atrial-natriuretic-factor and Ductus-Arteriosus--Patent

To evaluate the role of atrial natriuretic peptide (ANP) in differentiating the aetiology of heart failure in children with left ventricular (LV) volume overload.. The study was conducted on 48 patients with LV volume overload (G one: rheumatic heart disease in failure; G2: compensated rheumatic heart disease; G3: congenital left to right shunt; and G4: dilated cardiomyopathy). Twelve healthy children served as a control group. New York Heart Association (NYHA) class, LV dimensions and functions using Vivid 7 dimensions were evaluated. Serum ANP was measured using the ELISA technique, before and 3 months after treatment with angiotensin converting enzyme inhibitor.. ANP was raised in all patients as compared to controls (G one: 28.33 ± 5.78, G2: 26.5 ± 4.11, G3: 28.5 ± 6.6, G4: 29.25 ± 4.5 pg/mL, control group: 5.54 ± 1.4 pg/mL, P < 0.001 for all) and varied significantly between different NYHA classes regardless of the underlying cardiac lesion. It was significantly higher in group 1 than 2 (P < 0.05). It decreased significantly after treatment (G1: 15.3 ± 5.3, G2: 10.7 ± 2.5, G3: 11.5 ± 3.8, G4: 15.7 ± 10.7 pg/mL, P < 0.001). The rate of change of ANP correlated with that of LV end diastolic diameter (r = 0.3, P < 0.05) irrespective of the underlying cause.. ANP increases in cases of LV volume overload irrespective of the aetiology of heart failure. It can differentiate between children in quiescent state from those in clinical failure even in the absence of echocardiographically detectable systolic dysfunction. Furthermore, it can monitor LV remodelling with treatment.

Topics: Adolescent; Angiotensin-Converting Enzyme Inhibitors; Atrial Natriuretic Factor; Biomarkers; Cardiomyopathy, Dilated; Case-Control Studies; Child; Child, Preschool; Ductus Arteriosus, Patent; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Heart Failure; Heart Septal Defects; Heart Valve Diseases; Humans; Infant; Infant, Newborn; Male; Prospective Studies; Rheumatic Heart Disease; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Remodeling

The evaluation of the patent ductus arteriosus (PDA) in the very premature neonate is a challenge. Echocardiography provides an interpretation of the hemodynamic condition. It is however, only a snapshot. Biomarkers may represent a physiological response to the hemodynamic alterations brought on by the PDA and may add to the identification of the clinical significant PDA.. To investigate the association between mid regional proadrenomodulin (MR-proADM), N-terminal pro b-type natriuretic peptide (NT-proBNP), mid regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro endothelin-1 (CT-proET1) and copeptin and echocardiographic measures of PDA.. Cohort study with echocardiography performed on day 3 and 6. Blood samples from day 3.. 139 consecutive neonates born at a gestational age <32 weeks.. The main outcomes were presence of a PDA day 3 and 6, PDA diameter, left atrium to aorta ratio (LA:Ao-ratio), and descending aorta diastolic flow (DADF).. Adjusted plasma levels of all investigated biomarkers, except CT-proET1, were found to be associated with both PDA diameter and LA:Ao-ratio, and also the presence of a large PDA. CT-proET1 and copeptin was found to be associated with abnormal DADF. Using pre-specified cut-off values NT-proBNP and MR-proANP day 3 seemed to be of value in identifying a large PDA day 3 and 6 in very preterm neonates.. Among the investigated biomarkers NT-proBNP and MR-proANP performed best in relation to echocardiographic markers of PDA severity in very preterm neonates.

Topics: Adrenomedullin; Atrial Natriuretic Factor; Biomarkers; Ductus Arteriosus, Patent; Echocardiography; Electrocardiography; Endothelin-1; Female; Glycopeptides; Humans; Infant, Newborn; Infant, Premature; Male; Natriuretic Peptide, Brain

