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B Podesser

Publications and source records attributed to B Podesser.

At least 19 recordsLinked to original sources
PubMed2004

Quantitation of transverse maxillary dimensions using computed tomography: a methodological and reproducibility study.

The present investigation was a methodological study of a new method of quantification of a series of factors in the transverse dimension of the maxilla including the nose, maxillary bones and dental arches, based on computer tomographic (CT) scanning. The aim was to investigate a series of parameters thought to be relevant in the differential diagnosis of discrepancies in the morphology of this area and probably affected by orthodontic appliances. Based on a standardized CT scanning registration of 10 subjects, a series of points on the scans were identified and then measured in a special cephalometric computer system (linear and angular values). The quantitation was repeated by each observer and inter- and intra-observer differences were calculated. The results demonstrated that virtually all the parameters showed a high degree of reproducibility at both levels and confirmed the statistical suitability of the method described. The method will be used in a series of ongoing studies regarding the morphology and treatment of discrepancies of the midface and therefore supplement the relatively sparse information based on quantitative reports concerning this important anatomical area.

Adult↗
PubMed2001

Diltiazem versus nitroglycerin for myocardial protection following coronary artery bypass grafting as assessed by dobutamine stress echocardiography.

BACKGROUND: Perioperative infusion of the calcium channel antagonist diltiazem reduces the occurrence and extent of postoperative myocardial ischemia. However, recent reports also mention nitroglycerin as the drug of choice to prevent conduit spasm after coronary bypass grafting. The diagnosis of myocardial ischemia in the perioperative setting is still problematic. Dobutamine stress echocardiography (DSE) is an established technique that combines inotropic stimulation with real-time myocardial imaging and delineates normal and abnormal regional contraction patterns. We assessed the perioperative anti-ischemic effects of diltiazem and nitroglycerin during hemodynamic stress using DSE. METHODS: 50 adult patients were included in a prospective randomized study. Diltiazem or nitroglycerin was used from the onset of extracorporeal circulation until 24 h postoperatively. Dobutamine stress echocardiography was performed in a stepwise fashion 2 to 3 h after elective coronary artery bypass grafting. RESULTS: In 42 of 49 patients, dobutamine stress echocardiography either reached a level of 40 micrograms/kg/min dobutamine or achieved the target heart rate. One patient improved in terms of segmental wall motion abnormalities and three patients developed new abnormalities without corresponding electrocardiographic changes. Analysis of ischemia-sensitive parameters showed lower creatine kinase MB (p = 0.032) and troponin I levels (p = 0.1) in the diltiazem group 24 h postoperatively. Heart rate was significantly lower in the diltiazem group (p = 0.0003). CONCLUSIONS: Under conditions of hemodynamic stress, DSE revealed no significant difference between diltiazem and nitroglycerin with regard to renewed ischemia.

Adrenergic beta-Agonists↗
PubMed2000

Significance of right bundle branch block in the diagnosis of myocardial ischemia in patients undergoing coronary artery bypass grafting.

BACKGROUND: Perioperative diagnosis of myocardial ischemia following cardiac surgical procedures remains a challenging problem. Particularly, the role of new conduction disturbances as markers of postoperative ischemia is still questionable. The goal of this study was to elucidate the diagnostic significance of new postoperative right bundle branch block (RBBB) for the detection of perioperative myocardial ischemia in patients undergoing elective coronary artery bypass grafting (CABG). METHODS: In 169 consecutive patients, three-channel Holter monitoring and serial assessment of serum enzymes were performed for 48 h, and 12-lead ECG repeated for up to 5 days postoperatively. Postoperative events were classified as either myocardial infarction (MI), transient ischemic events (TIE) or various conduction disturbances. RESULTS: Transient (n=9) or permanent (n=4) RBBB occurred in 13 patients (8%); 14 patients (8%) showed signs of perioperative MI and 18 patients (11%) evidence of TIE. Peak activity of creatine-kinase (CK, 561+/-135 vs. 316+/-19, P<0.05) and CK-MB (22.7+/-3.2 vs. 13.4+/-0.8, P<0.01) were higher in patients with RBBB than in patients without perioperative ischemic events. Peak CK-MB levels were significantly higher in patients with MI as compared to those with RBBB (33.4+/-7.6 vs. 22.7+/-3.2, P<0. 05). Patients with TIE had similar perioperative enzyme levels as patients with no events. CONCLUSION: It is concluded that the combined assessment of repeated 12-lead ECG, continuous Holter monitoring and enzyme analysis allows a reliable diagnosis of perioperative myocardial ischemia and conduction disturbances. The occurrence of new RBBB following elective CABG is indicative of perioperative myocardial necrosis and thus serves as a valuable tool for the diagnosis of new, perioperative ischemic events.

