Plasma atrial and brain natriuretic peptide levels in dogs with congestive heart failure.

Plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured in 6 dogs with experimental mitral regurgitation (MR) and 19 canine patients with asymptomatic and symptomatic congestive heart failure (CHF). In dogs with experimental MR, ANP and BNP concentrations were significantly correlated with pulmonary capillary wedge pressure (PCWP) (ANP; r=0.852, P=0.0004, BNP; r=0.832, P=0.0008). ANP level was shown to have a predominant effect on PCWP in comparison with BNP using multiple regression analysis. In canine patients with asymptomatic and symptomatic CHF, ANP and BNP concentrations were significantly different among the heart failure classes according to the New York Heart Association functional classification (ANP; P=0.0165, BNP; P=0.0005). In addition, ANP and BNP levels in dogs with decompensated heart failure (n=10) significantly increased in comparison with those in dogs with compensated heart failure (n=9). There was however no correlation between ANP and BNP levels in each heart failure class. In conclusion, plasma ANP and BNP levels may become predictors of PCWP and the severity of heart failure in dogs with MR, although further investigations on ANP and BNP levels in more clinical cases are required.     

Prospective screening for occult cardiomyopathy in dogs by measurement of plasma atrial natriuretic peptide, B-type natriuretic peptide, and cardiac troponin-I concentrations

OBJECTIVE: To evaluate the use of measuring plasma concentrations of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and cardiac troponin-I (cTnI) to detect dogs with occult dilated cardiomyopathy (DCM). ANIMALS: 118 client-owned dogs. PROCEDURES: Dogs were prospectively examined by use of ECG; echocardiography; and evaluation of concentrations of ANP, BNP, and cTnI. Occult DCM was diagnosed by evaluation of echocardiographic left ventricular dimensions and detection of ventricular arrhythmias on ECG. Sensitivity and specificity of assays for measurement of plasma concentrations of ANP, BNP, and cTnI to detect dogs with occult DCM were determined. RESULTS: Occult DCM was diagnosed in 21 dogs. A concentration of > 6.21 pg/mL for BNP had a sensitivity of 95.2% and specificity of 61.9% for identifying dogs with occult DCM. In contrast, concentrations of ANP and cTnI had relatively low predictive values. CONCLUSIONS AND CLINICAL RELEVANCE: Blood-based screening for occult DCM in dogs can be accomplished by use of a BNP assay. Additional studies should be performed to optimize this method of screening dogs to detect occult DCM.     

Cardiopulmonary function values before and after heartworm removal in dogs with caval syndrome

Cardiopulmonary function values were determined before and after surgical removal of adult heartworms in 25 dogs with spontaneous and 4 dogs with drug-induced caval syndrome (CS). Fifteen dogs with spontaneous CS (recovery group) and 4 dogs with drug-induced CS (drug-induced CS group) recovered after removal, and 10 dogs with spontaneous CS were euthanatized or died (nonsurviving group). Before heartworm removal, injected radiographic contrast medium was regurgitated from the right ventricle to the right atrium. Mean pulmonary arterial pressure and total pulmonary resistance were not statistically different between the recovery and nonsurviving groups of dogs, but the end-diastolic right ventricular pressure (mean +/- SD, 6.9 +/- 9.1 mm of Hg) and the a (8.7 +/- 9.2 mm of Hg)- and v (6.3 +/- 8.5 mm of Hg)-waves of the right atrial pressure curve in the recovery group were less, respectively, than the end-diastolic right ventricular pressure (17.3 +/- 6.0 mm of Hg) and the a (15.8 +/- 6.1 mm of Hg)- and v (21.4 +/- 6.9 mm of Hg)-waves in dogs of the nonsurviving group. After heartworm removal, contrast medium regurgitation disappeared, and cardiac output of the right ventricle increased in dogs of the recovery (from 2.08 +/- 0.72 to 2.38 +/- 0.68 L/min; P less than 0.05) and drug-induced CS (from 1.42 +/- 0.19 to 1.88 +/- 0.26 L/min, P less than 0.05) groups. However, regurgitation remained, and cardiac output did not increase in some dogs of the nonsurviving group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma aldosterone concentrations and plasma renin activity in healthy dogs and dogs with hyperadrenocorticism

The mean (se) basal plasma aldosterone concentrations were significantly lower in 31 dogs with pituitary-dependent hyperadrenocorticism (PDH) (75 [9] pmol/litre) than in 12 healthy dogs (118 [14] pmol/litre), whereas in five dogs with hyperadrenocorticism due to an adrenocortical tumour they were significantly higher (205 [109] pmol/litre). The mean basal renin activity was not significantly different between the dogs with PDH (303 [48] fmol/litre/second), the dogs with an adrenocortical tumour (141 [63] fmol/litre/second), and the control dogs (201 [25] fmol/litre/second). At three and four hours after the intravenous administration of 0.1 mg/kg dexamethasone, the concentrations of aldosterone decreased significantly to about 60 per cent of their initial values in the control dogs but did not change in the dogs with PDH or an adrenocortical tumour. In the dogs with PDH the renin activity increased significantly after the administration of dexamethasone.     

