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Biomedical subjects

R Buchberger

Publications and source records attributed to R Buchberger.

At least 19 recordsLinked to original sources
PubMed2003

Effect of biventricular pacing on metabolism and perfusion in patients affected by dilated cardiomyopathy and left bundle branch block: evaluation by positron emission tomography.

AIMS: Evaluate the possible changes in myocardial metabolism and perfusion induced by biventricular pacing (BIVP) in patients affected by dilated cardiomyopathy (DC) and left bundle branch block (LBBB). METHODS AND RESULTS: Eight male patients (aged 60-79 years, mean 69) affected by DC (NYHA functional class III and ejection fraction <40%) were submitted to cardiac PET in basal condition and 3 weeks after the implantation of a biventricular device. Metabolism was evaluated using F18-fluorodeoxyglucose (FDG), by the glucose load-insulin technique, and perfusion by N13-ammonia (NH3), injected at rest. Visual and a semi quantitative analyses were performed, calculating by ROIs the septum to lateral uptake ratio (SLR). The myocardial blood flow (MBF) was also calculated in ml/min/g using a dynamic acquisition and a modified Patlak method. In all 8 patients a selective defect in FDG uptake in the septum was present in basal condition (mean SLR 0.59+/-0.17) with a 'reverse mismatch' effect with respect to NH3 (mean SLR 1.07+/-0.18). During BIVP the distribution of FDG in the septal area significatively improved (mean SLR 0.86+/-0.15 P=0.011 with respect to basal); on the contrary, no significant changes were found in NH3 uptake (mean SLR 1.02+/-0.23, P=ns). On quantitative analysis the mean MBF in the septum was 1.05+/-0.37 in basal condition and did not significantly change during BIVP (0.95+/-0.34, P=0.06). CONCLUSIONS: Our results suggest that, in patients affected by DC and LBBB, BIVP improves the septal glucose metabolism without significant changes in myocardial perfusion.

Aged↗
PubMed2002

Fluvoxamine: safety profile in extensive post-marketing surveillance.

The safety profile of the selective serotonin reuptake inhibitor, fluvoxamine, has been assessed in clinical and post-marketing studies. Post-marketing surveillance provides the opportunity to assess a drug's safety in every day clinical conditions in a much greater patient population than in clinical trials and therefore serves as a useful tool to detect signals for adverse effects with an incidence of less than 1 : 10,000. The safety profile of fluvoxamine was evaluated based on data from 17 years of global post-marketing surveillance in an estimated 28 million patients exposed to fluvoxamine. A total of 6,658 adverse drug reaction reports received from world-wide sources were reviewed and analysed. Post-marketing surveillance data confirmed the favourable safety profile already observed in clinical and post-marketing studies. A remarkably low level of suicidality, switch to mania, and sexual dysfunction was found. Serotonin syndrome appeared to be a very rare complication of fluvoxamine treatment. No signals for drug interactions unknown so far were identified. Withdrawal symptoms were observed in everyday clinical conditions, which were generally mild and resolved spontaneously. However, no cases suggestive for drug dependence have been reported. In conclusion, the data presented underlined that fluvoxamine offers a safe and well-tolerated option in the treatment of depression and obsessive-compulsive disorder.

Antidepressive Agents, Second-Generation↗
PubMed2001

Myocardial perfusion and metabolic changes induced by biventricular pacing in dilated cardiomyopathy and left bundle branch block: description of a case evaluated by positron emission tomography.

The effects of biventricular pacing on myocardial wall function are well known, but, at the moment, its real effects on myocardial metabolism are unclear. In patients affected by left bundle branch block, at positron emission tomography a septal defect of the uptake of 18F-fluorodeoxyglucose (FDG) was referred. There were no alterations in myocardial perfusion, suggesting possible metabolic damage. In this paper we report the case of a patient affected by dilated cardiomyopathy and left bundle branch block treated with a biventricular device. Biventricular pacing resolved both the wall motion alterations as well as the defect in FDG uptake present in the septal area. On the contrary, during biventricular pacing there were no modifications in myocardial perfusion as compared to basal evaluation.

