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Biomedical subjects

O Nyquist

Publications and source records attributed to O Nyquist.

18 recordsLinked to original sources
PubMed1991

Induction of a reduction in haemoglobin concentration by enalapril in stable, moderate heart failure: a double blind study.

OBJECTIVE: To study the long term effects (12 weeks) of enalapril on central haemodynamic function and on arterial oxygen content and its determinants--haemoglobin concentration and oxygen saturation--in patients with stable moderate heart failure. DESIGN: Double blind placebo controlled randomised study. PATIENTS: 17 patients with stable moderate heart failure caused by dilated cardiomyopathy which was treated with diuretics and digoxin. METHODS: Central haemodynamic function, arterial oxygen content, arterial haemoglobin concentration, and arterial oxygen saturation were measured at rest and during submaximal exercise. Plasma volume and total body haemoglobin were determined at rest. RESULTS: With enalapril treatment heart rate, pulmonary capillary wedge pressure, mean arterial pressure, and systemic vascular resistance decreased significantly both at rest and during submaximal exercise. Cardiac output did not change at rest but tended to increase (p = 0.06) during submaximal exercise. Arterial oxygen saturation remained unchanged while haemoglobin concentration and arterial oxygen content were significantly reduced. Total body haemoglobin was significantly reduced but the plasma volume remained unchanged. At rest, the reduction in arterial oxygen content resulted in a significantly reduced mixed venous oxygen content. However, during submaximal exercise the increase in cardiac output fully compensated for the reduction in arterial oxygen content and this effect was indicated by the unaltered mixed venous oxygen content. No changes were found in the placebo group after twelve weeks. CONCLUSIONS: Enalapril unloads the heart and reduces haemoglobin concentration. During submaximal exercise, the improvement in systemic blood flow was counterbalanced by this negative effect on the oxygen carrying capacity and systemic oxygen delivery was unchanged.

Adult↗
PubMed1990

Short term haemodynamic effects of converting enzyme inhibition before and after eating in patients with moderate heart failure caused by dilated cardiomyopathy: a double blind study.

The haemodynamic changes that follow a meal can mimic the response to a vasodilator drug. To avoid overestimating the beneficial effects of treatment in uncontrolled studies, measurements of haemodynamic function are usually performed with patients in the fasting postabsorptive state. But such recordings are not representative of the resting patient during daily life. In this double blind placebo controlled study the short term haemodynamic effects of enalapril were assessed during 12 hours in 19 patients with moderate heart failure caused by dilated cardiomyopathy. The patients ate lunch and dinner and were studied in the absorptive and postabsorptive phases. In the placebo group systemic vascular resistance, mean arterial pressure, and the rate-pressure product fell significantly (5-16%) after lunch. Four hours after lunch the haemodynamic function had returned to baseline--that is the postabsorptive state. Enalapril, accentuated the haemodynamic effects during the absorptive state producing a larger post-prandial fall in mean arterial blood pressure and rate-pressure product and changes in the absorptive phase were maintained into the post-absorptive phase. Pulmonary wedge pressure fell significantly after treatment with enalapril. These overall changes during the study period indicated that enalapril reduced the preload and afterload on the heart--over and above the reduction produced by eating. These findings suggest that the effects of enalapril given at rest to patients with moderate heart failure unload the heart and enhance the reduction of afterload induced by meals.

Adult↗
PubMed1990

The use of a vasodilator, felodipine, as an adjuvant to long-term oxygen treatment in COLD patients.

