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Biomedical subjects

Mike J L DeJongste

Publications and source records attributed to Mike J L DeJongste.

8 recordsLinked to original sources
PubMed2006

Prescription of beta-blockers in patients with advanced heart failure and preserved left ventricular ejection fraction. Clinical implications and survival.

BACKGROUND: The effects of beta-blockers in patients with heart failure (HF) and preserved left ventricular ejection fraction (LVEF) are not well established. AIMS: To assess the association between beta-blocker prescription at discharge and mortality in a cohort of patients with advanced HF and preserved LVEF. METHODS AND RESULTS: We prospectively studied a cohort of 443 patients with advanced HF and preserved LVEF (LVEF> or =40%). Mean age was 78 years, 56% female, 33% NYHA class IV. Overall, 227 patients (51%) had a beta-blocker prescribed at discharge. Mean duration of follow-up was 25 (+/-18) months. Death (all cause) occurred in 40 patients (17.6%) who were receiving a beta-blocker at discharge and 73 patients (33.8%) who were not on a beta-blocker. In multivariate Cox analysis, including adjustment for propensity score, prescription of a beta-blocker remained associated with a 43% relative mortality risk reduction (HR 0.57, 95% CI 0.37 to 0.88, p=0.01). CONCLUSIONS: In this cohort of patients with advanced HF and preserved LVEF, prescription of a beta-blocker was associated with a significant mortality reduction. This beneficial effect of beta-blocker use needs to be further confirmed in prospective, randomised clinical trials.

Adrenergic beta-Antagonists↗
PubMed2006

Myocardial perfusion quantification in patients suspected of cardiac syndrome X with positive and negative exercise testing: a [13N]ammonia positron emission tomography study.

BACKGROUND: The combination of angina pectoris, angiographically normal coronary arteries, and a positive exercise stress test (EST) is referred to as cardiac syndrome X. However, a large group of patients suspected of syndrome X reveals a normal exercise stress test and weakens the diagnosis of syndrome X. Previous studies demonstrated an impaired coronary flow reserve on ammonia positron emission tomography (PET) in patients with syndrome X. AIM: To evaluate the coronary flow reserve in patients suspected of syndrome X with positive and negative EST findings, using [(13)N]ammonia PET as the diagnostic aid. METHODS: Forty-two patients with chest pain and a normal coronary angiography, were analysed by exercise stress testing (EST) and the dypyridamole stress test (DST) on [(13)N]ammonia PET. Two subgroups were predefined, based on outcome of EST: an EST positive and negative group. A normal control group was used as the reference method. RESULTS: A total of 24 (57%) out of 42 patients had significant ST-T changes (EST positive). [(13)N]ammonia PET showed a significantly lower rest flow in the EST positive and EST negative group compared to controls (P<0.001 and P=0.0028, respectively). DST [(13)N]ammonia PET perfusion was significantly reduced in flow in both the EST positive and EST negative groups (P<0.001 both), as was the DST/rest [(13)N]ammonia perfusion reserve (P<0.001 for both), compared to normal controls. CONCLUSION: PET demonstrates a reduced coronary flow reserve in patients suspected of syndrome X, irrespective of the EST findings.

Adult↗
PubMed2005

The relationship between self-efficacy and self-reported physical functioning in chronic obstructive pulmonary disease and chronic heart failure.

In this study, the authors investigated whether self-reported physical functioning of patients with chronic obstructive pulmonary disease (COPD) and chronic systolic heart failure (CHF) was primarily explained by illness-specific differences related to diagnosis or whether more generic factors also contributed to their physical functioning. Consecutive patients with COPD (n = 56; mean age = 67.8, SD = 8.5) and CHF (n = 65; mean age = 60.0, SD = 10.2)from the outpatient clinics of a university hospital and a general hospital completed a self-report questionnaire, including the Rand-36 Health Survey, Cantril's ladder, the Mastery scale, the Perceived Health Competence Scale, and the Self-efficacy scale. COPD patients scored significantly worse in self-reported physical and psychological functioning and perceived health competence than did patients with CHF Regression analysis revealed that both the diagnosis and the illness severity contributed to self-reported physical functioning, although self-efficacy explained the main part of physical functioning. Therefore, important aims in the treatment of patients with COPD and CHF should be not only improving physical functioning but also enhancing self-efficacy.

