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Biomedical subjects

C Ilsley

Publications and source records attributed to C Ilsley.

At least 19 recordsLinked to original sources
PubMed1994

A randomized pilot trial of low-dose combination lipid-lowering therapy following coronary artery bypass grafting.

Vein graft atherosclerosis is a common and serious complication of coronary artery bypass grafting (CABG). There is mounting evidence that lipoprotein abnormalities play an equally important role in the development of lesions in saphenous vein grafts after CABG as in native coronary vessel disease. The potential benefit of low-dose lipid lowering combination therapy in these patients has not been investigated. In a randomized, double-blind, placebo-controlled study, we compared the efficacy and safety of a low-dose combination of colestipol 10 g and simvastatin 10 mg/day (CS) to colestipol 10 mg and bezafibrate 400 mg/day (CB) for 2 months in 33 patients with serum total cholesterol > 6.5 mmol/l and triglyceride < 4.5 mmol/l who had undergone CABG for severe coronary artery disease. In the CS group, total cholesterol decreased by 29% and low-density lipoprotein (LDL) cholesterol by 42%; similarly, CB reduced total cholesterol by 17%, LDL cholesterol by 23%, triglyceride by 19%, and increased high-density lipoprotein (HDL) cholesterol by 14%. Lipoprotein (a) and hemostatic factors were unaffected by either therapy in this study. Both combination therapies were well tolerated with no significant clinical or biochemical side effects. We conclude that low-dose combinations of colestipol and simvastatin or colestipol and bezafibrate are effective and well tolerated in the management of moderate hyperlipidemia in patients who had undergone CABG.

Analysis of Variance↗
PubMed1994

Postoperative hemodynamic improvement with paced linkage of the donor and recipient hearts following heterotopic cardiac transplantation.

It has been shown that following heterotopic heart transplantation the recipient left ventricle ejects more effectively when it contracts out of phase with the donor left ventricle. However, this is rarely the situation, as the two hearts beat independently of one another and the denervated donor heart tends to beat faster than the recipient. In this study the hemodynamic effects of connecting the two hearts by an external temporary dual-chamber pacemaker were evaluated. The donor right ventricle was sensed and the recipient right atrium paced after a timed delay. The delay was adjusted so that recipient systole coincided with donor diastole. Eleven patients were studied in the first postoperative day. Pacing resulted in an improvement in cardiac output from 5.0 to 5.6 l/min (p = 0.003) and a reduction in pulmonary capillary wedge pressure from 16 to 12 mmHg (p = 0.0035). This was associated with a 35% reduction in inotrope requirements. It is concluded that sequential pacing of the two hearts is a useful adjunct to inotropic support in the postoperative period.

Cardiac Output↗
PubMed1994

A rate responsive pacemaker that physiologically reduces pacing rates at rest.

Current rate responsive pacemakers incorporate sensors such as minute ventilation (MV) for adapting to changing patient conditions during exercise and periods of exertion. However, for sleep and/or rest periods, the only pacemakers currently on the market that slow the pacing rate utilize an internal timer to determine a decrease in pacing rate. It would be advantageous if the pacing rate could be automatically lowered during periods of sleep or rest. This study utilized a rate responsive sensor, MV, to track the patient's sleeping and resting periods and to decrease the pacing rate at such times. A total of eight patients implanted with Sentri 1210 single chamber MV sensor pacemakers were studied. A sleep rate (SR) of 45 beats/min was selected. A sleep rate response function, which indicated the relationship between changes in MV and corresponding heart rate, was initially set at a value of 16 and continually and automatically updated in a 3-month study. Adaptation was based on the premise that 3 hours per day should be spent at the SR. The average decrease in pacing rates from onset to 3 month for the eight patients was 12.4% +/- 5.3%. Correspondingly, the histograms of the lowest datalog histogram (40-59 beats/min) increased from 0% to 15.4% +/- 0.9% of paced beats. Correlation between the patients' 24-hour diary and Holter recordings showed that the pacing rates during sleep were consistently lower than when the patients were awake and active. This was also the case with a patient whose nocturnal and daily routine was intentionally altered.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Septal short atrioventricular delay pacing: additional hemodynamic improvements in heart failure.

