[Appetite depressants and pulmonary hypertension]

In 1996 the total number of prescriptions of the appetite depressant drugs fenfluramine and phentermine exceeded 18 million in the United States. Clinical observation and experimental evidence back in the early 1980's showed that these drugs can cause a pulmonary hypertension. We report the case of a 30-year old woman with a history of seven month medication with dexfenfluramine. She developed severe pulmonary hypertension and right heart failure during late pregnancy. She died of septicemia with multiorgan failure 4 days after cesarean section. Pulmonary hypertension has been reported in association with treatment with fenfluramine and dexfenfluramine. These drugs may cause the increased precapillary resistant pressure through the vasoconstrictor action of serotonin. The typical histological finding is a plexogene pulmonary arteriopathy and valvular heart disease. After these observations the drugs were withdrawn.

[Febrile state, bloody diarrhea and megacolon]

We report about a forty year old female patient with severe bloody diarrhoea and fever over a period of 14 days due to an infection with Salmonella enteritidis. X-ray of the abdomen showed a toxic megacolon. With the diagnosis of an infectious colitis we started therapy with ciprofloxacin i/v. The toxic megacolon progressed despite intensive care and parenteral nutrition. Additionally the patient received metronidazole i/v and in combination with a roll technique in bed in the knee-elbow-position the leucocytosis and the megacolon decreased. A toxic megacolon is in about 3% associated with an infection with Salmonella enteritidis. It is essentially diagnosed by X-ray. Patients should receive intensive care, and because of the high mortality rate an interdisciplinary management is required. The article discusses the major differential diagnosis of the toxic megacolon, as well as the pathogenesis and therapy of Salmonella ent, infection. In case of an infection with Salmonella ent. physicians should acknowledge the possibility of development of a toxic megacolon.

[Cardiopulmonary involvement in thyroid gland diseases]

Thyroid hormones exercise a direct influence on the lung and myocardium. It has been found that at the heart of patients suffering from hyperthyroidism there is an increased production of contractile proteins and a redistribution of myosin Isoenzymes. Reduced efficiency results from the increased oxygen consumption and insufficient adaptation of the heartbeat to stress. Thyroid hormones are responsible for reducing arterial resistance; a higher incidence of supraventricular arrhythmias has been observed. In contrast, the cardiac changes in hypothyroidism are associated with an enhanced deposition of glycosaminoglycan in the myocardium. Besides bradycardia and low voltage there is an increased incidence of pericardial, pleural and peritoneal effusions with high protein content. Patients suffering from hypothyroidism have a higher incidence of atherosclerotic changes. Hypothyroidism is associated with a reduction of the beta-adrenergic receptors, and hence disturbances of rhythm are rare and do not increase even under substitution therapy. Pulmonary involvement in hyperthyroidism is evident from an enhanced respiratory minute volume, a reduced vital capacity, and dyspnoea at rest. In patients suffering from hypothyroidism, hypoventilation reduces the efficiency. Over and above this, myopathic changes of the respiratory muscles have been described. Involvement of thyroid hormones in the maturing of type II pneumocytes and of the surfactant factor has also been under discussion.

Impaired cardiopulmonary exercise capacity in patients with hyperthyroidism

STUDY OBJECTIVE

Hyperthyroidism (H) has been implicated as a primary cause of decreased exercise tolerance. To our knowledge, analysis of respiratory gas exchange, an efficient noninvasive method in evaluating cardiopulmonary capacity, has not been performed in patients with H.

PATIENTS

Using cardiopulmonary exercise testing, 12 consecutive women with Graves' H were examined and controlled in euthyroidism (E). Eighteen women with E, in whom cardiac catheterization had ruled out heart disease, served as control subjects (C).

MEASUREMENTS

The ventilatory anaerobic threshold was determined by means of the V-slope method. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol of 20 W/min. Echocardiography at rest was performed in all patients.

RESULTS

In patients with H, heart rate at rest was higher than in patients with E (p < 0.05) and showed a markedly lower increase between rest and anaerobic threshold compared with E patients (p = 0.007) and C (p = 0.009). Work rate was reduced (H, 50% vs E, 70%; p = 0.038). In H patients, the anaerobic threshold occurred at 59.6% of maximal oxygen uptake and 72% in E patients, respectively (p = 0.024). In H patients, the linear regression of the heart rate to oxygen uptake ratio showed a reduced slope in comparison with E patients (p = 0.001) and C (p = 0.004). In patients with H, a reduced tidal volume (p = 0.021) and an increased respiratory rate (p = 0.003) in comparison to patients with E were demonstrated. Echocardiographically, H patients had an increased ejection fraction (p = 0.008) and a higher cardiac index (p = 0.008) in comparison with E patients.

CONCLUSIONS

Analysis of respiratory gas exchange showed marked alterations of cardiopulmonary exercise capacity in H patients, which are reversible in E patients. The impaired chronotropic response during exercise might be the primary limiting factor of reduced work capacity in patients with H.

[Cardiovascular parameters in transient hypothyroidism]

Cardiovascular manifestations are a frequent finding in hypothyroidism. Thus, blood-pressure measurements, longtime electrographic monitoring, and spiroergometry were examined in 20 patients with transitory hypothyroidism. In the patients with thyroid carcinoma, total thyroidectomy was performed. Measurements were made in hypothyroidism and after TSH-suppression with L-thyroxine. Thirty-five patients in whom intracardiac catheter examination ruled out cardiopulmonary disease served as controls. Cardiopulmonary exercise was done by bicycle exercise testing. In transitory hypothyroidism an increase of diastolic blood pressure was found at rest (p = 0.02) and during exercise (p = 0.002), which was reversible after T4-therapy. Compared to the controls diastolic blood pressure in hypothyroidism was increased at rest (p = 0.014) and during exercise (p = 0.005). ECG-monitoring showed a day-night difference in heart rate in hypothyroid patients and after therapy. The mean heart rate (74 vs. 88 beats per minute; p = 0.0006), the minimal (p = 0.0062) and the maximal heart rate (p = 0.0016) during the day were decreased in hypothyroidism compared to euthyroidism. There were no atrioventricular blocks in transitory hypothyroidism and no increase of ventricular or supraventricular premature beats after high-dose T4-treatment. Spiroergometry showed no change in ventilation and an increased growth in heart rate (p = 0.021) associated with good working capacity in hypothyroid patients. Heart rate at rest (p = 0.004) and at the anaerobic threshold (p = 0.03) were decreased in transitory hypothyroidism.

[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.