Atrial natriuretic peptide in congestive heart failure

Effect of intracoronary transplantation of autologous bone marrow-derived mononuclear cells on outcomes of patients with refractory chronic heart failure secondary to ischemic cardiomyopathy

Recent studies have indicated that stem cell implantation increases cardiac function by repairing damaged myocardium. We investigated whether intracoronary transplantation of autologous bone marrow-derived mononuclear cells (BMMCs) confers beneficial effects in patients with refractory chronic heart failure. Twenty-eight patients received standard heart failure medication and BMMC transplantation (BMMC treatment) or standard medication only (controls). BMMCs were harvested from each patient. Clinical manifestations, biochemical assays, rhythm studies, echocardiograms, and positron emission tomograms were recorded. Fourteen patients with cell grafting had symptomatic relief of heart failure within 3 days. Left ventricular ejection fraction increased by 9.2% and 10.5% at 1 week and 3 months after the procedure, respectively, versus baseline (p < 0.01 for the 2 comparisons). Left ventricular end-systolic volume decreased by 30.7% after 3 months (p < 0.01). Brain natriuretic peptide levels at days 3 and 7 after cell infusion significantly decreased by 69.2% and 70.4%, respectively, whereas atrial natriuretic peptide levels increased by 30.1% at day 7. Positron emission tomographic analysis showed a significant increase in cell viability of 10.3% in the infarcted zone. No patient died in the BMMC-treated group at 6-month follow-up. In contrast, heart failure did not improve in any control patient. Left ventricular ejection fraction decreased by 7.2% after 3 months. Two control patients died from heart failure within 6 months. In conclusion, this is the first demonstration in humans that intracoronary BMMC transplantation is a feasible and safe therapeutic strategy to decrease symptoms, increase cardiac function, and possibly prolong life in patients with end-stage heart failure refractory to standard medical therapy.

Natriuretic peptide and echocardiography after operation of atrial septal defect

Patients benefit from surgical seclusion of atrial septal defect but have excessive cardiovascular morbidity after the operation. We evaluated haemodynamics and looked for abnormalities of cardiac structures and function late after surgical seclusion of the defect. Serum N-terminal natriuretic peptide measurement and transthoracic and transoesophageal echocardiography were performed in 61 patients aged 43+/-15 years (mean+/-standard deviation) 21+/-5 years after surgery. The findings were compared with 67 control subjects. The patients had higher serum N-terminal atrial natriuretic peptide concentration than the control subjects (0.40+/-0.32 vs. 0.24+/-0.12 nmol/l, P=0.0001). Peptide levels correlated with current age (P=0.0001) and age at operation (P=0.0014), but not with age in the control subjects. In the patients, echocardiography measurements of cardiac dimensions correlated with hormone levels (atrial natriuretic peptide concentration with left atrial end-systolic diameter (P=0.042), left ventricular end-diastolic (P=0.021) and end-systolic diameter (P=0.042). There were only 10 patients (16%) without any abnormality in echocardiography. Their peptide concentration was 0.25+/-0.18 nmol/l (P=not significant compared to the control subjects). The association between increasing N-terminal atrial peptide levels and operation age together with echocardiography findings support the clinical consensus of treating atrial septal defect patients in their childhood and adolescence.

Serum N-terminal atrial natriuretic peptide in adult patients late after surgical repair of atrial septal defect

BACKGROUND

The purpose of surgical closure of atrial septal defect (ASD) is to relieve the cardiovascular system from a haemodynamic burden. Excessive amounts of atrial peptides are released in congestive heart failure, valvular diseases and congenital heart diseases.

AIMS

To examine whether patients after surgical repair of ASD have higher concentrations of N-terminal atrial natriuretic peptide (ANP-N) than age-, sex- and body mass index (BMI)-matched control subjects.

METHODS

Medical history, physical examination, standard 12-lead electrocardiogram, and ANP-N concentrations were obtained in 65 adult patients operated for ASD at the age of 21+/-13 years (mean+/-standard deviation), 21+/-6 years after surgical closure of ASD. Sixty-seven healthy subjects matched for age, sex and BMI served as controls.

