PubMed Health⌕ Search

Biomedical subjects

Thomas Bartel

Publications and source records attributed to Thomas Bartel.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of diagnostic and therapeutic value of transesophageal echocardiography, intravascular ultrasonic imaging, and intraluminal phased-array imaging in aortic dissection with tear in the descending thoracic aorta (type B).

Transesophageal echocardiography (TEE) and conventional intravascular ultrasound (IVUS) have limited capabilities in type B aortic dissection. To evaluate its diagnostic value, intraluminal phased-array imaging (IPAI) was compared with IVUS and TEE. In 23 patients with type B aortic dissection, IPAI was tested with respect to its ability to depict true lumen (TL) and false lumen (FL), to localize which abdominal arteries originate from the TL and FL, and to identify all entries and reentries. After the completion of TEE, 2 additional examiners performed angiography and positioned an AcuNav catheter inside the TL. An IVUS catheter was then introduced into the TL by a fourth examiner. All examiners were blinded to one another. Four additional patients with type B aortic dissection developed peripheral malperfusion due to TL collapse. Transvenous IPAI was used to guide emergency fenestration of the intimal flap. TL and FL could be equally well identified by all diagnostic methods. IPAI detected more entries than IVUS (3.0 +/- 1.2 vs 0.8 +/- 0.5, p <0.001), and thoracic IPAI depicted more entries than TEE (1.8 +/- 1.0 vs 1.2 +/- 0.5, p <0.001). IPAI and IVUS showed >90% of the abdominal side branches. In all patients with peripheral malperfusion, successful emergency intimal flap fenestration was safely guided by IPAI. In conclusion, in the detailed diagnostic evaluation of type B aortic dissection, IPAI is superior to IVUS and TEE in detecting communications between the TL and FL. IPAI is also highly useful as a guiding tool for emergency intimal flap fenestration.

Aortic Dissection↗
PubMed2006

Comparison of three-dimensional imaging to transesophageal echocardiography for preoperative evaluation in mitral valve prolapse.

Transesophageal echocardiography (TEE) is not optimally suited for recognizing which valve segments are involved in type II mitral valve dysfunction. This study was conducted to compare the diagnostic value of TEE and 3-dimensional image reconstruction (3DIR) in the assessment of Carpentier type II mitral valve lesions. In 74 patients (mean age 59+/-13 years) with mitral regurgitation due to type II valve dysfunction, TEE and 3DIR were performed and analyzed by 2 experts before surgical repair. Leaflet scallops and commissures were displayed in short-axis en face and long-axis views. Echocardiographic results were surgically validated. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated, broken down by valve segments and Barlow's disease. Interobserver variability was also determined. Compared with TEE, 3DIR was superior with respect to sensitivity, positive and negative predictive values, and accuracy, although not always significantly (p<0.05). Specificity was higher for P2 lesions. The clearest advantage of 3DIR over TEE was higher sensitivity in commissural and bileaflet defects (p<0.05). Interobserver agreement on 3DIR was stronger than on TEE results (kappa values 0.52 vs 0.82, p<0.0001). There were 16 disagreements (23%) on TEE but only 5 (7%) on 3DIR readings. In conclusion, the more complex the lesion, the more valuable 3DIR is compared with TEE. Before repair, 3DIR is beneficial for the evaluation and classification of the specific pathology in type II mitral valve dysfunction.

Adult↗
PubMed2006

Aortic valve calcification as quantified with multislice computed tomography predicts short-term clinical outcome in patients with asymptomatic aortic stenosis.

