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S Andreas

Publications and source records attributed to S Andreas.

At least 37 records · Page 2Linked to original sources
PubMed1997

Evaluation of an active coronary perfusion balloon device using Doppler flow wire during PTCA.

The aim of this study was to assess whether active coronary perfusion catheters (APC) can provide a sufficient coronary flow in large caliber vessels during balloon inflation. To prevent myocardial ischemia during PTCA, these APC may be employed. However, it is as yet unknown whether the active flow rate of these devices approaches the flow rate prior to PTCA during balloon inflation. Therefore, we measured the efficacy of the APC during balloon inflation in vessels supplying a large amount of myocardium. In 12 patients (1 female, 11 males, 53 +/- 12.6 yr) with stenosed vessels (average diameter 3.4 +/- 0.26 mm), the coronary flow velocity was measured using a 0.014" Doppler guidewire, which was placed distally bypassing the balloon of the APC. The active perfusion balloon catheter was advanced through a 7F guiding catheter along a 0.014" guidewire. After removal of the guidewire, arterial blood being withdrawn from the side port of the femoral angioplasty sheath was pumped through the catheter to the distal coronary vessel. The perfusion volumes of the pump were set to different levels between 30 to 60 ml/min. Intracoronary flow rate was calculated by the angiographically assessed vessel luminal area [symbol: see text] average peak velocity [symbol: see text] 0.5. The mean coronary flow rate prior to PTCA was 43 +/- 17.7 ml/min. Maximum flow during PTCA was 55 +/- 19.6 ml/min. We found a good correlation between the preset external pump rate and the coronary flow in situ (r = 0.92). Pre-PTCA flow rates were achieved in 11 of 12 patients (92%) during balloon inflation. No relevant decrease in the arterial pressure occurred during dilation times of 4.6 +/- 1.63 min. Only two patients showed significant ECG changes during these balloon inflations. After an average follow-up period of 13 +/- 6.3 mo, only one patient (8%) had a significant re-stenosis requiring the implantation of a stent. The combination of intravascular Doppler velocity measurements with quantitative coronary angiography offers the opportunity of exact online flow registration during angioplasty. Using APC, It is possible to maintain a sufficient coronary flow in the distal vessel during balloon inflation even in large vessels. Therefore, as compared with mechanical circulatory assist devices, coronary assist by APC is a little invasive, but according to our measurements it might be a sufficient tool for performing PTCA also in high-risk patients.

Adult↗
PubMed1997

Acute papillary muscle rupture in a patient with clostridial sepsis.

We describe the clinical course of a 58-year-old man who died from acute papillary muscle rupture as a complication of clostridial sepsis. There was no evidence for myocardial infarction, infective endocarditis, prior chest trauma or other known causes of papillary muscle rupture. Histological specimens taken at autopsy demonstrated clostridial infection of the heart. To our knowledge the occurrence of papillary muscle rupture in the setting of clostridial sepsis has not yet been reported in the literature.

Acute Disease↗
PubMed1997

[Development and evaluation of a spectroscopy system for classification of laser-induced arterial fluorescence spectra].

The present study evaluated the potential of fluorescence guidance of laser angioplasty without using a second laser for fluorescence excitation. A prototype spectroscopy system with a grating spectrograph, microchannel plate, CCD array and digital image processor on a personal computer was developed and coupled to a clinical XeCl excimer laser. Using multifibre catheters, specimens of human aorta were ablated in physiological saline and blood. The spectra thus generated were recorded and validated histologically. Five types of spectra could be differentiated. Based on a training set, classification algorithms were developed using multiple linear regression and linear discriminant analysis with intensity ratios as predictor variables. Discriminant analysis yielded prospective classification of the remaining validation spectra with high sensitivity and specificity for each type. These data demonstrate that fluorescence spectroscopy during excimer laser ablation at 308 nm does not require a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically in physiological saline and blood.

Adult↗
PubMed1996

Cheyne-Stokes respiration and prognosis in congestive heart failure.

