Serum Brain Natriuretic Peptide Concentration Research Articles

Diagnostic utility of velocity ratio for paradoxical low-flow/low-gradient aortic stenosis.

Calcification score by cardiac computed tomography (CT) is required for diagnosis of paradoxical low-flow/low-gradient (PLFLG) aortic stenosis (AS). According to the guideline, velocity ratio (VR) < 0.25 by echocardiography is defined as severe AS, but utility of VR in patients with PLFLG AS remains unknown. This retrospective study was therefore conducted to investigate the utility of VR for a diagnosis of severe AS based on CT in patients with PLFLG AS. We studied 58 patients with PLFLG AS. Severity of AS was defined as calcium score derived from cardiac CT. Of the 58 patients, 28 (48.3%) were diagnosed with severe AS based on CT, while 23 of them (82.1%) had VR < 0.25. It was noteworthy that receiver operating characteristic curve analysis showed that the optimal VR cutoff value for a diagnosis of severe AS was 0.25, with an area under the curve of 0.870 (P < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value of VR < 0.25 for a diagnosis of severe AS were 82.1%, 86.7%, 85.2% and 83.9%, respectively. Furthermore, patients who match the value of VR and severity of AS based on CT had higher prevalence of atrial fibrillation, higher serum brain natriuretic peptide concentration, larger left ventricular end-diastolic volume, and left ventricular stroke volume index. The measurement of VR is simple, and VR < 0.25 can be used for diagnosis of patients with PLFLG AS as severe. Our findings may thus have clinical implications for routine clinical practice.

ET-1 receptor type B (ETBR) overexpression associated with ICAM-1 downregulation leads to inflammatory attenuation in experimental autoimmune myocarditis.

An experimental autoimmune myocarditis rat model was established by subcutaneous injection of porcine myocardial myosin (PCM). The effect of ET-1 receptor type B (ETBR) overexpression on autoimmune myocarditis was observed via tail vein injection of ETBR overexpression lentivirus in rats. We further investigated the mechanisms involved in the regulation of autoimmune myocarditis by ETBR overexpression. Six rats were randomly selected from 24 male Lewis rats as the NC group, and the remaining 18 rats were injected with PCM on Day 0 and Day 7, to establish the experimental autoimmune myocarditis (EAM) rat model. The 18 rats initially immunized were randomly divided into three groups: the EAM group, ETBR-oe group, and GFP group. On Day 21 after the initial immunization of rats, cardiac echocardiography and serum brain natriuretic peptide (BNP) analysis were performed to evaluate cardiac function, myocardial tissue HE staining was performed to assess myocardial tissue inflammatory infiltration and the myocarditis score, and mRNA expression of IFN-γ, IL-12, and IL-17 was detected by qRT-PCR. Subsequently, immunohistochemical analysis was performed to detect the localization and expression of the ETBR and ICAM-1 proteins, and the expression of ETBR and ICAM-1 was verified by qRT-PCR and western blotting methods. On Day 21 after initial immunization, left ventricular end-diastolic diameter (LVEDd), left ventricular end-systolic diameter (LVEDs), and serum BNP concentrations increased in the hearts of rats in the EAM group compared with the NC group (P < 0.01), and ejection fraction (EF) and fractional shortening (FS) decreased compared with those of the normal control (NC) group (P < 0.01). LVEDd, LVEDs, and serum BNP concentrations decreased in the ETBR-oe group compared with the EAM group, while EF and FS increased significantly (P < 0.01). HE staining showed that a large number of inflammatory cell infiltrates, mainly lymphocytes, were observed in the EAM group, and the myocarditis score was significantly higher than that of the NC group (P < 0.01). Compared with that of the EAM group, myocardial tissue inflammatory cell infiltration was significantly reduced in the ETBR-oe group, and the myocarditis scores were significantly lower (P < 0.01). The mRNAs of the inflammatory factors IFN-γ, IL-12 and IL-17 in myocardial tissue of rats in the EAM group exhibited elevated levels compared with those of the NC group (P < 0.01) while the mRNAs of IFN-γ, IL-12 and IL-17 were significantly decreased in the ETBR-oe group compared with the EAM group (P < 0.01). Immunohistochemistry showed that the staining depth of ETBR protein in myocardial tissue was greater in the EAM group than in the NC group, and significantly greater in the ETBR-oe group than in the EAM group, while the staining depth of ICAM-1 was significantly greater in the EAM group than in the NC group, and significantly lower in the ETBR-oe group than in the EAM group. The ICAM-1 expression level was significantly higher in the EAM group than in the NC group (P < 0.01), and was significantly lower in the ETBR-oe groupthan in the EAM group (P < 0.01).