RESULTS

In the patients serum ANP-N was higher than in the control subjects 0.41+/-0.32 nmol/l, median 0.31 nmol/l, interquartile range (IQR) 0.21-0.49 nmol/l vs. 0.24+/-0.12 nmol/l, median 0.23 nmol/l, IQR 0.17-0.29 nmol/l, (P=0.0003). Patients with concomitant diseases had higher ANP-N concentrations (0.51+/-0.39 nmol/l, median 0.34, IQR 0.26-0.73 nmol/l) than ASD patients without any history or signs of disease (0.28+/-0.16 nmol/l, median 0.27, IQR 0.17-0.40 nmol/l, P=0.01). The 'healthy' ASD patients had higher hormone concentrations than age-, sex- and BMI-matched control subjects (0.28+/-0.16 median 0.27 nmol/l, IQR 0. 17-0.40 nmol/l and 0.21+/-0.07 nmol/l, median 0.20 nmol/l, IQR 0. 15-0.27 nmol/l, P=0.01). Multiple stepwise linear regression analysis showed that age at operation was strongly associated with the post-operative ANP-N concentration (r(2)=0.25, P=0.0002).

CONCLUSION

ASD patients have higher ANP-N concentrations late after surgical repair. Hormone levels correlate with age at operation. Our finding supports the clinical praxis of operating on these patients in their childhood and adolescence.

Low-dose vasopressin restores diuresis both in patients with hepatorenal syndrome and in anuric patients with end-stage heart failure

OBJECTIVES

The purpose of this study was to confirm earlier reports that low-dose vasopressin (LDVP) analogues promote urine output in patients with hepatorenal syndrome (HRS) and to check whether this mode of therapy could also be effective in renal shutdown due to nonhepatic conditions.

DESIGN

A prospective, open, interventional study.

SETTING

An intermediate-level (step-down) medical intensive care unit within a general medical ward of a large university-affiliated hospital.

SUBJECTS

Eighteen successive hospitalized patients with HRS (mean age 65 +/- 13 years) and 11 patients with end-stage congestive heart failure (CHF) (mean age 81 +/- 5 years) who failed to restore urine output with conventional treatment (fluids, dopamine, and diuretics) given for at least 24 h.

INTERVENTIONS

The patients received LDVP (1 IU h-1) continuously in addition to the conventional treatment.

MAIN OUTCOME MEASURES

Urine output and creatinine clearance every 24 h.

RESULTS

In the HRS group, before treatment the urine output was 155 +/- 9 mL 24 -1h (mean +/- SD). After treatment with LDVP for 24, 48, and 72 h, urine output improved to 1067 +/- 87, 1020 +/- 501, and 1311 +/- 988 mL 24 -1h, respectively (P < 0.0001 for all measures; two-tailed paired t-test). In the CHF group, before treatment the urine output was 99 +/- 99 mL 24 -1h. After treatment with LDVP for 24, 48, and 72 h, this improved to 1125 +/- 994 mL 24 -1h (P = 0.0028), 1821 +/- 1300 mL 24 -1h (P = 0.004), and 2920 +/- 2423 mL 24 -1h (P = 0.0012), respectively. The improvement in urine output was not accompanied by a parallel improvement in creatinine clearance. The overall outcome did not change, and all patients except two in each group succumbed to their end-stage disease, due to nonrenal causes.

CONCLUSIONS

LDVP is effective in restoring urine output both in HRS and in CHF. This suggests that LDVP affects mechanisms not specifically related to liver disease. LDVP may be useful in critical patients with renal shutdown whilst awaiting liver or heart transplantation.

The circulating renin-angiotensin system during treatment with metoprolol or captopril in patients with heart failure due to non-ischaemic dilated cardiomyopathy

OBJECTIVE

To investigate the effects of beta-blocker (metoprolol) or angiotensin-converting enzyme inhibitor (captopril) treatment on neurohormonal function in a randomized prospective study on patients with heart failure due to dilated cardiomyopathy.

PATIENTS

Fifty-four patients (42 men and 12 women, mean age 50 years) were studied. There were three patients in NYHA (New York Heart Association) functional class I, 32 patients in class II and 19 patients in class III.