Patients with congestive heart failure (CHF) frequently demonstrate Cheyne-Stokes respiration (CSR) with repetitive arousals and oxygen desaturations during sleep. Although it was evident from early publications that CSR during the daytime is a poor prognostic indicator in patients with CHF, it was speculated recently that CSR occurring during sleep could impede left ventricular function and even survival. We therefore followed up 36 patients with CHF and a left ventricular ejection fraction < or = 40% who underwent a sleep study at our institution. The patients showed a reduced ejection fraction (20 +/- 8%) and CSR with a median of 19% of total sleep time (lower and upper quartiles 9% and 56%). In 12 +/- 9% of their time in bed, the arterial oxygen saturation was <90%. No patient was lost to follow-up, which lasted for 32 +/- 15 months (range 11 to 53). One-year survival was 86 +/- 6%, and 2-year survival was 66 +/- 8%. Univariate comparisons for survival between groups stratified by the amount of CSR revealed no significant difference (log rank test, p = 0.84). However, the 20 patients with a left ventricular ejection fraction <20% had a shorter mean survival time than patients with an ejection fraction >20% (9.5 vs 28.3 months; log rank test, p = 0.013). Two patients with CSR during the daytime died within 1 month. No other patient had CSR during the daytime, and only 1 patient without daytime CSR died within 1 month (chi-square test, p <0.001). Higher age, reduced carbon dioxide end-tidal partial pressure, and increased transit time were found to be significantly related to the amount of nocturnal CSR. In conclusion, CSR occurring during sleep has no important prognostic impact in patients with CHF, but CSR present during the daytime suggests a high likelihood of dying within a few months.

Aged↗
PubMed1996

Improvement of exercise capacity with treatment of Cheyne-Stokes respiration in patients with congestive heart failure.

OBJECTIVES: The aim of this study was to determine the impact of nasal nocturnal oxygen therapy on respiration, sleep, exercise capacity, cognitive function and daytime symptoms in patients with congestive heart failure and Cheyne-Stokes respiration. BACKGROUND: Cheyne-Stokes respiration is common in patients with congestive heart failure and is associated with significant nocturnal oxygen desaturation and sleep disruption with arousals. Oxygen desaturations and arousals cause an increase in pulmonary artery pressure and sympathoneural activity and therefore may reduce exercise capacity. Oxygen is an effective treatment of Cheyne-Stokes respiration and should improve exercise capacity in these patients. METHODS: The study was designed as a randomized crossover, double-blind, placebo-controlled trial: 22 patients were assigned to 1 week each of nocturnal oxygen and room air. After each week, polysomnography, maximal bicycle exercise with expiratory gas analysis and trail-making test were performed, and a health assessment chart was completed. RESULTS: Nocturnal oxygen significantly reduced the duration of Cheyne-Stokes respiration (162 +/- 142 vs. 88 +/- 105 min [mean +/- SD]; p < 0.005). Sleep improved as evidenced by less stage 1 sleep and fewer arousals (20 +/- 13 vs. 15 +/- 9/h total sleep time; p < 0.05) as well as more stage 2 and slow-wave sleep; nocturnal oxygen saturation also improved. Peak oxygen consumption during exercise testing increased after oxygen treatment (835 +/- 395 vs. 960 +/- 389 ml/min; p < 0.05). Cognitive function evaluated by the trail-making test improved, but daytime symptoms in the health assessment chart did not improve significantly. CONCLUSIONS: Successful treatment of Cheyne-Stokes respiration with nocturnal nasal oxygen improves not only sleep, but also exercise tolerance and cognitive function in patients with congestive heart failure.

Adult↗
PubMed1996

Infective endocarditis in the elderly in the era of transesophageal echocardiography: clinical features and prognosis compared with younger patients.