Impact of donor-specific anti-HLA antibody on cardiac hemodynamics and graft function 3 years after pediatric heart transplantation: First results from the CTOTC-09 multi-institutional study

The aim of this study (CTOTC-09) was to assess the impact of “preformed” (at transplant) donor-specific anti-HLA antibody (DSA) and first year newly detected DSA (ndDSA) on allograft function at 3 years after pediatric heart transplantation (PHTx). We enrolled children listed at 9 North American centers. The primary end point was pulmonary capillary wedge pressure (PCWP) at 3 years posttransplant. Of 407 enrolled subjects, 370 achieved PHTx (mean age, 7.7 years; 57% male). Pre-PHTx sensitization status was nonsensitized (n = 163, 44%), sensitized/no DSA (n = 115, 31%), sensitized/DSA (n = 87, 24%), and insufficient DSA data (n = 5, 1%); 131 (35%) subjects developed ndDSA. Subjects with any DSA had comparable PCWP at 3 years to those with no DSA. There were also no significant differences overall between the 2 groups for other invasive hemodynamic measurements, systolic graft function by echocardiography, and serum brain natriuretic peptide concentration. However, in the multivariable analysis, persistent first-year DSA was a risk factor for 3-year abnormal graft function. Graft and patient survival did not differ between groups. In summary, overall, DSA status was not associated with worse allograft function or inferior patient and graft survival at 3 years, but persistent first-year DSA was a risk factor for late graft dysfunction.

Effects of exercise on serum ischemia-modified albumin, brain natriuretic peptide and copeptin levels in boxers and kick boxers.

Introductionboxing and kick boxing are combat sports that can cause severe head, neck, face and hand injuries during fighting. Then, traumatic brain injury (TBI) incidence is high in these sports. Ischemia-modified albumin (IMA), brain natriuretic peptide (BNP) and copeptin have diagnostic and prognostic value for cardiac and non-cardiac ischemic events. The purpose of this study is to evaluate exercise-induced variations of serum IMA, BNP and copeptin.Methodstwenty male boxers, twenty-three male kick boxers and twenty-three age-matched male were enrolled in the study. Health assessment data were analysed. Boxers and kick boxers underwent an exercise program including training plus fighting matches. Serum samples were collected in the pre- and post-exercise periods. Serum IMA, BNP and copeptin concentrations were measured in these specimens using ELISA reagents.Resultscomparative analysis of analytes before and after exercise showed that exercise significantly increased serum IMA, BNP and copeptin levels both in boxers and kick boxers.Conclusionin conclusion, IMA, BNP and copeptin levels may be candidate biomarkers for exercise-related traumatic brain injuries. The identification of new biomarkers in patients with acute and chronic neurological disorders is of considerable interest to clinicians. Then, further studies should be conducted to evaluate the possible role of IMA, BNP and copeptin in TBI pathophysiology.

The evaluation of the serum brain natriuretic peptide concentrations in preeclamptic and healthy pregnant women and its potential relationship with mean arterial blood pressure

