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Biomedical subjects

A Battler

Publications and source records attributed to A Battler.

At least 91 records · Page 5Linked to original sources
PubMed1994

The applicability of color-labeled microspheres in a rabbit model of ischemia-reperfusion.

This study was designed to examine the ability of color-labeled microspheres to depict different states of myocardial perfusion in a rabbit model of ischemia-reperfusion. A thread was passed under the left anterior descending artery (LAD) and the first left marginal artery of anesthetized New Zealand White rabbits. Blue-labeled microspheres (500/g body wt) were injected into the left atrium. The thread was tightened in rabbits belonging to the experimental group (n = 8), and red-labeled microspheres (500/g body wt) were injected. The snare was loosened, and yellow-labeled microspheres (500/g body wt) were injected before (n = 5) or after (n = 3) methylene blue injection. In animals belonging to the "sham" group (n = 4 and n = 2, respectively), the sequence of injections was similar, but the snare was not tightened. The animals were euthanized, and 0.3-1 g sections were cut from ischemic and nonischemic regions, as determined by methylene blue in the experimental subgroups and from the corresponding regions in the "sham" subgroups. The tissue samples were digested with 4 M KOH, ethanol 70%, and ultrasonication, and the microspheres were recovered by vacuum filtration. The dye was chemically removed from the microspheres, and the photometric absorption of each sample was determined. There was no significant difference between the experimental and "sham" groups in baseline uptake of blue-labeled microspheres. Rabbits belonging to the experimental subgroups had significantly lower mean uptake of red microspheres during ischemia relative to "sham" (0.51 +/- 0.08 vs 1.06 +/- 0.24 and 0.36 +/- 0.19 vs 0.91 +/- 0.12, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Failure of captopril to attenuate myocardial damage, neutrophil accumulation, and mortality following coronary artery occlusion and reperfusion in rat.

Captopril, a sulfhydryl-containing angiotensin-converting enzyme inhibitor, has been suggested as possessing antiischemic and antiinflammatory properties. To test the hypothesis that captopril may prevent neutrophil-induced myocardial injury during acute myocardial infarction (AMI), the authors subjected rats to coronary occlusion for thirty minutes and reperfusion for twenty-four hours (MI) or to sham operation (sham MI). Oral captopril (100 mg/kg) or vehicle was administered thirty minutes before coronary occlusion. The effect of captopril on mean arterial blood pressure was assessed in separate group of animals (n = 8). Infarct size and neutrophil accumulation in myocardium were determined by measuring creatine phosphokinase depletion and myeloperoxidase (MPO) activity, respectively, in the left ventricular free wall (LVFW). Animals treated with 100 mg/kg of captopril exhibited significant reduction in mean arterial blood pressure compared with vehicle-treated animals (P < 0.01). Compared with vehicle-treated animals, administration of 100 mg/kg of captopril to MI animals attenuated neither twenty-four-hour mortality (56% vs 52%, respectively), nor infarct size (36 +/- 7% vs 34% +/- 7% respectively), nor MPO activity (1.0 +/- 0.17 vs 1.26 +/- 0.19). Thus, in the present experiment captopril did not reduce neutrophil-induced myocardial damage following coronary occlusion and reperfusion. These findings may be partly explained by the negative effect of captopril on arterial blood pressure during AMI.

Animals↗
PubMed1994

Successful pregnancy in a woman with cyanotic congenital heart disease after a palliative pulmonary-systemic shunt. A case report.

A 20-year-old woman with cyanotic congenital heart disease composed of corrected transposition of the great vessels, severe pulmonic stenosis, atresia of the left pulmonary artery and a large ventricular septal defect, had a successful pregnancy following a pulmonary-systemic shunt (Blalock-Taussig). The hemoglobin decreased from 21 to 16 g/dL following the operation. The antepartum course was complicated by intrauterine growth retardation and pregnancy-induced hypertension. A normal fetal nonstress test and biophysical profile permitted continuation of the pregnancy until 38 weeks' gestation, with delivery of a healthy infant.

Abnormalities, Multiple↗
PubMed1994

Cardiovascular effects of nisoldipine in essential hypertension.