Aged↗
PubMed2001

[Efficacy and safety of ambulatory electric cardioversion of atrial fibrillation with monophasic and biphasic shock].

BACKGROUND: The aim of this study was to evaluate the safety and efficacy of ambulatory external cardioversion (EC) by means of monophasic and biphasic shock in patients with persistent atrial fibrillation (AF). METHODS: One hundred and twenty-seven consecutive patients with AF were submitted to EC, preceded by short general anesthesia with propofol, after pretreatment with oral anticoagulants for at least 3 weeks and, if not contraindicated, with amiodarone. In 87 of these patients we used monophasic shock and in 40 patients we used biphasic shock. Our protocol provided for up to 3 shocks delivered at an energy level ranging between 200 and 360 J for monophasic and from 70 to 175 J for biphasic shock. The patients were discharged after 4 hours of ECG monitoring and following a determination of serum CK-MB at the fourth hour. RESULTS: The mean age of the patients submitted to EC with monophasic and biphasic shock (65 +/- 9 vs 67 +/- 7 years) and the duration of AF (34 +/- 22 vs 32 +/- 25 days) were similar. The efficacy of EC with monophasic shock was 85% and the mean energy delivered was 266 +/- 81.5 J. The efficacy of the EC with biphasic shock was 98% and the mean energy delivered was 127 +/- 40 J. The difference between the percentage of efficacy and the number of joules delivered was statistically significant (p < 0.05). The mean value of the CK-MB after 4 hours following delivery of the shock was not significantly different: 2.5 ng/ml for monophasic vs 1.7 ng/ml for biphasic shock (p = NS). CONCLUSIONS: In our patients, ambulatory EC of persistent AF is safe and feasible; biphasic shock is more efficacious and requires less energy with respect to monophasic shock.

Age Factors↗
PubMed2000

Accuracy of low load exercise-induced T wave normalization in predicting the presence of contractile reserve after an anterior myocardial infarction.

BACKGROUND AND METHODS. Exercise-induced T wave normalization occurring at a low (less-than-or-equal50 watt) workload in infarct-related electrocardiographic leads was studied in 30 consecutive patients with a recent transmural anterior acute myocardial infarction. Patients underwent both ergometric stress testing (within 30 days after the infarction) and low dose dobutamine echocardiography. The T wave normalization was considered significant when it occurred in at least two infarct-related leads. A significant contractile reserve was considered present in an infarcted region when 50% or more of the dyskinetic segments functionally improved on exercise during dobutamine infusion. RESULTS. Eighteen patients showed exercise-induced T wave normalization (group 1), and 12 patients did not (group 2). Myocardial contractile reserve in the infarct area was detected in 16 patients of group 1 (88%) and in 3 patients (25%) of group 2 (p=0.004). The overall sensitivity, specificity, and diagnostic accuracy of T wave normalization, as it reflects contractile reserve in the infarct area, were 84%, 82%, and 83%, respectively. CONCLUSION. Low load exercise-induced T wave normalization in infarct-related leads appears to be an accurate marker of residual contractile reserve in the infarct area in patients with recent transmural acute anterior myocardial infarction. (c) 2000 by CHF, Inc.

Journal Article↗
PubMed2000

[Electrocardiography and myocardial viability].

After an acute myocardial infarction, the cardiologist cannot discard data regarding myocardial viability. The most frequently used diagnostic methods for this are echocardiographic or scintigraphic techniques; unfortunately, these techniques are operator sensitive or expensive. However, also by simple electrocardiography is it possible to obtain important information about myocardial viability, in an objective and economic way. There are three electrocardiographic modifications potentially related to myocardial viability: 1) spontaneous modifications after an acute myocardial infarction: early or late T wave normalization, and Q wave regression; 2) exercise-induced modifications: ST segment elevation, T wave normalization, ventricular arrhythmias; 3) dobutamine-induced modifications: ST segment elevation and T wave normalization. In this editorial, the authors report the literature data on the various electrocardiographic signs and analyze their accuracy and utility in myocardial viability assessment.