Objective In this study, we aimed to investigate the correlation between serum brain natriuretic peptide (BNP) concentrations and blood pressure levels by comparing serum brain natriuretic peptide (BNP) concentrations in preeclamptic and normotensive pregnant women and to assess its potential role in the preeclampsia pathogenesis. Methods A total of 48 preeclamptic and 39 normotensive patients were included in the study prospectively. Systolic diastolic and mean arterial blood pressure of the pregnant women were measured. Serum BNP concentrations were measured by enzyme immunoassay method. The variable differences between the groups were analyzed by independent samples t-test. Potential correlations between the variables were assessed by Pearson’s correlation analysis. Results There was no difference between the groups in terms of age (26.18±11.49 years vs. 26.04±14.06 years), gestational age (31.59± 6.94 weeks vs. 30.17±5.72 weeks), parity (2.62±1.4 vs. 2.53±1.82) and body mass index (30.71±16.33 kg/m2 vs. 30.09±13.82 kg/m2) (p&gt;0.05). Systolic (148.66± 61.82 mmHg vs. 126.44±97.47 mmHg; p=0.015), diastolic (81.19±52.25 mmHg vs. 97.29±14.27 mmHg; p=0.019) and mean arterial pressure (113.97±41.76 mmHg vs. 96.26±27.25 mmHg; p&lt;0.001) levels were higher in the pregnant women complicated with preeclampsia. In addition, serum BNP concentrations were also higher in the preeclamptic pregnant women than the control group (139.42±62.19 pg/mL vs. 99.28±19.32 pg/mL; p=0.028). BNP levels were significantly associated with only mean arterial pressure (b=0.241, p=0.037). Also, there was a significant positive correlation between BNP levels and mean arterial pressure (r=0.406, p=0.002). Conclusion We recommend further prospective studies with wider populations to assess whether BNP levels, which increase in preeclampsia, are associated with blood pressure levels or not.

The Effect of Xinmailong Infusion on Sepsis-Induced Myocardial Dysfunction: a Pragmatic Randomized Controlled Trial.

Sepsis-induced myocardial dysfunction (SIMD) contributes significantly to cardiovascular dysfunction during septic shock. We aimed to evaluate the potential role of Xinmailong injection (XMLI), a polypeptide medicine extracted from Periplaneta americana, in reversing the progression of myocardial damage to SIMD in sepsis patients. This was a multicenter, randomized, double-blind, parallel-group trial. We recruited all patients consecutively admitted to intensive care units (ICUs) who were aged 18 to 85 years old and met the sepsis 3.0 criteria. The primary outcome measure was the incidence of sepsis-induced myocardial dysfunction while in the ICU. Of the 192 patients, 96 were assigned to the treatment group, and 96 to the control group. Subsequently, 41 patients [41/96 (42.7%)] in the XMLI group and 61 patients in the placebo group [61/96 (63.5%)] were confirmed to have diastolic dysfunction on the fifth day (D5). The incidence of diastolic SIMD was significantly different between the two groups (P = 0.004). There were 36 deaths in the two groups during the 28-day follow-up, with a general mortality rate of 18.8% (36/192). The 28-day mortality rates were not significantly different between the groups (P = 0.45). However, the brain natriuretic peptide (BNP) plasma concentration trends on D0, D2, and D5 significantly differed between the two groups (P = 0.049). In septic patients, XMLI decreased the occurrence rate of diastolic SIMD more effectively than the placebo. The improvement in serum BNP concentration was also greater in the XMLI group. XMLI may, therefore, effectively and safely improve cardiac function in patients with sepsis.

Brain Natriuretic Peptide is a Predictor of Cardiac Thrombus in Critically Ill Acute Ischemic Stroke Patients

CONTEXT: Plasma brain natriuretic peptide (BNP) levels are elevated in patients with acute ischemic stroke, particularly when accompanied by atrial fibrillation (AF). Plasma BNP might be a useful marker of vulnerability to thromboembolism in non-valvular AF patients.&#x0D; AIM: The aim of the present study was to assess whether the BNP level can serve as a biomarker of the left atrial (LA) thrombus in AF patients with acute ischemic stroke.&#x0D; SETTINGS AND DESIGN: This was a multicenter prospective cohort study.&#x0D; PATIENTS AND METHODS: Thirty AF patients with acute ischemic stroke were included in the study. Their transesophageal echocardiography (TEE) and BNP were assessed.&#x0D; RESULTS: There was a positive significant relation between serum BNP levels and LA thrombus detection by TEE. BNP with a cutoff value &gt;498 pg/l can be used as a diagnostic biomarker for the presence of the LA thrombus. A significant positive correlation existed between serum BNP and LA diameter. Furthermore, a statistically significant positive correlation between serum BNP and AF rate and duration was found in all patients. In addition, a statistically significant inverse correlation was detected between serum BNP and direct bilirubin, international normalized ratio, and albumin. A statistically significant positive correlation existed between serum BNP and prothrombin concentration.&#x0D; CONCLUSION: BNP can be a good diagnostic biomarker for the detection of the LA thrombus in chronic AF patients with acute ischemic stroke.