METHODS

Measurements of plasma renin activity (PRA). plasma angiotensin II (A II) concentration and plasma atrial natriuretic peptide (ANP) concentration were made at rest and also in a subgroup (n = 32) during exercise. The urinary excretion of aldosterone was also determined. Investigations were performed at baseline, and after 3 and 6 months. Therapy was then stopped and the patients were re-investigated 1 month thereafter.

RESULTS

The mean level of PRA was normal at baseline, reduced during therapy with metoprolol, and increased during therapy with captopril. The mean plasma concentration of A II was reduced during exercise and there was a trend towards a reduction even at rest in the metoprolol group, but not in the captopril group. The urinary excretion of aldosterone decreased in both groups. The mean plasma concentration of ANP was elevated at baseline and declined during exercise in the metoprolol group.

CONCLUSION

In patients with dilated cardiomyopathy and only a partly activated renin-angiotensin system, both metoprolol and captopril reduced urinary excretion of aldosterone. Furthermore, metoprolol suppressed the exercise-induced increase in ANP, suggesting a favourable effect on ventricular performance.

Plasma brain natriuretic peptide--an independent predictor of cardiovascular mortality in acute heart failure

PURPOSE

To examine the prognostic importance of both plasma atrial natriuretic and B-(brain natriuretic peptide) following an episode of acute heart failure.

SUBJECTS AND METHODS

A prospective cohort of 91 patients admitted into hospital with acute heart failure were recruited. After initial in-hospital management plasma ANP and BNP levels were measured by radioimmunoassay, and echocardiography was performed on the same day. Patients were followed up for 12 months and the main outcome measure was cardiovascular death.

RESULTS

Plasma ANP and BNP levels were significantly higher in patients who died of a cardiovascular cause within 12 months (P<0.001 and P<0.0001, respectively) or at 1-month (P<0.05 and P<0.001) after recruitment. By Kaplan-Meier estimated life-table curves, patients with above median plasma ANP or BNP levels had significantly higher 1-year mortality (42.5% vs. 11.6%, both P<0.005). By multivariate Cox proportional hazard regression analysis, the plasma BNP level was the most important prognostic factor predicting mortality (chi2 = 18.3, P<0.0001), followed by age (chi2 = 11.5, P<0.001). Other factors including ANP, left ventricular ejection fraction by M-mode echocardiography, pulmonary arterial pressure, sex, cause of heart failure as well as New York Heart Association class were not significant.

CONCLUSION

A plasma BNP level has independent and at least short-term prognostic significance in patients admitted with acute heart failure. This non-invasive and readily available blood test should be considered for risk stratification in patients with acute heart failure.

Analysis of peptides derived from Pro Atrial Natriuretic Peptide that circulate in man and increase in heart disease

The present investigation was designed to determine the levels and circulating forms of peptides derived from Pro Atrial Natriuretic Peptide (ProANP) and to assess their usefulness as markers for severity of heart disease. A sensitive and specific "two-site" immunoradiometric assay (IRMA) for the measurement of C-terminal ProANP 99-126 (alpha ANP) and two radioimmunoassays (RIAs) for the measurement of N-terminal ProANP 31-67 and ProANP 79-98 were developed. Immunoassays were validated by measurement of circulating peptide concentrations in 15 normal volunteers and 44 patients with varying degrees of heart disease. Mean concentrations of immunoreactive (ir) alpha ANP, ProANP 79-98 and ProANP 31-67 in normal volunteers (n = 15) were 8.5 +/- 1.1, 143 +/- 16 and 587 +/- 83 pmoles/l, respectively, increasing in patients with mild heart disease (NYHA I to II; n = 22) to 17.1 +/- 2.1, 691 +/- 197 and 2160 +/- 540 pmoles/l with greatest increases being observed in patients with severe heart disease (NYHA III to IV; n = 22) of 103 +/- 23, 4550 +/- 590 and 10,600 +/- 1350 pmoles/l, respectively. RP-HPLC of pooled plasma revealed peaks corresponding to alpha ANP, beta ANP, ProANP 1-126, ProANP 1-98, ProANP 31-67 and ProANP 79-98, all apparently increased in heart disease. In conclusion, using a series of immunoassays, we observed the graded increase of alpha ANP, irProANP 31-67 and irProANP 79-98 with increasing severity of heart disease. All peptides proved useful markers, but only ProANP 79-98 levels were able to distinguish patients with mild heart disease (NYHA I) from normals. Finally, RP-HPLC analysis indicated that ProANPs 31-67 and 79-98 circulate as distinct entities, in addition to ProANP 1-98.