Arrhythmias, Cardiac↗
PubMed2000

Effects of left bundle branch block on myocardial FDG PET in patients without significant coronary artery stenoses.

UNLABELLED: Cardiac PET studies in patients with left bundle branch block (LBBB) are few, and the results are conflicting. In particular, even if a reduced uptake of FDG is reported, confirmation in a large group of patients and exact understanding of the underlying cause are lacking. METHODS: We selected 29 consecutive patients who had complete LBBB and no significant stenosis on coronary angiography scheduled for FDG and 13N-NH3 PET for myocardial viability evaluation at our center. Wall motion was evaluated using 2-dimensional echocardiography. Ten volunteers without coronary stenosis or LBBB served as a control group. RESULTS: All LBBB patients had a reverse mismatch in the septum, defined as reduced uptake of FDG in comparison with 13N-NH3. The mismatch extended to the anterior and inferior walls in 17 patients. The mean (+/-SD) septal-to-lateral ratio was 0.57 +/- 0.11 for FDG (range, 0.28-0.76) and 0.99 +/- 0.12 for 13N-NH3 (range, 0.75-1.18), with P < 0.0001. In contrast, no significant differences in uptake were seen in the control group, which had a septal-to-lateral ratio of 0.95 +/- 0.13 for FDG (range, 0.78-1.15; P < 0.01 with respect to LBBB patients) and 0.94 +/- 0.11 (range, 0.85-1.20) for 13N-NH3. CONCLUSION: Our study suggests that in LBBB patients without significant coronary stenosis, FDG uptake in the septum changes without a correlating change in perfusion. To avoid possible overestimation of necrosis, especially in the LAD territory, this phenomenon must be considered in evaluations of myocardial viability using FDG images.

Adult↗
PubMed1999

From Billroth to PCV: a century of gastric surgery.

The development of gastric surgery is one of the most fascinating chapters in surgical history. The first operations on the stomach were done during the second half of the nineteenth century; at first they were minor procedures but then gradually became more daring, major procedures-albeit with considerable mortality. The work of Theodor Billroth and his pupils ushered in the era of major resectional therapy, first for cancer and later also for ulcer disease. Complications due to the lack of understanding gastric physiology plagued the early days of ulcer surgery, and a variety of modifications tried to remedy these problems. Although the role of the vagus was known through Pavlov's studies, its practical application had to wait until well into the twentieth century. For several decades, resection and vagotomy, separately or combined, were practiced until more sophisticated types of vagotomy began to dominate and replace resection in the surgical treatment of ulcer disease. Resection remained the treatment for cancer. We thus see over a period of 100 years, owing to the increased understanding of physiologic factors, a gradual shift from major resections toward smaller, better directed procedures. The pioneering work of Billroth and his generation, however, must not be forgotten.

Digestive System Surgical Procedures↗
PubMed1998

T wave normalization in infarct-related electrocardiographic leads during exercise testing for detection of residual viability: comparison with positron emission tomography.