BACKGROUND AND AIM OF THE STUDY: Aortic valve calcification may be an independent risk factor for adverse clinical outcome. The study aim was to assess the predictive value of possible risk factors, including the severity of aortic valve calcification as quantified with 16-multislice computed tomography (MSCT) for adverse short-term clinical outcome in patients with asymptomatic, degenerative aortic stenosis (AS). METHODS: Possible risk factors for adverse short-term clinical outcome were prospectively tested in 34 consecutive patients with asymptomatic AS as follows: (i) aortic valve calcium (AVC) score as quantified with MSCT; (ii) echocardiographic parameters--aortic valve area (AVA) calculated with continuity equation, mean and maximal transvalvular pressure gradients, end-diastolic septal wall diameter; and (iii) laboratory tests (brain natriuretic peptide (BNP), C-reactive protein (CRP)). RESULTS: Within 18-24 months of follow up, 11 of 34 patients developed a major adverse clinical outcome. Ten patients suffered from onset of symptoms accompanied by hemodynamic progression, and one patient died from sudden cardiac death. Six of these 10 patients underwent aortic valve replacement, one patient declined surgery, and three patients were not accepted for surgery (one of these died suddenly shortly afterwards). The aortic valve calcium score was the strongest predictor of a major adverse clinical event (p < 0.001) among all parameters assessed (1,928 +/- 789 versus 5,111 +/- 2,409 Agatston units). The plasma level of BNP (p = 0.003), mean transvalvular pressure gradient (p = 0.002) and AVA (p = 0.003) were also risk factors for adverse clinical outcome. CONCLUSION: The AVC score as quantified with MSCT predicted adverse short-term clinical outcome in patients with asymptomatic AS. In patients with severe aortic valve calcification, close follow up examinations are mandatory, and early elective surgery may be considered even in the absence of symptoms. MSCT provides a comprehensive non-invasive imaging approach for risk stratification in patients with asymptomatic AS.

Aortic Valve↗
PubMed2005

Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome.

AIMS: To investigate the results of endovascular stent-graft placement for the treatment of patients with type B aortic dissection (B-AD). METHODS AND RESULTS: A total of 38 patients (62+/-10 years, 32 male) with acute (n=10) and chronic (n=28) type B-AD were treated with endovascular stent-grafts. The implantation procedure was successful in all patients. Peri-procedural non-fatal complications occurred in four (11%) patients. Overall, 4/38 (11%) patients died during the in-hospital period. Patients undergoing stent-graft placement for acute AD had a significantly higher in-hospital mortality than patients with chronic AD (40 vs. 0%, P=0.001). During a median follow-up of 18 (1-57) months, there were six additional deaths. Overall survival rates were 97.4+/-2.6% at 30 days, 80.4+/-6.7% at 1 year, 73.2+/-7.8% at 2 years, and 54.9+/-16.9% at 4 years. Patients with a poor clinical health status (ASA class > 3) had a significantly reduced life expectancy compared with patients with only moderate co-morbidities (ASA class </= 3) (1-year survival rate 28.6+/-17.1 vs. 92.6+/-6.7%, P=0.0001). Multivariable analysis revealed that a poor clinical health status (ASA>3) pre-operatively (HR=29.5, 95% CI 1.5-581.9, P=0.026) and increased age (HR=1.1, 95% CI 0.9-1.2, P=0.084) were independent determinants of post-interventional mortality. CONCLUSION: Endovascular stent-graft treatment is a safe alternative for patients with AD. The pre-operative clinical health status of the patient is the most important determinant of post-interventional outcome. Careful patient selection is thus of particular importance.

Acute Disease↗
PubMed2005

Assessment of coronary flow velocity reserve by noninvasive transthoracic Doppler echocardiography in patients with angiographically normal coronary arteries.

The measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) with invasive intracoronary Doppler flow wire technique (ICD) was validated and the pathological factors which influence CFVR in patients with angiographically normal coronary arteries were analyzed. CFVR was determined successfully in left anterior descending artery (LAD) in 37 of 40 patients with angiographically normal coronary arteries (men 22, women 15, age 20-75 years, mean age 54 +/- 12 years). Coronary flow velocity was measured in the distal LAD by TTDE with contrast enhancement at baseline and during intravenous adenosine infusion of 140 microg/kg per min within 48 h after ICD technique. Average peak velocity at baseline (APVb), average peak velocity during hyperemia (APVh) and CFVR determined from TTDE were correlated closely with those from ICD measurements (APVb: y = 0.64x + 5.04, r = 0.86, P < 0.001; APVh: y = 0.63x + 14.36, r = 0.82, P < 0.001; CFVR: y = 0.65x + 0.92, r = 0.88, P < 0.001). For CFVR measurements, the mean differences between TTDE and ICD methods were 0.12 +/- 0.39. CFVR in patients with history of hypertension was significantly lower than that in patients without history of hypertension (P < 0.05). Intravascular ultrasound (IVUS) was performed in 34 patients. Plaque formation was found in LAD by IVUS in 17 (50%) patients. No significant difference in CFVR was found between the patients without plaque formation (3.11 +/- 0.49) and those with plaque formation (2.76 +/- 0.53, P = 0.056). It is suggested that TTDE with contrast enhancement provides reliable measurement of APV and CFVR in the distal LAD. The early stage of atherosclerosis could be detected by IVUS, which may be normal in angiography. CFVR is impaired in patients with history of hypertension compared with that in patients without history of hypertension.

Adenosine↗
PubMed2005

[Coronary heart disease associated with the use of highly active antiretroviral therapy (HAART). A case report and review].

The use of highly antiretroviral therapy (HAART) significantly reduced morbidity and mortality by inhibition of virus replication. Even though long-term side effects are not fully known, this antiviral strategy has revolutionized the care of HIV-infected patients and is widely used in industrial countries. Until now, a variety of metabolic side effects, such as hyperlipidemia and insulin resistance, have been described. These metabolic alterations of antiretroviral therapy increase the cardiovascular risk profile of HIV-infected patients. It could be expected, that the increased cardiovascular risk profile in combination with long-term survival of this patient population, will increase the diagnostics and therapy of coronary diseases of HIVinfected patients in the next years. The present article (1) contains the case report of a 39-year-old HIV-infected male with an acute myocardial infarction, and (2) gives an overview about arteriosclerosis and coronary events in HIV-infected patients and the impact of antiretroviral therapy.

Adult↗
PubMed2005

Intracardiac echocardiography: an ideal guiding tool for device closure of interatrial communications.

BACKGROUND: This study sought to evaluate safety and radiation exposure when using intracardiac echocardiography (ICE) in comparison to transesophageal echocardiography (TEE) in order to guide transcatheter closure of interatrial communications. METHODS: Eighty patients (44 males, 36 females, mean age 46, SD 13 years) undergoing device closure of atrial septal defect (n=12) or patent foramen ovale (n=68) had the procedure guided by ICE (n=50, group 1) or TEE (n=30, group 2). In group 1, all procedural stages were completely guided by ICE, including imaging of the interatrial communication during balloon sizing, device unfolding and release, and during the final check for adequate positioning. In group 2, exclusive implantation of devices was guided by use of TEE. RESULTS: Especially, the spatial relationship between device and cardiac structures (e.g. the ascending aorta, the interatrial septum and the superior vena cava) was accurately demonstrated in group 1. Image resolution provided by ICE was superior to that of TEE. No severe complications, including any related to ICE, were seen. Fluoroscopy time (FT) and procedure time (PT) were shorter in group 1 than in group 2 (FT: 5.5+/-1.5 min vs. 9.3+/-1.6 min, P<0.0001; PT: 31.9+/-4.6 min vs. 38.8+/-5.8 min, P<0.01). Neither sedation nor anesthesia was required in group 1. CONCLUSIONS: ICE is a safe tool to guide device closure of interatrial communications. For the patient, procedural stress and radiation exposure are negligible. ICE can be considered the guiding tool of choice for device closure, particularly when long or repeated echocardiographic viewing is required.

Balloon Occlusion↗
PubMed2005

A rare case of acute 'infective' myocardial infarction triggered by acute parvovirus B19 myocarditis.