The acute hemodynamic effects of nisoldipine (Bay K552) in patients with essential hypertension were studied using nuclear ventriculography. In a cohort of 16 essential hypertension patients, an oral dose of 15 mg nisoldipine significantly lowered blood pressure within 20 min. The effect lasted at least 3 h. Blood pressure that was 160.5 +/- 20.3/108.0 +/- 10.1 mm Hg initially was reduced to 137.0 +/- 14.9/93.8 +/- 9.4 mm Hg at 3 h (P < 0.001). Cardiac output rose, total peripheral resistance fell and ejection fraction rose significantly. End systolic and end diastolic volumes did not change significantly with this dose of nisoldipine. The acute hemodynamic effects of 15 mg nisoldipine administered orally, measured by repeat nuclear ventriculography, were maintained during therapy for the 8 weeks of observation. Thus, nisoldipine is a powerful antihypertensive agent, significantly decreasing BP as well as total peripheral resistance and increasing cardiac index. This effect was prominent after 3 h and wore off about 12 h after each dose. Five of the patients had an initially high heart rate. To these patients propranolol was added in small doses (20-40 mg/day, mean 25 +/- 26 mg/day). This addition did not change the results when the patients were analyzed separately.

Administration, Oral↗
PubMed1993

Left ventricular pseudohypertrophy in cardiac tamponade: an echocardiographic study in a canine model.

OBJECTIVES: This study was designed to establish whether left ventricular pseudohypertrophy in cardiac tamponade can be reproducibly induced in an experimental canine model and to investigate the mechanism of its production. BACKGROUND: Past experimental and clinical studies have shown reduction of ventricular volumes resulting from cardiac tamponade. Left ventricular pseudohypertrophy, a transient thickening of myocardial walls, was recently described as a new echocardiographic sign of cardiac tamponade. METHODS: Cardiac tamponade was induced in seven anesthetized open chest dogs with serial bolus injections of 50 ml each of 0.9% saline solution into the pericardial sac. Under hemodynamic monitoring, M-mode and two-dimensional echocardiographic measurements were performed from a right parasternal window at each stage of graded cardiac tamponade. RESULTS: There was a progressive increase of interventricular septal and posterior wall diastolic thickness. Mean wall thickness (interventricular septal thickness + posterior wall thickness divided by 2) was 9.8 +/- 1.3 mm at baseline, 14.3 +/- 0.9 mm at peak tamponade and 9.0 +/- 1.5 mm after fluid withdrawal (p < 0.0001). Mean wall thickness correlated directly with the severity of cardiac tamponade, as estimated from the level of right arterial pressures (r = 0.75 and p < 0.0001), and with the decrease of left ventricular cavity volume (r = -0.67 and p < 0.0001). Left ventricular mass did not change significantly. CONCLUSIONS: Left ventricular pseudohypertrophy is a constant manifestation of cardiac tamponade in a canine model. The degree of myocardial thickening correlates with the reduction of ventricular dimensions and with the severity of hemodynamic compromise, representing a constant facet of heart remodeling in cardiac tamponade.

Animals↗
PubMed1993

Intracoronary injection of basic fibroblast growth factor enhances angiogenesis in infarcted swine myocardium.

OBJECTIVES: This study was performed to examine the effect of intracoronary exogenous basic fibroblast growth factor (bFGF) on angiogenesis in infarcted myocardial regions. BACKGROUND: Exogenous bFGF is a potent promoter of angiogenesis. Little information is available on its effect on myocardial angiogenesis. METHODS: Myocardial infarction was induced in 10 pigs by intracoronary injection of microscopic beads. Four pigs served as a control group; in six pigs slow-release bFGF was delivered by the beads. Cardiac performance was evaluated by repeated echocardiographic measurement and angiogenesis was evaluated by immunohistochemical studies 14 days later. RESULTS: As compared with control pigs, pigs treated with bFGF had higher microvessel counts (mean +/- SEM) in both viable tissue (141 +/- 27 per field vs. 39 +/- 4, p = 0.01) and nonviable tissue (329 +/- 26 per field vs. 95 +/- 7, p < 0.001) within the infarct area. No significant differences in total regional left ventricular wall motion were noted between the two groups throughout the 14-day study period. CONCLUSIONS: In the swine, direct intracoronary application of bFGF to infarcted myocardium enhances myocardial neovascularization within 2 weeks.

