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P J De Feyter

Publications and source records attributed to P J De Feyter.

At least 19 recordsLinked to original sources
PubMed2005

Non-invasive coronary angiography with 64-slice computed tomography.

Multislice computed tomography is a rapidly emerging technique for the non-invasive visualization of coronary arteries. Over the past 5 years several scanner generation were introduced with a progressive improvement in the diagnostic accuracy in the detection of coronary artery stenosis in selected patients populations. The introduction of 64-slice technology has further improved the diagnostic performance. This technique is at the edge of clinical implementation and, even though large clinical trials are still missing, an increased demand for these type of studies is observed all over the world. We describe our experience of more than 1 year with 64-slice CT coronary angiography providing clues on reasonable clinical applications.

Coronary Angiography↗
PubMed2000

[Intravascular ultrasound in cardiology].

Intravascular ultrasound (IVUS) is a clinically useful tool that provides cross-sectional images of the coronary arterial lumen and wall. Diagnostic applications of IVUS include the evaluation of ambiguous lesions on angiography particularly at the bifurcations. IVUS is also useful in the assessment of coronary vasculopathy in cardiac transplant patients or it can help to diagnose abnormalities such as syndrome X or coronary artery spasm. IVUS can optimize the performing of percutaneous coronary interventions, especially stent implantation. It represents as well an optimal tool for assessing regression of atherosclerosis. Three-dimensional reconstruction, elastography and imaging guide wires are some of the recent advances in the field of intravascular ultrasound.

Angioplasty, Balloon, Coronary↗
PubMed1995

New invasive techniques of assessment of the physiological significance of coronary stenoses in humans.

Pressure and flow velocity can be measured distal to coronary stenoses by means of miniaturized sensors with guidewire technology. This is an alternative non-invasive method of assessing functional coronary vessel stenosis severity, applicable for the intermediate stenoses and for the results of coronary interventions. The complexity of the coronary circulation, however, limits the possibility of establishing simple cut-off criteria to identify flow-limiting stenoses. In this paper, we review advantages and limitations of the different pressure and velocity indices and their application in different clinical settings.

Blood Flow Velocity↗
PubMed1995

Immediate outcome following coronary angioplasty. A contemporary single centre audit.

UNLABELLED: To study the in-hospital outcome of all coronary angioplasty procedures performed in a single centre over a 1 year period, with regard to angiographic success and the clinical complications of death, myocardial infarction, emergency coronary bypass surgery and abrupt coronary occlusion necessitating reintervention. METHODS: One thousand one hundred and thirty-three lesions were treated in 970 procedures in 799 patients between October 1993 and October 1994. Clinical, procedural, angiographic and outcome data were entered into a dedicated computer data-base and variables tested with respect to outcome using the chi-square test and univariate and multivariate analysis techniques. RESULTS: Angioplasty was performed for stable angina in 473 (49%) patients, unstable angina in 410 (42%) and 80 procedures were emergency--primary myocardial infarction in 44 (4.5%), shock in two, abrupt closure in 34 (3.5%) and other indications in seven patients. There were 10 (1.0%) deaths and 71 (7.3%) patient were documented to have suffered a myocardial infarction as a result of angioplasty. Nineteen (2.0%) patients underwent emergency coronary artery bypass surgery. Age >60 and a type C lesion were found to be associated with angiographic failure. The chance of a complication was increased if the patient was aged >60 years, suffered unstable angina, had an ejection fraction <50%, was treated with a new device or suffered a significant dissection. CONCLUSION: Despite refinement in techniques and increased experience, coronary angioplasty retains a significant associated chance of angiographic failure. The complication rate remains significant and there has been little reduction in mortality, infarction and abrupt closure rates over the last 15 years. The requirement for emergency coronary artery bypass surgery appears to be diminishing with the introduction of improved bail-out techniques, in particular intracoronary stenting.