PURPOSE: Advanced age is considered to be associated with a more severe prognosis in infective endocarditis (IE), which is relevance in view of a change in epidemiology of the disease with an increasing proportion of elderly people. We wanted to examine whether in the era of improved diagnostic sensitivity for IE by transesophageal echocardiography the clinical course in elderly persons would be still more severe than in younger patients. PATIENTS: During the period from 1989 to 1993, 104 patients with 106 episodes of IE were treated at our university hospital. Three groups were compared: group A with 28 patients younger than 50 years, group B with 58 patients aged 50 to 70, and group C with 20 patients older than 70. Transesophageal echocardiography was performed in 78% of the patients; it was not performed in 22% of the patients with a conclusive transthoracic examination. The patients were followed up for an average of 25 months after the diagnosis. RESULTS: No significant differences were observed among the age groups with respect to the possible source of infection, the frequency of positive blood cultures, and the type of infective organisms. Elderly patients more often had predisposing valvular conditions (eg, degenerative and calcified lesions and prosthetic valves), which decreased the sensitivity of transthoracic echocardiography to 45% as compared with 75% in group A. Transesophageal echocardiography improved the diagnostic yield by 45% in group C and by 47% in group B. Vegetations were smaller in group C and B as compared with group A, whereas other echocardiographic characteristics were similar. Fever and leukocytosis were less frequent in group C (55% and 25%, respectively) than in group A (82% and 61%, respectively). The interval between the onset of symptoms and the diagnosis of IE was similar in all groups. Elderly patients underwent surgical therapy as frequently (65%) as the other groups. The 1-year survival in group C (26%) was comparable with that in group A (22%) and group B (22%). The major determinant of survival was the occurrence of embolic complications. CONCLUSION: Infective endocarditis in elderly patients caused less severe clinical symptoms than in young patients. The early diagnosis in elderly patients was facilitated by the high sensitivity of transesophageal echocardiography, which enabled the timely initiation of an appropriate medical and surgical therapy. This led to a clinical outcome similar to that for younger patients.

Adolescent↗
PubMed1996

Human corticotropin-releasing hormone and thyrotropin-releasing hormone modulate the hypercapnic ventilatory response in humans.

Human corticotropin-releasing hormone (hCRH) and thyrotropin-releasing hormone (TRH) are known to stimulate ventilation after i.v. administration in humans. In a placebo-controlled, single-blind study we aimed to clarify if both peptides act by altering central chemosensitivity. Two subsequent CO2-rebreathing tests were performed in healthy young volunteers. During the first test 0.9% NaCl was given i.v.; during the second test 200 micrograms of hCRH (n = 12) or 400 micrograms of TRH (n = 6) was administered i.v. Nine subjects received 0.9% NaCl i.v. during both rebreathing manoeuvres. The CO2-response curves for the two tests were compared within the same subject. In the hCRH group a marked parallel shift of the CO2-response curve to the left was observed after hCRH (P < 0.01). The same effect occurred following TRH but was less striking (P = 0.05). hCRH and TRH caused a reduction in the CO2 threshold. The CO2-response curves in the control group were nearly identical. The results indicate an additive effect of both releasing hormones on the hypercapnic ventilatory response in humans, presumably independent of central chemosensitivity.

Carbon Dioxide↗
PubMed1996

Clinical outcome and echocardiographic findings of native and prosthetic valve endocarditis in the 1990's.

