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Biomedical subjects

N Treese

Publications and source records attributed to N Treese.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Clinical, neurophysiologic and biopsy findings in neurotoxic amiodarone syndrome].

PATIENTS: Three patients complained of proximal weakness and paraesthesia of the legs and difficulties in walking during amiodarone treatment. Examination showed signs of a predominantly distal sensory neuropathy, a proximal myopathy, and a cerebellar gait disorder. All had amiodarone dosages of 600 mg per day, amiodarone serum levels above 2.7 mg/l and a total amount of amiodarone ingestion of 300 to 500 g. The clinical symptoms subsided within six to eleven months after treatment was stopped. RESULTS: The neurophysiologic investigations showed slowing of sensory and motor nerve conduction velocities with dissociation of the action potentials and delay of SEP latencies. With discontinuation of the drug these abnormalities were progressive in one patient. The biopsy (muscle, nerve and skin) in the most severely affected patient showed numerous intracellular lysosomal inclusions in cells of different tissues. It is supposed that the storage of amiodarone in muscle cells results in a predominantly proximal myopathy whereas storage in Schwann cells results in a secondary neuropathy. A similar storage in Purkinje cells may be responsible for the cerebellar gait disorder. CONCLUSION: The clinical picture should be termed a neurotoxic amiodarone syndrome rather than amiodarone neuropathy.

Amiodarone↗
PubMed1994

Corticotropin-releasing hormone (CRH) is a respiratory stimulant in humans: a comparative study of human and ovine CRH.

Previous experimental and clinical studies clearly demonstrated that exogenously administered CRH possesses respiratory properties. Until now, these effects were investigated using human (h) CRH in both healthy volunteers and patients under long-term respiration. We now compared the effects of hCRH with those of ovine (o) CRH in ten healthy young males. In particular it should be evaluated whether oCRH with its longer plasma half-life induces a more profound respiratory stimulation. On two separate days within two weeks, ventilation and cardiac performance were measured during steady state conditions by using a computerized cardio-pulmonary exercise testing system. In this placebo controlled double-blind-crossover study h- and oCRH (100 ug i.v. each) both augmented minute volume significantly during the observation period. Heart rate also increased after both analogues. All effects were comparable without a significant difference between both substances. There were no major side effects observable. Our data thus demonstrate that both analogues might be suitable for both diagnostic (i.e., testing of respiratory and autonomic responses) and therapeutic purposes.

Adrenocorticotropic Hormone↗
PubMed1994

[Extensive aneurysm of the internal carotid artery with free floating round thrombus].

A large asymptomatic aneurysm of the internal carotid artery containing a free floating thrombus was detected in a 90-year-old woman. The alteration was documented by duplex sonography of the extracranial carotid arteries. At a second examination 4 days later the thrombus was observed to be fixed to the dorsal and distal aneurysm wall. With regard to the age and reduced general state of health of the patient, invasive diagnostic examinations and reconstructive surgery were not indicated and the patient was released in a good condition.

Aged↗
PubMed1994

[Incidence of myocardial bridges after adrenergic stimulation and decreasing afterload in patients with angina pectoris, but normal coronary arteries].

The prevalence of myocardial bridging in patients with angina pectoris but normal coronary arteries was evaluated in 1780 patients who consecutively underwent coronary angiography. 62 patients (3.5%) were free of coronary atherosclerosis or other organic heart disease. In four of these patients systolic narrowing of the LAD was present. The other 58 patients received 0.2 mg nitroglycerin (NTG) intracoronarily and 30 micrograms/ml orciprenalin (ORC) intravenously up to a heart rate of 130/min. Repeated angiography revealed systolic compression of the LAD due to myocardial bridging (MB) in 40% (25 of 62). The length of MB raised from 1.4 +/- 0.9 cm to 2.1 +/- 1.1 cm (p < 0.001) after NTG and to 2.8 +/- 1.1 cm (p < 0.001) after ORC. Coronary luminal stenosis increased from 48 +/- 29% to 67 +/- 25% after NTG (p < 0.001) and to 83 +/- 18% (p < 0.001) after ORC. The prevalence of myocardial bridging in 40% of patients with stress-induced angina pectoris but normal coronary arteries is high. Nearly always coronary compression by myocardial bridging is only evident after adrenergic stimulation or after afterload reduction. Therefore, NTG and ORC are useful drugs to facilitate diagnosis of myocardial bridging by increasing coronary compression.

