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Biomedical subjects

G Heinz

Publications and source records attributed to G Heinz.

At least 37 records · Page 2Linked to original sources
PubMed2000

Pharmacokinetics of cefpirome during continuous venovenous hemofiltration: rationale for an 8-hour dosing interval.

OBJECTIVE: Cefpirome is a new semisynthetic cephalosporin, primarily eliminated by the kidneys, that requires dosage adjustment in patients with kidney failure. The optimal dosing regimen of cefpirome in patients with continuous veno-venous hemofiltration (CVVH) is unknown. METHODS: Pharmacokinetic properties of cefpirome were investigated in eight anuric patients with acute kidney failure treated by CVVH. All patients received a dosage of 2 g cefpirome every 8 hours after starting the hemofiltration with high-flux polysulfone membranes. Concentrations of cefpirome in plasma and ultrafiltrate were measured by HPLC. RESULTS: Total clearance and hemofiltration clearance of cefpirome were 589.1 +/- 164.5 mL/min and 43.3 +/- 7.8 mL/min, respectively. Serum elimination half-life was 2.36 +/- 0.59 hours. The highest plasma drug concentration was 14.8 +/- 3.2 microg/mL, and it declined to trough levels of 3.1 +/- 0.8 microg/mL at the end of the dosing interval. CONCLUSION: On the basis of previously published pharmacodynamic characteristics of cefpirome and the pharmacokinetic parameters obtained in this study, we calculated a required total daily dose of 2 g every 8 hours to achieve sufficient plasma antibiotic levels to cover the majority of target pathogens. However, this dosage may be insufficient during CVVH for intermediate resistant strains of Pseudomonas aeruginosa.

Acute Kidney Injury↗
PubMed2000

High prevalence of hyperhomocysteinemia in critically ill patients.

OBJECTIVE: To test the hypothesis that the prevalence of hyperhomocysteinemia is increased in critically ill patients and correlates with disease severity and mortality in these patients. DESIGN: A prospective study. SETTING: Three medical intensive care units at the University of vienna Medical School serving both medical and surgical patients. PATIENTS: All consecutive admissions (n = 56) during a period of 4 wks. A total of 112 age- and gender-matched healthy individuals constituted the control group. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blood samples were drawn within 24 hrs after admission for analysis of total homocysteine (tHcy), folate, vitamin B6 levels, and vitamin B12 levels as well as to identify the 677C-->T polymorphism in the gene coding for the enzyme 5,10-methylenetetrahydrofolate reductase. Acute Physiology and Chronic Health Evaluation III scores at admission and 24 hrs after admission as well as 30-day survival were documented in all patients. Hyperhomocysteinemia was more prevalent in critically ill patients (16.1%; 95% confidence interval, 7.6% to 28.3%) compared with age- and gender-matched healthy individuals (5.4%; 95% confidence interval, 2.0% to 11.3%; chi-square test; p = .022). There was no difference in tHcy plasma concentrations in the first 24 hrs after admission to an intensive care unit between survivors and nonsurvivors. The 5,10-methylenetetrahydrofolate reductase 677C-->T polymorphism had no influence on tHcy levels and survival of intensive care unit patients. CONCLUSIONS: The prevalence of hyperhomocysteinemia is increased in critically ill patients compared to age- and gender-matched healthy individuals. The clinical significance of this finding remains to be determined.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗
PubMed2000

Transient swallow syncope during periods of hypoxia in a 67-year-old patient after self-extubation.

OBJECTIVE: To describe the case of an adult patient with swallow syncope after bypass surgery, possibly related to hypoxia. DESIGN: Case report. SETTING: University hospital, medical-cardiologic intensive care unit. PATIENT: A 67-yr-old patient after second aortocoronary bypass operation for unstable angina. MAIN RESULTS: After the patient managed to extubate himself, he was in a borderline respiratory condition with an oxygen mask. When drinking for the first time after extubation, asystole was observed coincidentally with interruption of oxygen insufflation. During the next days, similar events occurred during food ingestion or when drinking liquids after a fall of oxygen saturation. The bradyarrhythmia was readily reversible on administration of atropine and ventricular backup pacing via temporary pacing wires. After normalization of gas exchange, no more episodes of swallowing-associated asystole were observed and the patient was discharged without a permanent pacemaker. There was no esophageal or gastrointestinal disease. Pre- and postoperative PR and QRS durations were normal. CONCLUSION: Extrinsic and transient mechanisms, rather than intrinsic conduction system disease, seem to have been operative in this case. It is suggested that hypoxia reinforced the vagal pharyngocardiac reflex as described in pediatric patients.