Prosthetic valve endocarditis is considered to be associated with a more severe prognosis than native valve endocarditis. Among other factors, inappropriate visualization of vegetations in prosthetic valve endocarditis by transthoracic echocardiography is responsible for this observation. Since the introduction of transoesophageal echocardiography into clinical practice the diagnostic sensitivity and specificity of the detection of vegetations located on prosthetic valves have been enhanced. Therefore we aimed to determine and compare the prognosis of prosthetic valve endocarditis and native valve endocarditis in the era of this improved diagnostic approach. One hundred and six episodes of infective endocarditis in 104 patients were seen at our institution between 1989 and 1993. Eighty patients (77%) had native valve endocarditis and 24 (23%) had late prosthetic valve endocarditis. In the latter group two patients had recurrent infective endocarditis. Patients with prosthetic valve endocarditis were older (mean age 64 vs 54 years in native valve endocarditis; P < 0.001) and the majority was female (62% vs 38% in native valve endocarditis; P < 0.05). In prosthetic valve endocarditis, infection of a valve in the mitral position predominated (65% vs 30% in native valve endocarditis; P < 0.01), whereas in native valve endocarditis more than half the cases had isolated aortic valve endocarditis (51% vs 27% in prosthetic valve endocarditis; P < 0.01). In prosthetic valve endocarditis more cases were caused by Staphylococcus aureus (31% vs 14% in native valve endocarditis; P = 0.08), whereas in native valve endocarditis the most frequent organisms were streptococci (29% vs 19% in prosthetic valve endocarditis; P = 0.12). Differences in the clinical features of native valve endocarditis and prosthetic valve endocarditis could not be found except for a higher rate of embolism in native valve endocarditis (40% vs 19% in prosthetic valve endocarditis; P < 0.05). Vegetations could be detected by transthoracic echocardiography more frequently in native valve endocarditis (71% vs 15% in prosthetic valve endocarditis; P < 0.0001). Transoesophageal echocardiography visualized vegetations in 95% of the episodes of native valve endocarditis and in 80% of the episodes of prosthetic valve endocarditis (P = 0.09). Thus, the diagnostic gain by transoesophageal echocardiography was greatest in prosthetic valve endocarditis. Patients with native valve endocarditis had significantly larger vegetations than patients with prosthetic valve endocarditis (P < 0.05 for length, P < 0.001 for width). The median time to diagnosis was similar in native valve endocarditis and prosthetic valve endocarditis (31 vs 28 days). Surgery was performed in 74% of patients with native valve endocarditis and in 58% of those with prosthetic valve endocarditis; the median time delay between the diagnosis of infective endocarditis and surgery tended to be shorter in prosthetic valve endocarditis than in native valve endocarditis (45 vs 60 days). The in-hospital mortality and the mortality during a follow-up of 22 +/- 10 months did not significantly differ between native valve endocarditis and prosthetic valve endocarditis (21% vs 17%; 28% vs 25%). In summary in the era of transoesophageal echocardiography, late prosthetic valve endocarditis does not seem to carry a worse prognosis than native valve endocarditis. This can be attributed in part to the improved diagnostic accuracy achieved by transoesophageal echocardiography leading to comparable diagnostic latency periods in both patient groups. Finally, better characterization of vegetations on prosthetic valves by transoesophageal echocardiography allows early lifesaving surgery in patients with prosthetic valve endocarditis.

Endocarditis, Bacterial↗
PubMed1996

Ventilatory response to exercise and to carbon dioxide in patients with heart failure.

Patients with heart failure exhibit an increased ventilatory response to exercise; their slope of the overall ventilation/carbon dioxide production ratio (VE/VCO2) is elevated. This elevation is related to impaired exercise performance and is commonly explained by an increased ventilation-perfusion mismatch. However, the concept of afferents to the respiratory centre modulating ventilation during exercise has been raised. In healthy subjects, ventilation during exercise is related to the hypercapnic ventilatory response during rebreathing. This is explained by a similar response of the respiratory centre to different stimuli. The aim of this study was to analyse the relationship between the ventilatory response to exercise and to carbon dioxide in patients with chronic heart failure. The hypercapnic ventilatory response was measured at rest using the rebreathing method in 31 patients with chronic heart failure and a left ventricular ejection fraction < 40% and 25 controls. Thereafter a maximal bicycle exercise test with evaluation of VE/VCO2 was performed. The maximal oxygen uptake during exercise was 13.1 +/- 5.2 ml. min-1.kg-1. The slope of the hypercapnic ventilatory response was normal (1.1 +/- 0.81. min-1. mmHg-1) but minute ventilation breathing room air was increased in the patients as compared to the controls. VE/VCO2 during exercise was positively correlated to the hypercapnic ventilatory response (r = 0.70; P < 0.00001). This relationship supports the concept that in patients with heart failure, ventilation during exercise is not only influenced by an increased ventilation-perfusion mismatch but is in part mediated by the responsiveness of the respiratory centre. Different afferents to the respiratory centre, such as central command or muscle ergoreflex may play a role in modulating ventilation during exercise.