Adult↗
PubMed1994

[The VO2 performance index for evaluation of cardiopulmonary capacity in respiratory minute volume controlled VVI-R stimulation].

This study was designed to assess the effect of acute minute ventilation sensing, rate-responsive pacing on cardiopulmonary exercise capacity in 27 patients (mean age 60 years) with chronotropic incompetence. The exercise protocol consisted of bicycle exercise in semisupine position with breath-to-breath analysis of gas exchange. At the anaerobic threshold heart rate increased from 75 +/- 9 in the VVI-mode to 113 +/- 21 beats/min in the VVI-R-mode (p < 0.001), oxygen uptake from 9.3 +/- 3.4 to 10.9 +/- 4.3 ml/kg/min (p < 0.001) and work rate from 52 +/- 20 to 65 +/- 24 watts (p < 0.001). Compared to 41 normal subjects, VVI-R pacing increased oxygen uptake up to 75% and work rate up to 79% of normal values, while heart rate increased similarly in both groups. The VO2 to work rate ratio (dVO2/dWR), calculated as the slope of the relation of oxygen uptake to work rate below the anaerobic threshold, improved from 7.9 +/- 2.3 to 10.2 +/- 2.4 ml/min/watts (p < 0.001) in the VVI-R-mode; so it did not differ from normal values. Thus, acute respiratory dependent rate-responsive pacing results in substantial improvement in cardiopulmonary exercise capacity in patients with chronotropic incompetence. The VO2 to work rate ratio demonstrated to be a reliable parameter for assessing this improvement.

Adolescent↗
PubMed1994

[Cardiopulmonary stress in hyperthyroidism].

Spiroergometry might be applicable to detect alterations of cardiopulmonary functions related to hyperthyroidism. Thus, cardiac and respiratory changes as well as work capacity in hyperthroid female patients were to be assessed with the help of the Cardiopulmonal Exercise Test System. Twelve female hyperthyroid patients with Graves' disease of whom all were controlled in euthyroidism, were examined. Eighteen euthyroid female patients in whom intracardiac catheter examination ruled out cardiopulmonary disease served as controls. The anaerobic threshold was determined by means of the V-slope method. An echocardiography was performed in all patients. Ergometry was performed in a semisupine position using a continuous ramp protocol of 20 watt/min. A markedly reduced work capacity, and a high heart rate in rest and exercise were found. In the ratio heart rate/oxygen uptake a lower rise (p = 0.001) due to a decreased growth in the heart rate was noticed. Regarding the pulmonary system a decreased tidal volume in hyperthyroidism (p = 0.021), and a higher breathing frequency (p = 0.003) were recognized, as well as an impaired oxygen consumption, in comparison with the euthyroid state. Also, echocardiographically an increased cardiac index (p = 0.008) and a markedly reduced stroke volume (p = 0.005) in comparison to the control group were observed. Heart rate, work capacity, oxygen uptake, and the ratio heart rate to oxygen uptake were normalized in euthyroidism. With the help of the CPX-System noninvasive measure of marked cardiopulmonary changes in hyperthyroidism are possible, especially the lower growth of the heart rate in exercise, which might be the limiting factor of work capacity.

Adult↗
PubMed1994

[Semi-supine cardiopulmonary stress test in middle-aged probands with healthy hearts].