Myocardial Contractile Function in Patients with Liver Cirrhosis and Syndrome of Bacterial Overgrowth Syndrome

to study myocardial contractile function in patients with liver cirrhosis and ascites in the presence of bacterial overgrowthsyndrome (BOS) and pathological bacterial translocation. We included in this study 59 patientswith Child-Pugh class B and C liver cirrhosis (LC) of various etiology and ascites. Control group comprised 12 patients withischemic heart disease complicated by chronic heart failure (CHF). Examination included history taking and laboratory andinstrumental investigation. LC was diagnosed basing on clinical symptoms and instrumental studies. Child-Pugh and MELDscores were used for assessment of LC severity and prognosis. International ascites club grading system was used for evaluationof severity of ascites. Hydrogen breath test was applied for diagnosing BOS. Syndrome of pathological bacterial translocationwas established based on blood levels of lipopolysaccharide-binding protein and detection of bacterial DNA in ascitic fluid.Structural-functional parameters of the myocardium and hemodynamics were assessed by echocardiography. Brain natriureticpeptide (BNP) concentration was measured in blood serum and ascitic fluid. In 13 of 59 patients with LC the hydrogenbreath test was negative, in 33 positive and in 13 patients the positive hydrogen test was combined with the presence of BOSand pathological bacterial translocation. Blood serum and ascitic fluid BNP concentrations in LC patients were low and withinnormal limits (62.5±4.1 and 53.3±4.9 rg / ml, respectively), what contrasted with high BNP concentrations in patients withCHF (1820±95.5 and 497.1±39.6 rg / ml, respectively). Total protein level in ascitic fluid also was significantly lower in patientswith LC than in patients with CHF (1.77±0.1 and 4.43±0.35 mg / dL, respectively). The serum-ascitic albumin gradient(SAAG) in both groups of patients exceeded 1.1 (1.58±0.13 in patients with CHF and 1.88±0.19 in patients with LC).Conclusions. In patients with liver cirrhosis the presence of BOS and bacterial translocation did not produce a distinct negativeimpact on contractile function.

Beneficial effects of upgrading to His bundle pacing in chronically paced patients with left ventricular ejection fraction

Heart failure is common in patients with permanent pacemakers. Right ventricular (RV) pacing may worsen cardiac function, while the nonresponder rate of cardiac resynchronization therapy (CRT) for heart failure treatment remains 25%-30%. The purpose of this study was to assess clinical outcomes of upgrading to permanent His bundle pacing (pHBP) in patients with heart failure who underwent device upgrade from right ventricular pacing or CRT nonresponse. Eighteen patients with pacing-dependent heart failure and left ventricular ejection fraction (LVEF) <50% underwent pHBP attempts at device replacement. Of those 18 patients, 16(88.9%) received pHBP successfully and followed for a mean of 36.2 months. All these patients underwent clinical evaluation, echocardiography, brain natriuretic peptide assay, and chest radiography immediately before replacement and during follow-up visits. Of the 16 patients (mean age 70.6 ± 12.9 years; 9[56.3%] men), 11 (68.8%) patients had pacing-induced cardiomyopathy (PICM) while the remaining 5 (31.2%) patients were CRT nonresponders. After upgrading to pHBP, QRS duration was significantly shortened (from 156.9 ± 21.7 to 107.1 ± 16.5 ms; P < .01). At 1-year follow-up after HBP, left ventricular end-diastolic dimensions decreased from baseline 62.3 ± 6.9 to 55.5 ± 7.7 mm (P < .01) and LVEF increased from baseline 35.7% ± 7.9% to 52.8% ± 9.6% (P < .01). Other improvements after HBP upgrade included mitral valve regurgitation, serum brain natriuretic peptide concentrations, cardiothoracic ratios, and New York Heart Association functional class (P < .01 for all). In paced patients with clinically symptomatic heart failure and LVEF <50%, pHBP upgrade was feasible in 88.9%, with improved left ventricular function and remodeling. Hence, pHBP can be an alternative for patients with pacing-induced cardiomyopathy and CRT nonresponders.