Aged↗
PubMed1996

[Nocturnal oxygen administration and cardiac arrhythmias during Cheyne-Stokes respiration in patients with heart failure].

Cheyne-Stokes respiration (CSR) is common during sleep in patients with severe congestive heart failure. It is not clear, if there is a relation between CSR and arrhythmias. Therefore in this study the impact of the nocturnal CSR on ventricular arrhythmias and the heart rate, as well as the influence of nasal nocturnal oxygen on CSR and sleep was studied. In a randomized, double-blind, crossover study 22 patients were assigned to 1 week each of oxygen and room air. The age of the patients was 57 +/- 10 years. Their mean left ventricular ejection fraction was 18.9 +/- 6.4%. Breathing oxygen significantly reduced the duration of CSR by over 50% (162 +/- 142 vs 88 +/- 106 min, p < 0.05). Sleep did improve as evidenced mainly by less arousals (21 +/- 13 vs 15 +/- 9/h total sleep time; p < 0.05) and stage 1 sleep as well as more stage 2 and slow wave sleep. Nocturnal oxygen resulted in a reduction of ventricular arrhythmias for ventricular ectopic beats (53.1 +/- 157.7 vs 44.7 +/- 97.1/h), couplets (9.0 +/- 38.3 vs 3.7 +/- 14.3/h) and tachycardias (1.8 +/- 7.2 vs 0.4 +/- 0.8/h). Due to the high day-today variability these differences were not significant, but the decrease of average nocturnal heart rate with oxygen was (71 +/- 14 vs 68 +/- 14/min; p < 0.05). In conclusion, nocturnal oxygen causes a reduction of CSR, an improvement of sleep and a decrease of arousals. A significant reduction of arrhythmias by nocturnal oxygen could not be proved.

Adult↗
PubMed1996

Prevalence of obstructive sleep apnoea in patients with coronary artery disease.

BACKGROUND: Obstructive sleep apnoea (OSA) is characterized by recurring upper airway collapse with continual respiratory effort during sleep, causing apnoea, a fall in arterial oxygen saturation, arousal and excessive daytime sleepiness. It is a common disorder, with an estimated prevalence of about 1-5% in the adult population. OSA is related to arterial hypertension, an essential risk factor for the development of coronary artery disease (CAD). Furthermore, a high dietary intake is a common risk factor for OSA as well as for CAD. OBJECTIVE: To investigate the prevalence of OSA in CAD patients. METHODS: A random sample of 50 patients (aged 61 +/- 6 years, body mass index 26.8 +/- 3.8 kg/m2) diagnosed to have CAD by coronary angiography was investigated prospectively. Respiration and nocturnal oxygen saturation were registered during one night. Snoring and daytime sleepiness were evaluated by a questionnaire. RESULTS: In 25 patients the apnoea index was > 10/h sleep. Excessive daytime sleepiness was exhibited by eight of these patients. Nineteen of the patients with an apnoea index > 10/h participated in a full night polysomnography. The apnoea index was 17.0 +/- 10.9/h and the apnoea-hypopnoea index was 32.4 +/- 16.5/h sleep. The mean nadir oxygen saturation was 87.3 +/- 1.6% and the minimal oxygen saturation was 75.5 +/- 10.6%. For seven patients the apnoea index was > 20/h. CONCLUSION: CAD patients have a high prevalence of OSA. Since obstructive apnoeas may trigger severe cardiac events such as myocardial ischaemia or ventricular tachycardias in CAD patients, the presence of OSA in these patients should be considered.

Aged↗
PubMed1995

[Sleep-related breathing disorders in patients with coronary heart disease].

