2-hr ischemic myocardium does not significantly differ from that produced by non-ischemic mitochondria, the rate produced by 2-hr ischemic, 2 hr reperfused mitochondria is significantly higher. Also, Ca++ content was observed to be higher in reperfused than in non-reperfused ischemic mitochondria. The addition of EDTA, EGTA, or oligomycin to the reperfused ischemic mitochondria resulted in the inhibition of ATPase activity. These results indicate that mitochondrial ATPase in ischemic myocardium is activated by Ca++ ions and that ischemic reperfused myocardium may contain mitochondria with uncontrolled ATPase activity such that high energy phosphate supplies are excessively depleted when the cells are reperfused.

Adenosine Triphosphatases↗
PubMed1982

Correlation of left ventricular wall motion abnormalities with ventricular arrhythmias in patients with coronary artery disease.

We studied 71 patients with 12-hour Holter monitoring to determine if the incidence and complexity of ventricular arrhythmias in symptomatic coronary artery disease patients were related to the extent of left ventricular dysfunction. Their average age was 51 years, and each had cardiac catheterization within 3 months of study. Thirty-six patients had left ventricular aneurysms, 10 had normal left ventricular angiograms and 25 had left ventricular hypokinesis or akinesis without dyskinesis. The patients with aneurysms had significantly more heart failure, prior infarction, cardiomegaly and impaired ejection fractions. The mean premature ventricular contractions per hour for the aneurysm patients was 34 +/- 52, 3 +/- 5 for those with normal left ventricles, and 11 +/- 24 in the remainder. Complex premature ventricular contraction were noted in 50% of the aneurysm patients, in 10% of the patients with normal left ventricles and in 23% of the patients with hypokinesis or akinesis. Ventricular arrhythmias increase with greater left ventricular wall motion abnormality in patients with symptomatic coronary artery disease.

Adult↗
PubMed1982

Immediate and long-term posttherapy neuropsychologic performance in children with acute lymphoblastic leukemia treated without central nervous system radiation.

Intellectual and neuropsychologic test performance was studied in 41 children with acute lymphoblastic leukemia within one year of completing multidrug therapy in which intrathecal methotrexate was the sole agent of central nervous system prophylaxis. To control for possible effects of intensive systemic chemotherapy and the disruptive psychosocial effects of treatment on psychometric test function, 33 children with embryonal rhabdomyosarcoma who had no CNS disease or treatment were similarly studied. All patients studied had been in continuous complete remission since diagnosis. Within each diagnostic group, patients were placed in a younger (less than 8 years) or an older (more than 8 years) group depending on age at the time of testing. No significant difference was found in intellectual function between the young ALL and ERMS groups or between the total ALL and ERMS groups. Further five-year follow-up of 12 of the youngest ALL patients showed no significant long-term change in intellectual or other specific neuropsychologic functions. Children with ALL who remained in continuous complete remission from diagnosis and who were treated with prophylactic intrathecal methotrexate and no CNS radiation did not have global or specific neuropsychologic impairment.

Adolescent↗
PubMed1982

Survival in subgroups of patients with left main coronary artery disease. Veterans Administration Cooperative Study of Surgery for Coronary Arterial Occlusive Disease.

This report presents the 42-month survival experience of 91 patients with a significant lesion of the left main coronary artery in the Veterans Administration Cooperative Study of Coronary Bypass Surgery. Survival in surgical patients was significantly better than that in the medical group (p = 0.016), even after adjustments were made for two important differences in baseline characteristics--duration of angina and high risk by angiographic criteria--between the two groups (p = 0.019). Subgroups based on severity of left main stenosis and on left ventricular (LV) function showed significant trends in favor of surgery in patients with more than 75% left main stenosis and in those with abnormal LV function. A similar but nonsignificant trend was seen in the two subgroups with 50-75% stenosis or with normal LV function. The surgical benefits were not significantly different between the categories of the subgroups defined separately by stenosis and LV function. Low-, middle- and high-risk subgroups based on four noninvasive clinical predictors also showed significantly improved survival with surgery in the high-risk group. The low-risk groups showed a slight, nonsignificant disadvantage with surgical treatment. These data support the view that patients with left main disease are not a homogeneous group. High- and low-risk subgroups with different outcomes and responses to treatment can be delineated by angiographic or clinical criteria. For most patients with left main disease, coronary artery bypass grafting offers improved longevity.