Biomarkers↗
PubMed1999

Local anaesthesia versus general anaesthesia for cardioverter-defibrillator implantation.

AIMS: Cardioverter-defibrillators are conventionally implanted under general anaesthesia. However, implantation under conscious sedation is being increasingly used. It has been shown that cardioverter-defibrillators can be implanted in a more pacemaker-like approach: under local anaesthesia for the surgical procedure, and with mild sedation for defibrillation threshold testing only. The aim of the present study was to compare local and general anaesthesia in defibrillation threshold testing and implantation of cardioverter-defibrillators. METHODS AND RESULTS: Forty patients were assigned to two groups: in the first 20 consecutive patients the cardioverter-defibrillator was implanted under general anaesthesia (GA), and in the subsequent 20 patients under local anaesthesia (LA). There was no significant difference between the two groups in regard of age, body weight, underlying disease, left ventricular ejection fraction, and NYHA classification. The defibrillation threshold was 13.7 +/- 5.5 J under local anaesthesia versus 10.7 +/- 4.7 J under general anaesthesia (n.s.). For defibrillation threshold testing 7.9 +/- 3.6 shocks had to be applied in patients under general anaesthesia versus 6.2 +/- 1.3 shocks under local anaesthesia (n.s.). Mean heart rate, arterial oxygen saturation and mean arterial blood pressure remained stable throughout defibrillation threshold testing, irrespective of the type of anaesthesia used. The duration of the surgical procedure was 62 +/- 16 min under GA and 60 +/- 14 min under LA (n.s.), however, the entire implantation procedure was significantly longer in patients under general anaesthesia than in those under local anaesthesia (124 +/- 24 min and 97 +/- 22 min, respectively, p < 0.005). There were no complications in either group and the procedure was well tolerated. With the use of local anaesthesia the cost of anaesthesia were reduced by 72%. CONCLUSION: Local anaesthesia in combination with mild sedation is as safe and well tolerated as general anaesthesia in cardioverter-defibrillator implantation. Lidocaine used for local anaesthesia does not adversely affect the defibrillation threshold. Device implantation in a pacemaker-like approach results in a significant reduction in total procedure time and costs, and facilitates scheduling of the procedure.

Anesthesia, General↗
PubMed1999

Intestinal tuberculosis presenting as fever of unknown origin in a heart transplant patient.

Patients undergoing transplantation have an increased risk of developing infections such as tuberculosis, Pneumocystis carinii pneumonia, Candida infections or cytomegalovirus infections because of their immunosuppressive therapy with cyclosporin A, azathioprine and steroids. Mycobacterial infection is well recognized as a complication in the immunocompromised host but diagnosis and therapy are very difficult.

Antitubercular Agents↗
PubMed1998

Predictors of outcome in patients with implantable cardioverter defibrillators.

