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J J Bax

Publications and source records attributed to J J Bax.

At least 37 records · Page 2Linked to original sources
PubMed2006

Diagnostic and prognostic value of non-invasive imaging in known or suspected coronary artery disease.

The role of non-invasive imaging techniques in the evaluation of patients with suspected or known coronary artery disease (CAD) has increased exponentially over the past decade. The traditionally available imaging modalities, including nuclear imaging, stress echocardiography and magnetic resonance imaging (MRI), have relied on detection of CAD by visualisation of its functional consequences (i.e. ischaemia). However, extensive research is being invested in the development of non-invasive anatomical imaging using computed tomography or MRI to allow detection of (significant) atherosclerosis, eventually at a preclinical stage. In addition to establishing the presence of or excluding CAD, identification of patients at high risk for cardiac events is of paramount importance to determine post-test management, and the majority of non-invasive imaging tests can also be used for this purpose. The aim of this review is to provide an overview of the available non-invasive imaging modalities and their merits for the diagnostic and prognostic work-up in patients with suspected or known CAD.

Coronary Artery Disease↗
PubMed2006

Quality of life in longterm exogenous subclinical hyperthyroidism and the effects of restoration of euthyroidism, a randomized controlled trial.

OBJECTIVE: The impact of prolonged subclinical hyperthyroidism on quality of life is unclear. Therefore, we evaluated quality of life in patients with differentiated thyroid carcinoma (DTC) on TSH-suppressive thyroxine therapy as a model for subclinical hyperthyroidism and we investigated whether restoration to euthyroidism affects quality of life. DESIGN: We performed a prospective, single-blinded, placebo-controlled, randomized trial of 6 months' duration with two parallel groups. PATIENTS AND METHODS: Twenty-four subjects with a history of differentiated thyroid carcinoma with > 10 years TSH-suppressive therapy with L-thyroxine completed the study. L-thyroxine dose was replaced by study medication containing L-thyroxine or L-thyroxine plus placebo. Medication was titrated to establish continuation of TSH suppression (low-TSH group) and euthyroidism (euthyroid group). Both groups consisted of 12 patients. We evaluated quality of life using five validated questionnaires. RESULTS: At baseline, the somatic disorder questionnaire (SDQ) indicated more somatic dysfunction in patients as compared with reference values, whereas the depression score (HADS) revealed a better score than the reference group. All other quality of life parameters were normal. At baseline, no significant differences between the low-TSH and the euthyroidism groups were observed. After 6 months, none of the quality of life parameters in the low-TSH group was different from baseline values. In the euthyroid group, motivation was significantly improved (Multidimensional Fatigue Index-20, P = 0.003), although this parameter did not differ from the reference group at baseline. A probable worsening in role limitations as a result of physical problems (Short Form-36; P = 0.050) was observed. No improvement in the SDQ score was observed. CONCLUSION: In summary, quality of life in patients with DTC and long-term subclinical hyperthyroidism in general is preserved. Restoration of euthyroidism in general does not affect quality of life.

Fatigue↗
PubMed2005

Diagnostic and clinical perspectives of fusion imaging in cardiology: is the total greater than the sum of its parts?

Positron emission tomography, cardiovascular magnetic resonance and multislice computed tomography have contributed to changing our pathophysiological understanding of many conditions. Clinically, they have provided new tools for the identification of preclinical disease and a better understanding of how disease progresses. The application of these imaging modalities to preclinical disease and the use of these techniques in patients with overt cardiovascular disease are reviewed.

Cardiovascular Diseases↗
PubMed2005

Beta-blockers improve in-hospital and long-term survival in patients with severe left ventricular dysfunction undergoing major vascular surgery.