Cardiopulmonary function in dogs with serious chronic heartworm disease.

Cardiopulmonary function was examined in 18 dogs with serious chronic heartworm disease showing ascites, subcutaneous edema, prostration, weakness, jaundice and so on. After surgical heartworm removal from the pulmonary arteries, 10 dogs recovered (surviving group), and 8 dogs died or were euthanatized because of poor prognosis (nonsurviving group). The number of live heartworms residing in the pulmonary arteries of the surviving group tended to be larger than that in the nonsurviving group. At necropsy, severe pulmonary arterial lesions such as thromboembolism including dead heartworms, proliferative and villous lesions and intimal hyperplasia were noticed in all dogs examined, and tended to be severer in the nonsurviving group. Heartworm-coiling around the tricuspid valve chord was found in 1 dog of the surviving group and 4 dogs of the nonsurviving group. Before heartworm removal, there was no significant difference in the mean pulmonary arterial pressure (MPAP) between the surviving and nonsurviving group. Right atrial pressure (v-wave) was higher, and the cardiac index (CI) was lower in the nonsurviving group. Arterial oxygen tension was lower in the surviving group than in the heartworm-free group, and it was lower in the nonsurviving group than in the surviving group. Carbon dioxide tension was lower in the surviving group than in the heartworm-free group. Bicarbonate concentration (HCO3-) was lower both in the surviving and nonsurviving groups than in the heartworm-free group. One week after heartworm removal, MPAP decreased (P less than 0.05), and CI and HCO3- tended to increase in the surviving group.     

Effects of dilated cardiomyopathy on the renin-angiotensin-aldosterone system, atrial natriuretic peptide activity, and thyroid hormone concentrations in dogs

OBJECTIVE: To evaluate the effect of dilated cardiomyopathy (DCM) on activity of the renin-angiotensin-aldosterone system (RAAS), the N-terminal fragment of proatrial natriuretic peptide (NT-proANP), and thyroid hormone concentrations in dogs. ANIMALS: 15 dogs with clinical signs of DCM, 15 dogs without clinical signs of DCM, and 15 age-, breed-, and sex-matched control dogs. PROCEDURE: Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs, and blood and urine samples were collected. RESULTS: Plasma renin activity (PRA), plasma aldosterone concentration (PAC), urine aldosterone-to-creatinine ratio, and NT-proANP concentrations were significantly increased in dogs with clinical signs of DCM, compared with dogs without clinical signs and control dogs. Thyroid-stimulating hormone and total thyroxine concentrations did not differ significantly among groups; however, free thyroxine (FT4) concentrations were significantly decreased in dogs with clinical signs of DCM, compared with control dogs and DCM-dogs without clinical signs. Concentrations of PRA, PAC, FT4, and urine aldosterone-to-creatinine ratio were significantly correlated, whereas plasma concentrations of NT-proANP only correlated with FT4 concentration. CONCLUSION AND CLINICAL RELEVANCE: In dogs with clinical signs of DCM, increased concentrations of components of the RAAS were associated with increased concentrations of NT-proANP Analysis of the neurohormonal system may aid in identification of clinical stages of DCM for groups of dogs, but the range is too great and there are too many dogs that have neurohormonal concentrations within reference ranges to assess dogs on an individual basis.     

Cardiopulmonary values in dogs with artificial model of caval syndrome in heartworm disease.

Cardiopulmonary values were determined in dogs with an artificial model of heartworm caval syndrome, which was produced by insertion of heartworm-like silicone tubes into the tricuspid valve orifice and right atrium. Fifteen to 25 tubes with some knots were inserted in 6 dogs (knot group), and 7 to 11 tubes (small-number group) or 29 to 37 tubes (large-number group) without a knot in 3 dogs, respectively. After tube insertion, angiographic contrast medium infused into the right ventricle regurgitated to the right atrium in all cases, and the regurgitation was the most severe in the large-number group. On electrocardiographic findings, the atrial and/or ventricular premature beat developed. The height of a- and v-wave of right atrial pressure curves elevated in all groups. The elevation in v-wave was obvious in the large-number group. The pulmonary arterial pressure tended to fall or to elevate slightly, and total pulmonary resistance increased in all groups. The right cardiac output decreased significantly in all cases. The right heart hemodynamics of the model might resemble those in spontaneous cases without disturbed pulmonary circulation.     

