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Jens Jensen

Publications and source records attributed to Jens Jensen.

12 recordsLinked to original sources
PubMed2006

Ischemia induces aggravation of baseline repolarization abnormalities in left ventricular hypertrophy: a deleterious interaction.

Epidemiological studies show that left ventricular hypertrophy (LVH) and hypertension (HT) in coronary artery disease increases the risk for cardiovascular events including sudden cardiac death (SCD). According to experimental studies, myocardial hypertrophy is associated both with altered electrophysiological properties (including prolonged repolarization) and increased vulnerability to ischemia. However, human data to support a repolarization-related mechanism for the increased SCD risk has not been provided. We therefore studied 187 patients undergoing three-dimensional vectorcardiographic monitoring during coronary angioplasty. Eight parameters reflecting different aspects of ventricular repolarization were used: 1) the ST segment (ST-VM and STC-VM), 2) the T vector (QRS-T angle, Televation, and Tazimuth), and 3) the T vector loop (Tavplan, Teigenv, and Tarea). Data collection was performed at rest and at the time of maximum ischemia during coronary occlusion. The patients were divided into three groups: 33 patients with ECG signs of LVH (18 with HT), 54 with HT but without LVH signs, and 100 patients with neither. Coronary artery disease patients with LVH not only had the most abnormal baseline repolarization (as expected) but also a significantly more pronounced repolarization response during coronary occlusion, whereas HT patients had mean parameter values between LVH patients and those without neither HT nor LVH signs. Because there is a relation between increased SCD risk and repolarization disturbances in various clinical settings, the results of the present study are in agreement with animal data and epidemiological observations, although other factors than disturbed repolarization might be of importance.

Aged↗
PubMed2006

Usefulness of preprocedural serum N-terminal pro-brain natriuretic peptide levels to predict long-term outcome after percutaneous coronary intervention in patients with normal troponin T levels.

Our objective was to evaluate the prognostic information of preprocedural serum N-terminus pro-brain natriuretic peptide (NT-pro-BNP) levels to predict the long-term outcome after percutaneous coronary intervention (PCI). A total of 891 consecutive patients with stable or unstable angina pectoris with normal serum troponin T levels (< or =0.03 microg/L) undergoing PCI were investigated. For each patient with a cardiovascular event (death or nonfatal myocardial infarction), 2 event-free patients were used as controls. The procedure was successful in all patients, and follow-up was complete. By the end of the follow-up period (mean 2.6 years), 75 patients had had a cardiovascular event (41 deaths and 34 nonfatal myocardial infarctions). On multivariate analysis, lesion severity, diabetes mellitus, and NT-pro-BNP levels in the highest quartile (>490 mg/L) were identified as independent factors for death or nonfatal myocardial infarction after PCI. In conclusion, preprocedural NT-pro-BNP levels are associated with long-term outcome after PCI. The use of NT-pro-BNP can be of value in risk stratification in patients undergoing PCI.

Aged↗
PubMed2006

Follow-up of patients operated on with arterial patch angioplasty of the left main coronary artery.

BACKGROUND: Surgical angioplasty of the left main coronary artery (LMCA) can be performed with good results in selected patients. It restores the native antegrade blood flow in the LMCA and does not leave the patient with a graft-dependent retrograde perfusion. By using a proximal segment of the right internal mammary artery as patch material, we assumed that this would minimize the risk of restenosis of the LMCA. We here review our experience and results. METHODS: Forty-three patients were operated on with LMCA angioplasty from 1997 to 2003. Follow-up at a mean of 45 months (range, 7 to 79) included a stress test, echocardiography, and angiography with intravascular ultrasound (IVUS) of the LMCA. RESULTS: There were three late deaths, none related to failure of the angioplasty. All patients included in the follow-up had preserved preoperative left ventricular function, and there was no aortic incompetence. The angioplasties investigated were patent, and no signs of restenosis or dilatation could be observed. The dimensions of the LMCA after angioplasty was in diameter 4.8 mm (3.35 to 6.75 mm) and 5.6 mm (4 to 7.6 mm), and in area 18.9 mm2 (12.3 to 31.9 mm2) and 24.8 mm2 (14.5 to 37 mm2) in the distal and proximal parts, respectively. CONCLUSIONS: Surgical angioplasty of the left main coronary artery using a proximal segment of the right internal mammary artery as an onlay patch is safe, with good long-term results.

Adult↗
PubMed2005

Response of serum C-reactive protein to percutaneous coronary intervention has prognostic value.