Adaptation, Psychological↗
PubMed2003

Cardiac nociception in rats: neuronal pathways and the influence of dermal neurostimulation on conveyance to the central nervous system.

Neurostimulation for refractory angina pectoris is often advocated for its clinical efficacy. However, the recruited pathways to induce electroanalgesia are partially unknown. Therefore, we sought to study the effect of neurostimulation on experimentally induced cardiac nociception, using capsaicin as nociception-induced substance. Four different groups of male Wistar rats were pericardially infused with either saline or capsaicin with or without neurostimulation. Group StimCap was infused with capsaicin, and group StimVeh was infused with saline. Both groups were treated with neurostimulation. Group ShamCap was only infused with capsaicin without stimulation, whereas group ShamVeh was only infused with saline. Neuronal activation differences were assessed with cytochemical staining, revealing the cellular expression of c-fos. Pain behavior was registered on video and was quantitatively analyzed. In the StimCap and ShamCap groups, all animals exerted typical pain behavior, whereas in the StimVeh group only moderate changes in behavior were observed. Group ShamVeh animals were unaffected by the procedure. The upper thoracic spinal cord showed high numbers of c-fos-positive cells, predominantly in laminae III and IV in both StimCap and StimVeh groups. Almost no c-fos expression was noticed in groups ShamCap and ShamVeh in these sections of the spinal cord. In groups StimCap and ShamCap a significantly higher number of c-fos-positive cells in comparison with groups StimVeh and ShamVeh were noticed in the periambigus region, the nucleus tractus solitarius, and the paraventricular hypothalamus. In the paraventricular thalamus, periaqueductal gray, and central amygdala, no significant differences were noticed among the first three groups, and the c-fos concentration in these three groups was significantly higher than in group ShamVeh. It is concluded that neurostimulation does not influence capsaicin-induced cardiac nociceptive pain pulses to the central nervous system. Furthermore, capsaicin-induced cardiac pain and neurostimulation may utilize two different pathways.

Afferent Pathways↗
PubMedDate not supplied

An integrated study of heart pain and behavior in freely moving rats (using fos as a marker for neuronal activation).

The awareness in specific brain centers of angina pectoris most often results from ischemic episodes in the heart. These ischemic episodes induce the release of a collage of chemicals that activate chemosensitive and mechanoreceptive receptors in the heart, which in turn excite receptors of the sympathetic afferent pathways. Ascending pain signals from these fibers result in the activation of the brain centers which are involved in the perception and integration of cardiac pain. Cytochemical studies of the nervous system provide the opportunity to identify these areas at the cellular level. In the present investigation, cardiac nociception was studied in the brains and the spinal cords of rats, using Fos protein as a marker of neuronal activation, following the application of pain-inducing chemicals to the heart. Induction of myocardial pain in conscious rats was achieved by infusion of bradykinin (0.5 microg) or capsaicin (5 microg) into the pericardial sac. During pain stimulation, the rats demonstrated pain behavior, in conjunction with alterations in heart rate and blood pressure. The cerebral Fos expression pattern was studied 2 h after pain stimulation. In contrast to the control group, increased Fos expression was found following the use of both capsaicin and bradykinin in a variety of areas of the brain. Bradykinin, but not capsaicin, induced Fos expression in the upper thoracic and upper cervical spinal cord; these segments are the sites where cardiac sympathetic fibers terminate. This finding suggests that these two chemicals use two different pathways, and provides extra evidence for the role of the vagus nerve in the transmission of cardiac nociception. Different cerebral areas showed an increase in the c-fos activity following pericardial application of pain-inducing chemicals. The role of these cerebral areas in the integration of cardiac pain is discussed in relation to the identified pathways which transmit cardiac pain.

Analysis of Variance↗