None listed
Conditions
Brief summary
This is a prospective observational pilot study of the diagnostic utility of a novel biomarker B-type natriuretic peptide signal peptide (BNP-SP)in the assessment of inducible cardiac ischemia. Previously performed studies have demonstrated a clear, consistent and early peak of BNP-SP in the setting of indisputable cardiac ischemia and necrosis in patients presenting with ST elevation myocardial infarction. The patterns of release in the setting of less extreme forms of cardiac ischemia have not been previously defined. Serial sampling of BNP-SP in patients with controlled induced cardiac ischemia in the form of dobutamine stress testing and treadmill exercise tolerance testing is proposed. Venous blood samples will be drawn at baseline (0), 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 hours. Later sampling (=1wk) will not be carried out. For each blood sample, we will measure plasma BNP-SNP, troponin and NT-proBNP. Other signal peptides will be looked at namely ghrelin SP. Depending on results this biomarker has the potential to improve the sensitivity of stress testing. In addition, this study may provide insights into the mechanisms of release of this novel group of peptides.
Interventions
Serial sampling of plasma Pre-pro Brain natriuretic peptide Signal Peptide (BNP-SP)patients recruited over 1 year with controlled induced cardiac ischemia in the form of either dobutamine stress testing or treadmill exercise tolerance testing is proposed.
The dobutamine stress echocardiograph test takes about 1 hour and involves an injection of 10-40mcg/kg/min of dobutamine to stimulate the heart in a similar way to exercise while measuring the effect using ultrasound.
The Treadmill exercise tol
Serial sampling of plasma Pre-pro Brain natriuretic peptide Signal Peptide (BNP-SP)patients recruited over 1 year with controlled induced cardiac ischemia in the form of either dobutamine stress testing or treadmill exercise tolerance testing is proposed. The dobutamine stress echocardiograph test takes about 1 hour and involves an injection of 10-40mcg/kg/min of dobutamine to stimulate the heart in a similar way to exercise while measuring the effect using ultrasound. The Treadmill exercise tolerance test takes about 30 minutes in total and involves an electrocardiogragh recording while walking on a treadmill. Venous blood samples will be drawn at baseline (0), 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 hours. Later sampling (=1wk) will not be carried out. For each blood sample, we will measure plasma BNP-SNP, troponin and N-terminal Brain natriuretic peptide (NT-proBNP). Other signal peptides will be looked at namely ghrelin SP. Depending on results this biomarker has the potential to improve the sensitivity of stress testing. In addition, this study may provide insights into the mechanisms of release of this novel group of peptides.
Sponsors
Christchurch Cardioendocrine Research Trust
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
Protocol 1) Inclusion criteria: Intermediate to high pretest probability of cardiac ischemia as judged by cardiac risk factors, nature of chest pain and past cardiac history. 5 healthy volunteers with no history of cardiovascular or other significant illness will enrolled as a control group. Protocol 2) Inclusion criteria: Intermediate to high pretest probability of cardiac ischemia as judged by cardiac risk factors, nature of chest pain and past cardiac history. 5 healthy volunteers with no history of cardiovascular or other significant illness will enrolled as a control group.
Exclusion criteria
Protocol 1: Exclusion Criteria: Patients with atrial fibrillation, pacemakers, significant valvular disease, aged over 70, recent infarction will be excluded. Patients in whom resting electrocardiograms (ECGs) show abnormalities that preclude interpretation of exercise-induced changes for example left bundle branch block, left ventricular hypertrophy, 1 mm ST segment changes or pre-excitation will be excluded. Patients with poor echo windows will be excluded. Anemia as defined as a hemoglobin level less than 100 Unable to give informed consent Unable to comply with study requirements Protocol 2: Exclusion criteria: Poor echocardiographic windows. Chronic atrial fibrillation. Age less than 18 or greater than 80. Anemia as defined as a hemoglobin level less than 100 Unable to give informed consent Unable to comply with study requirements
Outcome results
None listed