OBJECTIVES: To study whether beta-blockers reduce in-hospital and long-term mortality in patients with severe left ventricular dysfunction (LVD) undergoing major vascular surgery. DESIGN: Observational cohort study. MATERIALS: Five hundred and eleven patients with severe LVD (ejection fraction<30%) undergoing major non-cardiac vascular surgery. METHODS: In all patients, cardiac risk factors, medication (including beta-blockers), and dobutamine stress echocardiography (DSE) results were noted prior to surgery. DSE was evaluated for rest and stress-induced new wall motion abnormalities. Endpoint was in-hospital and long-term mortality. Propensity scores for beta-blockers were calculated and regression models were used to analyse the relation between beta-blockers and mortality. RESULTS: Mean age was 64+/-11 years and 383 patients (75%) were male. 139 patients (27%) used beta-blockers. Stress-induced ischemia occurred in 82 patients (16%). Median follow-up was 7 years (interquartile range: 3-10). In-hospital and long-term mortality was observed in 64 (13%) and 171 (33%) patients, respectively. After adjusting for clinical variables, DSE results and propensity scores, beta-blockers were significantly associated with reduced in-hospital and long-term mortality (OR: 0.18, 95% CI: 0.04-0.74 and HR: 0.38, 95% CI: 0.22-0.65, respectively). CONCLUSION: In patients with severe LVD undergoing major vascular surgery, the use of beta-blockers is associated with a reduced incidence of in-hospital and long-term postoperative mortality.

Adrenergic beta-Antagonists↗
PubMed2005

Cardiac resynchronisation therapy in chronic atrial fibrillation: impact on left atrial size and reversal to sinus rhythm.

OBJECTIVE: To evaluate the impact of long term cardiac resynchronisation therapy (CRT) on left atrial and left ventricular (LV) reverse remodelling and reversal to sinus rhythm (SR) in patients with heart failure with atrial fibrillation (AF). PATIENTS: 74 consecutive patients (age 68 (8) years; 67 men) with advanced heart failure and AF (20 persistent and 54 permanent) were implanted with a CRT device. MAIN OUTCOME MEASURES: Patients were evaluated clinically (New York Heart Association (NYHA) class, quality of life, six minute walk test) and echocardiographically (LV ejection fraction, LV diameters, and left atrial diameters) before and after six months of CRT. Additionally, restoration of SR was evaluated after six months of CRT. RESULTS: NYHA class, quality of life score, six minute walk test, and LV ejection fraction had improved significantly after six months of CRT. In addition, left atrial and LV end diastolic and end systolic diameters had decreased from 59 (9) to 55 (9) mm, from 72 (10) to 67 (10) mm, and from 61 (11) to 56 (11) mm, respectively (all p < 0.01). During implantation 18 of 20 (90%) patients with persistent AF were cardioverted to SR. At follow up 13 of 18 (72%) patients had returned to AF and none had spontaneously reverted to SR; thus, only 5 of 74 (7%) were in SR. CONCLUSION: Six months of CRT resulted in significant clinical benefit with significant left atrial and LV reverse remodelling. Despite these beneficial effects, 93% of patients had not reverted to SR.

Aged↗
PubMed2005

Reversible diastolic dysfunction after long-term exogenous subclinical hyperthyroidism: a randomized, placebo-controlled study.

BACKGROUND: Subclinical hyperthyroidism has been reported to affect systolic and diastolic cardiac function. However, the reversibility of these effects is not well established. OBJECTIVE: Our objective was to investigate the presence and reversibility of cardiac abnormalities in patients with long-term exogenous subclinical hyperthyroidism. DESIGN: We conducted a prospective, single-blinded, placebo-controlled randomized trial of 6 months duration with two parallel groups. SETTING: The study occurred at the Leiden University Medical Center, a tertiary referral center for thyroid carcinoma. PATIENTS: As a model for subclinical hyperthyroidism, 25 patients with a history of differentiated thyroid carcinoma with more than 10 yr of TSH suppressive therapy with L-T4 were studied. INTERVENTIONS: L-T4 dose was replaced by study medication containing L-T4 or placebo. Medication was titrated in a single-blinded fashion to establish continuation of TSH suppression (low-TSH group) or euthyroidism (euthyroid group). MEASUREMENTS: We assessed serum levels of free T4 and TSH and used echo Doppler cardiography including tissue Doppler to establish left ventricular (LV) dimensions and function as well as diastolic function. Baseline echocardiography data were compared with 24 controls. RESULTS: There were no differences in baseline cardiac parameters and TSH levels between the two groups. Although mean LV mass index was increased as compared with 24 controls, only four patients had LV hypertrophy at baseline. This was not improved by restoration of euthyroidism. At baseline, diastolic function was impaired in all patients as indicated by abnormal values for the peak flow of the early filling phase (E, 55.3 +/- 9.5 mm/sec), the ratio of E and the peak flow of the atrial filling phase (E/A ratio, 0.87 +/- 0.13), the early diastolic velocity obtained by tissue Doppler (E', 5.7 +/- 1.3 cm/sec), and the peak atrial filling velocity obtained by tissue Doppler (A', 6.8 +/- 1.4 cm/sec), prolonged E deceleration time (234 +/- 34 msec), and isovolumetric relaxation time (121 +/- 15 msec). After 6 months, significant improvements were observed in the euthyroid group in the E/A ratio (+41%; P < 0.001), E deceleration time (-18%; P = 0.006), isovolumetric relaxation time (-25%; P < 0.001), E' (+31%; P < 0.001), and the E'/A' ratio (+40%; P < 0.001). CONCLUSIONS: We conclude that prolonged subclinical hyperthyroidism is accompanied by diastolic dysfunction that is at least partly reversible after restoration of euthyroidism. Because isolated diastolic dysfunction may be associated with increased mortality, this finding is of clinical significance.

