Search PubMed⌕ Search

Biomedical subjects

H I Miller

Publications and source records attributed to H I Miller.

At least 73 records · Page 4Linked to original sources
PubMed1994

Detection of restenosis following percutaneous coronary angioplasty in single-vessel coronary artery disease: the value of clinical assessment and exercise tolerance testing.

Chest pain and submaximal exercise testing were prospectively assessed over a 6-month period, for detecting the evolution of restenosis in patients undergoing percutaneous coronary angioplasty, following either acute myocardial infarction or treatment of an anginal syndrome. Seventy-eight patients with one-vessel coronary artery disease underwent a modified treadmill exercise test at the 1-week, 3-month and 6-month follow-up after angioplasty, when a final angiogram was also performed. Forty-four patients (group A) were examined after myocardial infarction; in 34 patients (group B) angioplasty was done for incapacitating angina. Both groups showed similar results with low sensitivity and relatively moderate specificity of both chest pain and exercise tests; this was also the case for the time of restenosis to occur. It is thus concluded that the parameters examined are somewhat limited markers of restenosis following coronary angioplasty.

Adult↗
PubMed1994

Percutaneous transluminal coronary angioplasty in elderly patients.

Fifty-six patients aged 75 years and older underwent percutaneous transluminal coronary angioplasty (PTCA) at our institution from 1984 to 1991. The average age was 76.7 +/- 1.5 years, and 84% of the patients were males. Single-vessel disease occurred in 21 patients, double-vessel disease in 16, and three-vessel disease in 19 patients. The mean left ventricular ejection fraction was 57 +/- 5%, and 8 patients had an ejection fraction of < 40%. The anginal functional class was I in 1 patient, II in 3, III in 6, and IV in 46 patients. Single-vessel PTCA was attempted in 43 patients, two-vessel PTCA in 8, and three-vessel PTCA in 5 patients. Revascularization was complete in 35% of the patients, incomplete in 57, and no revascularization was obtained in 8% of the patients. Ninety-one percent of the patients had a successful procedure. In 5 patients there was severe dissection, 1 patient died, 1 patient had an acute myocardial infarction, and 1 patient had emergency bypass surgery. Long-term follow-up (6-96 months, mean 21 +/- 4) in the 51 successfully treated patients revealed late cardiac death in 1 patient, repeated PTCA for restenosis in 9, and coronary bypass surgery in 2 patients. Twenty-two patients were asymptomatic, 12 had improved symptoms, and 5 remained symptomatic. PTCA appears to be a safe and effective treatment in elderly patients with one- and two-vessel disease, with excellent long-term results. Age is not a contraindication to PTCA. The results in elderly patients with three-vessel disease are less encouraging.

Aged↗
PubMed1994

Conjoined double internal mammary artery grafting.

Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patients. In ten of them one IMA was used as a free graft, and was proximally connected to the other ("conjoined" double IMA), the indications being insufficient supply of adequate veins, diseased aortic wall, availability of only a short right IMA segment for free grafting, occluded left subclavian artery, and when distal and scattered lesions of relatively important vessels had to be bypassed. Additional sequential IMA anastomoses were performed in four patients and an additional sequential vein graft in a fifth. All patients became angina-free postoperatively and have remained so during observation up to 16 months. Recatheterization studies were performed in six patients and in all of them the IMA-to-IMA (n = 6) and distal anastomoses (n = 26) were patent. Conjoined double IMA grafting is an important option available to the cardiac surgeon for management of selected patients with coronary artery disease.

Cardiac Catheterization↗
PubMed1994

Arterial revascularisation with the conjoined double internal mammary artery grafting.

A free graft Internal Mammary Artery (IMA) was proximally connected end-to-side to an in-situ IMA in 6 patients, a method we have named: "The conjoined double IMA". This alternative surgical technique was applied in patients where important vessels had to be grafted in presence of diseased aortic wall, insufficient supply of adequate veins, or a mammary not long enough, thus precluding the performance of other, more conventional methods for Double IMA grafting. Early clinical and angiographic follow-up demonstrate the feasibility of this technique in selected patients.

Aged↗
PubMed1993

Effect of surgical mask position on bacterial contamination of the operative field.

The influence of surgical mask usage on bacterial contamination of the operative field was studied during 30 cardiac catheterization procedures. Mask position was varied during each procedure according to a predesigned random table. The number of bacterial colonies recoverable when no mask was worn was significantly higher than that detected when a full mask was worn (P < 0.002). Shedding of Staphylococcus epidermidis was greater when no mask was worn (mean 5.2 colonies 10 min-1) than shedding with full mask (mean 2.7 colonies 10 min-1; P < 0.004). Although mask placement below the nose was associated with higher mean colony counts than that above the nose, these differences were not statistically significant.

Bacteria↗
PubMed1993

Myocardial risk area defined by technetium-99m sestamibi imaging during percutaneous transluminal coronary angioplasty: comparison with coronary angiography.