UNLABELLED: This study determined the impact of clinical characteristics on shock occurrence and survival in patients with implantable cardioverter-defibrillator (ICD). METHODS AND RESULTS: During a follow-up of 27 +/- 18 months, the actuarial incidence of appropriate shocks in 200 consecutive patients was 18, 36 and 72% at 1, 3, and 5 years, respectively. Coronary artery disease was the only significant predictor for shock occurrence (relative risk 1.32, p = 0.03). The actuarial incidence of total mortality was 10, 17 and 33% at 1, 3, and 5 years, respectively. The most powerful predictors for total mortality were: New York Heart Association functional class (NYHA) III (relative risk 4.8, p = 0.001) and a history of congestive cardiac failure (relative risk 3.6, p = 0.01). CONCLUSION: During long-term follow-up, the majority of patients receive appropriate shocks. No strong predictors for shock occurrence can be identified from the data analyzed. A history of congestive cardiac failure and the NYHA III are the most powerful predictors for total mortality. These clinical factors may provide valuable criteria to identify patients who will benefit from the implantation of ICD.

Arrhythmias, Cardiac↗
PubMed1997

Epicardial branches of the coronary arteries and their distribution in the rabbit heart: the rabbit heart as a model of regional ischemia.

BACKGROUND: The rabbit heart has been frequently used to study regional ischemia, but there is hardly any detailed information on the epicardial branching of the coronary arteries. Therefore, we wanted to determine whether there is a constant branching pattern and how comparable this pattern is with the human heart. METHODS: We investigated epicardial branching of the coronary arteries in 30 adult rabbit hearts. For vessel visualisation, we used injections of Technovit, followed by corrosion. RESULTS: We found that there is not one constant pattern but rather a bifurcation or a trifurcation of the arteria coronaria sinistra (15 of 15 hearts). The left coronary artery is always the dominant artery; a vessel comparable to the human ramus interventricularis anterior is rarely found in the bifurcation type. The ramus circumflexus is a constant but minor branch of the posterior or posterolateral division and does not originate directly from the main stem of the left coronary artery, as it does in humans. As a consequence, ligation of the left ramus interventricularis anterior leads to severe ischemic injury only where trifurcation exists (50% of our population). A ligation of the ramus circumflexus proximal to its origin produces a large posterolateral infarction in the bifurcation type (50% of our population). CONCLUSIONS: Because a defined ischemic area is difficult to reproduce under these anatomical conditions, the rabbit heart may be a model only for regional ischemia if the investigator is knowledgeable about the distributions of the coronary arteries.

Animals↗
PubMed1997

Myocardial revascularization without cardiopulmonary bypass in pigs: a comparison between beta-blockers and Ca2+-channel blockers.

The purpose of this study was to develop the surgical technique for internal mammary artery grafting on the beating heart. In 10 pigs, heart rate was reduced with esmolol (n = 5) or verapamil (n = 5). In addition, the anti-ischaemic and anti-arrhythmic potencies of these drugs were investigated. Haemodynamics, mechanical function and ischaemia-sensitive laboratory measurements were assessed perioperatively. There were no differences in pre-ischaemic data including ischaemic clamping time of the left anterior descending artery. At the end of ischaemia haemodynamic parameters were significantly lower in the esmolol-group (P < 0.05). In the verapamil-group, one pig died from ventricular fibrillation during ischaemia, and one showed fibrillation during reperfusion (P < 0.01). There were no differences in cardiac function or enzymes between the groups. Reduction of heart rate was provided by both drugs, but no conclusive evidence was provided with regard to additional anti-ischaemic and anti-arrhythmic protection.

Adrenergic beta-Antagonists↗
PubMed1996

Preischemic bolus application of piroximone studied on the isolated rabbit heart--a second look including biochemical data.