Péptido natriurético cerebral sérico en preeclámpticas y embarazadas normotensas

Objetivo: Comparar las concentraciones séricas de péptido natriurético cerebral en pacientes con preeclampsia y embarazadas normotensas sanas. Diseño: Estudio de casos y controles. Institución: Hospital Central “Dr. Urquinaona”, Maracaibo, Venezuela. Participantes: Se seleccionó un total de 180 embarazadas. Se incluyeron 90 preeclámpticas como grupo de estudio (grupo A) y un grupo de control seleccionado por tener edad e índice de masa corporal similares al grupo de estudio, que consistió en 90 embarazadas normotensas sanas (grupo B). Métodos: Las muestras de sangre se recolectaron en todas las pacientes antes del parto e inmediatamente después del diagnóstico en el grupo A, para determinar las concentraciones de péptido natriurético cerebral. Principales medidas de resultados: Características generales, concentraciones de péptido natriurético cerebral y eficacia diagnóstica. Resultados: Se encontraron diferencias estadísticamente significativas en las concentraciones séricas de péptido natriurético cerebral entre las pacientes del grupo A (65,1 +/- 14,1 pg/mL) y las pacientes del grupo B (43,2 +/- 9,8 pg/mL; p &lt; 0,001). No se observaron correlaciones significativas con los valores de presión arterial sistólica y diastólica en las preeclámpticas (p = ns). Un valor de corte de 55 pg/mL presentó un valor por debajo de la curva de 0,88, sensibilidad 71,1%, especificidad 83,3%, valor predictivo positivo 81,0% y valor predictivo negativo 74,2%, con una exactitud diagnóstica del 77,2%. Conclusión: Las preeclámpticas presentaron concentraciones séricas significativamente más altas de péptido natriurético cerebral al compararlo con embarazadas normotensas sanas.

Serum Brain Natriuretic Peptide Concentration 60 Days After Surgery as a Predictor of Long-Term Prognosis in Patients Implanted With a Left Ventricular Assist Device: Erratum

Serum Brain Natriuretic Peptide Concentration 60 Days After Surgery as a Predictor of Long-Term Prognosis in Patients Implanted With a Left Ventricular Assist Device: Erratum

Serum Brain Natriuretic Peptide Concentration 60 Days After Surgery as a Predictor of Long-Term Prognosis in Patients Implanted With a Left Ventricular Assist Device

Mechanical circulatory support by a left ventricular assist device (LVAD) is used to bridge patients with advanced heart failure to transplant or as a definitive treatment. We retrospectively sought predictors of long-term outcome in a cohort of 83 patients who had undergone LVAD treatment. We subjected perioperative clinical data of patients to statistical analysis to establish parameters associated with all-cause mortality, and the cutoff values, sensitivity, and specificity of those that had a statistically significant relation with survival. Mean follow-up was 717 days (standard deviation, 334 days; range, 17-1,592 days). Fourteen patients (16.8%) died, but nine (10.8%) were weaned from support. Serum brain natriuretic peptide (BNP) concentration measured 60 days after implantation was significantly associated with all-cause mortality. The optimal BNP cutoff value to predict death during LVAD support was 322 pg/ml, with a sensitivity of 71.4% and specificity of 79.8%. Two-year survival was 92.0% in those with 60 days serum BNP concentration <322 pg/ml compared with 70.5% in those in whom it was ≥322 pg/ml (p = 0.003). The relation between BNP and survival likely reflects recovery of native myocardial function and improvements in global health and should assist clinicians in the on-going management of long-term LVAD therapy.