Adult↗
PubMed2005

[Severe insuffiency of the aortic and tricuspidal valves associated with pergolide use].

A 58-year-old woman with Parkinson's disease was treated with high-dose pergolide for 10 years. After the addition of citalopram, a selective serotonin reuptake inhibitor, to treat an anxiety disorder, she developed cardiac decompensation that was most likely related to typical pergolide-related fibroproliferative abnormalities of the tricuspidal, aortic and mitral valves, without cardiomyopathy or coronary heart disease. The aortic and tricuspidal valves were replaced with prosthetics and pergolide was switched to ropinirol. At a control visit after one year, patient's heart function was stable. Pergolide is an ergot-derived dopamine agonist used in the treatment of Parkinson's disease and restless-legs syndrome. In 2002, it was first associated with heart-valve defects. Patients treated with pergolide should be monitored for clinical signs of heart-valve failure. If there is no evidence of heart-valve defects, then regular monitoring of cardiac function is indicated. In case of indications of heart-valve failure pergolide should be discontinued. In some cases the heart-valve abnormalitites are reversible.

Antiparkinson Agents↗
PubMed2005

Long term prognostic value of myocardial viability and ischaemia during dobutamine stress echocardiography in patients with ischaemic cardiomyopathy undergoing coronary revascularisation.

OBJECTIVE: To evaluate the relative merits of viability and ischaemia for prognosis after revascularisation. METHODS: Low-high dose dobutamine stress echocardiography (DSE) was performed before revascularisation in 128 consecutive patients with ischaemic cardiomyopathy (mean (SD) left ventricular ejection fraction (LVEF) 31 (8)%). Viability (defined as contractile reserve (CR)) and ischaemia were assessed during low and high dose dobutamine infusion, respectively. Cardiac death was evaluated during a five year follow up. Clinical, angiographic, and echocardiographic data were analysed to identify predictors of events. RESULTS: Univariable predictors of cardiac death were the presence of multivessel disease (hazard ratio (HR) 0.21, p < 0.001), baseline LVEF (HR 0.90, p < 0.0001), wall motion score index (WMSI) at rest (HR 4.02, p = 0.0006), low dose DSE (HR 7.01, p < 0.0001), peak dose DSE (HR 4.62, p < 0.0001), the extent of scar (HR 1.39, p < 0.0001), and the presence of CR in > or = 25% of dysfunctional segments (HR 0.34, p = 0.02). The best multivariable model to predict cardiac death included the presence of multivessel disease, WMSI at low dose DSE, and the presence of CR in > or = 25% of the severely dysfunctional segments (HR 9.62, p < 0.0001). Inclusion of ischaemia in the model did not provide additional predictive value. CONCLUSION: The findings of the present study illustrate that in patients with ischaemic cardiomyopathy, the extent of viability (CR) is a strong predictor of long term prognosis after revascularisation. Ischaemia did not add significantly in predicting outcome.

Echocardiography, Stress↗
PubMed2005

Contrast echocardiography as a useful additional diagnostic tool in evaluating a primary cardiac tumor.

The current report describes a case of a primary cardiac lymphoma. For early and appropriate treatment of a cardiac mass it is not only important to determine its localization and extension but also to differentiate between malignant and benign lesions. This report demonstrates that not only transthoracic echocardiography but also the other different forms of echocardiography such as transesophageal echocardiography, as well as contrast and intracardiac echocardiography, are useful tools in the diagnostic workup of cardiac masses.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Intracardiac pseudotumor caused by mitral annular calcification.