Pathophysiology of heart failure update: the role of neurohumoral activation in the progression of heart failure

Understanding the pathophysiologic mechanisms responsible for producing heart failure is necessary before effective treatments can be developed that increase survival and improve quality of life. Recent advances in the treatment of heart failure can be traced directly to improved appreciation of the role of neurohumoral activation in the pathophysiology of heart failure. Initially adaptive, neurohumoral activation ultimately results in a series of overadjustments that actively participate in the progression of heart failure. In this article, the role of neurohumoral activation, ventricular remodeling, and various peripheral vascular abnormalities in the pathophysiology of heart failure are explored.

Influence of angiotensin converting enzyme inhibition on relation of atrial natriuretic peptide concentration to atrial pressure in heart failure

OBJECTIVE

To examine the relation between haemodynamics and atrial natriuretic peptide concentration during short term angiotensin converting enzyme inhibition.

DESIGN

Patients were randomly allocated to receive placebo or one of three doses of the angiotensin converting enzyme inhibitor ramipril.

SETTING

Cardiac units of two tertiary referral hospitals.

SUBJECTS

38 Patients with stable congestive heart failure caused by ischaemic heart disease.

METHODS

Data were collected over a 24 hour period and assessed with the aim of distinguishing between the haemodynamic effects on plasma concentrations of atrial natriuretic peptide and the direct effects of the study drug, vasopressin concentrations, and angiotensin converting enzyme activity.

RESULTS

Pulmonary capillary wedge pressure was the main predictor of the plasma concentration of atrial natriuretic peptide. A higher plasma concentration of this peptide with a given pulmonary capillary wedge pressure was found after 24 hours of treatment with 2.5 mg and 5 mg of ramipril. Plasma concentration of the active metabolite, change in arginine vasopressin concentration or degree of angiotensin converting enzyme inhibition did not significantly predict change in plasma concentration of atrial natriuretic peptide or in the ratio of atrial natriuretic peptide concentration to pulmonary capillary wedge pressure.

CONCLUSIONS

A gradual increase in plasma concentration of atrial natriuretic peptide with a given pulmonary capillary wedge pressure, occurs during short term high degree inhibition of angiotensin converting enzyme. The causative mechanisms are yet to be identified. Such a change in the relation between central haemodynamics and atrial natriuretic peptide concentration may contribute to the beneficial effects of angiotensin converting enzyme inhibition in patients with congestive heart failure due to ischaemic heart disease.

Short-term effects of eating on vasoactive hormones and haemodynamics in patients with heart failure

OBJECTIVES

To investigate if eating can influence the measurements of vasoactive hormones or their relationship to important haemodynamic variables.

DESIGN

Haemodynamic variables and plasma concentrations of atrial natriuretic peptide (ANP), arginine vasopressin and angiotensin enzyme (ACE) activity were measured. During the 24-h study period the patients ate ordinary hospital meals and thus were studied both in the absorptive and post-absorptive phases.

SETTING

Two university hospitals in Sweden participated in the study.

SUBJECTS

Ten patients with heart failure, due to ischaemic heart disease.

INTERVENTION

Eating.

MAIN OUTCOME MEASURES

Change in haemodynamic variables and plasma concentrations of vasoactive hormones related to eating.

RESULTS

After a meal (absorptive phase) pulmonary capillary wedge pressure and plasma concentrations of ANP were significantly lower compared to the postabsorptive phase, 13 +/- 1.7 vs. 16 +/- 1.9 mmHg and 57 +/- 9.5 vs. 72 +/- 12.2 pmol l-1, respectively. The relationship between ANP and its main predictor, pulmonary capillary wedge pressure, was not altered during the study period. Plasma concentration of arginine vasopressin, ACE activity and mean right atrial pressure decreased with time and the cardiac index increased with time over the study period.