Normal values for cardiopulmonary bicycle exercise testing in semisupine position using a ramping protocol in a middle-aged group of untrained men and women are presented. We exercised 23 men and 16 women aged from 33 to 66 years without evidence of cardiopulmonary or cardiovascular disease and normal findings during complete heart catheterization. Clinical findings, x-ray, resting and exercise ECG, and laboratory findings were normal. Exercise testing was performed using a ramping protocol with a work rate increase of 20 watts/min. Respiratory gas analysis (breath-to-breath method) was performed and oxygen uptake (VO2), carbon-dioxide production (VCO2), and minute ventilation (VE) were determined at maximal work load and at the ventilatory anaerobic threshold. Work rate increase and heart rate were continuously monitored. From these data oxygen pulse, the respiratory quotient (RQ), and the ventilatory equivalents VE/VO2 and VE/VCO2 were derived. Furthermore, the VO2 to work rate ratio, and the VO2 to heart rate ratio were analyzed. Maximal VO2 was within the 95% confidence interval of predicted VO2max. The anaerobic threshold (V-slope method) was 60% of VO2 max at the RQ of 0.81 for men and 66% of VO2max at the RQ of 0.84 for women. The O2 pulse was 100% of the age predicted value. The VO2 to work rate ratio was 10.7 +/- 1.4 for men and 9.7 +/- 1.2 ml/watts/min for women (p < 0.05). The slope of heart rate to VO2 from rest to peak exercise as a measure of chronotropic competence was nonlinear in 59% of the subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Subacute thrombotic complications after intracoronary implantation of Palmaz-Schatz stents.

Despite excellent results as a bail-out procedure for the management of abrupt closure after balloon angioplasty and the potential beneficial effects on restenosis after angioplasty, intracoronary stenting is limited, especially by subacute stent thrombosis. In 100 consecutive patients with intracoronary implantation of 118 Palmaz-Schatz stents, 10 patients (10%) developed subacute stent thrombosis during their hospital course 3 to 9 days after implantation. Therapy included intravenous thrombolysis, mechanical recanalization by balloon angioplasty, and emergency bypass surgery. Although successful recanalization was maintained in eight of nine nonsurgically treated patients within 2 hours after the onset of symptoms, seven patients developed myocardial infarction, with two patients having Q wave myocardial infarction and five patients having non-Q wave myocardial infarction. By univariate analysis, several variables could be identified as risk factors for the development of subacute stent thrombosis: bail-out implantations (odds ratio: 6.42; 95% confidence interval: 1.53 to 26.38; p = 0.007), unstable angina (12.32; 1.50 to 101.37; p = 0.006), long (5.44; 1.31 to 22.65; p = 0.015) and complex (type C) lesions (8.17; 1.93 to 34.50; p = 0.002) with large plaque areas (9.85; 1.96 to 44.51; p = 0.002), symptomatic postangioplasty dissections (4.36; 1.10 to 16.90; p = 0.029), incomplete wrapping of the dissection after stenting (6.50; 1.10 to 42.30; p = 0.039), and vessel irregularities distal to the stented segment (21.70; 4.12 to 113.18; p < 0.001). These variables, except the variable large plaque area, were confirmed as independent predictors of subacute stent thrombosis by a stepwise multivariate logistic regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Ventilation and heart rate response during exercise in normals: relevance for rate variable pacing.

The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope method, oxygen uptake (VO2-AT) was 15.2 +/- 3.0 mL/kg in males versus 13.8 +/- 2.3 mL/kg in females and heart rate (HR-AT) was 109 +/- 18 beats/min versus 119 +/- 20 beats/min, respectively. Heart rate was highly correlated (r > or = 0.9) to VO2 and minute ventilation (VE). A linear regression for HR-VO2, however, was found only in 16/39 and for HR-VE in 11/39 subjects. Assuming the AT as the breakpoint of two linear curves, it could be demonstrated that compared to low exercise HR appeared to increase at maximal exercise more in relation to VO2 but less in relation to VE; in men the individual slopes for HR-VO2 were 2.6 +/- 0.7 below but 3.2 +/- 1.0 above AT (P < 0.05) and the slopes for HR-VE were 1.6 +/- 0.5 below but 1.0 +/- 0.4 above AT (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic Threshold↗
PubMed1992

[Long-term follow-up of thrombolytic treatment of acute infarct in combination with acute and elective revascularization].