BACKGROUND: Data are sparse regarding the association between C-reactive protein (CRP) and percutaneous coronary intervention (PCI) in long-term prognosis. Previous studies have shown that PCI evokes an inflammatory response. We tested the hypothesis that the CRP response to PCI has a prognostic value. METHODS: We investigated 891 consecutive patients presenting with stable or unstable angina pectoris, with serum concentrations of cardiac troponin T < or =0.03 microg/L, who were undergoing a variety of PCIs. Serum concentrations of CRP and cardiac troponin T were determined before and the day after PCI. The mean follow-up time after PCI was 2.6 years, and the endpoint was death or nonfatal myocardial infarction. RESULTS: Seventy-six patients reached the endpoint (4.6% death, 3.9% nonfatal myocardial infarction), whereas 21% developed myocardial infarction during the procedure. CRP increased more than 2-fold after the procedure. Patients in the third tertile of the CRP response to PCI had an increased risk for death or nonfatal myocardial infarction in multivariate analysis. CONCLUSIONS: Increased serum CRP in response to PCI is an independent predictor of death or nonfatal myocardial infarction independent of myocardial injury during the procedure. CRP determinations might be of value in risk stratification after PCI.

Angina Pectoris↗
PubMed2005

Stent implantation, but not pathogen burden, is associated with plasma C-reactive protein and interleukin-6 levels after percutaneous coronary intervention in patients with stable angina pectoris.

BACKGROUND: The systemic inflammatory response to percutaneous coronary intervention (PCI) is associated with recurrent cardiac events; however, the pathophysiology of this inflammatory response is not well understood. The present study was performed to investigate the role of pathogen burden of infection in determining the magnitude of C-reactive protein (CRP) and interleukin 6 (IL-6) response to PCI. METHODS: One hundred patients with stable angina pectoris undergoing elective PCI at a single center were recruited. Antibodies against cytomegalovirus, Chlamydia pneumoniae , Epstein-Barr virus, Helicobacter pylori , and herpes simplex virus types 1 and 2 were determined before PCI. Plasma CRP and IL-6 levels were measured before and 6, 24, 48, 72 hours after PCI and data presented as area under the curve. RESULTS: Plasma CRP and IL-6 concentrations increased significantly after PCI. Neither antibodies against single nor multiple pathogens were associated with the CRP or IL-6 response to PCI. No correlations were found between the inflammatory markers and troponin T levels after PCI. With the exception for CRP and body mass index (R = 0.20, P < .05), neither risk factors for coronary heart disease nor medication but stent implantation was associated with increased plasma CRP (76 vs 61 mg/L, P < .005) and IL-6 (74 vs 64 pg/mL, P < .005) levels after PCI. CONCLUSION: Stent implantation, but not pathogen burden, is associated with the plasma CRP and IL-6 response to PCI.

Aged↗
PubMed2005

Development and validation of the Dartmouth Operative Conditions Scale.

Studies of pediatric sedation practice have suffered from the lack of an objective scale that would allow for a comparison of the effectiveness and safety of sedation provided by various providers and techniques. We present the Dartmouth Operative Conditions Scale (DOCS), which is designed as a research tool to codify the appropriateness of the procedural conditions provided by various sedation interventions. To begin, human factors methodology was used to develop a model of the pediatric sedation process and to define the criteria for measuring a patient's condition during a procedure (DOCS). To accomplish validation, 70 video clips (30-s duration) were then selected from more than 300 h of procedural video tape for testing/grading purposes. Inter-rater reliability was tested by comparing the score for each video clip among 10 different raters. Intra-rater reliability was evaluated by retesting all of the raters 1 yr after their initial rating. Construct validity was confirmed by analyzing the change in DOCS score relative to the time that sedation intervention was undertaken. Criterion validity was tested by comparing the DOCS to a modified COMFORT score. The DOCS was completed with excellent inter-rater (kappa = 0.84) and intra-rater (kappa = 0.91) agreement by 10 health care providers with various backgrounds during the 1-yr study period. Criterion validity was supported by the close correlation between the DOCS and the modified COMFORT scores for 20 distinct video clips (Spearman correlation coefficient = 0.98; P <0.001). The distribution of DOCS scores 20 min after the anesthetic induction was significantly lower than the scores before initiation of sedation, and scores after emergence were consistently higher than those 20 min after sedation (P <0.001), thus confirming construct validity of the scale. The DOCS is a validated research tool when used with video data for comparing the effectiveness and safety of pediatric sedation service, regardless of technique used for decreasing anxiety or pain during a procedure.

Child↗
PubMed2005

A method for measuring system safety and latent errors associated with pediatric procedural sedation.