Angioplasty, Balloon, Coronary↗
PubMed1994

Intracoronary stents: a review of the experience with five different devices in clinical use.

Atherosclerotic cardiovascular disease remains one of the most important causes of morbidity and mortality in the industrialized world. Treatment is basically aimed at palliation and consists of either pharmacological intervention or revascularization. The first significant advances in the latter were largely surgical. However, the pressing need for treatment with less invasive and potentially less expensive techniques, have stimulated the development of nonsurgical revascularization techniques. Percutaneous transluminal coronary balloon angioplasty, which was first performed by Andreas Gruentzig in 1977, is one of the most successful examples and provided the stimulus for a rapid technological growth of interventional cardiology. It is now widely accepted as a safe and effective treatment of obstructive coronary artery disease. However, the risk of abrupt vessel closure during or immediately after the intervention and the risk of late luminal renarrowing or restenosis continue to compromise its overall safety and efficacy. To improve the immediate and long-term results of balloon angioplasty, a number of new technologies such as intracoronary stenting, directional or rotational atherectomy, and laser therapy have been developed and represent the leading edge in the battle against atherosclerosis. The purpose of this paper is to review the experience and results of the various types of stents in clinical use.

Coronary Artery Disease↗
PubMed1990

Recovery of regional myocardial dysfunction after successful coronary angioplasty early after a non-Q wave myocardial infarction.

More aggressive therapy has been suggested for patients who have a non-Q wave myocardial infarction (MI) because of the frequency of subsequent unstable angina, recurrent MI, and high mortality rate compared to patients with Q wave MI. The present study was undertaken to investigate the effect of coronary angioplasty on regional myocardial function of the infarct zone in patients with angina early after a non-Q wave MI. The study population consisted of 36 patients undergoing successful coronary angioplasty within 30 days of a non-Q wave MI, in whom sequential left ventricular angiograms of adequate quality were obtained before the initial procedure and at follow-up angiography. The global ejection fraction increased significantly from 60 +/- 9% to 67 +/- 6% (p = 0.0003). This significant increase in the global ejection fraction was primarily due to a significant improvement in the regional myocardial function of the infarct zone. The results of the present study show not only that ischemic attacks early after a non-Q wave MI may lead to prolonged regional myocardial dysfunction but more important that this depressed myocardium has the potential to achieve normal contraction after successful coronary angioplasty.

Angiography↗
PubMed1990

Successful multiple segment coronary angioplasty: effect of completeness of revascularization in single-vessel multilesions and multivessels.

A long-term follow-up study was performed to evaluate the long-term value of performing multiple dilatations according to their procedural (single-vessel multilesion or mutltivessel dilatations) and anatomic types (single-vessel disease with multiple dilatations or multivessel disease dilatations with complete and incomplete revascularization). From 1980 until 1988, 248 patients met the following criteria: (1) at least two lesions dilated (range: 2 to 4) and (2) all attempted lesions successfully dilated. The mean length of follow-up was 33 months. The end points analyzed were death, myocardial infarction, redilatation, and bypass surgery. No differences were found for these events between the single-vessel multilesion group (144 patients) and the multivessel group (104 patients). The 4.5-year probability of event-free survival was 68% and 70%, respectively, for the multilesion group and the multivessel group. In the event-free patients, 57% versus 59% were asymptomatic and 45% versus 46% were not taking antianginal drugs. In the anatomic subgroups, there were less event-free patients in the cohort of incompletely revascularized multivessel disease patients (55% of 55 patients) when compared with the cohort of those who were completely revascularized (84% of 79 patients) or when compared with the single-vessel disease multiple dilatation patients (74% of 107 patients). The 4.5-year event-free survival probability for each group was 44%, 78%, and 74%, respectively. This difference was caused by more infarctions (9% versus 2% versus 4%, respectively) and bypass operations in the multivessel disease, incomplete revascularization group (20% versus 5% versus 10%, respectively). In event-free patients, improvement of angina was similar and was documented in over 85% of patients in each group. Furthermore, the number of asymptomatic patients at follow-up was similar in all groups except that within the incomplete revascularization group, less patients were free of antianginal drugs (21% versus 51% versus 48%). Finally, 48% of the entire cohort performed an exercise test 4.6 months (mean) after dilatation and no difference was found in any of the variables in any group. About 10% of the patients experienced angina and approximately 30% had a positive exercise test for ischemia by ST segment criteria. The functional performance in every group was over 90% of the predicted work load. These results suggest that completeness of revascularization in multivessel disease patients is an important prognostic variable. However, the symptomatic improvement after dilatation is very rewarding in all subsets of patients and argues in favor of the continued use of multiple dilatations as a treatment strategy.