Animals↗
PubMed1993

Evaluation of a new mechanical atherectomy system (TRAC) in normal canine coronary arteries. Transluminal Rotary Atherectomy System.

BACKGROUND: The feasibility and safety of a new mechanical atherectomy device, the Transluminal Rotary Atherectomy System (TRAC), for coronary application was examined in vivo in eight dogs. The system operates over a standard balloon coronary guide wire and excises and removes the atherosclerotic material in a single application. METHODS: The TRAC was introduced percutaneously using routine cardiac catheterization technique in four open-chest dogs (acute experiments) and in four closed-chest dogs (chronic experiments). RESULTS: Coronary angiography at the end of the procedure and 1-3 days later demonstrated normal coronary arteries without evidence of dissection, perforation, spasm, or thrombus formation. Macroscopic examination revealed perivascular bleeding along the treated coronary arteries in two out of eight dogs. Microscopic examination of these arteries demonstrated minimal endothelial peeling. Histology of the other coronary arteries demonstrated normal intact blood vessels without evidence for thrombus formation. CONCLUSIONS: These results demonstrate that it is feasible and relatively safe to introduce and operate the new TRAC mechanical atherectomy system in the normal coronary arteries of a beating dog heart.

Animals↗
PubMed1993

Activated protein C and antithrombin-III activity during arterial thrombolysis with recombinant tissue-type plasminogen activator in rabbits.

BACKGROUND: Protein C and antithrombin III (AT-III) are endogenous anticoagulants that regulate thrombotic processes. This experimental study examined the effect of recombinant tissue-type plasminogen activator (rt-PA) thrombolysis on the activity of these natural anticoagulants. METHODS: Blood clots were produced in the femoral artery segments of six rabbits with endothelial damage and stenosis (group A). Five rabbits with only surgical dissection served as controls (group B). Both groups received an infusion of rt-PA at 30 micrograms/kg/min for 60 min. The plasma activity of activated protein C (APC) and AT-III was determined using chromogenic assays. Blood samples were taken at baseline (t1), after surgical dissection with (group A) or without (group B) thrombosis induction (t2), after rt-PA infusion (t3), and 1 h later (t4). RESULTS: In group A rabbits, the mean (+/- SEM) APC activity rose significantly (P = 0.02) from 2.2 +/- 0.3 and 3.7 +/- 1.5 mOD units/min at t1 and t2, respectively, to 59.3 +/- 17.8 mOD units/min at t3 and decreased to 8.0 +/- 3.4 mOD units/min at t4. In group B rabbits, the mean (+/- SEM) APC activity rose (P = 0.01) from 1.1 +/- 0.1 and 1.2 +/- 0.1 mOD units/min at t1 and t2 to 17.1 +/- 3.2 mOD units/min at t3 and decreased to 2.4 +/- 0.2 at t4, (P = 0.011 for comparison between groups using two-way analysis of variance). The mean APC value at t3 was higher for group A than for group B (P = 0.06). A slight but statistically significant decrease (P < 0.01) in AT-III activity was noted in both groups, from 92 +/- 3% and 96 +/- 2% at t1 in groups A and B, respectively, to 79 +/- 3% and 86 +/- 2% at t4 (P = 0.028 for comparison between groups). CONCLUSION: These data show a transient rise in APC and a slight decrease in AT-III activity during rt-PA thrombolysis. Whether these changes influence thrombolysis outcome remains to be determined.

Animals↗
PubMed1993

The Bard Rotary Atherectomy System (BRAS): initial experience in patients with peripheral vascular disease.

Sixteen patients with a mean age of 65.4 +/- 9.8 years and suffering from peripheral vascular disease underwent peripheral atherectomy using a new mechanical device--the BARD Rotary Atherectomy System (BRAS). The BRAS is an "over the wire" system that consists of a spiral guidewire and a handheld motor drive unit, which rotates at 1,500 rpm. Prior to the procedure angiography demonstrated the presence of 18 obstructions (1 tibial, 2 popliteal, 15 superficial femoral arteries) with a mean stenosis of 95.7 +/- 8%. Successful atherectomy was achieved in 16 of 18 lesions and resulted in an 89% immediate success rate and a significant (P less than 0.01) reduction of stenosis to 37.8 +/- 12.5%. There were no significant complications. The excised and removed material embedded over the spiral guidewire demonstrated the presence of fibrotic tissue, fatty lesions, and calcium deposits. Medial or adventitial layers were not present in the removed atherosclerotic material. Mean ABI was significantly (P less than 0.01) increased from 0.38 +/- 0.17 to 0.55 +/- 0.21 following atherectomy. Angiographic follow-up obtained in ten patients 8.8 +/- 5.2 months following the procedure demonstrated restenosis in six of those ten patients. The ABI at this time remained unchanged. These results demonstrated that the new BRAS mechanical atherectomy system is feasible and safe for recanalization of severely stenosed arteries in patients with peripheral vascular disease.