In a randomized prospective experimental study on 48 adult white Elco rabbits biochemical and rhythmic changes after bolus administration of the phosphodiesterase inhibitor piroximone were investigated using a working heart model. The treatment group (n = 21) intravenously received 1 mg/kg of piroximone 15 min before thoracotomy. Twenty-three untreated hearts served as the control group. From 6 hearts of each group myocardial biopsies were taken before ischemia, 4 (2/2) hearts were excluded. Hemodynamic results of a previous study with an identical protocol were reanalyzed; a biochemical analysis of myocardial high-energy phosphates was investigated after 60 min of global ischemia and at the end of the experiments after 45 min of reperfusion. Already prior to ischemia, in the treatment group depletion of high-energy phosphates was detected. After 60 min of ischemia during early reperfusion in the treatment group ATP and creatine phosphate depletion became even more evident and increased until the end of the experiments. The incidence of reperfusion-induced arrhythmias was significantly lower in the treatment group. Consequently these results and the hemodynamic results of prior studies indicate a possible positive effect of piroximone during the early reperfusion period by optimizing hemodynamics and arrhythmias.

Adenosine Triphosphate↗
PubMed1994

Hemodynamic changes during prolonged laparoscopic surgery.

7 healthy pigs, anesthetized with ketamine/azaperon/thiopentone and ventilated with O2/N2O by volume control, underwent anterior resection of the descending colon by laparoscopic view. During operation of pneumoperitoneum by inflating CO2 to an abdominal pressure of 14 mm Hg was installed. Immediately (+2 min) after the onset of insufflation, both systemic and pulmonary arterial pressure increased. However, pulmonary artery pressure started to decrease after 10 min, whereas systemic arterial pressure remained elevated until the end of the experimental protocol. Left ventricular (LV) pressure and LV dp/dt increased in parallel with the systemic arterial pressure. Peak inspiratory pressure and central venous pressure increased in parallel with the abdominal pressure. Blood gas analysis of arterial and pulmonary blood demonstrated increased pCO2 associated with mild acidosis. Arterial pO2 did not change significantly indicating that the decreased pulmonary distensibility did not endanger the oxygenation. Pulmonary pO2 and pulmonary O2 saturation increased early (+10 min) after start of insufflation and were stable during the 2 h of observation indicating either increased cardiac output or decreased O2 extraction. We conclude that the sharp initial rise of both arterial pressures could be the effect of a mechanical action, whereas sustained hemodynamic alterations would involve complex regulatory mechanisms like an increase of sympathetic activity, baroreceptor control, or a response to acidosis. The acute and, in the systemic circulation, stable increase of ventricular afterload should be considered in patients with underlying cardiac diseases such as ischemic heart disease or valvular dysfunction or in patients taking drugs which interfere with normal compensatory processes.

Animals↗
PubMed1994

Myocardial protection with Bretschneider cardioplegic solution--an evaluation of full oxygenation.

In the present study the effect of oxygenated Bretschneider cardioplegia on high-energy phosphates [adenosine triphosphate (ATP), adenosine diphosphate (ADP) and creatine phosphate (CP)] and hemodynamics was evaluated in the isolated working rabbit heart. Hearts were obtained from 37 adult white Elco rabbits (3,100 +/- 110 g). After a 20-min working period 14 hearts were arrested with Bretschneider cardioplegia (8 degrees C) oxygenated with 98% oxygen (O2) and 2% carbon dioxide in comparison to 14 hearts receiving Bretschneider solution saturated with 98% nitrogen (N2) and 2% carbon dioxide as a control group for either 60 or 90 min (O(2)60, O(2)90, N(2)60, N(2)90 groups, n = 7). Seven hearts were used to determine preischemic baseline values of ATP, ADP and CP, 2 were excluded. The results showed a significantly poorer preservation of high-energy phosphates in hearts receiving oxygenated Bretschneider cardioplegia as compared to hearts receiving nitrogenated cardioplegia (p < 0.05). Postischemic recovery of hemodynamics did not demonstrate any statistically significant differences between the groups. However, the intragroup analysis showed a tendency towards weaker hemodynamic recovery in hearts treated with oxygenated cardioplegia. in contrast to the beneficial effect of oxygenated St. Thomas solution. In conclusion our findings suggest that oxygenated Bretschneider cardioplegia leads to significantly poorer preservation of high-energy phosphates and depressed hemodynamic recovery.

Adenosine Diphosphate↗
PubMed1994

Postischemic hemodynamic changes after piroximone administration in isolated rabbit heart.

