PubMed Health⌕ Search

Biomedical subjects

F Rademakers

Publications and source records attributed to F Rademakers.

9 recordsLinked to original sources
PubMed1998

Sudden death in hypertrophic cardiomyopathy: risk stratification and prevention.

Hypertrophic cardiomyopathy is an important cause of sudden death in young and asymptomatic patients. Young athletes and patients with unexplained sudden death, including their relatives, should be screened for its presence. Risk stratification identifies a high-risk group, in which preventive measures should be taken to reduce the risk for sudden death: moderate to heavy physical activity has to be avoided and arrhythmias with haemodynamic impact should be rigorously prevented.

Adolescent↗
PubMed1998

Cardiac graft vasculopathy: aetiologic factors and therapeutic approaches.

Heart transplantation has become an accepted and successful treatment for end-stage heart disease with survival rates of 80-90% after one year and 70% after 5 years. During the early posttransplant period (6-12 months), patients are subject to two major complications: rejection and infection. Fortunately, a certain degree of graft tolerance develops, allowing the immunosuppressive therapy to be progressively tapered off with a concomitant decrease in infectious problems. Long-term survival, however, is largely dependent on the development of an accelerated atherosclerosis in the graft, which is believed to represent some kind of chronic rejection. This transplant vasculopathy is documented by means of coronary angiography with an incidence of approximately 5 to 10% per year. It is not surprising therefore that major interest has risen concerning risk factors promoting this pathology.

Graft Occlusion, Vascular↗
PubMed1996

Left ventricular radial tagging acquisition using gradient-recalled-echo techniques: sequence optimization.

Myocardial tagging with magnetic resonance (MR) imaging offers unique possibilities for noninvasive left ventricular (LV) strain analysis. True three-dimensional strain analysis can be achieved with tags implemented in cardiac short axis and long axis images. Spin-echo (SE) techniques have been used for these studies. However, this approach is time-consuming: images at different phases of the cardiac cycle have to be obtained in successive measurements and hence the total number of measurements equals the number of time frames. Moreover, the images are often degraded by flow and motion artifacts. The purpose of this study was to optimize a faster and more robust MR tagging sequence for use on a clinical whole-body 1 T MR system with optimal persistence of the tags during the entire cardiac cycle. The tagging pulses were implemented in gradient-recalled-echo (GRE) sequences and compared to SE-based acquisitions. The effects of the use of flow-compensating gradients, the excitation angles, and the angles of the saturation pulses have been studied with MR signal simulations and in comparative measurements in volunteers. GRE acquisitions with flow-compensating gradients are robust techniques for myocardial tagging acquisitions. Use of optimized flip angles and saturation pulses can significantly improve delineation of the tag and can be used up to at least 700 ms after the R-wave. Therefore, LV tagging with GRE acquisitions using optimized MR parameters is a robust and promising technique.

Heart↗
PubMed1995

Transverse arch hypoplasia predisposes to aneurysm formation at the repair site after patch angioplasty for coarctation of the aorta.

OBJECTIVES: This study used magnetic resonance imaging (MRI) to evaluate the morphology and pathophysiology of aneurysm formation after patch angioplasty for coarctation of the aorta. BACKGROUND: Late aneurysm formation at the repair site is a well known and frequent complication after patch angioplasty. However, because the underlying mechanisms remain unresolved, postoperative outcome is unpredictable and adequate follow-up difficult. METHODS: Seventy-three of 85 patients with patch angioplasty for coarctation of the aorta were screened for aneurysm formation. Magnetic resonance imaging was performed in all 33 patients with an aneurysm, and results were compared with those for 13 control patients and 10 normal subjects. Mean (+/- SD) time between operation and MRI was 12.0 +/- 2.0 years. Aneurysm was defined as the ratio of the diameter of the aorta at the repair site to the diaphragmatic aorta > or = 1.5. Hypoplasia of the transverse arch and recoarctation at the repair site were defined as a ratio < 0.9. Transverse arch ratios on MRI were compared with those on preoperative cineangiography and the pressure gradient between the patient's right and left arm. RESULTS: All 33 patients with an aneurysm had a hypoplastic transverse arch. The 13 patients with a normal ratio at the repair site had a normal transverse arch ratio (chi square, p < 0.0001). Logarithmic regression showed a significant negative correlation (r = 0.62) between the repair site and transverse arch ratios. A significant pressure difference between the patient's right and left arm was found in patients with versus those without aneurysm (p = 0.0009). No significant difference was found between transverse arch ratios on preoperative cineangiography and postoperative MRI (mean 0.014 +/- 0.1, p = 0.4). CONCLUSIONS: Aneurysm formation at the repair site is highly related to hypoplasia of the transverse arch. Sufficient catch-up growth of a hypoplastic transverse arch is rare after late patch angioplasty. Dynamic phenomena, such as flow acceleration and turbulence, originating in a narrow transverse arch, may contribute to aneurysm formation at the repair site after patch angioplasty.