INTRODUCTION AND AIM OF STUDY: Obstructive sleep apnoea (OSA) favours the development of arterial hypertension independently of body-weight and may thus have an effect on coronary heart disease (CHD). This study was undertaken to determine the prevalence of OSA in patients with CHD. PATIENTS AND METHODS: From among all patients in whom left heart catheterization with coronary angiography had provided the diagnosis of coronary heart disease 50 were randomly chosen (47 men, 3 women; mean age 61 +/- 6 years) for further investigations. During the night airway flow, heart rate, body position and arterial oxygen saturation were recorded. The patients also had to fill in a questionnaire concerning tiredness during the day and any snoring. Polysomnography was performed in all those whose apnoea index (AI) was > 10/h. RESULTS: 25 patients had an apnoea index of > 10/h. Eight of them also had increased tiredness during the day. The patients with an AI > 10/h were significantly older than those in whom it was < or = 10/h (63.1 +/- 3.5 vs 58.4 +/- 7.2 years; P < 0.002) and also had a higher body-mass index (27.8 +/- 4.2 vs 25.7 +/- 3.0 kg/m2; P < 0.05). Polysomnography, done in the sleep laboratory, in 19 of the 25 patients with an AI > 10/h registered an average AI of 17.0 +/- 10.9 per hour sleep; in seven patients it was > 20/h. CONCLUSIONS: The prevalence of obstructive sleep apnoea (OSA) is higher in patients with coronary heart disease (CHD) than in the healthy population. As OSA associated with a marked fall in nocturnal blood oxygen saturation and a rise in blood pressure may cause myocardial ischaemia, OSA should also always be considered when CHD is diagnosed.

Anthropometry↗
PubMed1995

Ventilation and dyspnoea during exercise in patients with heart failure.

Patients with chronic heart failure have an increased ventilation/carbon dioxide production ratio (VE/VCO2) during exercise. Recently it was discussed whether the cause of this increase was a ventilatory stimulus driven other than by CO2. Dyspnoea during exercise is thought to be related to impaired respiratory function. However, clinical confirmation is scarce. Ninety-two patients (age 51 +/- 9 years) with heart failure due to idiopathic dilated cardiomyopathy exercised on a bicycle ergometer to exhaustion, and measurement of ventilatory gases and Swan-Ganz catheterization were performed. The maximal oxygen consumption corrected for body weight (VO2max. kg-1) was 16.6 +/- 5.5 ml x min-1 x kg-1. The increase in (VE/VCO2) during exercise was related to an increase in respiratory rate (r = 0.43; P < 0.00001) but not to an increase in cardiac index or capillary wedge pressure. Nineteen patients stopped exercising because of dyspnoea. Their maximal tidal volume and VO2max . kg-1 were lower than the 67 patients who stopped exercise because of fatigue (P < 0.001 and P < 0.00001 respectively). Other variables showed no significant difference. In conclusion, the increase in VE/VCO2 during exercise may reflect a non-CO2 driven ventilatory stimulus as it cannot be attributed to increased pulmonary vascular pressures or an insufficient increase in cardiac output leading to a ventilation-perfusion mismatch. Low oxygen uptake is a prominent finding in patients with chronic heart failure who experienced dyspnoea during exercise, and dyspnoea is in part related to impaired respiratory function.

Adult↗
PubMed1995

Obstructive sleep apnoea and signal averaged electrocardiogram.

Patients with obstructive sleep apnoea demonstrate an increased rate of ventricular arrhythmias. The present study was designed in order to investigate whether these arrhythmias may be related to myocardial injury, since myocardial injury of various aetiologies has been observed to change the signal averaged electrocardiogram (ECG). Signal averaged ECG was registered in 23 patients with obstructive sleep apnoea diagnosed by polysomnography (apnoea index 43 +/- 20 events.h-1, age 55 +/- 10 yrs). QRS duration, root mean square voltage of the last 40 ms of QRS, and low amplitude (< 40 mV) signal duration were determined from the vector magnitude of the QRS, high-pass filtered at 40 Hz. Patients with coronary heart disease or bundle branch block were excluded. No patient showed an abnormal signal averaged ECG. Mean duration of the filtered QRS complex was 96 +/- 9 ms, root mean square voltage 38 +/- 18 microV and low amplitude signal duration 26 +/- 8 ms. These results were not significantly different from 14 snoring subjects with an apnoea/hypopnoea index < 10. Four patients showed no ventricular arrhythmias and six patients had Lown III or IVa in the Holter ECG. Echocardiography revealed increased left atrial (43.7 +/- 4.1 mm) and interventricular septal diameters (11.3 +/- 1.4 mm). In conclusion, obstructive sleep apnoea does not generate a substrate for late potentials in the signal averaged ECG.