Prophylactic Subclavian Artery Intraaortic Balloon Counter-Pulsation is Safe in High-Risk Cardiac Surgery Patients.

Mechanical circulatory support by a left ventricular assist device (LVAD) is used to bridge patients with advanced heart failure to transplant or as a definitive treatment. We retrospectively sought predictors of long-term outcome in a cohort of 83 patients who had undergone LVAD treatment. We subjected perioperative clinical data of patients to statistical analysis to establish parameters associated with all-cause mortality, and the cutoff values, sensitivity, and specificity of those that had a statistically significant relation with survival. Mean follow-up was 717 days (standard deviation, 334 days; range, 17–1,592 days). Fourteen patients (16.8%) died, but nine (10.8%) were weaned from support. Serum brain natriuretic peptide (BNP) concentration measured 60 days after implantation was significantly associated with all-cause mortality. The optimal BNP cutoff value to predict death during LVAD support was 322 pg/ml, with a sensitivity of 71.4% and specificity of 79.8%. Two-year survival was 92.0% in those with 60 days serum BNP concentration <322 pg/ml compared with 70.5% in those in whom it was ≥322 pg/ml (p = 0.003). The relation between BNP and survival likely reflects recovery of native myocardial function and improvements in global health and should assist clinicians in the on-going management of long-term LVAD therapy.

Impairment of Left Ventricular Longitudinal Contraction is Associated with Serum Brain Natriuretic Peptide Concentration in Patients with Acute-Phase Kawasaki Disease.

It is well known that brain natriuretic peptide (BNP) is elevated in the acute phase of Kawasaki disease (KD). We hypothesized that mitral annular plane systolic excursion (MAPSE) could identify LV dysfunction in the acute phase of KD. Fifty patients with KD were enrolled in this study. BNP sampling and an echocardiographic study were performed just before and after intravenous immunoglobulin administration. MAPSE was measured in M-mode in the apical four-chamber view. The %MAPSE was calculated as the MAPSE measured in the acute phase divided by that measured in the convalescent phase. We compared the acute and the convalescent phases of KD. The values of the MAPSE were significantly reduced (45 out of 50 patients) during the acute phase and immediately recovered in the convalescent phase (10.0 ± 1.9 vs. 12.7 ± 1.9 mm, P < 0.0001). Of the parameters tested, %MAPSE was the only echocardiographic parameter that was associated with Log-BNP. Additionally, %MAPSE had a significant negative correlation with Log-BNP (r = -0.45, P < 0.0039). Longitudinal LV contraction is impaired in the acute phase of KD, but it immediately recovers in the convalescent phase. Measuring the longitudinal LV contractility should be essential for evaluating LV function in the acute phase of KD, and MAPSE is useful for this evaluation.

Pulmonary Hypertension in Sickle Cell Disease: Correlation With Echocardiographic Assessment and Serum Brain Natriuretic Peptide Concentration

Background &amp; Purpose Pulmonary hypertension (PH) in sickle cell disease (SCD) is an important risk factor for complications including sudden death. In this study, we aimed to determine the prevalence of PH and correlate the echocardiographic parameters and general laboratory data with markers of hemolysis and serum NT pro-brain natriuretic peptide [BNP] concentrations in Omani SCD patients. Methods A cohort of 163 SCD patients [Mean age 25.4±8.4 years], in steady state was prospectively screened for PH with Doppler echocardiography (defined as a tricuspid regurgitation jet flow velocity of ≥ 2.5 m/sec and/or mean pulmonary artery pressure [mPAP] ≥25 mmHg). After a written informed consent, all patients were investigated with a complete blood count, renal chemistry, hemolytic parameters including LDH, haptoglobin, liver function tests, coagulation studies, HPLC studies including HbS and HbF level estimations, X ray Chest, ECG, ABG, Pulmonary function tests, Pulse oximetry, and Serum NT pro-BNP levels. Results In the evaluable patient cohort of 116 subjects [63 females, 53-males], the prevalence of PH was 5.2%. No statistically significant differences were detected in Hb levels, ECG, chest radiography, pulmonary function tests between patients with and without PH. However, plasma NT pro-BNP levels were significantly correlated with PAH [r=0.934, p&lt;0.000], TRV jet [r=.671, p&lt;0.000], Abnormal ECHO [r=0.672, p&lt;0.000], and direct Bilirubin levels [r=0.278,p&lt;0.009] in SCD patients. Furthermore, in SCD patients with PH, there was a statistically significant increase in plasma NT pro-BNP levels [ p&lt;0.001], ALT [p&lt;0.02], S. Creatinine [p=0.045] and Total bilirubin [p&lt;0.0001] and direct Bilirubin levels [p&lt;0.0001][Table]. Conclusions Serum NT pro-BNP is a strong indicator of PH in SCD patients. Doppler ultrasound echocardiography is a useful initial screen for PH in SCD patients. The correlation between PH and hemolytic markers suggests an implication in the pathogenesis of PH. Disclosures: No relevant conflicts of interest to declare.