Adult↗
PubMed2000

Soluble selectins and the systemic inflammatory response syndrome after successful cardiopulmonary resuscitation.

OBJECTIVE: Elevated cytokine levels have been reported after ischemia/reperfusion injury and might cause a systemic inflammatory response syndrome (SIRS) after successful cardiopulmonary resuscitation (CPR). It is unknown whether patients with SIRS after CPR exhibit higher levels of soluble adhesion molecules than patients without SIRS and whether SIRS or elevation of adhesion molecules is associated with outcome after CPR. We analyzed the relationships among various CPR-related variables, plasma levels of E- and P-selectin, the occurrence of SIRS after CPR, and the development of sepsis and outcome. DESIGN: Prospective, controlled study. SETTING: Intensive care unit at a university hospital. PATIENTS: A total of 25 patients on the second day after successful CPR and 7 non-critically ill control patients. INTERVENTIONS: Blood sampling for determination of plasma levels of soluble (s) E- and P-selectin. MEASUREMENTS AND MAIN RESULTS: SIRS was a frequent finding after CPR (66% of all patients) unrelated to time until return of spontaneous circulation (SIRS, 17+/-13 mins; no SIRS, 19+/-16 mins; p = .761), epinephrine dose (SIRS, 4+/-5 mg; no SIRS, 5+/-6 mg; p = .906), or serum lactate level after CPR (SIRS, 8.6+/-2.6 mmol/L; no SIRS, 8.7+/-4.0 mmol/L; p = .174). sP-selectin levels were higher in patients with SIRS (291.7+/-227.4 ng/mL) compared with patients without SIRS (113.4+/-88.4 ng/mL; p = .018) or with non-critically ill patients (116.9+/-33.4 ng/mL; p = .031). Compared with non-critically ill control patients (42.8+/-19.4 ng/mL), sE-selectin levels were higher in patients with (96.2+/-47.3 ng/mL; p = .023) and without SIRS (99.5+/-65.7 ng/mL; p = .030). sP-selectin was higher in patients developing sepsis within 1 wk after CPR (n = 9) than in patients without sepsis (350.2+/-233.4 ng/mL vs. 158.5+/-157.8 ng/mL; p = .022) and sE-selectin levels were higher in nonsurvivors (n = 5) than in survivors (144.2+/-62.4 ng/mL vs. 85.7+/-45.3 ng/mL; p = .025) whereas SIRS was unrelated to the development of sepsis (p = .4) and unrelated to survival (p = .4). CONCLUSIONS: SIRS is an unspecific finding after CPR with only minor impact on outcome. Determination of sP- and sE-selectin early after CPR might help to identify patients at a high risk for sepsis or for an adverse outcome, respectively.

Adult↗
PubMed1999

[Infection, sepsis and cardiac arrhythmia].

In clinical practice, the occurrence of arrhythmias in a critical ill patient is often assumed to be due to underlying infection or sepsis. This relationship has been suggested by both case reports and textbooks of Internal Medicine. Two scenarios are deemed possible: The occurrence of "preexisting" arrhythmias in susceptible patients (those with an arrhythmogenic substrate, e.g. a myocardial infarction scar) and the occurrence of arrhythmias mediated in some way through the infection/sepsis in otherwise unsusceptible patients. The present overview portrays the scarcity of data and shows that neither scenario is supported by firm data. While sinus tachycardia is among the spectrum of expected abnormalities during infection or sepsis, bradycardia may be observed in selected cases. This seems to occur relatively frequently in patients with fungemia.

Arrhythmias, Cardiac↗
PubMed1999

IV milrinone for cardiac output increase and maintenance: comparison in nonhyperdynamic SIRS/sepsis and congestive heart failure.