OBJECTIVES: We investigated the sensitivity and specificity of exercise-induced T wave normalization (TWN) in infarct-related electrocardiographic leads (IRLs) for detection of residual viability in the infarct area. BACKGROUND: The meaning of exercise-induced TWN on IRLs is not yet well understood. Recent reports suggest that TWN during dobutamine echocardiography could indicate the presence of viable myocardium. METHODS: We evaluated 40 consecutive patients with a recent acute myocardial infarction and negative T waves in at least two IRLs. All patients underwent exercise testing; positron emission tomography (PET) with nitrogen-13 ammonia and fluorine-18 fluorodeoxyglucose; and coronary angiography. RESULTS: Twenty-four patients showed exercise-induced TWN: 18 at a work load < or =50 W (group la) and 6 at a work load > or =75 W (group 1b); 16 patients did not show TWN (group 2). On the PET study, viability in the infarct area was present in 17 patients (94%) from group la, in only 1 (16%) from group 1b and in 4 (25%) from group 2 (p < 0.0001). The sensitivity, specificity and diagnostic accuracy of exercise-induced TWN, in comparison with residual viability, were, respectively, 82%, 67%, 75% for TWN at every work load and 77%, 94%, 85% for TWN at a work load < or =50 W. Moreover, the sensitivity and diagnostic accuracy of TWN at the low work load were higher for anterior infarctions (87% and 88%, respectively). CONCLUSIONS: Exercise-induced TWN on IRLs at low work loads is a sensitive and specific index for the presence of residual viability in the infarct area. Sensitivity and diagnostic accuracy of this sign are higher for anterior infarctions.

Adult↗
PubMed1998

[Effects of spinal cord stimulation on regional myocardial blood flow in patients with refractory angina. A positron emission tomography study].

BACKGROUND: Spinal cord stimulation (SCS) is an alternative therapy in patients with refractory angina pectoris when coronary revascularization cannot be performed. Several hypotheses have been given to explain the effects of SCS in reducing the number and the intensity of anginal crises. These hypotheses include possible variations in myocardial blood flow (MBF). The aim of our study was to assess regional MBF in a group of patients with spinal cord stimulator, using positron emission tomography (PET). METHODS: We studied 15 patients (9 male and 6 female), mean age 74 +/- 7 years, who were carriers of a spinal cord stimulator implanted 17 +/- 14 (range 1-48) months before. All patients had been affected with angina pectoris that was refractory to maximal tolerated pharmacological therapy. Eight patients had had a previous myocardial infarction and four patients had undergone a revascularization procedure. Every patient underwent two PETs with nitrogen-13-ammonia as the perfusion tracer. The first one was performed with the stimulator switched off for at least 20 hours, and the second one with the stimulator switched on for at least 4 hours. The quantitative evaluation of regional MBF (anterior, inferior, lateral, septal walls and apex) was performed with Patlak graphic analysis. The normal value of basal MBF in our laboratory is 0.6-1 ml/min/g. RESULTS: The mean value of MBF increased from 0.72 +/- 0.33 ml/min/g with the stimulator off, to 0.80 +/- 0.33 ml/min/g with it on (p = 0.004). An increase in regional myocardial perfusion, with the stimulator on as opposed to off, was observed in 47 (62%) of the 75 regions studied. With the stimulator on, in comparison with off, the value of MBF increased from 0.45 +/- 0.11 ml/min/g to 0.56 +/- 0.19 (p = 0.0001) in the 35 regions with low basal MBF (< 0.6 ml/min/g), and from 0.77 +/- 0.14 ml/min/g to 0.92 +/- 0.29 ml/min/g (p = 0.013) in the 23 regions with basal MBF between 0.6 and 1 ml/min/g. Instead, in the 17 regions with high basal MBF (> 1 ml/min/g) it decreased with the stimulator on instead of off, going from 1.22 +/- 0.20 to 1.13 +/- 0.22 ml/min/g (p = 0.112). CONCLUSIONS: Our study suggests that the beneficial effects of SCS in refractory angina may also be related to an increase in mean MBF and to a redistribution of MBF between the regions with low or normal basal flow and the regions with high basal flow.

Aged↗
PubMed1997

[Role of transesophageal echocardiography in the diagnosis of obstructive hypertrophic myocardiopathy. Report of 2 cases and review of the literature].

Two cases of obstructive hypertrophic cardiomyopathy, in which the transthoracic echocardiography was not enough to reach the right diagnosis, are reported. The transesophageal echocardiography revealed to be the most useful technique to reach the exact diagnosis and more information about the mechanism of the left ventricular outflow tract obstruction. Moreover, this technique could be useful to direct to a surgical treatment and to monitorize the mitral valve function and the possible complications during operation.

