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.

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).

[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.

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.

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.

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.

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.

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.

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.

[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.

[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.

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.

[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.

Periodic respiration in patients with heart failure.

Patients with heart failure are known to demonstrate periodic respiration (PR) during sleep. The factors causing PR are not well known. We therefore studied 20 patients (aged 18-66 years) with idiopathic dilated cardiomyopathy.

Validation of automated sleep stage and apnoea analysis in suspected obstructive sleep apnoea.

Full-night polysomnography is necessary for the diagnosis of obstructive sleep apnoea (OSA). However, analysis of the sleep stages and apnoeas is time-consuming. Computer systems for automated analysis have, thus, been developed to alleviate this task.

[Why is the Doppler pressure gradient higher than the one measured by catheter?].

Hemodynamic assessment of aorto-iliac occlusive disease is necessary for successful arterial reconstruction of the legs. Various methods have been proposed and the "pull-through" intra-arterial pressure measurement method is accepted as the best standard. The pressure readings, however, seemed to depend on the intraluminal position of the catheter.

Changes in heart rate during obstructive sleep apnoea.

The mechanisms behind the decrease in heart rate during apnoeas in patients with obstructive sleep apnoea (OSA) are little known. Recent findings in animal experiments indicate that stimulation of the upper airway activates postinspiratory and cardiac vagal neurones in the medullary respiratory centre, causing alterations in heart rate and respiratory rhythm. Since OSA leads to a collapse of the airway and consequent stimulation of upper airway receptors, we studied the interrelations between heart rate and respiratory rhythm during apnoea and during negative intrathoracic pressure generated by the Mueller manoeuvre (MM).

[ST segmental changes and arrhythmias in obstructive sleep apnea].

Patients with obstructive sleep apnea show a fall in arterial oxygen saturation during apneas. Whether this is causing myocardial ischemia and consecutively ST segment depressions in the electrocardiogram is not known. Therefore 15 consecutive patients (53 +/- 8 years, apnea index 45 +/- 28, minimal oxygen saturation 71 +/- 14%) with OSA were studied by Holter electrocardiogram and polysomnography.

[Impaired diastolic ventricular function in dilated cardiomyopathy with variously reduced systolic function. A Doppler echocardiography analysis].

Diastolic ventricular function was assessed by Doppler echocardiography in 50 patients with idiopathic dilated cardiomyopathy (DCM) and sinus rhythm. The patients were subdivided into two groups with either a moderately reduced ejection fraction (less than 32%; group 1, n = 25) or a severely reduced ejection fraction (less than 32%; group 2, n = 25), the latter having an unfavorable prognosis. The degree of heart failure according to the NYHA classification was more pronounced in group 2 (p less than 0.

Doppler echocardiographic analysis of cardiac flow during the Mueller manoeuver.

The inspiration against a closed airway, the Mueller manoeuver, leads to a negative intrathoracic pressure. It is controversially discussed whether this is causing an augmentation of right heart murmurs. There is only limited knowledge on the temporal relationship of the negative intrathoracic pressure with right and left ventricular filling and stroke volume.

[Doppler echocardiography determination of systolic and diastolic function in sequential and ventricular stimulation].

In 16 patients with sequential pacing and partly impaired left-ventricular function (mean shortening fraction 23 +/- 7%), the flow through the mitral and aortic valves were studied with Doppler echocardiography at different AV-intervals, keeping heart rate constant at 70/min. The time-velocity integral of the early and late diastolic filling, the first one-third filling fraction, and the diastolic-filling time were found to be significantly dependent on the length of the AV interval (p less than 0.001).

Embolic mononeuropathy in subacute bacterial endocarditis.

A 49-year-old man presented with temperature up to 39.5 degrees C, a sudden peroneal nerve lesion, and a cardiac murmur. The peroneal nerve lesion was likely caused by an embolic occlusion of an artery supplying the nerve.

[Estimated relation of Doppler echocardiography parameters of diastolic ventricular function and pulmonary capillary pressure in acute ischemia].

A close relation between the Doppler-echocardiographic transmitral flow signal (TMF) and the left ventricular filling pressure in patients with coronary heart disease (CHD) was described in several reports. The present study investigated the validity of this relation during an episode of acute ischemia induced by coronary angioplasty (PTCA) by simultaneous recording of TMF and mean pulmonary capillary wedge pressure (PCm). Thirty-nine patients were examined at rest, and 33 of them were further studied during a subsequent PTCA of the left anterior descending artery (n = 22) or the right coronary artery (n = 11).

Impaired relationship between Doppler echocardiographic parameters of diastolic function and left ventricular filling pressure during acute ischemia.

The relationship between left ventricular filling pressure and Doppler echocardiographic parameters of diastolic mitral flow (MF) was evaluated in patients with ischemic heart disease during acute ischemia induced by percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery. Thirty-two patients were examined by simultaneous recordings of the Doppler MF signal and the mean pulmonary capillary wedge pressure (PCm) as an approximation of left ventricular filling pressure. At rest PCm was correlated with the early/late velocity integral ratio (Ei/Ai: r = 0.