The diagnostic and prognostic appraisal of patent ductus arteriosus (PDA) in preterm infants is still debatable.. To compare plasma cardiovascular biomarkers with echocardiographic indices alongside ductus arteriosus (DA) evolution in very preterm infants within the first week of life.. Mid-regional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET-1) levels were prospectively measured on the second and sixth days of life (DOL) in 52 preterm infants born before 32weeks of gestation. Echocardiographic indices to define DA patency and significance were simultaneously obtained. Logistic regression and receiver operating characteristics (ROC) analyses were used to assess and quantify the biomarkers' diagnostic capacities.. Thirty infants exhibited PDA on DOL 2; in 21 of these infants, DA was characterized as hemodynamically significant. Treatment failure after a first course of indomethacin was noted in 8 infants (DOL 6), whereas 7 participants underwent later surgical ligation. The diagnostic accuracy of cardiovascular biomarkers was moderate on DOL 2 but high on DOL 6. PDA was the only significant predictor of MR-proANP levels on DOL 6, independent of the effect of clinical confounders (regression coefficient 0.426, R(2) 0.60). Infants with MR-proANP ≥850pmol/l on DOL 2 had 3.9-fold higher risk (95% CI 1.01 to 14.5) of being diagnosed with significant DA, whereas infants with MR-proANP ≥700pmol/l on DOL 6 had 7.1-fold higher risk (1.9 to 27.2) for pharmaceutical treatment failure.. The cardiovascular plasma biomarker MR-proANP is a promising candidate for monitoring PDA evolution in very preterm infants.

Topics: Atrial Natriuretic Factor; Biomarkers; Cross-Sectional Studies; Ductus Arteriosus, Patent; Endothelin-1; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Logistic Models; Prognosis; Prospective Studies; Treatment Outcome; Ultrasonography

To evaluate the prevalence of cardiac troponin I (cTnI) and autoantibodies to cTn in children with congenital heart defects with volume or pressure overload fulfilling the criteria for treatment, and in healthy children.. The study groups comprised 78 children with volume overload caused by an atrial septal defect or a patent ductus arteriosus, and 60 children with pressure overload caused by coarctation of the aorta or stenosis of the aortic or the pulmonary valve, and 74 healthy controls. Serum levels of natriuretic peptides, cTnI, and autoantibodies to cTn were analyzed at baseline, prior to treatment and in 64 patients 6 months after treatment.. At baseline, one child with volume overload, 12 children with pressure overload, and one healthy control had positive cTnI. Further analysis of the pressure overload subgroup revealed that the children with positive cTnI were younger than those with negative cTnI, and had higher levels of natriuretic peptides. The pressure gradient at the coarctation site or stenotic valve was higher in those with positive TnI. Six months after treatment, 63 of 64 children examined were cTnI negative.. The cTnI release is more frequently associated with pressure than volume overload which resolves after treatment in most children.

Topics: Adolescent; Aortic Coarctation; Aortic Valve Stenosis; Atrial Natriuretic Factor; Autoantibodies; Biomarkers; Case-Control Studies; Child; Child, Preschool; Ductus Arteriosus, Patent; Female; Heart Defects, Congenital; Heart Failure; Heart Septal Defects, Atrial; Hemodynamics; Humans; Infant; Infant, Newborn; Male; Natriuretic Peptide, Brain; Peptide Fragments; Prognosis; Prospective Studies; Pulmonary Valve Stenosis; Time Factors; Troponin I; Young Adult

In very preterm infants, clinical decision-making, such as closing a patent ductus arteriosus (PDA), may be aided by measuring circulating natriuretic and endothelial pro-peptides.. To investigate the association between perinatal characteristics, PDA echocardiography and plasma concentrations of stable pro-peptides of B-type natriuretic peptide (NT-proBNP), atrial natriuretic peptide (MR-proANP) and endothelin-1 (CT-proET-1).. A prospective, cross-sectional, single-center study was performed in 66 infants who were less than 32 weeks of gestational age. Pro-peptide concentrations were determined at birth and at day 2-3 of life.. Plasma concentrations of all 3 pro-peptides increased on average 2- to 5-fold from birth to day 2-3 of life. NT-proBNP and MR-proANP were closely related at birth and at day 2-3 (Rs 0.902 and 0.897, respectively, p < 0.001), whereas CT-proET-1 was related to NT-proBNP and MR-proANP at birth (Rs 0.478 and 0.460, respectively, p < 0.001) but not at day 2-3. Birth weight was negatively related to all 3 pro-peptides at birth (p < 0.01); however, preeclampsia and compromised placental perfusion were associated with elevated NT-proBNP and MR-proANP concentrations at birth. At day 2-3, MR-proANP and NT-proBNP correlated significantly with the ductal diameter (Rs 0.416 and 0.415, respectively, both p = 0.011), whereas CT-proET-1 correlated with the left atrium/aorta ratio (Rs 0.506, p = 0.027). CT-proET-1 was elevated in infants with treated compared to untreated PDA [median (5-95% range) 388 (272-723) vs. 303 (152-422) pmol/l, p = 0.011], but not NT-proBNP or MR-proANP.. CT-proET-1 is a promising predictor in determining the need for PDA intervention.