OBJECTIVE: To characterize the effect of the phosphodiesterase inhibitor (PDEI) milrinone in adult patients with a non-hyperdynamic condition during the course of the systemic inflammatory response syndrome (SIRS) or sepsis when compared with patients with congestive heart failure (CHF). PDEIs are potent inhibitors of cytokine production and expression. We hypothesized that there might be an outstanding beneficial effect of PDEIs in the setting of SIRS/sepsis. DESIGN: Prospective, open labeled, protocol-driven pilot study. PATIENTS: Nine patients with a nonhyperdynamic hemodynamic condition during SIRS/sepsis (group 1) and seven patients with CHF (group 2) requiring inotropic support. All patients were having heart disease. All patients had a combination of various catecholamines at the time of inclusion in the study and had received fluid resuscitation to an extent that left ventricular stroke work index (LVSWI) did not increase further. INTERVENTION: Milrinone infusion at a rate of 0.5 microg/kg per min in addition to preexisting catecholamine therapy. MEASUREMENTS AND RESULTS: Measurements of cardiac index (CI; thermodilution) and calculation of vascular resistance and LVSWI was done every 8 h for at least 40 h during milrinone infusion. CI and LVSWI significantly increased in both groups (p < 0.001 and p = 0.006, respectively). There were no significant differences between groups in these parameters (p > 0.11 and p > 0.13, respectively). The LVSWI increase occurred while there was a decrease in pulmonary capillary wedge pressure, suggesting a true and comparable improvement in cardiac function relatively independent of loading conditions. Preexisting catecholamines had to be increased in both groups (NS). Milrinone had to be discontinued in one patient due to hypotension. CONCLUSION: Milrinone administration is feasible in selected patients with a non-hyperdynamic condition during SIRS/sepsis and with preexisting heart disease. Under the conditions of this study, milrinone was no better in terms of CI and LVSWI maintenance in septic cardiac dysfunction when compared with CHF. These results do not necessarily extend to other cohorts with no preexisting heart disease.

Adult↗
PubMed1998

Benign prognosis of early sinus node dysfunction after orthotopic cardiac transplantation.

Previous reports raised concern about the prognosis of patients with sinus node (SN) dysfunction after cardiac transplantation and led to a low threshold for permanent pacemaker (PM) placement at most institutions. The present study addresses the survival in patients with normal and impaired post operative SN function and the effect of permanent pacing with respect to overall and cardiac mortality. There were 120 patients with normal (corrected SN recovery time < 520 ms, group I) and 47 patients with imparied SN function (corrected SN recovery time > 520 ms and/or sinus arrest +/- escape rhythms). Pacing support was deemed unnecessary in 23 of 47 patients with SN dysfunction (group II; asymptomatic SN bradycardia and corrected SN recovery time 3,812 +/- 5,800 ms) while a total of 24 patients had PM placement a mean of 29 +/- 44 days after transplantation (symptomatic bradycardia or absence of sinus rhythm at discharge, group III). Patients were followed for a mean of 46.7 months. Thirty-five deaths occurred during the study period. Sixteen deaths were cardiac but none were causally related to the SN dysfunction (graft failure due to rejection or atheropathy n = 14; myocardial infarction n = 2). Four of these cardiac deaths were sudden and all occurred in the presence of widespread structural abnormalities (rejection/vasculopathy/myocardial infarction). SN dysfunction was not related to overall (P = 0.25) or cardiac mortality (P = 0.33). Regarding either endpoint, patients who had permanent PM placement did no better than their unpaced counterparts in group II (P = 0.53 and P = 0.33, overall and cardiac mortality, respectively). Likewise, survival did not differ between groups I and III for either endpoint (P = 0.77, P = 0.65, respectively). These data suggest that patients with mild SN abnormality, who are in sinus rhythm at the time of discharge, can be followed by observation without specific therapy.

Adult↗
PubMed1997

Significance of morphological abnormalities detected by MRI in patients undergoing successful ablation of right ventricular outflow tract tachycardia.

BACKGROUND: MRI can demonstrate subtle morphological changes of the right ventricle in patients with idiopathic right ventricular outflow tract tachycardia (RVOT). The present study examines the incidence and significance of right ventricular (RV) abnormalities detected by MRI with respect to the site of successful radiofrequency catheter ablation of the clinical tachycardia. METHODS AND RESULTS: The study population comprised 20 patients (mean age, 40+/-12 years) undergoing elimination of recurrent RVOT by radiofrequency catheter ablation. MRI studies were performed before ablation to assess RV volumes and function, as well as structural abnormalities of the RV myocardium. Ten healthy age- and sex-matched subjects served as control subjects. The successful ablation sites, as documented by radiographs of the catheter position, were compared with MRI findings. Patients with RVOT showed no difference in respect to RV volumes and ejection fractions compared with control subjects. Whereas RV abnormalities were limited to prominent fatty deposits of the right atrioventricular groove extending into the inlet portion of the RV wall in 2 of 10 control subjects, MRI studies demonstrated morphological changes of the RV free wall in 13 (65%) of 20 patients with RVOT, including presence of fatty tissue (n=5), wall thinning (n=9), and dyskinetic wall segments (n=4). Eight of these patients had additional fat deposits, thinning, or a saccular aneurysm in the RV outflow tract, corresponding with the ablation site in 6 patients. CONCLUSIONS: In RVOT, structural abnormalities of the right ventricle can be detected in a substantial number of patients despite normal RV volumes and global function. MRI abnormalities within the RV outflow tract are significantly associated with the origin of tachycardia.