Aged↗
PubMed1993

Balloon aortic valvuloplasty in the elderly: useful when there is no alternative.

Of 63 elderly patients with calcific aortic stenosis in whom balloon aortic valvuloplasty was performed, 26 treated with the new technique of Cribier and Letac are the subject of this report. Patients were referred for the procedure because they were at high surgical risk, or were not candidates for surgery. Seven matched patients who fit the criteria for balloon valvuloplasty but refused the valvuloplasty procedure served as controls. Aortic gradient decreased from 78 +/- 27 mm Hg to 35 +/- 20 mm Hg and aortic valve area increased from 0.47 +/- 0.16 cm2 to 0.83 +/- 0.38 cm2 (P < 0.0001). Symptomatic improvement was immediately obtained in each patient. Complications were rare, with only one patient needing vascular repair for femoral artery occlusion. Three patients died during the initial hospitalization (none during the procedure). Valvuloplasty patients were followed for a mean period of 9.6 +/- 9.4 months. Three months survival was 87%, 6 months survival was 76%, and 12 months survival was 61%. Four of seven patients in the control group (57%) died within 3 months after initial referral. Balloon aortic valvuloplasty is a useful treatment in elderly patients who are poor surgical candidates. It may have a positive influence on short-term survival.

Actuarial Analysis↗
PubMed1991

Myocardial infarction during pregnancy: a case report.

Myocardial infarction during pregnancy is rare. This report presents a 28-year-old parturient with no risk factors for coronary heart disease, in whom an acute anterior myocardial infarction occurred in the 34th gestational week. A cesarean section was performed at term due to an obstetrical cause and under hemodynamic monitoring without complications. Coronary angiography performed 4 months after delivery revealed the presence of normal coronary arteries and mild regional left ventricular dysfunction.

Adult↗
PubMed1991

Pregnancy after myocardial infarction: are we playing safe?

The safety of pregnancy after myocardial infarction remains a significant dilemma for both the obstetrician and the cardiologist. Only 20 cases of pregnancy after myocardial infarction have been reported. To clarify this problem, we add our experience of four such cases in which conception occurred 9 months to 9 years after myocardial infarction with no previous consultation. Each woman had an uneventful pregnancy with no cardiac or obstetric complications related to the myocardial infarction. All patients were under the strict supervision of an obstetrician and a cardiologist during pregnancy in our conjoined antepartum-cardiologic clinic. The mode of delivery in all patients was related to the obstetric indications. Our experience and the accumulated experience in the literature demonstrate good prognosis for patients who conceive after myocardial infarction.

Adult↗
PubMed1990

Improved survival but not left ventricular function with early and prehospital treatment with tissue plasminogen activator in acute myocardial infarction.

One hundred ninety patients with acute myocardial infarction (AMI) were treated with recombinant tissue-type plasminogen activator (rt-PA) 2.0 +/- 0.8 hours after the onset of symptoms. Eighty-seven patients were enrolled via mobile intensive care units and 103 through the emergency ward. Patients who were enrolled via the mobile intensive care units were randomized to immediate, prehospital treatment initiation, or to delayed, in-hospital treatment initiation. All 190 patients except 2 underwent delayed coronary angiography and, when indicated, angioplasty at 72 hours after enrollment. Patients treated within 2 hours and those treated 2 to 4 hours after symptom onset had similar preservation of left ventricular function, and similar prevalence of congestive heart failure at discharge. Patients treated within 2 hours of symptom onset had significantly lower short- (0.0 vs 6.3%, p = 0.01) and long-term (1.0 vs 9.5%, p = 0.03) mortality. Prehospital initiation of rt-PA appeared to be safe and feasible and resulted in a 40-minute decrease in the time from symptom onset to treatment initiation.