Topics: Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Echocardiography; Endothelin-1; Female; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Male; Natriuretic Peptide, Brain; Peptide Fragments; Placenta; Pre-Eclampsia; Pregnancy; Protein Precursors

Alpha-human atrial natriuretic peptide (hANP) reportedly increases in premature infants with patent ductus arteriosus (PDA).. To clarify a possible hANP effect to reopen the postnatal ductus, we studied in vivo reopening of the postnatal DA by a recombinant hANP, carperitide, in rats.. Near-term rat pups were incubated at 33 degrees C following caesarean section. The inner diameter of the ductus was measured with a microscope and a micrometer following rapid whole-body freezing. The DA constricted quickly after birth, and the inner diameter was 0.80 and 0.08 mm at 0 min (fetal state) and 60 min after birth. hANP concentration in the pup blood and the ductus-dilating effect of hANP were studied by subcutaneous injection of hANP at 60 min after birth, and by measurement 7, 15, 30 and 60 min later.. The peak hANP concentration was 790 pg/ml at 7 min with 1 mg/kg, which is similar to the level seen in preterm infants with symptomatic PDA. hANP dilated the postnatal ductus dose dependently and maximally at 7 min after injection. hANP dilated the postnatal constricted ductus completely to 0.79 mm in diameter with a large dose (10 mg/kg) and to 0.55 mm with 1 mg/kg.. hANP reopens the constricted postnatal DA dose dependently in rats. The increased hANP, accompanying premature PDA, may delay closure of the DA.

Topics: Animals; Animals, Newborn; Atrial Natriuretic Factor; Cryopreservation; Dilatation; Dose-Response Relationship, Drug; Ductus Arteriosus; Ductus Arteriosus, Patent; Frozen Sections; Injections, Subcutaneous; Models, Animal; Rats; Rats, Wistar; Recombinant Proteins

The main purpose of this study was to investigate whether circulating natriuretic peptides in premature infants reflect the hemodynamic significance of a patent ductus arteriosus (PDA). The study comprises 120 examinations in 55 premature infants with a mean gestational age of 27.2 wk and a mean birthweight of 933 g. Based on clinical and echocardiographic findings, the hemodynamic influence of ductal shunting was classified as small, moderate or large. Blood samples for N-terminal proatrial natriuretic peptide (Nt-proANP) and brain natriuretic peptide (BNP) were analysed after completion of the clinical part of the study. Linear regression indicated a very strong association between Nt-proANP and BNP (adjusted R = 0.89). The mean levels of Nt-proANP and BNP increased with the size of the shunt through a PDA, and peptide values followed hemodynamic alterations. The size of PDA accounted for 50% and 47% of the total variation in the plasma values of Nt-proANP and BNP, respectively. In detecting an echocardiographically significant PDA, the area under a ROC curve was 0.94 for Nt-proANP and 0.90 for BNP.. The magnitude of shunting through a PDA is the main determinant of plasma levels of natriuretic peptides in premature infants. Nt-proANP and BNP seem to have the same pattern of secretion. Our findings indicate that measurements of natriuretic peptides may provide clinically relevant information in the hemodynamic assessment of premature infants.

Topics: Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Electrocardiography; Female; Hemodynamics; Humans; Infant, Newborn; Infant, Premature; Male; Regression Analysis

Haemodynamically significant patent ductus arteriosus worsens respiratory distress by initiating pulmonary congestion and inactivating of surfactant. Excepting size of the ductus, several factors influence ductal flow.. Atrial natriuretic hormones provide clinically useful data, especially in serial follow-up of the patient.

Topics: Atrial Natriuretic Factor; Blood Volume; Coronary Circulation; Ductus Arteriosus, Patent; Hemodynamics; Humans; Infant, Newborn

Peri-operative changes in echocardiographic measurements and plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were investigated for 1 month in 3 dogs with patent ductus arteriosus (PDA). Post-operative left ventricular end-diastolic dimention and fractional shortening decreased in all cases. Pre-operatively increased plasma ANP concentrations reduced dramatically after the operation. Peri-operative changes in plasma BNP levels had slightly S-shaped curves in all cases. These observations suggest that post-operative responsiveness of ANP and cardiac function are rapid in comparison with cardiac morphological changes, and BNP has a different pathophysiological significance from ANP in dogs with PDA.