Measurement of plasma atrial natriuretic peptide as an indicator of prognosis in dogs with cardiac disease

Twenty-three dogs with heart failure were evaluated in a 12-month study by measuring baseline plasma atrial natriuretic peptide (ANP) concentrations. Ten dogs were classified as having mild to moderate cardiac disease (group 1) and 13 dogs were classified as having severe cardiac disease (group 2). The mean plasma ANP concentration for the group 1 dogs was 64 +/- 45 pg/mL and for the group 2 dogs, 328 +/- 122 pg/mL. The median survival time (1,095 d) for group 1 dogs was significantly greater (P < 0.05) than for group 2 dogs (58 d). A significantly (P < 0.05) greater median survival was noted for dogs with plasma ANP < 95 pg/mL (1095 d) compared with those with ANP > 95 pg/mL (58 d). Plasma ANP concentrations are a potential noninvasive predictor of survival in dogs with heart failure.     

Peri-operative changes in echocardiographic measurements and plasma atrial and brain natriuretic peptide concentrations in 3 dogs with patent ductus arteriosus

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.     

Relationships between velocities of pulmonary venous flow and plasma concentrations of atrial natriuretic peptide in healthy dogs

OBJECTIVE: To investigate the relationship between velocities of pulmonary venous flow (PVF) and plasma concentrations of atrial natriuretic peptide (ANP) in healthy dogs. ANIMALS: 7 healthy Beagles. PROCEDURES: Dogs were anesthetized, intubated, and positioned in left lateral recumbency. Lactated Ringer's solution was infused (200 mL/kg/h) for 60 minutes via a cephalic vein. Transmitral flow and PVF velocities were measured echocardiographically by use of the apical 4-chamber view. Pulmonary capillary wedge pressure (PCWP) and ANP concentrations were determined. RESULTS: IV infusion significantly increased heart rate and PCWP. Similarly, the ANP concentration significantly increased from baseline (before infusion of lactated Ringer's solution) values. Transmitral flow velocities were significantly increased, although the ratio of velocity of the flow during early ventricular diastole (E wave) to velocity of the atrial flow (A wave; E:A ratio) was unchanged. Regarding the PVF velocities, forward flow during ventricular systole (S wave) and retrograde flow during atrial contraction were significantly increased, whereas velocity of the forward flow during ventricular diastole (D wave) was unchanged. Ratio of the velocity of the S wave to velocity of the D wave was increased significantly, and this ratio was significantly correlated with PCWP or ANP concentration. However, the E:A ratio was not correlated with PCWP or ANP concentration. CONCLUSIONS AND CLINICAL RELEVANCE: PVF velocities were strongly correlated with PCWP and plasma ANP concentration in clinically normal dogs. Therefore, PVF velocities may serve as a sensitive indicator and provide additional information for monitoring acute preloading conditions and estimating atrial filling abnormalities in dogs.     

Plasma big endothelin-1, atrial natriuretic peptide, aldosterone, and norepinephrine concentrations in normal Doberman Pinschers and Doberman Pinschers with dilated cardiomyopathy

BACKGROUND: Dilated cardiomyopathy (DCM) results in progressive myocardial and circulatory dysfunction causing activation of a number of neurohormonal systems, including the endothelin (ET) system, which is only beginning to be described in clinical veterinary medicine. Measurement of these circulating neurohormones possesses potential utility in the diagnosis, staging, and assessment of prognosis in cardiac disease. HYPOTHESIS: We hypothesized that plasma big ET-1, norepinephrine (NE), aldosterone, and atrial natriuretic peptide (ANP) concentrations in normal Dobermans would differ from those in Dobermans with DCM, and that concentrations of these hormones would be associated with time to congestive heart failure (CHF) or death. ANIMALS: Thirty client-owned Dobermans (10 each of normal, occult DCM, and overt DCM) were included in the study. METHODS: Dogs underwent an echocardiogram, ECG, and blood sample collection. Neurohormones were measured by high-pressure liquid chromatography (NE) or commercial assays. RESULTS: Dogs with occult DCM had significantly higher ANP concentrations compared with normal dogs (least squares means [95% confidence interval, CI]: occult female 53.7 pg/mL [40.2-71.7] versus normal female 31.6 pg/mL [24.8-40.3], P = .026; occult male 86.1 pg/mL [64.7-115] versus normal male 12.1 pg/mL [5.1-28.7], P = .011). Dogs with overt DCM had significantly higher concentrations of all neurohormones compared with the normal group. Furthermore, increasing big ET-1 (risk ratio [RR] 2.7, CI 1.3-8.6, P = .01) and NE concentrations (RR 3.9, CI 1.1-18.1, P = .03) over 1 month were associated with a shorter survival time. CONCLUSIONS AND CLINICAL IMPORTANCE: High ANP concentrations can identify dogs with advanced occult DCM. Increasing big ET-1 or NE concentrations over time can be useful predictors of poor prognosis.     