Arrhythmias, Cardiac↗
PubMed1995

[Elimination of periodic respiration in heart failure by heart transplantation].

Patients with heart failure are known to demonstrate periodic respiration during sleep. The mechanism behind periodic respiration is thought to be related to left heart enlargement causing an increased transit time between lung and chemoreceptors leading to an oscillation of the feed back loop controlling respiration. Additionally hyperventilation was shown to play an important role. We report of an 18 year old patient with idiopathic dilated cardiomyopathy (left atrial 52 mm, left ventricular end diastolic diameter 69 mm). Polysomnography revealed prolonged transit time and periodic respiration with impaired sleep. Hypocapnia and hyperventilation was demonstrated. Following successful cardiac transplantation periodic respiration was absent and transit time was normal. There was no hypocapnia or hyperventilation. Hypercapnic ventilatory response did no change. These findings support the model of an oscillation of the feed back loop controlling respiration as the main pathomechanism behind periodic respiration.

Adolescent↗
PubMed1995

Diagnostic value of transesophageal compared with transthoracic echocardiography in suspected prosthetic valve endocarditis.

To compare transthoracic (TTE) and transesophageal (TEE) echocardiography specifically in prosthetic valve endocarditis, 73 consecutive patients (age, 7 to 80 years) with 86 prostheses who had TTE and TEE for suspected endocarditis were analyzed retrospectively. Thirty-four patients proved to have endocarditis according to clinical criteria (pathoanatomical confirmation in 16), the remaining 39 served as controls. In the endocarditis group, a total of 38 (25 mitral, 13 aortic) prostheses were investigated. Vegetations were detected by TTE in 5 (all aortic) and TEE in 28 (20 mitral, 8 aortic) prostheses (13 vs 74%, p < 0.0001). An annular abscess was found on TEE in 1 mitral implant (3%). New perivalvular regurgitation was demonstrated on TTE in 7 (2 mitral, 5 aortic) and on TEE in 16 (10 mitral, 6 aortic) prostheses (18 vs 42%, p = 0.025). All in all, abnormalities suggestive of endocarditis were revealed on TTE in 10 (2 mitral, 8 aortic) and on TEE in 35 (23 mitral, 12 aortic) prostheses (sensitivity 26 and 92%, p < 0.0001). In the control group, TEE was false positive in 1 mitral prosthesis (specificity for TTE and TEE 100 and 97%, respectively; p = NS). These results indicate that TEE is markedly superior to TTE in prosthetic valve endocarditis. The diagnostic advantage is most evident in mitral prostheses. This holds for the detection of both morphologic changes and prosthetic malfunction.

Abscess↗
PubMed1995

[Therapy of Cheyne-Stokes respiration with nocturnal oxygen therapy].

Cheyne-Stokes respiration is common in patients with severe congestive heart failure and is associated with significant nocturnal oxygen desaturation and sleep disruption. The pathogenesis of Cheyne-Stokes respiration in patients with congestive heart failure has been well described and is related to prolonged circulation time between the lung and the carotid body mainly due to increased cardiac dimensions, reduced body stores of oxygen and carbon dioxide, disturbance of ventilation and respiratory control due to arousals and a relatively high hypercapnic ventilatory response. Oxygen is likely to reduce Cheyne-Stokes respiration by increasing oxygen and carbon dioxide stores and reduces the hypercapnic ventilatory response. In the following paper we describe a study designed to determine the impact of nasal nocturnal oxygen on Cheyne-Stokes respiration, sleep, peak oxygen consumption during bicycle exercise, cognitive function evaluated by the trailmaking test and daytime symptoms in patients with severe congestive heart failure. The study is designed as a randomized, cross-over, double-blind, placebo-controlled protocol on about 20 patients with a left ventricular ejection fraction < 35%.

Arousal↗