Topics: Animals; Atrial Natriuretic Factor; Brain Chemistry; Dogs; Ductus Arteriosus, Patent; Echocardiography; Female; Male; Natriuretic Peptide, Brain; Perioperative Care; Postoperative Period

We studied the correlation of atrial natriuretic factor (ANF) with lung compliance in a series of 16 premature infants with respiratory distress syndrome (RDS). The infants were followed during the first week of life by sequential Doppler echocardiography, lung compliance, and ANF measurements. Plasma ANF concentration varied between 38 and 2220 pg/mL; mean concentrations of 393 and 123 pg/mL with the ductus open and with it closed, respectively (P < 0.01). The arteriolar/alveolar oxygen-tension ratio showed an inverse correlation with the logarithm (In) of the ANF concentration (r = -0.55, P = 0.0002). Both mean airway pressure and In ANF showed an inverse correlation with the arteriolar/alveolar oxygen tension ratio (R = -0.77, F = 20.5 and 13.8, respectively). Plasma ANF was inversely correlated to lung compliance (r = -0.64, P < 0.0001). In infants with RDS, plasma ANF concentrations increase with the severity of respiratory distress. Because ANF increases endothelial permeability, in this preliminary investigation lead to the hypothesis that it may contribute to respiratory distress by causing extravasation of fluid from the pulmonary circulation in these patients.

Topics: Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Follow-Up Studies; Humans; Infant, Newborn; Infant, Premature, Diseases; Lung Compliance; Oxygen; Pulmonary Surfactants; Pulmonary Ventilation; Respiratory Distress Syndrome, Newborn; Severity of Illness Index

Atrial natriuretic peptide (ANP) is a hormone involved in fluid and blood pressure homeostasis. We studied the effects of left-to-right shunting through a patent ductus arteriosus on blood pressure changes and plasma ANP concentrations in newborn piglets. In five experimental piglets, the ductus arteriosus was bathed with PGE1 and infiltrated with formalin to maintain its patency. In four age-matched control piglets, the ductus arteriosus was ligated. Plasma ANP concentrations and blood pressure determinations were obtained prior to (base-line) and 25 +/- 1 h (day 1), and 48 +/- 1 h (day 2) after surgery. Radionuclide-microsphere determinations of left-to-right patent ductus arteriosus shunts were performed on days 1 and 2 in the 5 piglets with a patent ductus arteriosus. Plasma ANP concentrations were significantly elevated in the left atrium on day 1 and the right atrium on day 2 in the PDA piglets. No correlation was demonstrated between plasma ANP concentrations and right or left atrial pressures. We conclude that left and right plasma atrial ANP concentrations are significantly elevated in newborn piglets with left-to-right patent ductus arteriosus shunts.

Topics: Animals; Animals, Newborn; Atrial Natriuretic Factor; Body Weight; Ductus Arteriosus, Patent; Hemodynamics; Swine

The aim of this study was to measure plasma atrial natriuretic peptide in preterm infants with a patent ductus arteriosus before and after closure with indomethacin. Atrial natriuretic peptide was measured in 28 preterm infants with clinical and echocardiographic evidence of a patent ductus arteriosus and in eight preterm infants who did not develop clinical evidence of a patent ductus arteriosus. Plasma concentration of atrial natriuretic peptide was measured by radioimmunoassay. In 18 infants the patent ductus arteriosus closed after one course of indomethacin; atrial natriuretic peptide levels decreased from median 1240 pg/ml (range 201-5483 pg/ml) to 266 pg/ml (range 62-1108 pg/ml). In four infants the patent ductus arteriosus closed after two courses of indomethacin and two infants had surgical ligation after indomethacin treatment failed. The patent ductus arteriosus closed spontaneously in four infants (atrial natriuretic peptide median level 152 pg/ml, range 61-495 pg/ml). In the eight infants without patent ductus arteriosus, atrial natriuretic peptide level was median 224 pg/ml (range 38-876 pg/ml). Measurement of plasma atrial natriuretic peptide concentration has a role in predicting when indomethacin treatment is indicated.