Controversy exists as to whether short AV delay pacing is beneficial in left ventricular dysfunction with the studies performed coming to disparate conclusions. The right ventricular apical pacing previously studied results in asynchronous contraction and relaxation sequences and may limit the potential benefits of short AV delay pacing. In this study the hemodynamic effects of septal (resulting in a more physiological activation sequence) and apical right ventricular activation were compared in 15 patients with heart failure. VDD pacing with AV delays of 50, 100, and 150 msec was evaluated. Apical VDD pacing did not increase the cardiac output significantly, 4.1 +/- 0.75 to 4.45 +/- 0.74 L/min, whereas septal VDD pacing increased the cardiac output to 4.86 +/- 0.79 L/min (P = 0.037). Apical pacing increased the cardiac output in 10 patients and septal pacing in 11 patients. We conclude that selected patients with ventricular dysfunction benefit from short AV delay pacing. Septal ventricular activation confers significant hemodynamic improvements over apical activation.

Atrioventricular Node↗
PubMed1994

Coronary artery surgery in women compared with men: analysis of coronary risk factors and in-hospital mortality in a single centre.

OBJECTIVE: To determine differences in coronary risk factors between women and men and their relation to in-hospital mortality associated with coronary artery bypass grafting. DESIGN: Prospective observational study. SETTING: A regional cardiothoracic centre. PATIENTS: 482 (362 (75%) men and 120 (25%) women) consecutive patients who had primary isolated coronary artery bypass grafting. RESULTS: The women were on average three years older than the men (63 v 60 years, P < 0.001). Women more frequently had hypertension (47% v 33%, P < 0.01), diabetes mellitus (21% v 10%, P < 0.005), hypothyroidism (9% v 2%, P < 0.003), and a family history of premature coronary heart disease (49% v 31%, P < 0.0006). More of the men were cigarette smokers (67% v 45%, P > 0.00001). Many of the women and men had dyslipidaemia. Postmenopausal women had a higher concentration of serum total cholesterol than men of a comparable age, (7.3 mmol/l v 6.5 mmol/l, P = 0.0002). Although arterial grafts were often used in both sexes, they were more often used in men than in women (91% v 78% respectively, P = 0.0003). In-hospital mortality was 2.1% (1.4% in men and 4.2% in women, P = 0.14). The estimated one year probability of survival in men who had survived 30 days was 0.99 with 95% confidence interval 0.98 to approximately 1 while that for women was 0.97 with 95% confidence interval 0.91 to approximately 1. Univariate analysis showed that preoperative history of diabetes mellitus was a predictor of mortality (P = 0.03). CONCLUSION: There were differences in the incidence and type of risk factors in men and women who had coronary artery bypass grafting. Preoperative diabetes mellitus was a predictor of in-hospital mortality.

Age Distribution↗
PubMed1994

Hemodynamic and metabolic effects of paced linkage following heterotopic cardiac transplantation.