CONCLUSIONS

A meal may significantly influence plasma concentrations of ANP. Studies on vasodilator treatment and its interactions with ANP should take account of these basal fluctuations. The present data confirm previous reports on haemodynamic improvement during the first 24 h of supine cardiac catheterization in patients with heart failure, and add new information about decreasing concentrations of arginine vasopressin and ACE.

Calcitonin gene-related peptide is not elevated in rat plasma by heart failure or by neutral endopeptidase inhibition

Some studies have indicated that plasma calcitonin gene-related peptide (CGRP) increases in congestive heart failure (CHF). In vitro, neutral endopeptidase (NEP) cleaves CGRP. We studied CGRP-like immunoreactivity (CGRP-ir) in rat plasma in a coronary artery-ligation model of CHF with and without NEP inhibition. Rats with CHF (n = 6) and sham-operated controls (n = 6) were administered vehicle and, separately, SCH 34826, a NEP inhibitor, subcutaneously 90 mg/kg. Plasma sample was taken 60 minutes later. Seventeen untreated coronary-ligated rats with various degrees of CHF were studied separately. Systolic arterial pressure (SAP) was measured while conscious. All rats were killed by exsanguination, and heart and lungs were removed and weighed. In CHF rats, plasma atrial natriuretic peptide after vehicle (basal ANP) was 7.6-fold, but basal CGRP-ir was similar compared to controls. After SCH 34826, plasma CGRP-ir decreased marginally in CHF rats (57-> 51 ng/l, p = 0.011), and ANP increased 1.8-fold (418-> 730 ng/l, p = 0.001). In controls, these changes by SCH 34826 were small. Basal ANP correlated strongly with relative weight of heart (HE; R = 0.93, p < 0.001) and lungs (LU; R = 0.96, p < 0.001). There was no correlation between basal CGRP-ir, basal plasma renin activity (PRA), HE and LU. In the untreated coronary-ligated rats, plasma CGRP-ir did not correlate with HE, LU, SAP, plasma ANP or PRA, but plasma ANP correlated with HE (R = 0.62, p = 0.011) and LU (R = 0.70, p = 0.002). We conclude that, in rat plasma, CGRP-ir is not elevated either by NEP inhibition, or in post-infarction CHF.

Concurrent neutral endopeptidase and ACE inhibition in experimental heart failure: renal and hormonal effects

Neutral endopeptidase (NEP) inhibitors have been shown to strengthen the effects of endogenous atrial natriuretic peptide (ANP). It has been well documented that angiotensin I-converting enzyme (ACE) inhibitors act beneficially in chronic congestive heart failure (CHF). In the present study, renal and hormonal effects of SCH 34826, an orally active NEP inhibitor, were studied in a coronary-ligation model of experimental CHF in the rat. The effects were compared to those of captopril. The drugs were also administered in combination. In anaesthetized rats with CHF, SCH 34826 (90 mg kg-1 sc) elevated plasma ANP from 382 +/- 85 to 658 +/- 120 ng l-1 compared with vehicle (p = 0.002). In sham-operated control rats, plasma ANP also increased slightly from 52 +/- 6 to 70 +/- 9 ng l-1 (p = 0.05). Plasma renin activity did not change in either group. When given orally for 36 h (90 mg kg-1 b.i.d.), SCH 34826 enhanced natriuresis in controls but not in rats with CHF. Captopril (0.2 mg ml-1 in drinking water) enhanced natriuresis in CHF rats and both natriuresis and kaliuresis in controls. When SCH 34826 and captopril were combined, natriuresis was potentiated in control rats as compared with captopril alone; in rats with CHF, however, a brisk kaliuresis was seen. The excretion of cyclic guanosine monophosphate was enhanced in CHF rats by 52% during treatment with SCH 34826 but not with captopril or combination of the two drugs. Moreover, captopril suppressed aldosterone excretion both in CHF rats and controls when administered alone but not when combined with SCH 34826.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged neutral endopeptidase inhibition in heart failure