Adolescent↗
PubMed1993

Apical hypertrophic cardiomyopathy.

Illustrated by a case report, which was rather suggestive of coronary ischemic heart disease, the principle characteristics of apical hypertrophic cardiomyopathy are outlined. Outside East Asia, it remains a very uncommon variant of hypertrophic cardiomyopathy. The electrocardiogram in basal conditions showed giant negative T-waves (-14 mm) in the precordial leads, while the ventriculogram in RAO projection revealed the typical, so called "ace of spades" configuration. Based on the present literature and the follow-up of these patients a review of apical hypertrophic cardiomyopathy is presented. One of the most important consequences of the identification of this variant seems to be the rather good prognosis when compared to other forms of hypertrophic cardiomyopathy.

Biopsy↗
PubMed1991

The physiologic response of CPR training.

STUDY OBJECTIVE: To determine the physiologic response of CPR training. DESIGN: Cardiovascular and ventilatory parameters were investigated during 40 minutes of CPR performance and during a maximum exercise test in seven female and nine male subjects (mean age, 30 years; range, 16 to 49 years). RESULTS: During CPR performance, mean oxygen consumption (0.36 +/- 0.10 L/min), and mean minute volume (21.9 +/- 6.0 L/min) were 16% and 26%, respectively, of the levels reached during a maximum exercise test. Systolic blood pressure (153 +/- 23 mm Hg) and heart rate (132 +/- 25 beats/min) were 75% and 73%, respectively, of the levels reached during a maximum exercise test. Serum lactate levels at rest and after CPR performance were not significantly different (1.08 +/- 0.99 vs 1.54 +/- 1.03 mEq/L). Valsalva reflex remained present throughout total CPR time at varying degrees depending on individual differences in CPR technique (eg, incomplete extension of the manikin's head, holding the breath during chest compression). CONCLUSION: CPR performance seems to be a primarily aerobic effort that induces changes in cardiorespiratory parameters that were reasonably well tolerated by our study population.

Adolescent↗
PubMed1989

Blood viscosity parameters in coronary heart disease: effect of fish oil supplementation.

We have evaluated blood viscosity parameters in 20 men suffering from coronary heart disease (CHD) and in 15 control subjects. Whole blood viscosity at a standardized haematocrit of 45% was significantly increased in the CHD-patients, both at low (p less than 0.001) and high (p less than 0.05) shear rate. The increased whole blood viscosity in these patients was explained by an increased plasma viscosity (p less than 0.01), while the erythrocyte suspension viscosity values at a standardized haematocrit of 70%, reflecting erythrocyte deformability, were within the normal range. We have studied the effects of a daily supplementation of 1.5 g omega-3 polyunsaturated fatty acids on blood viscosity in the CHD patients. After 6 weeks of treatment whole blood viscosity, at low and high shear rate, and plasma viscosity were significantly improved (all p less than 0.05), although not normalized. There was no effect of the fish oil on erythrocyte deformability.

Aged↗
PubMedDate not supplied

Right atrial tumor arising on an atrial septal aneurysm. Assessment by MR imaging.

An elderly women presenting with transient ischemic events underwent transesophageal echocardiography, which detected an aneurysm of the interatrial septum. A tumor protruding from the right atrial aspect of the aneurysm also was found incidentally. Not only was magnetic resonance (MRI) imaging helpful in better characterizing the aneurysm, but also the use of gadolinium diethylaminetriamine pentaacetic acid permitted differentiation between the tumor and adherent thrombus. To the best of our knowledge, this represents the first report of a tumor arising from an atrial septal aneurysm.

Aged↗