From March 1983 to June 1986 in 206 patients with acute transmural myocardial infarction, combined intravenous and intracoronary therapy with streptokinase was initiated. After intravenous thrombolysis and randomization in two groups we performed a coronary angiography with selective intracoronary lysis. Infarct related vessels still occluded after intracoronary streptokinase application were opened mechanically in group I. In group II we performed additionally a percutaneous transluminal coronary angioplasty (PTCA) after mechanical recanalisation (occluded vessels) or after thrombolysis (open vessels). In 85 of 87 cases in group II, PTCA could be performed in the acute phase. Elective PTCA was performed in 22 patients of group I (21%) and in nine patients of group II (9%). Up to five years after myocardial infarction, coronary artery bypass grafting (CABG) was necessary in 22 patients (21%) of group I and in 23 patients (22%) of group II. Within four weeks after infarction CABG was performed in 32% and 17% of group I and II respectively. The six-year survival rate was 78% in group I and 82% in group II. Taken all patients together, the six-year survival rate was significantly higher (p = 0.002) for those with early reperfusion (less than or equal to 3.5 h). The survival rates of CABG-patients, PTCA-patients and patients without reperfusion were 91%, 74% and 65% respectively. Streptokinase thrombolysis results, combined with acute or elective PTCA and/or coronary bypass surgery, in a high six-year survival rate after acute transmural myocardial infarction. This rate is about 20% higher than ten years ago.

Angioplasty, Balloon, Coronary↗
PubMed1992

Increase in endogenous fibrinolysis and platelet activity during exercise in young volunteers.

The influence of physical exercise and intake of oral contraceptives on endogenous fibrinolytic activity and platelet aggregation behaviour was studied in young healthy women and compared to an age matched group of male volunteers. Physical exercise beyond the anaerobic threshold significantly increased the activity of tissue-plasminogen activator (t-PA) in male and female volunteers from initial values of 1.6 +/- 0.1 and 1.8 +/- 0.2 IU/ml to 5.5 +/- 1.0 and 5.3 +/- 0.9 IU/ml (P less than 0.01), respectively. In women taking low-dose estrogen oral contraceptives t-PA increased from 1.5 +/- 0.2 to 3.8 +/- 0.5 (P less than 0.01). There were no major alterations in plasminogen activator inhibitor - I (PAI-I) plasma activities. Platelet activity during exercise was significantly enhanced in male test persons indicated by a significant decrease in the ED50 values for ADP. In contrast, in women ED50 values were basically unaltered, irrespective of the intake of oral contraceptives.

Adolescent↗
PubMed1992

Acute hemodynamic effects of nicorandil in coronary artery disease.

Nicorandil is a potent vasodilator with antianginal and anti-ischemic properties that acts on both the coronary and the peripheral vascular bed. Because of its dual vasodilatory mechanisms mediated by an increase in cyclic GMP similar to that of nitrates and by a selective increase in the K+ conductance of the smooth muscle cell membrane, nicorandil unloads the right and left ventricles at rest and during exercise. Thus, compared with the classic nitrates, nicorandil is a more balanced vasodilator, i.e., it affects not only the venous capacitance vessels (as predominantly affected by nitrates) but also the arterial resistance vessels. In clinical pharmacologic trials, nicorandil has been administered intravenously (2 to approximately 14 mg) as well as sublingually and orally in single doses of 10-60 mg. In patients with coronary artery disease and impaired left ventricular function, the decrease in preload resulted in a significant improvement of cardiac output. Depending on the doses applied and the patient populations studied, observed decreases in systemic blood pressure were consistent with decreases in peripheral vascular resistance. The effect on heart rate was small, and no influence on atrioventricular conduction could be detected. Nicorandil enhanced exercise capacity in patients with ischemic heart disease. This benefit can be attributed to the reduction in loading of the right and left ventricle as well as to an improvement of regional wall motion abnormalities secondary to the coronary dilatory properties of the drug. Nicorandil appears to be a valuable additive to the antianginal and anti-ischemic management of coronary artery disease.

Animals↗
PubMed1992

Current status of phosphodiesterase inhibitors in the treatment of congestive heart failure.

The phosphodiesterase inhibitors have been recognised as potent inotropic and vasodilating drugs. In acute congestive heart failure they increase cardiac output, decrease left pulmonary capillary wedge pressure, and reduce total peripheral resistance with an improvement in loading conditions of the failing heart. Their potency in reversal of symptoms of acute congestive heart failure is quite similar to, or even better than, treatment with intravenous catecholamines and sodium nitroprusside. In chronic congestive heart failure, however, these agents increase mortality and have deleterious effects in the outcome of patients with severe left ventricular dysfunction.

