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J J Bax

Publications and source records attributed to J J Bax.

At least 19 recordsLinked to original sources
PubMed2004

[Prophylactic perioperative beta-blockade reduces cardiac morbidity and mortality following non-cardiac surgery in patients at risk].

Approximately 5% of all patients undergoing non-cardiac surgery suffer some form of perioperative cardiac morbidity, usually preceded by myocardial ischaemia. In the Netherlands, the cardiac mortality following non-cardiac surgery is 0.68%. The patient groups at risk for cardiac complications are: age 65 years and older, patients with coronary artery disease or risk factors for coronary artery disease, and those undergoing major surgery. The period of greatest risk is the early postoperative phase. Prophylactic beta-blockade significantly reduces perioperative cardiac morbidity and mortality: the odds ratio for myocardial ischaemia is 0.34 (95% CI: 0.23-0.52), for non-fatal myocardial infarction 0.15 (95% CI: 0.06-0.40) and for cardiac mortality 0.25 (95% CI: 0.09-0.73). Long-term continuation of the beta-blockade also reduces cardiac morbidity and mortality in the first two years following the operation.

Adrenergic beta-Antagonists↗
PubMed2004

Cardiogenic shock shortly after initial success of cardiac resynchronization therapy.

Cardiac resynchronisation therapy (CRT) has been shown to improve symptoms, exercise capacity and left ventricular function, as well as a reduction in morbidity/mortality in heart failure patients. Failures following initial success of this treatment are mostly related to lead dislodgement. Another entirely different reason is presented in this case study.

Aged↗
PubMed2004

Long-term prognostic value of asymptomatic cardiac troponin T elevations in patients after major vascular surgery.

BACKGROUND: Cardiac troponin T (cTnT) is a sensitive and specific marker for myocardial injury, but elevations of cTnT without clinical evidence of ischemia and persistent or new electrocardiographic (ECG) abnormalities are common in patients undergoing major vascular surgery. We explored the long-term prognostic value of cTnT levels in these patients. METHODS: A follow-up study was conducted between 1996-2000 in 393 patients who underwent successful aortic or infrainguinal vascular surgery and routine sampling of cTnT. Patients were followed until May 2003 (median of 4 years [25th-75th percentile, 2.8-5.3 years]). Total creatine kinase (CK), CK-MB, and cTnT were routinely screened in all patients, and included sampling after surgery and the mornings of postoperative days 2, 3 and 7. Electrocardiograms were also routinely evaluated for sign of ischemia. An elevated cTnT was defined as serum concentrations >/=0.1 ng/ml in any of these samples. All-cause mortality was evaluated during long-term follow-up. RESULTS: Eighty patients (20%) had late death. The incidence of all-cause mortality (41% vs. 17%; p<0.001) was significantly higher in patients with an elevated cTnT level compared to patients with normal cTnT. After adjustment for baseline clinical characteristics, the association between an elevated cTnT level and increased incidence of all-cause mortality (adjusted hazard ratio, 1.9; 95% CI, 1.1-3.1) persisted. Elevated cTnT had significant prognostic value in patients with and without renal dysfunction, abnormal levels of CK-MB, and in patients with transient ECG abnormalities. CONCLUSIONS: Elevated cTnT levels are associated with an increased incidence of all-cause mortality in patients undergoing major vascular surgery.

Aged↗
PubMed2004

A combination of statins and beta-blockers is independently associated with a reduction in the incidence of perioperative mortality and nonfatal myocardial infarction in patients undergoing abdominal aortic aneurysm surgery.

