Biomedical subjects

R Coppoolse

Publications and source records attributed to R Coppoolse.

4 recordsLinked to original sources

PubMed1999

[Hemodynamic indications for DDD mode pacing therapy].

BACKGROUND AND OBJECTIVE: Because there are limits to the drug treatment or surgical intervention of advanced heart failure, alternative methods are being explored. It was the aim of this study to investigate the extent to which optimal atrioventricular (AV) sequence of dual pacemaker stimulation in patients with advanced dilated cardiomyopathy (DCM) of different aetiology increases their usually much reduced cardiac output. PATIENTS AND METHODS: The study group consisted of 22 patients (five women, 17 men; aged 54-84 years) with heart failure in class I-IV (New York Heart Association classification). Temporary dual electrode stimulations (in the right atrium and ventricle) in the VDD or DDD mode were performed with programmed AV intervals between 80 and 180 ms. Cardiac output (CO), pulmonary capillary and pulmonary arterial pressures were measured via an indwelling catheter. RESULTS: In 17 patients with a 1 degree AV block and/or left bundle branch block in the surface ECG pacing produced a significant increase in CO (from 3.7 +/- 0.75 to 4.6 +/- 0.65 l/min; P < 0.005) and cardiac index (from 2.05 +/- 0.43 to 2.47 +/- 0.37 l/min/m2; P < 0.005). There was no increase in patients with normal PR interval and QRS duration. Mean pulmonary capillary and pulmonary arterial pressures remained unchanged. CONCLUSION: Alteration of AV sequence by pacemaker in selected patients in the late stage of heart failure, particularly if there is also abnormal atrioventricular and/or intraventricular conduction delay, may be an effective complementary method of treatment.

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PubMed1999

Interval versus continuous training in patients with severe COPD: a randomized clinical trial.

Limited information is available regarding the physiological responses to different types of exercise training in patients with severe chronic obstructive pulmonary disease (COPD). The aim of this study was two fold: firstly, to investigate the physiological response to training at 60% of achieved peak load in patients with severe COPD; and secondly to study the effects of interval (I) versus continuous (C) training in these patients. Twenty-one patients with COPD (mean+/-SD forced expiratory volume in one second: 37+/-15% of predicted, normoxaemic at rest) were evaluated at baseline and after 8 weeks' training. Patients were randomly allocated to either I or C training. The training was performed on a cycle ergometer, 5 days a week, 30 min daily. The total work load was the same for both training programmes. C training resulted in a significant increase in oxygen consumption (V'O2) (17%, p<0.05) and a decrease in minute ventilation (V'E)/V'O2 (p<0.01) and V'E/carbon dioxide production (V'CO2) (p<0.05) at peak exercise capacity, while no changes in these measures were observed after interval training. During submaximal exercise a significant decrease was observed in lactic acid production, being most pronounced in the C-trained group (-31%, p<0.01 versus -20%, p<0.05). Only in the I-trained group did a significant increase in peak work load (17%, p<0.05) and a decrease in leg pain (p<0.05) occur. Training did not result in a significant improvement in lung function, but maximal inspiratory mouth pressure increased in both groups by 10% (C: p<0.05) and 23% (I: p<0.01). The present study shows a different physiological response pattern to interval or continuous training in chronic obstruction pulmonary disease, which might be a reflection of specific training effects in either oxidative or glycolytic muscle metabolic pathways. Further work is required to determine the role of the different exercise programmes and the particular category of patients for whom this might be beneficial.

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PubMed1999

Routine minimal invasive vein harvesting reduces postoperative morbidity in cardiac bypass procedures. Clinical report of 1400 patients.

OBJECTIVE: Minimal invasive endoscopic vein harvesting has not gained widespread acceptance although potential improvements in wound healing and patient comfort are undebatable. The main objections to routine application have been impaired graft quality and prolonged operation time. The feasibility of introducing the minimal invasive approach to vein harvesting into a high volume cardiac bypass surgery program was to be investigated in 1400 patients. METHODS: Our preferred technique is based on standard videoscopic equipment for endoscopic surgery. No disposables are used. The subcutaneous tissue above the saphenous vein is tunnelled by exclusively sharp dissection. No shear stresses are applied to the vein graft or its side branches. Side branches are closed by clips or bipolar coagulation. The differences between endoscopic and conventional surgical vein harvesting with regard to operation time, graft quality, wound healing disturbances and postoperative pain were compared in two groups of 300 concurrently operated patients. Subsequently, a further 1100 patients underwent endoscopic vein harvesting, giving a total experience of 1400 endoscopic procedures. RESULTS: After a learning curve of approximately 100 procedures for an experienced surgeon, harvesting time using minimal invasive techniques was 16 +/- 4 min/graft vs. 10 +/- 2 min for the conventional technique (P < 0.01). Severe wound healing disturbances requiring re-intervention were observed in 0.1% following endoscopic harvesting, moderate wound healing disturbances were observed in 1.7% of patients. By comparison, conventional harvesting led to severe wound healing disturbances in 5% and to moderate disturbances in 8% (P < 0.05). Incidence of peri-operative myocardial infarction as an indirect measure of graft quality was 1.7% with endoscopic vs. 2.3% (n.s.) with conventional technique. Early postoperative mobilisation was faster, pain and need of analgesics were distinctly reduced in patients with endoscopic harvesting. Overall operation time was not significantly prolonged by the described technique. CONCLUSIONS: Minimal invasive endoscopic vein harvesting can be developed into a routine procedure resulting in a lower incidence of wound complications, less postoperative pain and much superior cosmetic results. Graft quality appears to be comparable to standard saphenectomy. There is, however, a higher demand of surgical training and expertise.

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PubMed1997

Effect of acute bicarbonate administration on exercise responses of COPD patients.

Patients with severe chronic obstructive pulmonary disease (COPD) are limited in their exercise tolerance by the level of ventilation (VE) they can sustain. We determined whether acutely increasing blood bicarbonate levels decreased acid stimulation to the respiratory chemoreceptors during exercise, thereby improving exercise tolerance. Responses were compared with those obtained during 100% O2 breathing (known to reduce VE in these patients) and to the responses of healthy young subjects. Participants were six patients with severe COPD (forced expired volume in 1 s = 31 +/- 11% predicted) but without chronic CO2 retention and 5 healthy young subjects. Each subject performed three incremental cycle ergometer exercise tests: 1) control, 2) after ingestion of 0.3 g.kg-1 of sodium bicarbonate and 3) while breathing 100% O2. During these tests VE was measured continuously and arterialized venous blood (patients) or arterial blood (healthy subjects) was sampled serially to assess acid base variables. Bicarbonate loading increased standard bicarbonate by 4-6 mmol.L-1 and this elevation persisted during exercise. In both groups, bicarbonate loading resulted in a substantially higher arterial pH; arterial PCO2 was either unchanged (healthy subjects) or mildly (averaging 5 torr) higher (COPD patients). However, in neither group did bicarbonate loading result in an altered VE response to exercise or an increase in exercise tolerance. In contrast, superimposing hyperoxia on bicarbonate ingestion yielded, on average, 24% reduction in VE and 50% increase in peak work rate in the patients (but not in the healthy young subjects). We conclude that acute bicarbonate loading is not an ergogenic aid in patients with severe COPD.

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