Acute Disease↗
PubMed1992

[Cardiac morbidity and fatalities in patients with vascular surgery. Identification of risk groups].

Incidence and type of cardiac complications in 701 patients undergoing arterial vascular surgery were prospectively investigated to identify high-risk groups. Cardiac morbidity was 10.1%. Cardiac complications were responsible for 28 deaths (57%). Using logistic regression analysis, age (cardiac morbidity greater than 7017.3%), impaired renal function (19.8%), and congestive heart failure (17.3%) were the main independent risk factors. In addition, 4 risk factors (arrhythmia, coronary artery disease, anemia, emergency surgery) showed significant individual association with cardiac complications. Cardiac morbidity increased to 27.8% in patients with more than 2 of these 7 risk factors. A further association could be demonstrated between the degree of peripheral vascular disease and cardiac morbidity, but not with the extent of the operation. Based on our results a distinction between three groups of different cardiac risk can be made. A clinical algorithm for further cardiac assessment in high-risk patients is presented.

Adolescent↗
PubMed1991

Sudden cardiac death while wearing a Holter monitor.

The Holter tapes of 61 patients (46 men, mean age +/- standard deviation 65 +/- 11 years) with sudden cardiac death while being monitored were analyzed. Thirty-eight patients were known to have coronary artery disease, 5 had cardiomyopathy, and 7 had aortic valve disease. Etiology remained unknown in 11 patients. Mean New York Heart Association functional class was 2.5 +/- 0.7. Thirty patients had received antiarrhythmic drugs and 32 had received digitalis. Sudden death occurred at rest in 73%. In the hours before death, repetitive ventricular arrhythmias were found in 50 patients (82%), with atrial fibrillation in 34%. Patients with bradyarrhythmic death (18%) had less complex ventricular activity compared to patients with tachyarrhythmic death (p less than 0.01). Lethal arrhythmias--monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, torsades de pointes, primary ventricular fibrillation, and 1:1 conducting atrial tachycardia--were found in 26 (43%), 15 (25%), 5 (8%), 3 (5%), and 1 patient, respectively. The coupling interval of the final ventricular tachycardia correlated inversely with the initial frequency of ventricular tachycardia (p less than 0.05). For patients with tachyarrhythmic death, an increase of heart rate within the last 3 hours was noted (83 vs 89 beats/min, p less than 0.05). Ventricular premature complexes and the proportion of patients with greater than 2 couplets and greater than 2 triplets increased significantly only within the last hour before death.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Extrasystoles during extracorporeal biliary shockwave lithotripsy. Their incidence and clinical significance].

Incidence and clinical significance of cardiac side effects of extracorporeal shock-wave lithotripsy (ESWL) were prospectively analysed for 85 patients (26 men, 59 women; mean age 44 [17-81] years) with cholecystolithiasis (n = 70) or choledocholithiasis (n = 15). 24-hour ECG monitoring was undertaken on the day of treatment. Additionally, during ESWL cardiac rhythm and blood pressure were monitored. ESWL was performed with an electromagnetic lithotriptor under light anaesthesia with intravenous diazepam (10 mg) and pethidine (75-100 mg). There were no superventricular premature systoles in any of the patients during treatment. In 15 patients with occasional ventricular premature systoles (VPS) (6-81 per 23 hours) in the 24-hour ECG the number of VPS increased during the one-hour ESWL procedure significantly to 6-55 (P less than 0.05). 14 of these patients had an unremarkable cardiac history. Changing the lithotriptor coupling angle failed to suppress the VPS in only two patients. In these two it was necessary to trigger the shock wave with the ECG. Blood pressure rose markedly (up to 220 mm Hg systolic) during ESWL in only three patients, known hypertensives. But this rise was easily controlled with nifedipine, 10 mg sublingually. These data demonstrate that ESWL is a safe alternative to operative treatment, even in the presence of existing cardiac disease. Nonetheless, precautions should be taken in case there are complications.

Adolescent↗