The practice of sedating patients in the hospital for diagnostic and therapeutic procedures may be associated with life-threatening respiratory depression. We describe a method that uses a simulated event to identify latent system failures. A simulated scenario was developed that was reproducible with realistic physiology that degraded over time if no interventions occurred and improved when treated appropriately. Management of the scenario was observed in an ideal setting, a radiology department, and an emergency department. Event management was videotaped. The simulator's physiological data were saved automatically at 5-s intervals. Deviations from "best practice" were measured by using a set of video markers for event detection, diagnosis, and treatment. The simulator data files were used to calculate time out of range for critical variables. Hypoxia and hypotension lasted 4.5 and 5.5 min in the radiology and emergency departments, respectively, compared with 0 min in the gold standard setting. Many latent failures were identified by reviewing the video. This study supports the feasibility of using available human simulation as a crash-test dummy to more objectively quantify rescue system performance in actual sedation care settings. This method revealed vulnerabilities in personnel and in care systems even though sedation care regulatory requirements were met.

Anesthesiology↗
PubMed2004

T vector and loop characteristics in coronary artery disease and during acute ischemia.

OBJECTIVE: Three-dimensional characterization of the ventricular repolarization by the T vector and T vector loop morphology in coronary artery disease (CAD), and their response to short-term (no flow) ischemia induced by coronary occlusion during a percutaneous intervention (PCI). BACKGROUND: The risk for sudden cardiac death is increased in conditions of acute or permanently heterogeneous ventricular repolarization, for which ischemia is a risk factor. METHODS: Fifty-six CAD patients without visible collateral circulation were studied during an elective single-vessel PCI, and 10 healthy controls twice at rest. T vector parameters (Televation, Tazimuth, and QRS-T angle), and T loop parameters (Tarea, Tavplan, and Teigenv) were measured by vectorcardiography. ST vector magnitude (ST-VM) and its change (STC-VM) were used for reference. RESULTS: At rest, T vector loop morphology (Tarea, Teigenv) was significantly different in CAD patients and controls, while T vector angles did not separate the groups. Ischemia induced significant changes in T loop parameters in the entire CAD group, whereas in the LAD subgroup significant changes were seen also in T vector angle. The T loop morphology was significantly different at baseline and a more pronounced response to ischemia (Tarea) was seen in patients with, than in those without, a history of hypertension. CONCLUSION: T loop morphology, rather than the T vector angle, separated CAD patients from healthy controls. Coronary occlusion had significant impact on ventricular repolarization, as assessed by T vector and morphology analysis, and most prominently in the LAD group. Hypertensive patients appeared especially vulnerable to ischemia.

Acute Disease↗
PubMed2004

Quantitative MRI assessment of Alzheimer's disease.

The development of a noninvasive method to detect early, subtle changes in the brains of patients with Alzheimer's disease (AD) would have considerable clinical value as therapy. This therapy is most likely to be successful if intervention could occur before neurons were irreversibly damaged or lost. An ideal biological neuroimaging marker would be an early, sensitive, and valid indicator of brain changes, capable of discriminating the effects of normal aging. The introduction of high field-strength clinical magnetic resonance imaging (MRI) systems now offer a powerful new noninvasive tool that may be capable of detecting brain pathology resulting from AD. Here we present results from high field-strength MRI in transgenic mice along with a new MRI technique for imaging brain iron. The successful translation of this research to the clinic could prove important to both the early diagnosis and monitoring of the efficacy of potential therapies in humans.

Alzheimer Disease↗
PubMed2002

[Treatment of coronary artery stenosis. Considerable improvement of the catheter-based technique].

The technique to treat coronary artery stenoses by percutaneous coronary intervention (PCI) was introduced in 1977 and has since undergone considerable improvement. Important developments have been: 1. The use of stents, which minimize the risk of acute occlusions and reduce the incidence of restenosis. 2. Improvement in antiplatelet therapy, which decrease the risk of thromboembolic complications during and after PCI. 3. Specific treatment against restenosis by drug-eluting stents. PCI treatment with stents and reinforced antiplatelet therapy is well established today. If the initial encouraging results with PCI using drug-eluting stents without restenosis hold their promise, the vast majority of coronary revascularisations will be performed by PCI in the future.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

[PCI is now a refined method for treatment of coronary stenoses].

The technique of Percutaneous Coronary Intervention (PCI) has improved considerably over the last decades. Important developments have been the introduction of stents and better anticoagulation treatment. PCI is used most commonly in the treatment of unstable angina pectoris or non ST-elevation myocardial infarction. In Sweden today, more than half of the patients with ST-elevation myocardial infarction are treated primarily with PCI. Despite the high degree of opening of the infarct-related artery, the reduction in mortality is modest compared with treatment with thrombolysis indicating that there is room for considerable improvement. There is a need for randomised studies of adjunctive therapies but it can be speculated that thrombectomy devices and specific reperfusion injury therapy might reduce mortality in PCI treatment of ST-elevation myocardial infarction.

Angina Pectoris↗