Adult↗
PubMed1981

Ewing's sarcoma: ten-year experience with adjuvant chemotherapy.

Since May 1970, 67 consecutive patients with primary (nonmetastatic) Ewing's sarcoma were treated with adjuvant chemotherapy (CT) in addition to radiation therapy (RT) or surgery for the primary tumor. The first 19 patients were treated with four-drug sequential CT (T-2). The second protocol was a seven-drug induction combination CT (T-6) followed by T-2 maintenance CT; in both protocols CT was continued for 18 months. The current protocol (T-9) consists of combination CT given continuously for a period of 9 months. Of the entire group of 67 patients, 47 (70%) had axial and proximal lesions (pelvis, spine, rib, humerus, and femur) and 20 (30%) had distal lesions (forearm, leg, and foot); 53/67 (79%) are surviving free of disease 12--118 months (median 41 months) from the start of treatment. Fifteen of 23 (65%) patients with axial lesions, 19/24 (79%) patients with proximal lesions, and 19/20 (95%) patients with distal lesions are free of disease. Disease-free survivors include 28/39 (72%) male patients and 25/28 (89%) female patients. Thirty-four patients had RT, and 33 had surgery or surgery and RT, in addition to chemotherapy, for local treatment. The disease-free survival rate was 76% in the RT group and 82% in the surgery group; failure in the RT group was attributable to local recurrence in 7/34 (21%) patients. Recent experience with T-9 CT has demonstrated that CT given prior to RT or surgery can cause a great reduction in the size of the primary tumor while allowing the pathologically-eroded bone to heal prior to the initiation of RT; this also allows the high-risk patient with an axial primary (pelvis or spine) to tolerate the aggressive CT needed to prevent distant metastases. In addition to dramatically increasing survival in patients with Ewing's sarcoma, combination CT has helped achieve permanent local control. The superior survival rates for all sites of primary tumor are attributable to the early use of aggressive combination CT.

Antineoplastic Agents↗
PubMed1981

Ventricular arrhythmia before and after aorto-coronary bypass surgery.

The influence of aorto-coronary bypass surgery (ACBS) on ventricular arrhythmia was examined in 57 patients. Six-hour Holter monitoring was done on the day prior to and 3 mth after ACBS. None of the patients were on any antiarrhythmic drugs during these recordings. Ventricular arrhythmia was classified into three groups: Group I (45 patients) had an average of less than 10 premature ventricular contractions (PVCs) per hour, Group II (7 patients), 11-30 PVCs per hour and Group III (5 patients), greater than 30 PVCs per hour. There was no significant change in the number of patients in each group after ACBS. Complex PVCs were present in 8 patients preoperatively and in 9 patients after ACBS. The number of diseased vessels and the extent of left ventricular wall motion abnormality noted preoperatively, had no effect on ventricular arrhythmia following surgery. These data show that ACBS, when performed to relieve angina, does not have a significant effect on the prevalence of PVCs and does not prevent or reduce the occurrence of complex PVCs.

Adult↗
PubMed1981

Systolic time intervals in the experimental animal with aortic outflow obstruction. Effect of digoxin.

This study shows significant changes occurring in systolic time intervals in an experimental animal model of aortic outflow obstruction with cardiac hypertrophy. The left ventricular ejection time is markedly prolonged and the preejection period/left ventricular ejection time ratio shortened. These changes are in the opposite direction of those usually observed with left ventricular dysfunction in man but similar to those described in man with aortic stenosis. Furthermore, the changes observed in systolic time intervals after digoxin in this experimental model are not comparable to those reported in man with normal or abnormal left ventricular function. Hence, the use of systolic time intervals, including digitalis effect, to evaluate the functional state of the left ventricle in aortic outflow obstruction are probably unreliable.