Adult↗
PubMed1997

Relation of hemodynamic variables to augmentation of left anterior descending coronary flow by intraaortic balloon pulsation in coronary artery disease.

Recent studies suggest prophylactic intraaortic balloon-pulsation (IABP) in patients undergoing coronary reperfusion therapy. However, variable effects of IABP on coronary blood flow are reported. It is suggested that augmentation of coronary flow is more effective in patients with a compromised hemodynamic status, which might have potential relevance in selecting IABP treatment in patients undergoing reperfusion therapy.

Aged↗
PubMed1997

Documented sudden onset of pseudothrombocytopenia.

A 66-year-old male patient was hospitalized for severe heart failure. Within 3 days after admission his platelet count dropped from 148 x 10(9)/l to 3 x 10(9)/l. Pseudothrombocytopenia was diagnosed based on the platelet count of 3 x 10(9)/l in K3-EDTA anticoagulated blood as opposed to 110 x 10(9)/l in sodium citrate. Platelet reactive antibodies were not detectable. To the best of our knowledge, this is the first report of a documented onset of pseudothrombocytopenia.

Aged↗
PubMed1997

Transperineal radiofrequency interstitial tumor ablation of the prostate: correlation of magnetic resonance imaging with histopathologic examination.

OBJECTIVES: Radiofrequency (RF) energy has recently been employed to destroy human tissue in vivo. The purpose of this study was to investigate the safety of this approach in localized carcinoma of the prostate (CaP) and specifically, the predictability of lesions obtained with radiofrequency interstitial tumor ablation (RITA). METHODS: Using RITA, a total of 21 lesions were induced in 10 patients with localized CaP (mean age 70.4 years). RF was delivered transperineally under transrectal ultrasound (TRUS) guidance. All patients underwent endorectal magnetic resonance imaging (MRI) before and after treatment. Radical prostatectomy was performed in all patients 1 to 7 days after RITA. Three of the patients were treated with local anesthesia only. The predictability of the thermal lesion was assessed by correlating the findings of intraoperative TRUS, pre- and post-RITA endorectal MRI, and the histologic examination of the specimen. RESULTS: Postoperatively, patients were catheterized for an average of 1.8 days (1 to 3 days). Lesions of 2 x 2 x 2 cm were targeted. Average lesion diameters obtained on MRI were 2.08 +/- 0.23 x 2.09 +/- 0.36 x 2.28 +/- 0.21 cm. Average lesion diameters defined by coagulative necrosis at histologic examination were 2.20 +/- 0.23 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm. There were no statistically significant differences (P = 0.377) between average lesion volume on MRI (5.37 +/- 1.83 cm3) and average lesion volume at histology (5.86 +/- 1.63 cm3). No complications or adverse events were noted. CONCLUSIONS: In this Phase I study, RITA was shown to be safe and feasible, and to result in lesions that were predictable in size and location. MRI accurately visualized and verified the area of coagulative necrosis as documented at histology. The procedure is technically simple and can even be performed under local anesthesia.

Aged↗
PubMed1997

Relation between left atrial size and secondary atrial arrhythmias after successful catheter ablation of common atrial flutter.

Catheter ablation provides an effective cure for patients with typical atrial flutter. However, these patients may have the potential to develop atrial tachyarrhythmias other than common atrial flutter. This study examines clinical and echocardiographic predictors for the occurrence of uncommon atrial flutter or atrial fibrillation after abolition of common atrial flutter. The study population comprised 17 patients (12 men, 5 women, age 32-74 years) who underwent successful radiofrequency catheter ablation of common atrial flutter. Common atrial flutter did not recur in any patient during a median follow-up time of 8 (range 1-25) months. Within a median of 7 (range 1-223) days, however, symptomatic atrial tachyarrhythmias occurred in 8 of 17 patients (47%): uncommon atrial flutter (n = 4); atrial fibrillation (n = 3); and both uncommon atrial flutter and atrial fibrillation in one patient. Preablation left atrial volume was significantly larger in patients who developed secondary arrhythmias compared with patients who remained in sinus rhythm (57.9 +/- 15.6 vs 43.7 +/- 16.4 cm3, P < 0.05). Enlarged left atrial volume dichotomized at 51 cm3 independently predicted postablation atrial arrhythmias (X2 = 5.11, rel. risk = 5.3, P < 0.05). On Kaplan-Meier analysis, time to occurrence of postablation atrial arrhythmias was significantly shorter in patients with enlarged left atrium (P < 0.02). In conclusion, symptomatic uncommon atrial flutter and atrial fibrillation develops in a substantial proportion of patients after successful ablation of common atrial flutter. Out of a series of clinical and echocardiographic parameters, preablation left atrial size is the best predictor for the occurrence of these postablation atrial arrhythmias.