Aged↗
PubMed1989

Short-, medium-, and long-term follow-up after percutaneous transluminal coronary angioplasty for stable and unstable angina pectoris.

The first 840 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) performed in the same institution were retrospectively assessed at an average follow-up period of 25 months after the initial procedure. The study population consisted of 506 patients with stable angina pectoris (group 1) and 334 patients with unstable angina pectoris (group 2). Clinical end points were death, nonfatal myocardial infarction, recurrent angina pectoris necessitating bypass surgery or repeat PTCA, and event-free survival. The two groups were comparable with respect to age, sex, previous myocardial infarction, ejection fraction, and number of diseased vessels. PTCA was successful in 83.0% of group 1 and 87.1% of group 2. Follow-up rates were expressed as events per attempted PTCA in a patient group. No difference in survival was observed between the two groups, the mortality rate being approximately 2.8% at 25 months. In the group with stable angina pectoris there was a lower incidence of nonfatal myocardial infarction within the first 24 hours after angioplasty; 4.3% vs 9.0% (p less than 0.01). During long-term follow-up the increase in the incidence of nonfatal myocardial infarction was similar, resulting in an overall long-term follow-up infarction rate of 8.3% and 14.2%, respectively (p less than 0.01). A higher event-free survival was observed in group 1 within 24 hours after PTCA: 93.7% vs 84.2% (p less than 0.01). During subsequent follow-up the difference in event-free survival between the two groups was no longer significant: 68.5% vs 61.2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Coronary blood flow velocity during percutaneous transluminal coronary angioplasty as a guide for assessment of the functional result.

To investigate the clinical usefulness of intracoronary Doppler recordings during percutaneous transluminal coronary angioplasty (PTCA), the changes of intracoronary blood flow velocity during PTCA were assessed in 20 patients with single proximal coronary stenosis, using a Doppler probe end-mounted on the tip of a PTCA catheter. A mean of 4 inflations was performed in each patient. Intracoronary velocities were measured before and after each inflation and during peak reactive hyperemia after each transluminal occlusion. Quantitative analysis of the coronary stenosis was assessed before and after PTCA, and the dilatation resulted in an increase in minimal luminal cross-sectional area from 1.1 +/- 0.8 to 2.7 +/- 1.2 mm2. A gradual and significant improvement in velocities was observed after the first 3 dilatations, but in 15 of the 20 patients the resting and hyperemic velocities were not affected by the fourth dilatation. Coronary flow reserve measured during reactive hyperemia after the last dilatation with the PTCA catheter across the lesion was 1.9. This value of coronary flow reserve is compatible with the residual stenosis measured after PTCA when corrected for the presence of the Doppler balloon catheter (0.68 mm2). This application of the Doppler technique may provide a new method of on-line functional monitoring of the PTCA procedure in individual patients, but does not yet allow an accurate prediction of the change in coronary geometry brought about by PTCA.

Adult↗
PubMed1988

Coronary vasodilatory action after a single dose of nicorandil.