We studied the hormonal, renal and hemodynamic effects of prolonged treatment with SCH 39370, a new neutral endopeptidase (NEP) inhibitor, in experimental congestive heart failure (CHF). Coronary-ligated CHF rats and sham-operated controls received vehicle or SCH 39370 30 mg/kg s.c. twice daily for six days. In rats with heart failure, SCH 39370 elevated the high plasma atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP) levels 2-fold both initially and at the end of the experiment. Initially, water balance was more negative in SCH 39370-treated CHF rats than in those treated with vehicle. In all SCH 39370-treated rats, ANP, cGMP and electrolyte excretion and diuresis were pronounced for 6 h after injection but attenuated thereafter. Blood pressure and pulse remained unchanged. On reverse phase high performance liquid chromatography (HPLC), ANP-(99-126) appeared to be the only circulating form of ANP in rats with heart failure. Three forms have been discovered in patients with heart failure. HPLC revealed only intact ANP in plasma of rats with heart failure during SCH 39370 treatment. NEP inhibitors may provide a new tool for treating chronic heart failure.

Effects of dobutamine and salbutamol on haemodynamics and atrial natriuretic factor in patients with severe congestive heart failure

The influence of two cardiac inotropic drugs, dobutamine and salbutamol, on plasma atrial natriuretic factor (ANF) was investigated in 20 patients with congestive heart failure. All were in New York Heart Association class-III or IV. The patients underwent right heart catheterization with determination of central pressures, cardiac output, and pulmonary arterial plasma ANF during incremental infusions with dobutamine or salbutamol. Fourteen patients completed the study. Both drugs induced comparable increases in cardiac index and decreases in total systemic vascular resistance (P less than 0.01) without significant changes in central pressures. Heart rate rose after salbutamol (P less than 0.05), but not after dobutamine. No changes in plasma ANF were observed after either of the drug infusions. ANF secretion rate was calculated from simultaneous measurements of ANF in right atrial and pulmonary arterial plasma before and after salbutamol infusion, and median values rose more than seven-fold (P less than 0.05). The results demonstrate that ANF secretion rate is augmented after beta-adrenergic agents, possibly by a direct beta 2-adrenergic stimulation, in patients with severe congestive heart failure, and that changes in plasma ANF are an insufficient measure of ANF release when patient samples are small.

Plasma levels of atrial natriuretic peptide in patients with Duchenne's progressive muscular dystrophy

To study the relationship between plasma alpha-atrial natriuretic peptide (alpha-ANP) and cardiac function in patients with Duchenne's progressive muscular dystrophy (DMD), we measured plasma alpha-ANP levels in 51 patients with DMD and evaluated them according to the clinical severity of the disease and the echocardiographic left ventricular function. In many of the patients with DMD, plasma alpha-ANP levels were mildly elevated, but no clear correlation was observed between alpha-ANP levels and wall motion abnormalities of the left ventricle. The alpha-ANP level was moderately or markedly elevated (81 to 120 pg/ml) in 3 of the 16 patients with respiratory failure and extremely high (1208 pg/ml) in the one patient with congestive heart failure. Two patients with respiratory failure and one with congestive heart failure, in whom alpha-ANP levels were elevated, died within 2 months. Elevation of left atrial pressure as a result of left ventricular dysfunction caused by impairment of the myocardium and elevation of right atrial pressure as a result of pulmonary hypertension caused by impairment of the respiratory muscles are considered to be involved in the mechanism of increased plasma alpha-ANP levels in patients with DMD. It can be concluded that a moderate or marked elevation in plasma alpha-ANP levels in patients with terminal DMD is a sign of a poor prognosis and may be a useful index for the management of the disease.

Endocrinologic Warfare: The Role of Angiotensin-Converting Enzyme Inhibitors in Congestive Heart Failure

The angiotensin-converting enzyme (ACE) inhibitors represent the gold standard of vasodilator therapy for congestive heart failure through blunting of the endocrinologic manifestations of heart failure. The future role of these agents may be in the asymptomatic and mild stages of heart failure. ACE inhibitors have been shown to decrease morbidity and mortality with the natural history of this disease being altered. The future will bring many new ACE inhibitors to market, with the challenge for physicians and pharmacists to understand the important distinctions of each specific agent. © 1990 by W.B. Saunders Company.