BACKGROUND AND PURPOSE: Heterotopic cardiac transplantation is a valuable surgical technique that maximizes the use of donor organs. However, recipient heart function may decline steadily postoperatively with resulting clinical deterioration. Paced linkage has the potential of reducing afterload and enhancing coronary flow of both hearts, thereby improving recipient- and donor-heart function. This may have long-term as well as short-term benefits. METHODS AND RESULTS: The study was performed on 11 heterotopic transplant recipients. The two hearts were linked with a pacemaker (paced linkage) to produce recipient heart systole during different periods of donor-heart diastole. The recipient ventricular contraction was timed to occur during early, mid, and late diastole of the donor heart. Hemodynamic baseline measurements were compared with the optimal counterpulsated data. Paced linkage produced significant improvements in total cardiac output, 5.0 +/- 0.9 compared with baseline 4.5 +/- 0.8 L/min (P = .021); recipient coronary sinus flow, 278 +/- 145 versus 186 +/- 108 mL/min (P = .022); and aortic systolic pressure, 135 +/- 27 versus 123 +/- 27 mm Hg (P = .005). There was an overall improvement in systolic ventricular performance in the recipient heart when pace linked, as evidenced by a significant increase in left ventricular systolic pressure of 118 +/- 36 compared with the baseline value of 108 +/- 33 mm Hg (P = .016), an increase in ejection period from 174 +/- 30 versus 203 +/- 48 (P = .046), and a decrease in the pre-ejection period of 147 +/- 37 when paced versus 181 +/- 39 milliseconds (P = .013). The metabolic studies showed a significant decrease in hypoxanthine release from a baseline level of 0.4 mumol/L to a paced value of -0.06 mumol/L (P = .002); these very low values would suggest that there is no evidence of ischemia. Hemodynamic changes in the donor heart included a significant reduction in the left ventricular end-diastolic pressure from 6.8 +/- 4.4 versus baseline of 10.5 +/- 5.8 mm Hg (P = .029) and in maximum -dP/dT from 3.2 +/- 1.7 versus baseline of 2.1 +/- 1.1. CONCLUSIONS: Paced linkage after heterotopic cardiac transplant produces significant functional improvements in both hearts. Permanent pacemaker implantation may sustain these acute benefits and prevent the premature deterioration of the recipient heart.

Adult↗
PubMed1993

Coronary angioplasty in cardiac transplant recipients.

Accelerated coronary artery disease following cardiac transplantation remains an important obstacle to long-term survival and the correct management strategy remains unclear. This observational, prospective study was designed to examine the feasibility of using percutaneous transluminal coronary angioplasty (PTCA) in the treatment of post-transplant coronary disease. Thirteen consecutive patients were selected from the total population of 276 transplant recipients who underwent routine coronary angiography between 1987 and 1990. Selection of patients was on angiographic criteria alone and PTCA was performed to all accessible stenoses with more than 80% luminal narrowing. PTCA was performed using standard angioplasty equipment and procedure as considered appropriate for the individual lesion. A successful PTCA was defined as more than 30% reduction in luminal narrowing and a residual narrowing of less than 50%. Restenosis was defined as a loss of 50% or more of the gain achieved at the time of successful PTCA or more than a 30% increase in narrowing at the site of stenosis. A total of 31 lesions were dilated in this group and a successful result was achieved in 29 of these (93%) and in 12 of the 13 patients. The one patient with failed PTCA underwent later successful coronary artery bypass grafting to complete revascularization. Four of the 13 patients have had two angioplasty procedures, two for restenosis and two for disease progression in other sites. One patient died 15 months after the initial PTCA and the remaining 12 were asymptomatic with good exercise tolerance and ventricular function at a mean of 19 months (range 1-39 months) following first PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1992

Limited value of the resting electrocardiogram in assessing patients with recent onset chest pain: lessons from a chest pain clinic.