Animals↗
PubMed1980

Immunotherapy with oral BCG and serial immune evaluation in childhood lymphoblastic leukemia following three years of chemotherapy.

Thirty-nine children with ALL who had completed three years of chemotherapy were randomized to receive oral BCG for immunotherapy or no treatment as controls. There was not a significant difference between the two groups in the relapse rate. Among the immune parameters, only in vitro blastogenic responses to PHA and PPD rose significantly in the BCG group compared with the controls. Skin testing also revealed evidence of tuberculin sensitization. The group as a whole was studied for the kinetic recovery of immune functions after the cessation of chemotherapy, which revealed a dissociation in both cellular and humoral systems. At three weeks after therapy, only peripheral blood lymphocyte count, non T-cells, and serum IgM showed a significant abnormality. There was a rise in these parameters in the subsequent weeks, and the non-T-cell count reached normal levels sooner than the other two parameters. Children who were less than 5 years of age at the time of diagnosis showed a lesser degree of immunosuppression after long-term chemotherapy compared with those who were greater than or equal to 5 years of age. The analysis of the data indicated a relationship between the low serum immunoglobulins (IgG, IgA) and disease status.

Administration, Oral↗
PubMed1980

A long-term clinical follow-up of children with acute lymphoblastic leukemia treated with intensive chemotherapy regimens.

One hundred and thirty-three children 15 years old and younger with acute lymphoblastic leukemia were treated with two different protocols. Both regimens consist of a multi-drug program, without CNS irradiation, administered for three years. Seventy-five children were enrolled on the first protocol, L-2; and 58 were treated on the subsequent regimen, L-10. Of the 70 evaluable patients on the L-2 program, 40 continue in complete remission from 72-111 months. Seventy-four percent of the children qualified for treatment cessation, and 59% have remained in continuous remission for six years. The estimated seven year disease-free survival for the 70 evaluable children on the L-2 protocol is 57% and for all entries is 53%. Of the 57 evaluable patients on the L-10 program, 35 are in complete remission from 15-67 months. The combined frequency of primary CNS leukemia for the two regimens is 7%. The off-therapy results of the L-2 protocol cannot be compared to the L-10 at present, but the on-therapy outcomes, despite the modifications that were designed to improve the L-10 regimen, are comparable.

Adolescent↗
PubMed1980

The long-term suppression of ventricular arrhythmia by oral acebutolol in patients with coronary artery disease.

The short-term efficacy of oral acebutolol was evaluated in 20 patients with coronary artery disease and frequent premature ventricular contractions (PVCs) by serial 24-hour Holter monitoring before and while the patients were receiving an average daily dose of 1,100 mg. of acebutolol for four weeks. Fifty-five percent of the 20 patients showed a greater than 70% PVC reduction from baseline values. The only serious side effect during short-term therapy was mild, reversible cardiac decompensation in one patient. The long-term safety and continued efficacy of acebutolol was then evaluated over the next 11 months in nine of the 11 patients showing greater than 70% PVC reduction at four weeks. Two-thirds of these nine patients continued to show greater than 80% PVC reduction from baseline values at 12 months. One patient developed alopecia during long-term therapy. The majority of patients not responding well to acebutolol at four weeks had an actual increase in PVCs on acebutolol therapy. We conclude that acebutolol produces long-term, effective reduction in PVCs without serious toxicity in the majority of patients with ventricular ectopy. However, this drug appears to either produce an excellent response or no response with regard to PVC control in most instances.

Acebutolol↗
PubMed1980

Digoxin-quinidine interaction. Changes in canine tissue concentration from steady state with quinidine.

Tissue concentrations of tritiated digoxin inthe dog are altered by simultaneous administration of quinidine. Serum levels rise as tissue concentration decreases significantly in all tissue except brain tissue, where an increase of 51 percent is noted over that of the control digitalized state. The digitalis toxicity associated with digoxin-quinidine interaction appears to be associated with rising brain levels of digoxin and falling levels in the myocardium. These findings suggest a neurally mediated form of toxicity with this interaction related to a change in the space of distribution. The question of possible loss of inotropic effect associated with diminished myocardial digoxin concentration requires further study.

Animals↗