Enalapril as initial and sole treatment in severe chronic heart failure with sodium retention

Five patients, who had never received any drug treatment but who had severe chronic congestive heart failure with salt and water retention, were studied before and after a single dose of enalapril (10 mg orally). Three patients continued on enalapril as monotherapy (10 mg b.d. orally) for one month. Central haemodynamics, body fluid volumes, renal function and plasma hormones were measured at rest. The initial mean right atrial pressure was 13 +/- 4 mm Hg, pulmonary wedge pressure 29 +/- 4 mm Hg and cardiac index 1.8 +/- 0.21/min/m2. Enalapril, given acutely, caused only small changes. Two patients were withdrawn after the single dose of enalapril and treated with diuretics for clinical reasons. The remaining three patients each lost more than 4 kg in weight after one month of treatment with enalapril alone. Total body exchangeable sodium and total body water were reduced but central haemodynamics were unchanged. Although enalapril was of some benefit when given alone to patients with severe congestive heart failure, all five patients were finally treated with diuretics for clinical reasons. Enalapril is not recommended as the initial and only therapy for patients with severe congestive heart failure.

The relation of atrial natriuretic factor to isolated atrial amyloid

Isolated atrial amyloid (IAA) is a very common age-related amyloid form which is seen only in the atria of the heart. Chemical characterization has indicated that the major subunit protein is atrial natriuretic factor (ANF). In this ultrastructural study we show that the fibrils in IAA most frequently are located extracellularly especially along the cell membranes of the myocytes, but that small deposits also seem to be present intracellularly. No obvious relation was noted between the fibrils and the endocrine granules. Antiserum to a low molecular fraction of IAA labeled amyloid fibrils and granules in the same way as a commercial antiserum to ANF, but no other structures in the myocyte. Finally we show that ANF can polymerize to fibrils with an amyloid appearance. The study thus supports the fact that ANF is an important and integrated part in the IAA fibrils.

Atrial natriuretic peptide during different pacing modes in a comparison with hemodynamic changes

The study investigates the response of atrial natriuretic peptide (ANP) to different cardiac pacing modes in comparison with hemodynamic changes. Ten patients underwent Swan-Ganz catheterization during pacemaker implant. Atrioventricular and ventricular pacing were performed consecutively at three pacing rate levels (80, 100, and 110 ppm). Blood samples were taken from the pulmonary artery for ANP determination, both basally and at the end of each pacing period. Concomitantly, mean pulmonary capillary wedge pressure (PCWP) and mean pulmonary artery pressure (PAP) were measured. Cardiac output (CO) was determined by thermodilution both basally and during the 110 ppm steps. During atrioventricular pacing, whereas no significant changes were observed for ANP, PCWP and PAP, CO increased significantly (P less than 0.0005). At the beginning of ventricular pacing hemodynamic parameters and ANP levels were comparable with those of baseline conditions. During subsequent ventricular pacing PCWP and ANP increased significantly at the 110 ppm rate step (P less than 0.05). PAP did not change significantly, whereas CO decreased in all cases (P less than 0.01). A positive correlation was observed between ANP and PCWP during ventricular (P less than 0.001), but not atrioventricular pacing. The results, while confirming the hemodynamic advantages of atrioventricular pacing, point to a major stimulation of ANP secretion during ventricular pacing. This fact, together with the observed drop in CO and the correlation between ANP and PCWP, suggest that the increase of ANP in ventricular pacing may be the expression of a compensatory mechanism to the hemodynamic disadvantages of atrioventricular asynchrony.

High serum erythropoietin levels are normalized during treatment of congestive heart failure with enalapril

Eighteen patients with dilated cardiomyopathy (three female, mean age 57 years), were treated for 48 weeks with enalapril added to digoxin and diuretic therapy for congestive heart failure of New York Heart Association (NYHA) functional class II (three patients). III (eight patients) and IV (seven patients), respectively. Serum levels of erythropoietin (EPO) were raised at the start (37 +/- 12.8 pmol 1(-1); mean +/- SD) and were normalized during enalapril treatment (17.5 +/- 9.9 pmol 1(-1) at 48 weeks; P less than 0.001). Serum EPO correlated at the start with NYHA functional class (r = 0.68; P less than 0.05). Normalization of elevated serum EPO concentrations during treatment with enalapril paralleled clinical and haemodynamic improvement, and probably reflected relief from renal hypoxia.