OBJECTIVE: To investigate the combined beneficial effect of statin and beta-blocker use on perioperative mortality and myocardial infarction (MI) in patients undergoing abdominal aortic aneurysm surgery (AAA). BACKGROUND: Patients undergoing elective AAA-surgery identified by clinical risk factors and dobutamine stress echocardiography (DSE) as being at high-risk often have considerable cardiac complication rate despite the use of beta-blockers. METHODS: We studied 570 patients (mean age 69+/-9 years, 486 males) who underwent AAA-surgery between 1991 and 2001 at the Erasmus MC. Patients were evaluated for clinical risk factors (age>70 years, histories of MI, angina, diabetes mellitus, stroke, renal failure, heart failure and pulmonary disease), DSE, statin and beta-blocker use. The main outcome was a composite of perioperative mortality and MI within 30 days of surgery. RESULTS: Perioperative mortality or MI occurred in 51 (8.9%) patients. The incidence of the composite endpoint was significantly lower in statin users compared to nonusers (3.7% vs. 11.0%; crude odds ratio (OR): 0.31, 95% confidence interval (CI): 0.13-0.74; p=0.01). After correcting for other covariates, the association between statin use and reduced incidence of the composite endpoint remained unchanged (OR: 0.24, 95% CI: 0.10-0.70; p=0.01). Beta-blocker use was also associated with a significant reduction in the composite endpoint (OR: 0.24, 95% CI: 0.11-0.54). Patients using a combination of statins and beta-blockers appeared to be at lower risk for the composite endpoint across multiple cardiac risk strata; particularly patients with 3 or more risk factors experienced significantly lower perioperative events. CONCLUSIONS: A combination of statin and beta-blocker use in patients with AAA-surgery is associated with a reduced incidence of perioperative mortality and nonfatal MI particularly in patients at the highest risk.

Adrenergic beta-Antagonists↗
PubMed2004

Aortic valve regurgitation due to cusp aneurysm: a case report.

Two-dimensional echocardiography is a valuable tool in visualizing and monitoring aortic valve and root abnormalities. We present a rare case of a patient with massive aortic regurgitation due to cusp aneurysm, which was accurately diagnosed by echocardiography and treated by valve replacement. A complicated course with recurrent aneurysms of the aortic wall after aortic valve replacement was remarkable in this case. Although different possible etiologies could not be determined, endocarditis and/or aortitis may be the most likely explanation of the complicated and finally fatal course of this patient.

Aortic Aneurysm↗
PubMed2004

Radiofrequency catheter ablation of ventricular tachycardia guided by intracardiac echocardiography.

AIMS: Ventricular tachycardia (VT) frequently has an anatomical substrate. Identification of areas prone to arrhythmogenicity facilitates radiofrequency catheter ablation (RFCA). Furthermore, direct monitoring of complications potentially increases safety of RFCA. The aim of this study was to evaluate the feasibility of guiding RFCA of VT with intracardiac echocardiography (ICE), in order to improve outcome and procedural safety. METHODS AND RESULTS: Eleven patients (age 59 +/- 15 years) with drug-refractory VT of various etiologies were studied. VT mapping and ablation were performed using standard techniques. ICE was performed with a multifrequency (5-10 MHz) phased-array transducer positioned in the right ventricle. Twenty different VTs were treated (CL 352 +/- 120 ms, 2.0 +/- 0.9 VT per patient). LV a- or dyskinesia was identified in all post-infarct patients. In patients with arrhythmogenic right ventricular dysplasia, right ventricular aneurysms and dyskinesia could be identified. In all patients catheter position and tip-tissue contact could easily be monitored with ICE. Procedural success (non-inducibility of hemodynamically stable VT) was achieved in all patients. Complications did not occur. CONCLUSION: ICE is feasible in guiding RFCA of VT of different etiologies. The use of ICE in adjunction with fluoroscopy and mapping procedures will facilitate treatment of VT and may contribute to the safety of the procedure.

Adult↗
PubMed2004

Thrombus in the left atrial appendage detected by intracardiac echocardiography.