BACKGROUND: A 25-year-old obese male (BMI 31.9 kg/m(2)) presented with atypical chest pain of sudden onset that was indistinguishable from acute myocardial infarction. He had tachycardia (104 beats/min) and dyspnea at a low level of exercise. He had no previous cardiac history, but his cardiovascular risk profile included a familial predisposition, smoking and hypertension. INVESTIGATIONS: Electrocardiogram, laboratory testing, chest radiography, echocardiography, coronary angiography, intravascular ultrasonography and endomyocardial biopsy. DIAGNOSIS: Acute myocardial infarction and parvovirus-B19-positive myocarditis. MANAGEMENT: Percutaneous transluminal coronary angioplasty with intracoronary abciximab, heparin and nitroglycerin infusion.

Acute Disease↗
PubMed2005

Rapid progression of discrete type A intramural hematoma: prevention of a "procedure-related" complication by intraoperative transesophageal echocardiography.

PURPOSE: To report a case illustrating the utility of transesophageal echocardiography (TEE) before planned stent-graft placement for chronic type B aortic dissection. CASE REPORT: A 64-year-old man with acute aortic syndrome and an 8-year-old interposition graft in the distal aortic arch for acute type B dissection was referred for dissection of the descending thoracic aorta down to the aortic bifurcation; the false lumen was dilated to 65 mm and was partially thrombosed. The ascending aorta showed discrete, eccentric, 4-mm wall thickening that was not considered clinically significant. Stent-graft closure of the entry tear in the proximal descending thoracic aorta was elected. However, as the endovascular procedure was about to commence, TEE showed striking eccentric thickening of the aortic wall of up to 18 mm. The endovascular procedure was stopped, as it was decided to urgently replace the ascending aorta. The next day, the patient underwent successful ascending aortic replacement and simultaneous antegrade stent-graft implantation over the descending thoracic aortic entry tear via the open aortic arch. The postoperative course was uncomplicated, and the patient was discharged 19 days after surgery. He remains well at 6 months after the procedure. CONCLUSIONS: Our case demonstrates that dissection of the ascending aorta may occur not only due to endograft-induced intimal injury, but may also occur due to underlying but undiagnosed or underestimated disease of the ascending aorta or arch. Besides procedural guidance, intraoperative TEE is a useful tool to detect such disease to avoid subsequent "procedure-related" complications.

Aortic Dissection↗
PubMed2004

Determinants of coronary blood flow in humans: quantification by intracoronary Doppler and ultrasound.

The direct determinants of coronary flow are lumen area and blood flow velocity; however, the precise mechanisms that control these factors are not fully understood. The aim of the present study was to assess by which mechanisms lumen area and coronary flow velocity interact with hemodynamic and morphometric factors, thereby influencing coronary flow. Intracoronary Doppler and ultrasound measurements were performed in 28 patients without coronary lumen irregularities. Flow velocity and lumen cross-sectional area were measured in the proximal segments of all three coronary arteries. Global lumen cross-sectional area and global flow were obtained by adding up the values of all three coronary arteries. Left ventricular mass was assessed by echocardiography. Stress-mass-heart rate and pressure-rate products reflecting myocardial oxygen demand were calculated. Global coronary flow increased during adenosine-induced hyperemia from 197 +/- 72 to 637 +/- 204 ml/min (P < 0.001). Global coronary flow closely correlated with the stress-mass-heart rate product (r = 0.62; P < 0.001). Looking at the two constituents of flow separately, global coronary cross-sectional area was closely related to left ventricular muscle mass (r = 0.61; P < 0.001), whereas mean coronary flow velocity at rest showed a strong linear relation with the pressure-rate product (r = 0.64; P < 0.001). There was no interaction between cross-sectional area and blood flow velocity in any of the coronary vessels. Coronary lumen size and flow velocity, the two determinants of coronary flow, are principally determined by different physiological factors. Long-term flow adaptation is achieved by an increase in coronary lumen size, whereas short-term myocardial oxygen requirements are met by changes in resting flow velocity.

Blood Flow Velocity↗
PubMed2004

Value of plasma fibrin D-dimers for detection of acute aortic dissection.