Aged↗
PubMed1990

The slope of the end-systolic pressure-volume relationship compared with the global end-systolic pressure-volume ratio in humans.

The slope of the end-systolic pressure-volume relationship (Emax), which is generated clinically by load manipulation, as well as the "absolute" peak systolic pressure end-systolic volume ratio (denoted as pressure-volume ratio), have been suggested as indices defining left ventricular function. This study represents an attempt to determine the relationship between these two indices by studying 20 patients (16 with coronary artery disease and 4 with normal coronary arteries) undergoing cardiac catheterization. Left ventriculography was performed three times in each patient: (1) in the control baseline state, (2) after rapid intravenous infusion of 250-300 cc of saline, and (3) after sublingual administration of 5 mg isosorbide dinitrate. Emax was approximated by linear regression using the peak left ventricular pressure (replacing end-systolic pressure) and the smallest left ventricular (end-systolic) volume for these three different loads. Acute ischemia with typical chest pain and ECG changes developed in 4 patients during saline loading. The pressure-volume ratio showed no change with load manipulation in patients who did not demonstrate ischemia. In the 4 patients who developed acute ischemia, the pressure-volume ratio dropped from 4.4 +/- 1.3 to 2.9 +/- 0.9 mmHg/ml (p less than 0.001). In all of the patients, the pressure-volume ratio, but not the Emax, correlated with the ejection fraction (r = 0.6; p less than 0.05). In addition, the Emax line demonstrated a markedly nonphysiological Vo. There was no correlation between Emax and pressure-volume ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Acute hemodynamic and arrhythmogenic effects of high-dose intravenous salbutamol in patients with chronic left ventricular dysfunction.

The short-term hemodynamic and possible arrhythmogenic effects of intravenous salbutamol at a dose of 30 or 60 micrograms/min were evaluated in 14 patients with severe chronic left ventricular dysfunction using equilibrium radionuclide angiocardiography and electrocardiographic monitoring. Salbutamol infusions at a dose of 30 micrograms/min did not cause significant hemodynamic changes; however, at a dose of 60 micrograms/min there was a significant increase in stroke volume, cardiac output, and left ventricular ejection fraction. Heart rate increased significantly while systemic peripheral resistance decreased significantly. Two patients developed ventricular premature beats and another two supraventricular tachycardia, but none were associated with adverse consequences. Thus, high-dose intravenous salbutamol is effective and safe, and may be used in the acute management of patients with poor left ventricular function.

Adult↗
PubMed1990

Analysis and prediction of left ventricular performance under load changes during cardiac catheterization.

The applicability of a computer model, which relates the transmural mechanical distribution in the left ventricle (LV) to its global function at different loading conditions, was evaluated in patients with normal to near normal LV function undergoing cardiac catheterization. Left ventriculography and measurements of aortic and LV pressures were performed at baseline conditions and repeated following rapid volume expansion with intravenous infusion of 250 to 300 ml of physiologic saline and also after sublingual isosorbide-dinitrate (ISDN) administration. Twenty patients (18 men and 2 women, average age = 53 years) underwent coronary angiography and left ventriculography. Sixteen patients had coronary artery disease with one- to three-vessel involvement and 4 had normal coronary arteries. The measured input data into the model included the end-diastolic LV volume and wall thickness, aortic pressure, heart rate, and the peripheral resistance. The model parameters of myocardial contractility and arterial system capacitance for the control baseline conditions were estimated so that an accurate match was obtained between the predicted and the measured end-systolic (ES) volume and pressure. Using these parameters, model predictions for the two load perturbations were compared to the measurements. An excellent correlation was found between the predicted and measured LV ES volumes and peak-systolic pressures (PSP) (R2 greater than 0.994). In four patients, who developed ischemic symptoms during saline injection, the prediction of end-systole volumes were lower than the measured values, suggesting an actual reduction in contractility during acute ischemia. Therefore, the model is sensitive to contractility changes. The model predicts global LV performance, under different loading conditions, including stroke work, peak developed wall stress, velocity of fiber shortening, and myocardial oxygen consumption.

Cardiac Catheterization↗