Heart dysfunction induced by choline-deficiency in adult rats: The protective role of l-carnitine

Choline is a B vitamin co-factor and its deficiency seems to impair heart function. Carnitine, a chemical analog of choline, has been used as adjunct in the management of cardiac diseases. The study investigates the effects of choline deficiency on myocardial performance in adult rats and the possible modifications after carnitine administration. Wistar Albino rats (n=24), about 3 months old, were randomized into four groups fed with: (a) standard diet (control-CA), (b) choline deficient diet (CDD), (c) standard diet and carnitine in drinking water 0.15% w/v (CARN) and (d) choline deficient diet and carnitine (CDD+CARN). After four weeks of treatment, we assessed cardiac function under isometric conditions using the Langendorff preparations [Left Ventricular Developed Pressure (LVDP-mmHg), positive and negative first derivative of LVDP were evaluated], measured serum homocysteine and brain natriuretic peptide (BNP) levels and performed histopathology analyses. In the CDD group a compromised myocardium contractility compared to control (P=0.01), as assessed by LVDP, was noted along with a significantly impaired diastolic left ventricular function, as assessed by (−) dp/dt (P=0.02) that were prevented by carnitine. Systolic force, assessed by (+) dp/dt, showed no statistical difference between groups. A significant increase in serum BNP concentration was found in the CDD group (P<0.004) which was attenuated by carnitine (P<0.05), whereas homocysteine presented contradictory results (higher in the CDD+CARN group). Heart histopathology revealed a lymphocytic infiltration of myocardium and valves in the CDD group that was reduced by carnitine. In conclusion, choline deficiency in adult rats impairs heart performance; carnitine acts against these changes.

Early diagnosis of rats with acute myocardial infarction by measurement of brain natriuretic peptide

The aim of this study was to detect early changes (within 1–4 h) in the brain natriuretic peptide (BNP) levels of rats with acute myocardial infarction (AMI). A total of 35 Wistar rats were established as models of AMI and 30 sham-operated rats were used as the control group. The myocardia of the two groups were observed using a transmission electron microscope (TEM) prior to and following surgery. A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect the serum BNP and cardiac troponin I (cTnI) concentrations before and 1–4 h after surgery. Following the successful establishment of the AMI models, serum BNP concentrations were significantly increased within 1–4 h compared with the values prior to surgery and with those of the control group (all P<0.01). The serum BNP concentration reached its highest level 2 h after AMI (532.25±15.16 ng/l). No significant changes were observed in the cTnI serum levels of the AMI group within 1–4 h compared with the values before AMI and those in the control group (all P>0.05). In the 1–4 h following the establishment of the AMI model, significant positive correlations were identified between the serum BNP concentrations and the size of the AMI and the most marked correlation occurred 2 h after AMI (r=0.72, P<0.05). No significant differences were noted in the serum concentrations of BNP and cTnI in the control group prior to and following the sham surgery (all P>0.05). BNP may be used as a blood marker for the early diagnosis of AMI, particularly 1–4 h after the onset of AMI, and to predict the size of the infarct area.