OBJECTIVES: The purpose of this research was to assess the value of systemic inflammatory biomarkers in the detection of acute aortic dissection (AD). BACKGROUND: Rapid diagnosis and initiation of treatment is pivotal for patients with acute AD. So far, there is no laboratory test to aid the diagnosis. METHODS: Plasma fibrin D-dimers, white blood cell (WBC) count, C-reactive protein (CRP), and fibrinogen were determined in 64 chest-pain (CP) patients (acute AD, n = 16; pulmonary embolism [PE], n = 16; acute myocardial infarction [AMI], n = 16; non-cardiac CP, n = 16); 32 asymptomatic patients with chronic AD served as a control group. RESULTS: All acute AD patients showed highly elevated D-dimer values that were similar to PE patients (2,238 +/- 1,765 microg/l vs. 1,531 +/- 837 microg/l, p = 0.15) but significantly higher than in chronic AD, AMI, or CP patients (p < 0.001). The WBC count was significantly increased in patients with acute AD compared with the other groups (p < 0.001); in addition, CRP values differed only non-significantly from PE patients(p = 0.71). There were no differences in the fibrinogen levels between the groups. CONCLUSIONS: D-dimers are highly elevated in both acute PE and acute AD. Patients with acute AD show significant systemic inflammatory reactions. Measurement of D-dimers may be a valuable addition to the current diagnostic work-up of patients with suspected AD.

Acute Disease↗
PubMed2004

Analysis of fossa ovalis membrane velocities by transesophageal Doppler tissue echocardiography: a novel approach to functional assessment of patent foramen ovale.

BACKGROUND: Recent studies have suggested that a higher mobility of the fossa ovalis membrane (FOM) may be associated with an increased risk for stroke in patients with patent foramen ovale (PFO). The current study analyzed whether Doppler tissue echocardiography is useful for quantitation of FOM motion velocities. METHODS: FOM dynamics were prospectively studied in 107 consecutive patients (average age 50.7 +/- 15.3 years, 48 men) with in sinus rhythm who underwent transesophageal echocardiography for various indications. With pulsed wave Doppler tissue echocardiography interrogation, a characteristic quadrophasic signal was recorded in all patients, consisting of a positive wave toward the left atrium (A-wave) at late diastole, followed by a negative wave (B-wave) toward the right atrium, a pronounced, again positive wave during midsystole (C-wave), and a final negative wave (D-wave). RESULTS: Peak velocities of A-wave, B-wave, C-wave, and D-wave were 0.08 +/- 0.02 m/s, 0.11 +/- 0.05 m/s, 0.17 +/- 0.07 m/s, and 0.14 +/- 0.06 m/s, respectively. In 21 of 107 (19.6%) patients, PFO was detected. Patients with PFO had significantly higher C-wave and D-wave peak velocities compared with the 86 patients without PFO (0.23 +/- 0.10 m/s vs 0.15 +/- 0.05 m/s, P < .001 and 0.16 +/- 0.07 m/s vs 0.12 +/- 0.06 m/s, P = .04, respectively). CONCLUSIONS: Assessment of FOM dynamics using Doppler tissue echocardiography is feasible. It allows definition of a characteristic quadrophasic FOM motion pattern, thereby providing new insights into the physiology of FOM mobility. Patients with PFO were found to have increased FOM mobility compared with patients without PFO.

Adult↗
PubMed2004

Impact of gender on femoral access complications secondary to application of a collagen-based vascular closure device.