Radiofrequency catheter ablation (RFCA) at the ostium of the pulmonary veins can potentially cure atrial fibrillation. Left-sided ablation procedures may carry a risk of thrombo-embolic events. Emboli from intracardiac thrombus originate from the left atrial appendage (LAA) in a substantial number of patients. The presence of spontaneous echo contrast in the left atrium (LA) and LAA peak emptying flow < or = 20 cm/s are also significantly related to thrombo-embolic events. Evaluation of the anatomy of the LA and LAA prior to left-sided procedures is therefore mandatory. Intracardiac echocardiography (ICE) appears an ideal technique to obtain this information during the RFCA-procedure. In the current report, we report on the use of ICE detecting a thrombus in the LAA in a patient planned to undergo RFCA of pulmonary veins for atrial fibrillation.

Atrial Appendage↗
PubMed2004

Relation between left ventricular contractile reserve during low dose dobutamine echocardiography and plasma concentrations of natriuretic peptides.

BACKGROUND: In ischaemic cardiomyopathy, raised plasma concentrations of natriuretic peptides are associated with a poor long term prognosis, while the presence of contractile reserve is a favourable sign. OBJECTIVE: To assess the relation between plasma natriuretic peptides and contractile reserve. DESIGN: Prospective observational study. SETTING: Tertiary referral centre. PATIENTS: 66 consecutive patients undergoing low dose dobutamine stress echocardiography to evaluate contractile reserve in regions with contractile dysfunction at rest, divided into two groups: group 1, 31 patients with ischaemic cardiomyopathy (left ventricular ejection fraction < or = 40%) and heart failure symptoms; group 2, 35 patients with normal left ventricular function. MAIN OUTCOME MEASURES: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), measured using immunoradiometric assays. Contractile reserve was defined as an improvement in segmental wall motion score during infusion of low dose dobutamine. RESULTS: Plasma ANP and BNP concentrations were higher in group 1 than in group 2 (mean (SD): ANP, 17.8 (32.8) v 7.2 (9.7), p < 0.005; BNP, 24.4 (69.0) v 5.0 (14.3) pmol/l, respectively; p < 0.001). In group 1, the presence of contractile reserve was inversely related to ANP and BNP levels; however, patients with contractile reserve had lower ANP and BNP concentrations than patients without contractile reserve (ANP, 14.2 (9.1) v 24.2 (44.2), p < 0.05; BNP, 20.2 (25.5) v 37.5 (93.8) pmol/l, respectively; p < 0.05). CONCLUSIONS: Plasma natriuretic peptide concentrations are raised in patients with left ventricular dysfunction, but in the presence of preserved myocardial contractile reserve, relatively low levels of ANP and BNP are present.

Echocardiography, Stress↗
PubMed2004

Pulsed wave tissue Doppler imaging for the quantification of contractile reserve in stunned, hibernating, and scarred myocardium.

OBJECTIVES: To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium. DESIGN: Observational study. SETTING: Tertiary referral centre. PATIENTS: 70 patients with reduced left ventricular function caused by chronic coronary artery disease. METHODS: Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred. RESULTS: 253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001). CONCLUSIONS: Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damage.

Cicatrix↗
PubMed2004

Prognostic value of dobutamine stress echocardiography in patients with previous coronary revascularisation.

OBJECTIVE: To assess the prognostic value of dobutamine stress echocardiography (DSE) in patients with previous myocardial revascularisation. DESIGN: Prospective study. SETTING: Tertiary referral centre in Rotterdam, the Netherlands. PATIENTS: 332 consecutive patients with previous percutaneous or surgical coronary revascularisation underwent DSE. Follow up was successful for 331 (99.7%) patients. Thirty eight patients who underwent early revascularisation (<or= 3 months) after the test were excluded from analysis. MAIN OUTCOME MEASURES: Cox proportional hazards regression models were used to identify independent predictors of the composite of cardiac events (cardiac death, non-fatal myocardial infarction, and late revascularisation). RESULTS: During a mean (SD) of 24 (20) months, 37 (13%) patients died and 89 (30%) had at least one cardiac event (21 (7%) cardiac deaths, 11 (4%) non-fatal myocardial infarctions, and 68 (23%) late revascularisations). In multivariate analysis of clinical data, independent predictors of late cardiac events were hypertension (hazard ratio (HR) 1.7, 95% confidence interval (CI) 1.1 to 2.6) and congestive heart failure (HR 2.1, 95% CI 1.3 to 3.2). Reversible wall motion abnormalities (ischaemia) on DSE were incrementally predictive of cardiac events (HR 2.1, 95% CI 1.3 to 3.2). CONCLUSIONS: Myocardial ischaemia during DSE is independently predictive of cardiac events among patients with previous myocardial revascularisation, after controlling for clinical data.