The current report describes a rare case of a pseudotumor in the left ventricle. Transthoracic and transesophageal echocardiography demonstrated a round, echodense, mobile mass attached to the posterior mitral leaflet and annulus. At surgical exploration caseous annular calcification of the posterior mitral leaflet was diagnosed. After resection of the mass, successful mitral valvular plasty was performed. Review of the literature indicated that mitral annular calcification is associated with an increased risk of stroke. Optimal treatment may be surgery, especially when valve plasty can be performed, although randomized trials are currently lacking.

Calcinosis↗
PubMed2005

Homozygous and heterozygous expression of a novel insulin-like growth factor-I mutation.

IGF-I is a key factor in intrauterine development and postnatal growth and metabolism. The secretion of IGF-I in utero is not dependent on GH, whereas in childhood and adult life, IGF-I secretion seems to be mainly controlled by GH, as revealed from studies on patients with GHRH receptor and GH receptor mutations. In a 55-yr-old male, the first child of consanguineous parents, presenting with severe intrauterine and postnatal growth retardation, microcephaly, and sensorineural deafness, we found a homozygous G to A nucleotide substitution in the IGF-I gene changing valine 44 into methione. The inactivating nature of the mutation was proven by functional analysis demonstrating a 90-fold reduced affinity of recombinantly produced for the IGF-I receptor. Additional investigations revealed osteoporosis, a partial gonadal dysfunction, and a relatively well-preserved cardiac function. Nine of the 24 relatives studied carried the mutation. They had a significantly lower birth weight, final height, and head circumference than noncarriers. In conclusion, the phenotype of our patient consists of severe intrauterine growth retardation, deafness, and mental retardation, reflecting the GH-independent secretion of IGF-I in utero. The postnatal growth pattern, similar to growth of untreated GH-deficient or GH-insensitive children, is in agreement with the hypothesis that IGF-I secretion in childhood is mainly GH dependent. Remarkably, IGF-I deficiency is relatively well tolerated during the subsequent four decades of adulthood. IGF-I haploinsufficiency results in subtle inhibition of intrauterine and postnatal growth.

Heterozygote↗
PubMed2005

Ischemic heart disease in renal transplant candidates: towards non-invasive approaches for preoperative risk stratification.

This editorial refers to the paper of R. Sharma et al. entitled "Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates". The editorial discusses different strategies for cardiac risk assessment in patients with end-stage renal disease undergoing renal transplantation.

Biomarkers↗
PubMed2005

Improvement of stress LVEF rather than rest LVEF after coronary revascularisation in patients with ischaemic cardiomyopathy and viable myocardium.

OBJECTIVE: To evaluate prospectively the response of left ventricular ejection fraction (LVEF) to high dose dobutamine infusion in patients showing substantial viability, with and without improved resting LVEF after revascularisation. METHODS: Before and 9-12 months after revascularisation, 50 patients with ischaemic cardiomyopathy (LVEF 32 (8)%) and substantial myocardial viability (> or = 4 viable segments) underwent radionuclide ventriculography and dobutamine stress echocardiography. Patients were divided into group 1, patients with, and group 2, patients without significant improvement in resting LVEF (> or = 5% by radionuclide ventriculography) after revascularisation. The response of LVEF during dobutamine stress echocardiography was compared in these two groups. RESULTS: Groups 1 and 2 were comparable in baseline characteristics, resting LVEF, and number of viable segments (mean (SD) 7 (4) v 6 (2), not significant). After revascularisation, the LVEF response during dobutamine stress echocardiography improved significantly in both groups (group 1, 34 (10)% to 56 (8)%; group 2, 32 (10)% to 46 (11)%; both p < 0.001). Interestingly, although resting LVEF did not improve in group 2, peak stress LVEF after revascularisation did (p < 0.001). Group 1 patients had, however, a greater increase in peak stress LVEF (group 1, 22 (10)%; group 2, 13 (9)%; p < 0.01). New York Heart Association and Canadian Cardiovascular Society classes decreased in both groups. CONCLUSIONS: Although patients with viable myocardium did not always have improved rest LVEF after revascularisation, peak stress LVEF improved. Assessment of improvement of resting function may not be the ideal end point to evaluate successful revascularisation.

Blood Pressure↗