BACKGROUND: Vascular complications at the femoral access site continue to be a significant problem after cardiac catheterization procedures. It was the aim of the present study to assess the impact of gender on the incidence of severe femoral access complications following the application of a collagen-based vascular closure device after transfemoral catheterization procedures. METHODS: A total of 1,294 consecutive patients (977 male, 317 female) underwent closure of femoral access sites with 8F collagen-based vascular closure devices (Angioseal) immediately after diagnostic or interventional coronary catheterization procedures, independently of the coagulation status. All patients were closely monitored for the occurrence of complications during the following 24 hours. RESULTS: Between male and female patients, there was no difference in the technical performance of the device with successful deployment being achieved in 96.7% and 95.9%, respectively (p=0.60). Severe access complications were found to be significantly higher in female versus male patients (1.6% vs. 0.2%; Odds ratio 7.7, 95% confidence interval 1.5-40.1; p=0.015), although similar accomplishment of an immediate hemostasis was seen in 92.8% and 92.4% of male and female patients (p=0.98). CONCLUSION: Women show a significantly increased risk of developing severe femoral access complications secondary to the application of a collagen-based vascular closure device, although the overall incidence of these complications is relatively low. We speculate that the increased risk in women may be related to smaller arterial dimensions, which could be evaluated by femoral angiography prior to deployment of a closure device.

Adult↗
PubMed2004

Accurate, simplified and rapid three-dimensional echocardiographic volume quantifications: Comparison of different algorithms in symmetric and asymmetric left ventricular geometry.

OBJECTIVE: A comparative investigation of dynamic three-dimensional freehand echocardiography (D3DFE) and magnetic resonance imaging (MRI) was conducted to determine the accuracy and rapidity of the average rotation method (ARM) and the disk summation method (DSM) for volumetric analysis. METHODS: In 15 patients with an asymmetric left ventricle and 12 normal subjects, end-diastolic and end-systolic left ventricular volumes were assessed by D3DFE and by MRI. Both DSM and ARM were used for volume determination. All echocardiographic readings were performed by two examiners blinded to each other and to the MRI results. The times needed for echocardiographic data acquisition and volumetric analysis with either algorithm were determined. RESULTS: Correlation between ARM and MRI measurements was tighter than between DSM and MRI measurements (end-diastolic volume: r=0.95, P<0.0001 versus r=0.94, P<0.0001 in asymmetric ventricles; and r=0.97, P<0.0001 versus r=0.96, P<0.0001 in symmetric ventricles; end-systolic volume: r=0.94, P<0.0001 versus r=0.93, P<0.0001 in asymmetric ventricles and r=0.96, P<0.0001 versus r=0.94, P<0.0001 in symmetric ventricles). In addition, ARM analysis was less time-consuming than DSM (6.4+/-0.4 min versus 7.6+/-0.3 min, P<0.05). CONCLUSIONS: For D3DFE, ARM is the most accurate and rapid approach to left ventricular volume determination. ARM benefits from advanced two-dimensional imaging and can be easily added to any standard transthoracic echocardiographic examination.

Adult↗
PubMed2003

Intracardiac echocardiography is superior to conventional monitoring for guiding device closure of interatrial communications.

BACKGROUND: This study sought to test whether intracardiac echocardiography (ICE) is superior to conventional monitoring in guiding device closure of interatrial communications (atrial septal defect [ASD] and patent foramen ovale [PFO]). METHODS AND RESULTS: Forty-four patients undergoing device closure of ASD (n=6) or PFO (n=38) were randomized to have the procedure guided by either ICE (group 1; n=22) or by transesophageal echocardiography (TEE) (group 2; n=22). All interventions were completed successfully. In 1 patient from group 2, atrial fibrillation occurred 1 day after device implantation; the patient was successfully cardioverted on the next day. There were no other complications. Fluoroscopy time (FT) (6.0+/-1.7 minutes versus 9.5+/-1.6 minutes; P<0.0001) as well as procedure time (PT) (33.4+/-4.7 minutes versus 37.8+/-5.6 minutes; P<0.01) were shorter in group 1 than in group 2. Group 2 patients required general anesthesia without (n=19) or with endotracheal intubation (n=3). In contrast, ICE allowed continuous monitoring of the whole procedure, including balloon sizing before device closure, without sedation. CONCLUSIONS: ICE is a safe tool to guide device closure of PFO and ASD. Supine patients tolerate ICE better than TEE. ICE reduces FT and PT. ICE seems to be advantageous, especially when long continuous or repeated echocardiographic viewing is required.

Atrial Fibrillation↗