OBJECTIVE: To evaluate a clinic set up specifically to assess patients with recent onset chest pain, particularly those presenting with a normal resting electrocardiogram. DESIGN: Retrospective review of case notes. SETTING: Cardiac department of a tertiary referral cardiothoracic centre. PATIENTS: 250 consecutive patients with recent onset chest pain seen within 24 hours of general practitioner referral. OUTCOME MEASURES: Clinical diagnosis and management. RESULTS: 40% of patients were seen within seven days of the onset of symptoms. Twenty seven per cent had non-cardiac symptoms and could be discharged while 60% were considered to have cardiac pain. Sixty six patients (26%) were admitted directly from the clinic and 48 of these underwent coronary angiography within three weeks. Seventy patients (28%) have so far undergone intervention (angioplasty or coronary artery surgery), 22 within one month of presentation. One hundred and nine patients (44%) presented with a normal resting electrocardiogram, 21 of whom were considered to have unstable angina. Forty one of these patients were investigated of whom 37 were found to have significant coronary disease and 26 have undergone intervention. CONCLUSIONS: This experience highlights the inadequacy of a routine electrocardiogram reporting service in patients with recent onset of chest pain. An alternative facility offering immediate and complete cardiac assessment produced patient benefit with early diagnosis and intervention. Investigation of these patients, however, accounted for 5% of cardiac catheterisation laboratory throughput; this was a significant additional and unscheduled workload.

Adult↗
PubMed1988

Acute thrombotic obstruction of a mitral valve prosthesis: the role of thrombolytic therapy.

An acute thrombotic occlusion of a mitral prosthesis in a hemodynamically compromised patient was successfully lysed with intravenous streptokinase. Unfortunately, the patient had a major cerebral embolus, from which she died several days later. A review of the current literature reveals that thrombolytic therapy successfully relieves the obstructing thrombus in 73% of cases, while it is partially successful in another 16% allowing deferral of surgical repair to a more optimal time. Mortality from thrombolytic therapy is 14% while hemorrhage or cerebral emboli occur in a further 11%. Reports of surgical intervention have shown an operative mortality rate of 25%, in those fit to undergo surgery. If hemodynamically unstable patients unfit for surgery are included on an intention to treat basis, overall mortality is 42%. Thus, thrombolytic therapy should be considered primarily in those compromised patients who have a thrombotic occlusion of a valvular prosthesis with a greater risk of operative mortality. Low dose, prolonged infusions should be favoured over rapid, high concentration infusions currently employed for coronary thrombolysis, as the latter regime could have contributed to the fatal cerebral embolus in our patient.

Aged↗
PubMed1985

Percutaneous transluminal coronary angioplasty: the early Dunedin experience.

Since May 1981 39 men and 11 women (mean age 55 years) have undergone percutaneous transluminal coronary angioplasty at Dunedin Hospital. Angioplasty was performed in 34 (68%) patients with stable angina, 13 (26%) with unstable angina and in three (6%) patients with acute myocardial infarction. Primary success (reduction in angiographic stenosis without associated myocardial infarction or emergency coronary bypass) was achieved in 77% of those patients with single vessel coronary disease (27 of 35 procedures) and of 62% in those patients with multiple vessel disease (16 of 26 procedures). Successful angioplasty was obtained in 81% (25/31) of those patients with anterior descending disease, 67% (4/6) of those with circumflex disease and 58% 14/24) of patients with right coronary disease. Thirty-four patients (68%) following successful angioplasty were rendered asymptomatic. Five (10%) underwent emergency coronary bypass grafting and one of these patients died. Percutaneous transluminal coronary angioplasty is a useful alternative to coronary artery bypass surgery and may be performed in a majority of patients with symptomatic single vessel coronary artery disease and in selected individuals with multiple vessel coronary disease.

Aged↗
PubMed1982

Influence of R wave analysis upon diagnostic accuracy of exercise testing in women.

Exercise electrocardiography in women with chest pain is associated with a high incidence of false positive ST segment depression. The recent observation that changes in R wave amplitude during exercise can also be used diagnostically may improve the value of stress testing in women. The results of 12 lead treadmill exercise and coronary angiography were reviewed in 62 women, mean age 51 years, presenting with "angina" without previous myocardial infarction. These were compared with exercise results in 14 healthy asymptomatic volunteers with a mean age of 26 years. In addition to conventional ST analysis, R wave amplitude changes during exercise, measured in leads II, III, a VF, and V4 to 6, were examined. While the sensitivity and specificity of ST and R wave changes were similar at about 67%, their combined interpretation was helpful. If both ST and R wave criteria were negative the predictive accuracy for normal coronary angiography was 94% (17/18). Alternatively, in tests showing both ST depression and an abnormal R wave response, coronary angiography was always abnormal (13/13). None of the normal volunteers developed ST segment depression and 93% (13/14) had a normal R wave response. If both were positive, however, coronary angiography was always abnormal (13/13). Although stress test interpretation in women is difficult, R wave analysis is a useful adjunct to ST change and can improve the predictive accuracy of the test in a significant number of patients.