Echocardiography, Stress↗
PubMed2003

Eligibility for biventricular pacing in patients with an implantable cardioverter defibrillator.

Implantable cardioverter defibrillator (ICD)-therapy prevents sudden death in patients at high risk, but incidence of death due to heart failure remains unaltered. Recent data suggest that biventricular (BV) pacing is useful in patients with heart failure. It is unclear, how many patients with an ICD indication may have an indication for BV pacing. Therefore all patients who received an ICD were analyzed for eligibility of BV pacing using the following criteria: NYHA class III or IV, QRS duration >120 ms, depressed LVEF. Three hundred and ninety consecutive patients received an ICD from June 1996 to March 2001. Underlying disease was ischemic heart disease in 66%. In the 390 patients the mean LVEF was 36+/-17%, 20% were in NYHA class III-IV and 16% were in NYHA class II with an LVEF <30%. Of these 140 patients, 79 had a QRS duration >120 ms. Thus, 79 (20%) patients were eligible for BV pacing in addition to ICD-therapy. Patients who received a BV pacemaker in addition to ICD-therapy had a superior survival, improved in NYHA class and showed a significantly lower hospitalization rate as compared to patients who received an ICD only. Screening for eligibility of BV pacing may be considered in patients with CHF scheduled for ICD implantation.

Aged↗
PubMed2003

Repetitive dobutamine stress echocardiography for the prediction of anthracycline cardiotoxicity.

AIMS: To evaluate whether repetitive assessment of systolic and diastolic cardiac function by dobutamine stress echocardiography (DSE) can predict anthracycline cardiotoxicity. METHODS AND RESULTS: Thirty-one patients (age, 57+/-13 years, 22 male) were studied before chemotherapy, with follow-ups during, at the end, and 6 months after chemotherapy. Left ventricular (LV) function was assessed by two-dimensional (2D) echocardiographic wall motion score index (WMSI) and by Doppler echocardiography of mitral valve inflow at rest and during DSE. Radionuclide ventriculography was used as an independent reference for ejection fraction (EF). A reduction of EF >/=5% occurred in 17 patients (group A) at the last follow-up. Patients without decreased EF comprised group B. Early/late diastolic velocity of mitral inflow (E/A ratio) at rest was lower in group A (0.91+/-0.2 vs 1.28+/-0.3, P<0.001), and it was an independent predictor of cardiotoxicity (adjusted for baseline patient characteristics and parameters of systolic and diastolic function). At follow-up, WMSI at rest paralleled radionuclide EF. Contractile reserve at low-dose DSE was preserved in group A. CONCLUSIONS: WMSI measured by 2D echocardiography parallels radionuclide EF at follow-up. Assessment of contractile reserve has no incremental value for the early detection of cardiotoxicity. A baseline abnormal E/A ratio is an independent predictor of anthracycline cardiotoxicity.

Anthracyclines↗
PubMed2003

Cardiac complications after elective major vascular surgery.

Cardiac complications are the major cause of perioperative and late mortality and morbidity in patients undergoing elective major vascular surgery. This review focuses on the pathophysiology of perioperative complications, risk assessment and risk reduction strategies, all related to cardiovascular disease. Patients without cardiac risk factors are considered to be at low risk and no additional evaluation for coronary artery disease is recommended; beta-adrenergic blockers may reduce perioperative cardiac events; patients with one or more risk factors represent an intermediate to high-risk population. beta-Adrenergic blockers should be prescribed to all patients and coronary revascularization should be reserved for patients who have a clearly defined need for revascularization independent of the need for vascular surgery.

Anesthesia↗