OBJECTIVES: The purpose of this study was to compare the assessment of myocardial area at risk in patients with coronary artery stenosis by coronary angiography and quantitative myocardial perfusion imaging with technetium-99m sestamibi. BACKGROUND: Decisions concerning patient management frequently rely on semiquantitative angiographic estimation of the myocardial area at risk, although this approach has not been well validated. Technetium-99m sestamibi is a perfusion imaging agent with little redistribution after initial myocardial uptake. This characteristic allows for injection during angioplasty and later imaging for visualization and quantitation of the nonperfused area at risk. METHODS: Thirty-nine patients referred for coronary angioplasty were studied. Technetium-99m sestamibi was injected intravenously during angioplasty balloon inflation. Planar (33 patients) or tomographic (6 patients) imaging was performed after completion of angioplasty. Imaging was repeated 24 to 48 h later. Myocardial risk area (perfusion defect on angioplasty image) was quantified as an integral using circumferential count distribution profiles and normal reference. Angiographic risk area was assessed using five scoring methods. RESULTS: The scintigraphic risk area was 14 +/- 15 on planar images and 39 +/- 16 on tomography. Scintigraphic risk area of patients with infarction was larger than in patients without (22 +/- 17 versus 7 +/- 8, p = 0.003). The left anterior descending coronary artery had a larger mean risk area than other vessels (22 +/- 15 versus 7 +/- 11, p = 0.002). The presence of angiographic collateral channels was associated with smaller risk areas. Angiographic risk scores correlated only moderately with the technetium-99m sestamibi risk area (r = 0.54 to 0.65), with considerable spread of data. CONCLUSIONS: Area at risk estimated from coronary angiography does not correlate well with that from quantitative myocardial perfusion imaging with technetium-99m sestamibi. These findings emphasize that the functional significance of coronary artery disease is not predicted by coronary anatomy alone.

Adult↗
PubMed1993

Time-consuming procedures and prehospital thrombolytic treatment.

OBJECTIVES: To assess time-consuming procedures in the prehospital stage of acute myocardial infarction patients who had received thrombolytic therapy at the scene, and to evaluate their effect on the clinical outcome. DESIGN: Prospective study. SETTING: Mobile intensive care unit staffed by an intern or a hospital-based physician. PARTICIPANTS AND INTERVENTIONS. Thrombolytic therapy with recombinant tissue-type plasminogen activator (total dose of 120 mg/6 hrs) was initiated at the scene in 167 patients. Treatment continued during transportation and thereafter in the cardiac care unit. During hospitalization, radionuclide ventriculograms and coronary angiography were performed in most patients. MEASUREMENTS AND MAIN RESULTS: Correct diagnosis was confirmed in 165 of 167 patients. Mean time to treatment was 96 +/- 42 (SD) mins with no significant difference between patients treated at home (n = 105) or in public places (n = 60). Global duration of treatment was significantly shorter when thrombolytic therapy was given in public as compared with treatment applied at home (50 +/- 13 vs. 57 +/- 16 mins, respectively, p < .002). CONCLUSION: If patients and physicians become aware of the potential advantages of prompt initiation of thrombolytic therapy at the scene, critical time may be saved in delivering thrombolysis to the clotted coronary artery.

Emergency Medical Services↗
PubMed1993

Rapid resolution of new right bundle branch block in acute anterior myocardial infarction patients after thrombolytic therapy.

The objectives of this retrospective study are to describe the effect of thrombolytic treatment on the clinical course of patients with acute anterior myocardial infarction complicated by acute right bundle branch block. Patients admitted to the intensive cardiac care unit within < 4 hours from onset of symptoms, and demonstrating an acute right bundle branch block with, or without left axis deviation, on the qualifying ECG were included. All were given intravenous thrombolytic treatment consisting of: streptokinase (1,500,000 IU/40 min) or recombinant tissue type plasminogen activator (120 mg/6 hours). Following admission, patients were continuously monitored and a 12-lead ECG was recorded during each of the first 3 hours and then every 3 hours over the next 21 hours. Eight patients were included (8/211 = 3.8%). Their mean age was 62 +/- 7 years and time elapse from onset to treatment was 122 +/- 26 minutes. Complete resolution of the right bundle branch block occurred within < 3 hours in all and left axis deviation normalized in two patients. Mean peak creatine kinase was 1214 +/- 604 IU and global left ventricular ejection fraction, measured by isotope ventriculography within 24 hours from admission, was 39% +/- 15%. Only one patient was prophylactically paced. In the others, rapid normalization of the conduction block with reperfusion exceeded the logistics required for the transvenous pacemaker implantation procedure. Coronary angiography performed in six patients during 72 hours from admission revealed high grade stenoses in the proximal portion of the left anterior descending coronary artery in five patients and complete occlusion in one.(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-Branch Block↗
PubMed1992

Drug approvals.

Explore the source record for details and available documents.

Biotechnology↗
PubMed1992

A novel mechanism for Ca(2+)-dependent regulation of hepatic gluconeogenesis: stimulation of mitochondrial phosphoenolpyruvate synthesis by Ca2+.

1. Isolated guinea pig liver mitochondria were used to assess a possible effect of Ca2+ on the rate of phosphoenolpyruvate (PEP) synthesis. 2. PEP synthesis from 2-oxoglutarate (2-OG), but not from malate, was stimulated by [Ca2+] between 200 and 1200 nM. The effect was more pronounced at low [2-OG] (i.e. 0.1 and 0.3 mM) and it reached 58 and 22%, respectively, at 1200 nM as compared to 200 nM [Ca2+]. 3. Ruthenium red (1.8 microM) totally suppressed the stimulatory effect of Ca2+. 4. Malonate (5 mM) abolished PEP formation with 2-OG alone but inhibited only slightly the process with 2-OG + malate. 5. The results suggest that the stimulation by Ca2+ of 2-OG dehydrogenase and, therefore, of GTP synthesis, provides a mechanism for an enhanced PEP synthesis and for regulation of hepatic gluconeogenesis by Ca(2+)-mobilizing hormones.

Animals↗