Adult↗
PubMed1996

[Effects on myocardial perfusion of epidural spinal cord stimulation in refractory angina. Description of a case studied with positron emission tomography].

We describe a case of patient with severe angina pectoris unresponsive to medical therapy who was treated with spinal cord stimulation. The patient was studied by dynamic positron emission tomography (PET) (13-N ammonia) and with heart rate variability. Spinal cord stimulation was effective in reducing anginal attacks and PET documented an enhancement of myocardial perfusion when spinal stimulator was activated. Heart rate variability did not change during spinal cord stimulation.

Aged↗
PubMed1996

[Dobutamine echocardiography and positron emission tomography in the assessment of viable myocardium after a thrombolized acute myocardial infarction. Comparison with spontaneous recovery].

BACKGROUND: Aim of the present study was to compare the ability of low-dose (5-10 gamma/Kg/min) dobutamine echocardiography (DE) and of positron emission tomography (PET), performed after a thrombolized acute myocardial infarction (AMI), to predict the spontaneous functional recovery (SFR) of viable but akinetic myocardial segments. PATIENTS AND METHODS: Twenty-one pts were studied by DE, 10 +/- 2 days (DE1) and 31 +/- 2 days (DE2), after a thrombolized AMI, and by PET (18F-FDS, glucose load) within 7 days after DE2; a basal echo was also performed 3 months after AMI. The left ventricle was divided in 16 segments, both in echo and PET examination. DE viability was defined as improvement in wall motion of akinetic seg; PET viability was defined as an FDG uptake > or = 40% of the maximum. RESULTS: In the 89 akinetic segments, DE1, DE2 and PET, respectively, identified, 16, 27 and 60 viable segments; the concordance with PET, in viable and not viable segments, resulted of 50% for DE1 and of 62% for DE2. After 3 months 29/89 segments had a SFR. In comparison with SFR the sensitivity of DE1 and DE2 was lower (51% and 68%) than PET (89%); the specificity was higher for DE1 and DE2 (98% and 96%) respect to PET (43%). CONCLUSIONS: In comparison with DE performed 10 days after a thrombolized AMI, DE performed 30 days after AMI revealed a greater extension of viable myocardium and a greater diagnostic accuracy in predicting SFR of akinetic segments. The concordance between DE and PET is high, if all myocardial segments are considered, and lower, if only akinetic segments are considered; in fact, PET identifies, as viable, a greater number of segments. In comparison with SRF, DE revealed the greatest specificity and PET the greatest sensitivity.

Adrenergic beta-Agonists↗
PubMed1995

[Traumatic rupture of the chordae tendineae in acute tricuspid insufficiency. Early detection with transesophageal echocardiography].

An uncommon case of traumatic rupture of chordae tendineae with tricuspid regurgitation is described. The early diagnosis, in a patient with polydistrectual injuries, was done by transesophageal echocardiography. This technique allowed accurate diagnosis of the type of lesion suggesting the opportunity to perform an echocardiogram, possibly transesophageal, in all patients with blunt thoracic trauma, even in the absence or with subtle clinical manifestations of cardiovascular involvement.

Accidents, Traffic↗
PubMed1994

[Left cor triatriatum in a man over 60].

A case of cor triatriatum in a 66-year-old man is reported. The patient died of pneumonia; ante mortem diagnosis was made with both transthoracic and transesophageal echocardiography. Autopsy finding showed a very good correlation between anatomical and echocardiographic abnormalities. Cor triatriatum is amenable to surgical correction and echocardiography is extremely helpful in the diagnosis.

Age Factors↗
PubMed1994

[Endocarditis at risk of embolism. An indication for prophylactic surgical treatment?].

Two cases of embolic infective endocarditis on bicuspid aortic valve are described. The trans-thoracic and trans-esophageal echocardiographic aspect could leave easily suppose the possibility of embolism. The prophylactic surgical treatment, during the active phase, also if the indication is debated, could have probably avoided the serious consequences of embolism.

Adult↗