In an experimental study on 22 adult Elco rabbits, hemodynamic parameters were investigated using a working heart model. The study group (10 rabbit hearts) received 1 mg/kg i.v. of the phosphodiesterase inhibitor piroximone 15 min before thoracotomy. 12 untreated rabbit hearts served as a control group. Hemodynamic parameters were measured before and after 60 min of hypothermic ischemia. The pre-ischemic period showed no significant differences between the two groups, except the higher levels of coronary flow in the piroximone group. The postischemic period showed significant increases in heart rate, coronary flow, aortic flow and cardiac output in the piroximone group in comparison to the control group. These results indicate as a main effect the positive influence of piroximone on coronary flow, given as a single shot 15 min preoperatively. This study provides evidence of the vasodilative properties on the coronary arteries beside the documented effects on the periphery. Therefore, piroximone represents an alternative tool in weaning from the cardiopulmonary bypass.

Animals↗
PubMed1994

Perioperative infusion of nifedipine and metoprolol provides antiischemic and antiarrhythmic protection in patients undergoing elective aortocoronary by-pass surgery.

A randomised study was performed on 70 patients undergoing elective coronary by-pass procedure to examine whether the combined, perioperative, 24-hour infusion of nifedipine and metoprolol reduces the incidence of perioperative myocardial ischemia and arrhythmias. The control group received nifedipine only. Repeated assessments of serum enzyme levels and 12-lead-ECG together with a 3-channel Holter monitoring over 48h were used to classify perioperative myocardial ischemia and supraventricular and ventricular arrhythmias. The two groups did not differ with respect to their demographic data, extracorporeal circulation, aortic cross-clamping time, or number of distal anastomosis. No perioperative myocardial infarction in either group was detected. However, a significantly lower incidence of transient ischemic event was observed in the NM group as compared transient ischemic events was observed in the NM group as compared to the N group. In addition, there was a tendency towards lower CK-MB-level and peak-values of CK- and CK-MB-enzymes in the NM group. With regard to perioperative dysrhythmias, there was a significantly lower incidence of sinus tachycardia and atrial flutter/fibrillation in the NM group as compared to the N group. In addition, postoperative heart rate was lower in the NM group starting from the 6th hour after opening the aortic cross-clamp. In conclusion, the combined perioperative infusion of nifedipine and metoprolol is superior in preventing perioperative myocardial ischemia and decreasing the incidence of supraventricular arrhythmias as compared to a single-drug regimen with nifedipine.

Arrhythmias, Cardiac↗
PubMed1993

New developments in the isolated working heart: a comparison of neonatal, immature, and adult rabbits after sixty minutes of ischemia in respect to hemodynamic and biochemical parameters.

Hemodynamic and biochemical changes were studied on 36 white ELCO-rabbits, seven adult older than 150 days, seven immatures between 21 and 27 days, and seven neonatals between 7 and 14 days. Five supplementary hearts of each age group served for preischemic biochemical values. Protection during 60 min of global ischemia was provided by topical cooling and selective coronary perfusion with Bretschneider cardioplegia (8 degrees C). A comparison between pre- and postischemic results showed decreases in coronary flow in the adult (p < 0.004), aortic flow (p < 0.04), cardiac output (p < 0.02), and stroke volume (p < 0.02) in the neonate. The preservation of ATP and CP was sufficient in the adult and immature myocardium, whereas a significant decrease in neonatal ATP was found (p < 0.01). According to these findings we consider immature myocardium to be more resistant against ischemia than the two other age groups. The apparatus used is a development of the conventional working heart, but combines a physiological flow-pressure relation, with instruments guaranteeing high accuracy, devices for drug application, and fits for different sizes of hearts. Therefore, this new approach promises to be of clinical relevance for investigations on the improvement of myocardial protection in both adults and children.