Eight patients with chronic obstructive lung disease (COLD) and pulmonary hypertension were given an infusion of a calcium antagonist, felodipine, during ongoing, long-term oxygen treatment (LTOT). The effects on central haemodynamics and ventilation-perfusion matching were studied. At rest pulmonary and systemic vascular resistances (PVR and SVR) were reduced by 18% (NS) and 26% (p less than 0.05), respectively. Cardiac output increased by 23%. There was a tendency to increased perfusion of low alveolar ventilation-perfusion ratio (VA/Q) areas (VA/Q less than 0.1) and to increased shunt compared to pretreatment values. Arterial oxygen tension (PaO2) fell by 0.7 kPa (p less than 0.001) but total oxygen transport increased by 23% (p less than 0.001). After treatment with oral felodipine (7.5-15 mg.day-1) for a mean time of 14 wks, PVR and SVR were reduced by 16% (p less than 0.05) and 7% (NS), respectively, as compared to pretreatment values at rest. Cardiac output rose by 13%. The VA/Q ratios and the PaO2 returned towards pretreatment values. The total oxygen transport increased by 11% (p less than 0.05) at rest and increased by 19% (p less than 0.05) during exercise as compared to the pretreatment value. The positive effect on central haemodynamics indicates that felodipine may be a valuable adjunct to ongoing LTOT.

Aged↗
PubMed1979

Peripheral hemodynamics in assisted circulation with intra-aortic balloon pumping in patients with cardiogenic shock.

Seven patients treated for cardiogenic shock were studied with and without intra-aortic balloon pumping (IABP). Calf and forearm blood flows were determined with a Dohn plethysmograph and arterial pressures were registered intra-arterially and in the great toe and thumb with the cuff method. During IABP, an augmented flow was registered in the arms and legs and accurate arterial BPs could also be determined from the extremities. The findings demonstrate a beneficial effect of IABP on peripheral flow, expecially in patients who could be weaned off the pump.

Aged↗
PubMed1979

Mortality, arrhythmias and pump failure in acute myocardial infarction in relation to estimated infarct size.

Serial estimations of total serum creatine kinase (S-CK) were made in 194 consecutive patients with acute myocardial infarction (AMI). By itself, the maximum CK value could not separate patients in terms of high and low mortality but when the maximum CK value was related to age for patients with and without a history of previous AMI, two subgroups became apparent, one with 46% mortality (high-risk group) and another with 6% (low-risk group) during the hospital stay plus the next 90 days. In 114 of the patients, infarct size could be calculated. A good correlation was found between maximum CK and calculated infarct size (r = 0.93). Calculated infarct size alone could not distinguish between high and low mortality but when it was related to age for patients with and without a history of previous AMI, two subgroups emerged, one with 43% mortality and another with 3% during the hospital stay plus the next 90 days. The incidence of ventricular tachycardia during the stay in the Coronary Care Unit did not differ between the two risk groups separated either by maximum CK value or calculated infarct size. However, the incidence of shock and severe left heart failure during the acute phase was higher in the high-risk groups.

Acute Disease↗
PubMed1979

Intraaortic balloon pumping in the treatment of cardiogenic shock complicating acute myocardial infarction.

A 5.1% incidence of cardiogenic shock was found in consecutive series of 680 patients with acute myocardial infarction (AMI) during a five-year period. The hospital mortality was 94%. Shock was treated according to a stepwise policy including assisted circulation with intraaortic balloon pumping (IABP). During the five-year period, only five patients, 14% of the shock patients, had shock for more than three hours (the minimal time for attempting medical therapy and preparing for assisted circulation), were below 75 years of age and without terminal diseases. Together with ten AMI patients in shock referred from or treated in other hospitals, altogether 15 patients were given IABP during 1--318 hours (mean 58). Shock was reversed in 12 (80%) of these patients and five (33%) could be weaned off IABP and discharged from the CCU. However, only two patients (13%) were long-term survivors.

Acute Disease↗
PubMed1979

Patients treated in a coronary care unit without acute myocardial infarction: identification of high risk subgroup for subsequent myocardial infarction and/or cardiovascular death.