Resting and dobutamine stress test induced serum concentrations of brain natriuretic peptide in German Shepherd dogs

Studies of clinical uses of brain natriuretic peptide (BNP) represent one of the most important advances in cardiology since the introduction of echocardiography as a clinical diagnostic procedure. Defining the clinical potential of BNP in canine cardiology has not been completed yet. The aim of this study is to measure BNP concentrations in healthy German Shepherd dogs of different ages as a baseline in resting and when conventional protocol of the dobutamine stress test (DST) is applied to dogs. Concentrations of BNP were measured in blood serum by the radioimmunoassay method. The values of BNP concentrations were compared to cardiac parameters obtained by standard cardiac diagnostic procedures (radiology, electrocardiography and echocardiography). No significant differences in serum BNP concentrations existed in dogs of different ages. A statistically significant increase in BNP concentrations was registered after DST. These changes in BNP concentrations were related to ST/T electrocardiographic changes, and correlated to changes in the left ventricular internal diameter in systole (LVESD). These data suggest that BNP is not increased in aged dogs with normal cardiac systolic function and renal function, and that myocardial ischemia leads to a significant increase in BNP concentrations even in dogs with normal left ventricular function.

Brain Natriuretic Peptide Concentrations After Aneurysmal Subarachnoid Hemorrhage: Relationship with Hypovolemia and Hyponatremia

Hyponatremia and hypovolemia occur often after aneurysmal subarachnoid hemorrhage (SAH) and are associated with poor outcome. The authors investigated whether brain natriuretic peptide (BNP) is related to hypovolemia and hyponatremia after SAH and whether it can differentiate between hypovolemic and non-hypovolemic hyponatremia. In 58 SAH patients, the authors daily measured serum BNP and sodium concentrations, and circulating blood volume by means of pulse dye densitometry, during the initial 10 days. For each patient, mean BNP concentrations were calculated until occurrence of the following events: hyponatremia (Na <130 mmol/l), hypovolemia (blood volume <60 ml/kg), and severe hypovolemia (blood volume <50 ml/kg). The median day of onset of each event was calculated. In patients without an event, the authors calculated and used for comparison the mean BNP concentration until the median day of onset of the particular event. Odds Ratio's (OR) for high versus low mean BNP concentrations (dichotomized on median values per event) were calculated for the occurrence of each event and adjusted for relevant baseline characteristics. Patients with BNP above median more often had severe hypovolemia (adjusted OR 4.2, 95% confidence interval, CI 1.2-15.0) and showed a trend toward hyponatremia (adjusted OR 3.3, 95% CI 0.7-9.2). In the 12 hyponatremic patients, BNP could not differentiate between hypovolemic and non-hypovolemic hyponatremia. High BNP concentrations are related to the occurrence of severe hypovolemia and possibly hyponatremia. These data do not support a role for BNP measurements to differentiate between hypovolemic and non-hypovolemic hyponatremia in SAH patients.

Persistent Left Bundle Branch Block in a Patient With Dilated Cardiomyopathy That Improved With Low Dose Carvedilol Therapy

A 43-year-old Japanese woman with dilated cardiomyopathy had complete left ventricular bundle branch block (CLBBB), which had persisted for at least two years. At the time of admission, the serum brain natriuretic peptide (BNP) concentration was 502 pg/mL (normal range, 0-18 pg/mL), the left ventricular diastolic dimension (LVDd) was 59 mm, the left ventricular systolic dimension (LVDs) was 54 mm, the %fractional shortening (FS) was 8%, and the left ventricular ejection fraction (LVEF) was 19.7% by echocardiography. Low dose carvedilol was initiated for the treatment of heart failure. Adverse effects, such as progression of cardiac conduction disturbances, did not occur after initiation of carvedilol therapy. About one year after initiation of carvedilol therapy, the CLBBB disappeared and a significant improvement in left ventricular function was noted. The LVDd was 44 mm, the LVDs was 30 mm, the %FS was 33%, and the LVEF was 61%, and the serum BNP concentration was decreased to 18.5 pg/mL. We describe a case in which low dose carvedilol was effective for treating both CLBBB and left ventricular function.