Adenosine Triphosphate↗
PubMed1993

Combined perioperative infusion of nifedipine and metoprolol provides antiischemic and antiarrhythmic protection in patients undergoing elective aortocoronary bypass surgery.

A randomized study was performed on 70 patients undergoing elective coronary bypass surgery to examine whether the combined, perioperative, 24-hour infusion of the calcium-channel blocker nifedipine (10 micrograms/kg/h) and the beta 1-blocker metoprolol (12 micrograms/kg/h) reduces the incidence of perioperative myocardial ischemia and arrhythmias (group NM, n = 34). The control group received nifedipine only (n = 36). Repeated assessment of serum enzyme levels (CK, CK-MB) and 12-lead ECG, together with 3-channel Holter monitoring over 48 h were used to define perioperative myocardial ischemia (transient ischemic event, myocardial infarction) and supraventricular and ventricular arrhythmias. The two groups did not significantly differ with respect to preoperative anamnestic and surgical data. No perioperative myocardial infarction was detected in either group. However, a significantly lower incidence of transient ischemic events was observed in the NM group as compared to the nifedipine group (3% versus 11%; p < 0.05). In addition, there was a tendency towards lower CK-MB levels and peak-values of CK- and CK-MB in the NM group. With regard to perioperative dysrhythmias, there was a significantly lower incidence of sinus tachycardia (9%) and atrial flutter/fibrillation (6%) in the NM group as compared to the nifedipine group (33 and 27%, p < 0.05). In addition, postoperative heart rate was lower in the NM group starting from the 6th hour after opening of the aortic cross-clamp. In conclusion, the combined perioperative infusion of nifedipine and metoprolol is superior in preventing perioperative myocardial ischemia and decreasing the incidence of supraventricular arrhythmias as compared to a single-drug regimen with nifedipine.

Aged↗
PubMed1992

Red blood cell partitioning of gallopamil, verapamil and norverapamil.

In-vitro binding of calcium-antagonists gallopamil and verapamil (and its main metabolite norverapamil) to human red blood cells (RBCs) was investigated. The drugs are bound reversibly and dose dependent to RBCs in the same order of magnitude, with partition-coefficients of kRBC = 0.12-0.34 for gallopamil, kRBC = 0.10-0.30 for verapamil and kRBC = 0.10-0.27 for norverapamil. The data indicate that, although RBCs may act as subcompartments of the blood for this class of compounds, they may have no influence on therapeutic plasma concentrations, due to their low kRBC.

Biological Availability↗
PubMed1991

Nifedipine reduces the incidence of myocardial infarction and transient ischemia in patients undergoing coronary bypass grafting.

A randomized study was performed on 104 patients undergoing elective coronary artery bypass grafting to examine whether the infusion of nifedipine (n = 53) reduces the incidence of perioperative myocardial ischemia and necrosis in the early postoperative period. Continuous hemodynamic and three-channel Holter monitoring was performed for 24 hours and serial assessment of serum enzymes and 12-lead electrocardiography were performed for 36 hours postoperatively. Nifedipine (minimum dose, 10 micrograms/kg/hr for 24 hours) was applied from the onset of extracorporal circulation. The control group (n = 51) received nitroglycerin (minimum dose, 1 micrograms/kg/min for 24 hours). Using the combined analyses of electrocardiography and Holter recordings, myocardial ischemia was defined as being either a transient ischemic event (TIE), transient coronary spasm (TCS), or myocardial infarction (MI). The two groups did not differ with respect to preoperative New York Heart Association classification, age, history of myocardial infarction, extracorporal circulation and aortic cross-clamp time, number of distal anastomoses, or systemic and pulmonary hemodynamics. The incidence of perioperative myocardial ischemia was substantially lower in the nifedipine than in the nitroglycerin group [TIE: three of 53 patients (6%) versus nine of 50 patients (18%), p less than 0.001; MI: two of 53 patients (4%) versus six of 50 patients (12%), p less than 0.001; and TCS: none of 53 patients (0%) versus two of 50 patients (4%), p = NS].(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