Topics: Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Female; Humans; Indomethacin; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases

The concentration of plasma atrial natriuretic factor (ANF) and the mechanism for its secretion were investigated in 17 preterm infants with respiratory distress. Their mean gestational age was 29 wk and wt 1250 g. The infants were followed during the first week of life by sequential Doppler ultrasound studies. Ductal openness versus closure and amount of ductal flow were correlated with plasma ANF concentrations. In a subset of 10 infants, sequential Doppler color flow mapping was used to quantify the ductal flow. During the first 72 h, plasma ANF was high, 361 pg/mL; it decreased to 96 pg/mL by the end of the 1st wk. The ANF level was significantly higher when the ductus was open than closed (393 versus 123 pg/mL, p less than 0.05). In patients with open ductus and bidirectional foramen ovale shunting (n = 3) ANF was 567 pg/mL and in those with left-to-right shunt 355 pg/mL (n 15, NS). The left atrial size, i.e. the left atrial to aortic root ratio, correlated with the amount of ductal shunting (r = 0.63, p less than 0.01) and with ANF concentration (r = 0.46, p less than 0.02). The correlation of ANF values and the magnitude of left-to-right ductal shunting assessed by color flow mapping was highly significant (r = 0.66, p less than 0.001). In these patients, the elevation of ANF is reflective of ductal flow.

Topics: Age Factors; Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Echocardiography; Humans; Infant, Newborn; Infant, Premature; Respiratory Distress Syndrome, Newborn

Infants experience dramatic changes in fluid balance during the first few days of life, which provides an opportunity to observe the interrelationships of changing atrial size, atrial natriuretic peptide (ANP) secretion, and renal function during a relatively short period. To study these relationships, we examined nine infant boys (mean birth weight 1180 gm and gestational age 30 weeks) at 20 to 28 hours of age and then at four 24-hour intervals. Measurements included plasma ANP concentration, two-dimensional echocardiographic estimations of left and right atrial volumes, Doppler determination of ductus arteriosus patency, creatinine clearance, urine flow rate, urinary sodium excretion, and cyclic guanosine monophosphate (cGMP) excretion. Plasma ANP concentration was found to decrease with age and to correlate with decreasing size of the right atrium, closure of the ductus arteriosus, urinary cGMP excretion, and sodium excretion. We speculate that elevated plasma ANP values in a preterm neonate reflect an expanded volume state. As volume contraction, reflected by decreasing atrial volume and body weight occurs, ANP levels decrease, which may diminish diuresis. These findings are compatible with a significant role for ANP in volume homeostasis of newborn infants.

Topics: Atrial Natriuretic Factor; Cardiac Volume; Creatinine; Cyclic GMP; Ductus Arteriosus, Patent; Echocardiography; Echocardiography, Doppler; Gestational Age; Heart Atria; Humans; Infant, Low Birth Weight; Infant, Newborn; Infant, Premature; Kidney; Male; Urine

The design of the study was to determine whether an increased blood flow as seen in shunt lesions could serve as a stimulus for the secretion of atrial natriuretic factor (ANF). Since atrial pressure, flow, and dilatation are closely related, an experimental ductus arteriosus model was utilized, in which acute changes of flow are assumed not to dilate the left atrium. In six dogs, a Dacron graft was constructed between the main pulmonary artery and the innominate artery. Constricting and releasing the tape around the graft adjusted the amount of "ductal" shunting. The total pulmonary flow and the shunt flow were measured by electromagnetic-flow transducers around the aortic root and around the graft. Plasma ANF concentration was measured from both cardiac atria. The size of the left atrium was determined from echocardiographic measurements made from a short-axis view. The total pulmonary flow varied between 1.2 and 5.8 1/min. The highest measured ANF was 396 pg/ml, and this was from the left atrium when the pressure was 18 mmHg, the highest left atrial pressure recorded. The highest right atrial pressure (5 mmHg) also correlated with the highest right-atrial level of ANF (366 pg/ml). The right atrial pressure had a significant correlation with plasma ANF concentration (R = 0.43, p less than 0.05). Pulmonary flow and plasma ANF concentration did not correlate; neither did left atrial size and ANF levels in 16 flow states where the size was measured. In the absence of atrial dilatation there was minimal stimulus for ANF secretion. A transient increase of left atrial pressure, without a concomitant significant atrial dilatation, did not serve as a significant stimulus for ANF secretion.