Plasma atrial natriuretic peptide concentration in warmblood horses with heart valve regurgitations

ObjectivesThis study measured plasma atrial natriuretic peptide (ANP) concentration in horses with heart valve regurgitations (HVR) with and without atrial and ventricular dilatation.BackgroundIn humans and small animals, plasma ANP concentration is increased in heart disease and correlates with the severity of clinical signs and heart enlargement.Animals, materials and methodsTen healthy horses (control) and 36 horses with HVR were evaluated by auscultation, electrocardiography, echocardiography, and determination of plasma ANP.ResultsControl horses demonstrated mean plasma ANP concentration of 21 ± 5.4 pg/mL. Of the 36 horses with HVR, 17 horses possessed normal echocardiographic heart size (group 1), 10 horses had a left atrial dilatation (group 2) and 9 horses had both left atrial and ventricular dilatation (group 3). Mean plasma ANP concentration of groups 1, 2 and 3 was 20.1 ± 5.6 pg/mL, 22.9 ± 11.0 pg/mL and 27.6 ± 17.4 pg/mL, respectively. The plasma ANP concentrations of HVR and control horses were not significantly different. The highest ANP concentrations were observed in horses with atrial and ventricular dilatation. No correlation between left atrial or ventricular size, weight, or sex and the plasma ANP concentration was found.ConclusionsNo significant differences in plasma ANP concentration was observed between groups. Further study, especially in horses with clinical signs of heart failure is needed.     

Plasma N-terminal pro-brain natriuretic peptide concentrations before and after pericardiocentesis in dogs with cardiac tamponade secondary to spontaneous pericardial effusion

Objective

To determine if concentrations of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) are increased in dogs with cardiac tamponade and if there is a significant increase in plasma NT-proBNP after pericardiocentesis.

Diagnostic accuracy of plasma atrial natriuretic peptide concentrations in cats with and without cardiomyopathies

Objectives

Plasma atrial natriuretic peptide (ANP) levels have been reported to be elevated in cats with cardiomyopathy. We investigated the diagnostic accuracy of plasma ANP concentration as an indicator of the severity of cardiomyopathies.

Brain natriuretic peptide concentration in dogs with heart disease and congestive heart failure

Plasma brain natriuretic peptide concentration ([BNP]) is high in humans with cardiac disease and is further increased with congestive heart failure (CHF). The hypotheses of this study were that dogs with moderate to severe mitral regurgitation due to myxomatous mitral valve disease (MVD) would have increased plasma [BNP] compared to normal dogs, that plasma [BNP] would be higher in dogs with CHP, and that plasma [BNP] would predict premature death from cardiovascular disease. The study population consisted of 34 dogs: 9 normal dogs and 25 dogs with MVD. Patients were divided into 4 groups: group 1-10 dogs with moderate to severe MVD and no radiographic evidence of CHF; group II--6 dogs with severe MVD and mild CHF; group III--7 dogs with severe MVD and moderate CHF; and group IV--2 dogs with severe MVD and severe CHF. Diagnostic tests included thoracic radiographs, an echocardiogram, a serum chemistry profile, and the measurement of plasma [BNP] by a canine-specific radioimmunoassay. There was a significant positive correlation between the plasma [BNP] and heart disease/failure groups (P = .0036). Plasma [BNP] increased with progressively increasing severity of MVD and CHE Group I dogs had higher plasma [BNP] than did control dogs (P < .0001), and plasma [BNP] was higher in dogs with CHF (groups II-IV versus group I; P = .012). Plasma [BNP] was also weakly positively correlated with left atrial size (r = 0.43, P = .04). For every 10-pg/mL increase in plasma [BNP], the mortality rate over 4 months' time increased approximately 44%.