Adult↗
PubMed1997

PR interval adaptation in the denervated transplanted heart.

In the present study, the dynamic PR response upon standardized treadmill exercise was investigated in 21 transplant recipients (recipient age 48 +/- 17 years, donor age 31 +/- 12 years, > 1 year after transplantation). HR and PR interval were measured at rest and at the end of each 25-W increase in workload till peak exercise. In 17 cases norepinephrine (NE) was assessed at rest, and at the end of each workload the HR increased from 99.3 +/- 14 to 143.4 +/- 25 beats/min at individual peak exercise, and NE increased from 1,307 +/- 1,163 to 3,688 +/- 2,036 pg/mL, while the PR interval shortened from 149.2 +/- 13 to 119.3 +/- 20 ms. On average, PR decreased by 3.4 ms for a 10-beat increase in HR, and the HR-PR interval relationship was described by a linear regression (y = 176.8-0.3469x, P = 0.0001). One patient who was unable to increase his NE levels upon exercise showed virtually no decrease in the PR interval and no HR increase. Both recipient age and donor age were moderately and significantly related to the minimum PR interval achieved at peak exercise (r = 0.6, P = 0.008 and r = 0.51. P = 0.049, respectively). These data show the following: (1) adaptation of the PH interval upon exercise does occur in the denervated transplanted heart; (2) the HR-PR relation is similar to that reported in the innervated heart; (3) the overall decline in PR interval is blunted, since denervated patients start at shorter resting PR intervals and achieve relatively longer PR intervals at peak exercise when compared to their innervated counterparts; (4) these exercise induced changes of the PR interval may be explained by circulating NE; and (5) NE levels achieved at peak exercise and the sensitivity of the AV node to NE seem to be age related.

Adaptation, Physiological↗
PubMed1997

Demonstration of retrograde conduction over an atriofascicular accessory pathway.

INTRODUCTION: Absence of retrograde conduction over a right atriofascicular accessory pathway causing reciprocating tachycardia has been considered a hallmark of this clinical entity. METHODS AND RESULTS: This report describes successful catheter ablation in a patient presenting with the distinctive pattern of preexcited left bundle branch block tachycardia utilizing a right atriofascicular accessory pathway. This pathway, however, exhibited the unique capability of ventriculoatrial conduction. Both anterograde and retrograde conduction were characterized by "node-like" properties. CONCLUSION: Demonstration of retrograde accessory pathway conduction in this particular setting does not exclude the diagnosis of a single, atriofascicular accessory pathway.

Adult↗
PubMed1997

Use of a collagen plug versus manual compression for sealing arterial puncture site after cardiac catheterization.

The aim of the study was to investigate (1) the safety and efficacy of the application of a collagen plug (Vasoseal) at arterial puncture sites, (2) the hemostasis time, and (3) the comfort for the patient of a collagen plug (Vasoseal) when compared with manual compression. Sixty-two patients were randomized either for application of a collagen plug (Vasoseal, group A, n = 33) or manual compression (group B, n = 29) after cardiac catheterization. All patients were evaluated for subjective pain score ranging from 1 to 5 (1 = no pain up to 5 = very strong pain). In addition the authors measured the time until hemostasis could be achieved. The patients were evaluated by duplex sonography for complications at days 1 and 7 after the procedure. The pain score demonstrated a significantly lower score in group A when compared with group B (P = 0.01). The mean time for hemostasis was significantly lower in group A (mean 9.6 minutes) when compared with group B (mean 23.6 minutes) (P = 0.0001). Regarding the complication rate there was no significant difference between the groups (group A vs group B, P = 0.82). The authors conclude that the application of a collagen plug at the arterial puncture site is a safe and time-saving method. In addition it is less painful and therefore better tolerated than manual compression.

Aged↗