Consecutive patients admitted to a coronary care unit (CCU) during one year were studied. The diagnosis of acute myocardial infarction was not substantiated by our criteria in 206 of the patients discharged from the CCU. Of these, 193 were retrospectively followed up during one year. Seventeen of the patients (9%) died from cardiovascular causes during the 1-year period. Another 14 patients (7%) had a subsequent non-fatal acute myocardial infarction during the same period. The majority of the patients had coronary artery disease. Only 32 (17%) could be classified as non-coronary cases, and these had an excellent prognosis without any subsequent acute myocardial infarctions or deaths. The occurrence of transient ST-T shifts in serial electrocardiograms obtained during the first 3 days in hospital selected a subgroup of patients who had a high risk for subsequent non-fatal acute myocardial infarction and/or cardiovascular death. This high risk subgroup provides a basis for more aggressive diagnostic and therapeutic intervention.

Acute Disease↗
PubMed1979

A high risk subgroup of patients with unstable angina pectoris treated medically or surgically.

Among patients consecutively admitted to a coronary care unit (CCU) without a subsequent diagnosis of acute myocardial infarction (AMI), a subgroup fo unstable angina was selected, defined as continued episodes of angina at rest during a 48-hour period, despite medical treatment in the CCU. During a four-year period, 15 patients fulfilled these criteria. Eight patients were medically treated, seven of whom developed an AMI with three subsequent deaths. Six of the infarcts occurred within eight days of admission. In six patients, fulfilling the criteria, surgical treatment was performed. Angiography and surgery in this group were associated with low incidences of myocardial infarction, late infarction and death. In one patient, surgery was declined due to unfavourable anatomical conditions. This patient subsequently developed an AMI and died. It is concluded that the combination of recent onset of angina and continued episodes of angina at rest, despite medical treatment, selects a high risk subgroup of unstable angina. Acute coronary angiography and surgery ought to be considered in this subgroup.

Aged↗
PubMed1979

Coronary artery spasm--a case with fatal outcome.

The case of a 45-year-old man with nocturnal angina and angiographically verified spontaneous spasm of the left anterior descending and left circumflex coronary arteries is described. The patient died suddenly one month after investigation, despite treatment with a beta-blocker and nitroglycerin. Other forms of pharmacological treatment should be tried in such patients.

Angina Pectoris↗
PubMed1975

Diazepam in cardioversion.

Diazepam has been used to an increasing extent in cardioversion, since avoiding general anaesthesia simplifier the procedure. The present study concerns the effect of diazepam on BP and blood gases in 13 cases of cardioversion. A moderate fall of both systolic and diastolic BP occurred. The arterial pO2 and pCO2 did not change significantly.

Aged↗
PubMed1975

Creatine phosphokinase after submaximal physical exercise in untrained individuals.

Serial estimations of total serum creatine phosphokinase (CPK) have been performed before and during 18-49 hours after submaximal physical exercise in 17 untrained individuals, mean age 50 years. The maximal CPK increase after exercise was 32 mU/ml (73%). The serum CPK did not exceed the upper normal limit (130 mU/ml) except in one individual (150 mU/ml). The maximal CPK increase in patients with acute myocardial infarction (AMI) varied between 101 mU/ml (133%) and 2 260mU/ml(3 790%), mean 900 mU/ml (1 184%). As the maximal CPK elevation in AMI occurs within the same period, it seems that heavy physical work of short duration just before the onset of symptoms will very seldom impair the diagnosis of AMI with the CPK technique used.

Adult↗
PubMed1975

Creatine phosphokinase following cardioversion.

Serial estimations of total serum creatine phosphokinase (CPK) have been performed before and during 18-51 hours after cardioversion of supraventricular tachyarrhythmias in 12 patients without acute myocardial infarction (AMI). The maximal CPK rise was 78 mU/ml (110%) and the CPK did not exceed the upper normal limit (130 mU/ml) in more than two patients (149 respectively 156 mU/ml). The CPK rise we have observed in a series of AMI patients varied between 101 (133%) and 2 260 mU/ml (3 780%), mean 900 mU/ml (1 184%). Therefore, cardioversion performed as described seldom seems to interfere with diagnosing AMI by serial estimations of serum CPK during the next 24 hours.

Aged↗