Topics: Animals; Aorta, Abdominal; Aorta, Thoracic; Atrial Natriuretic Factor; Blood Pressure; Dogs; Ductus Arteriosus, Patent

The plasma level of human alpha-atrial natriuretic peptide was measured in healthy children and patients, 1 month to 15 years of age, with congenital heart diseases. Significant increases were found in patients with a ventricular septal defect, tricuspid valve atresia, patent ductus arteriosus, and atrial septal defect but not in those with pulmonary valve stenosis or tetralogy of Fallot. The levels were significantly higher in children with ventricular septal defects (221 +/- 123 pg/mL) or patent ductus arteriosus (124 +/- 38 pg/mL) than in those with atrial septal defects (65 +/- 42 pg/mL) (P less than .01). The increased levels appeared to be correlated with enlargement of the left atrium (r = .85, P less than .01) but not with the right atrial size or the mean right atrial pressure. They were higher in younger than in older healthy infants, but this age difference did not affect the results. These findings indicate that human alpha-atrial natriuretic peptide is released into the circulation in response to chronic atrial expansion in patients with congenital heart disease and may have an important role in volume homeostasis.

Topics: Adolescent; Atrial Natriuretic Factor; Child; Child, Preschool; Ductus Arteriosus, Patent; Female; Heart Defects, Congenital; Heart Septal Defects, Atrial; Heart Septal Defects, Ventricular; Humans; Infant; Male; Pulmonary Valve Stenosis; Tetralogy of Fallot; Tricuspid Valve

Plasma concentrations of atrial natriuretic peptide (ANP) were measured in nine infants (age 4 days-9 months) before and after closure of patent ductus arteriosus. Initially all patients had marked distention of the left atrium as indicated by a left atrium to aortic root ratio greater than or equal to 1.3 on echocardiography. After closure of the ductus, operative in six and pharmacological in three patients, left atrial size normalized (left atrium to aortic root ratio less than 1.3) in all patients, except in one treated surgically. Before closure the plasma concentration of ANP was 86-2224 pg/ml and after closure 44-1400 pg/ml. There was a significant correlation between the size of left atrium and plasma concentration of ANP (r = 0.56; p = 0.01). Our results suggest that in infants with patent ductus arteriosus the left atrium is the main source of ANP. The secretory rate of ANP decreases immediately after restoring left atrial size by closure of the ductus.

Topics: Atrial Natriuretic Factor; Dilatation, Pathologic; Ductus Arteriosus, Patent; Female; Heart Atria; Humans; Infant; Infant, Newborn; Male

The plasma concentration of atrial natriuretic peptide (ANP) in 16 healthy subjects on a free diet was 41 +/- 23 pg ml-1 (mean +/- SD) when upright and 58 +/- 27 pg ml-1 in the supine position (P less than 0.05), which confirms the concept that the supine position raises plasma ANP. Water immersion to the neck for 2 h caused a brisk diuresis, natriuresis and raised plasma ANP in 8 healthy subjects, suggesting that ANP is a mediator of diuresis and natriuresis during immersion. Dynamic exercise (50-200 W per 4 min) on a bicycle ergometer caused a gradual increase in plasma ANP in 6 healthy males, with a close correlation between the increases in plasma ANP and heart rate (r = 0.96). Thus, plasma ANP levels are increased in healthy subjects by stimuli causing an increased preload and possibly by tachycardia itself. Markedly raised plasma levels of ANP were found in patients with congestive heart failure, and upright posture caused a further rise of plasma ANP which correlated with the increase in heart rate (r = 0.87). High plasma ANP concentrations were also found in 25 patients with end-stage renal failure maintained on haemodialysis. When these patients were subdivided into those with concomitant heart failure and those with normal cardiac function, changes in plasma ANP correlated with predialysis weight gain and weight loss during dialysis, but only in patients without heart failure. In 9 infants treated by operative or pharmacological closure of persistent ductus arteriosus, high pre-treatment plasma ANP values were lowered by successful therapy, and plasma ANP correlated with the degree of left atrial distension.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Female; Heart Failure; Humans; Immersion; Infant; Infant, Newborn; Kidney Failure, Chronic; Male; Physical Exertion

Preterm infants with symptomatic patent ductus arteriosus had considerably raised plasma concentrations of atrial natriuretic peptide. Surgical ligation of the patent ductus arteriosus was associated with an immediate fall in plasma atrial natriuretic peptide concentration. Thus left to right shunting and left atrial distension may cause atrial natriuretic peptide release in preterm infants with patent ductus arteriosus.

Topics: Atrial Natriuretic Factor; Ductus Arteriosus, Patent; Humans; Infant, Newborn; Infant, Premature, Diseases; Ligation