Adult↗
PubMed1982

Normal coronary arteriogram. An avoidable test?

Between 10 and 20% of coronary arteriograms in patients with chest pain show normal vessels, often in association with a history of "atypical" angina. Conventional non-invasive tests are inaccurate in this group of patients compared with those with classical angina. This study prospectively evaluates combined 12 lead exercise electrocardiography and thallium-201 scintigraphy as a screening test in patients with atypical angina in order to determine whether normal arteriograms are avoidable in this important subgroup of patients presenting with chest pain. Sixty seven consecutive patients with atypical angina underwent both maximal exercise testing and thallium scintigraphy before coronary arteriography. Chest pain during exercise was a poor predictor of coronary disease in this group. Eleven (16%) had abnormal arteriography, with the sensitivity of exercise and thallium tests being 45% and 73%, respectively. When both tests were applied the predictive accuracy for normal coronary arteries was 96% (54/56) and that for the presence of coronary disease was 82% (9/11). If coronary arteriography was withheld in patients in whom both the exercise test and thallium scintigraphy were negative, the number of normal coronary arteriograms could be reduced with only a very small risk of failing to detect individuals with coronary disease.

Adult↗
PubMed1981

R-wave amplitude and left ventricular volume: changes with nitroglycerine and atrial pacing.

The relationship between R-wave amplitude and left ventricular volume was examined using two groups of patients, undergoing diagnostic cardiac catheterisation for investigation of chest pain, who had simultaneous R-wave recording and left ventricular angiography. R-wave amplitude was measured in leads 1, 2, 3 and V4-6. Left ventricular volume was altered by nitroglycerine (n = 18) and atrial pacing (n = 13). In both groups, increase or decrease in left ventricular volume was associated with a concomitant change of R-wave amplitude. We conclude that left ventricular volume is an important determinant of surface-recorded R waves with increased amplitude reflecting increased left ventricular volume and vice versa.

Angiography↗
PubMed1980

R wave amplitude during exercise. Relation to left ventricular function and coronary artery disease.

Change in R wave amplitude (mean delta R) was measured sequentially during and after 12 lead maximal treadmill exercise tests in 14 subjects with normal coronary arteries and 62 patients with coronary artery disease. In normal subjects mean delta R decreased maximally one minute after exercise and returned to control levels within three minutes. In contrast, mean delta R increased in patients with coronary artery disease, the greatest change occurring in patients with either triple vessel or left main disease or those with an akinetic region on the left ventriculogram. R wave amplitude returned to resting levels in five minutes. Increase in R wave amplitude was not directly related to changes in the ST segment. Changes in R wave amplitude during maximal treadmill exercise may improve the discrimination between patients with and without coronary artery disease and may help to identify those patients with abnormal left ventricular function.

Adult↗
PubMed1979

Interference with polyhedral inclusion body (PIB) production in Trichoplusia ni cells infected with a high passage strain of Autographa californica nuclear polyhedrosis virus (NPV). Brief report.

Trichoplusia ni cells infected with a low passage (LP) strain of Autographa californica nuclear polyhedrosis virus (NPV) produce large numbers of polyhedral inclusion bodies (PIBs). Interference with PIB production occurs when T. ni cells are first inoculated with a high passage (HP) strain and then challenged with the LP strain. PIB production is reduced 100 fold to the level seen with HP virus infection only.

Cell Line↗