Coronary hemodynamics and vasodilatory effects on major epicardial arteries were investigated after a single dose of nicorandil in 22 patients undergoing cardiac catheterization for suspected coronary artery disease. Nicorandil, 20 mg, was administered sublingually to 11 consecutive patients and 40 mg to 11 others. Systemic blood pressure decreased significantly without affecting the heart rate. Coronary sinus blood flow did not change significantly. As the mean aortic pressure decreased significantly by 13% after 20 mg and 21% after 40 mg of nicorandil, the calculated coronary vascular resistance decreased but did not reach statistical significance. There was a decrease in myocardial oxygen consumption (-14% and -22%, respectively), and this was consistent with a significant decrease in the calculated pressure-rate product of 19% and 24%, respectively. A total of 103 selected coronary segments, including 17 stenotic segments, were analyzed quantitatively using a computer-assisted coronary angiography analysis system. After 20 or 40 mg of nicorandil, a significant increase of the mean diameter was observed in the proximal (+9% and +7%), midportion (+10% and +11%) and distal (+15% and +13%) parts of the left anterior descending coronary artery. Corresponding values for the proximal (+13% and +10%) and distal (+10% and +15%) segments of the circumflex artery were observed. An increase in the obstruction diameter was also observed in all but 3 of the analyzed stenotic segments. The results demonstrate that nicorandil, in the route and doses used, causes a significant vasodilation in the major epicardial coronary segments, including most stenotic segments, and decreases the myocardial oxygen demand with little effect on the resistance vessels.

Adult↗
PubMed1986

Coronary and systemic hemodynamic effects of intravenous nisoldipine.

Systemic and coronary hemodynamic effects of the new dihydropyridine calcium antagonist nisoldipine were studied over a 30-minute period in 12 patients with angina pectoris. Previously instituted beta-blocker therapy was continued. Nisoldipine was administered in an intravenous bolus of 6 micrograms/kg over 3 minutes. Heart rate increased as mean aortic pressure and systemic vascular resistance decreased in all patients. Cardiac output increased significantly, from 5.8 +/- 0.3 to 7.9 +/- 0.5 liters/min, 10 minutes after nisoldipine infusion. These trends were maintained over the 30-minute observation period. Coronary sinus blood flow increased from 103 +/- 11 to 139 +/- 13 ml/min immediately after nisoldipine, but had returned to the control level by 30 minutes, as had the reduction in coronary vascular resistance. Myocardial oxygen consumption and heart rate-systolic blood pressure product did not change significantly. Nisoldipine is a potent peripheral and coronary vasodilator free of major myocardial depressant effects after acute intravenous administration. The systemic vasodilatory effects appear to outlast the coronary effects over 30 minutes.

Adrenergic beta-Antagonists↗
PubMed1986

Maintenance of increased coronary blood flow in excess of demand by nisoldipine administered as an intravenous infusion.

Systemic and hemodynamic effects of nisoldipine, administered as a 4.5-micrograms/kg intravenous bolus over 3 minutes followed immediately by an infusion of 0.2 microgram/kg/min over 30 minutes, were studied in 13 patients undergoing diagnostic catheterization for suspected coronary artery disease or follow-up catheterization after coronary angioplasty. Responses to the drug tended to be exaggerated in the first 8 minutes of the infusion, but thereafter produced a steady state, with heart rate increased by 14 +/- 3% at 16 minutes and by 15 +/- 3% at 24 minutes (p less than 0.05), mean aortic pressure decreased 12 +/- 2% and 13 +/- 3% at the same times (p less than 0.05) and coronary venous blood flow increased by 31 +/- 5% and 34 +/- 6% (p less than 0.05). Myocardial oxygen consumption and the heart rate-systolic aortic pressure product were unchanged and cardiac output and stroke volume were significantly increased. Study during matched coronary sinus pacing produced similar trends. Nisoldipine is a potent coronary and peripheral vasodilator that maintains an increase in myocardial oxygen supply in excess of demand when given as an intravenous infusion.

Coronary Circulation↗