Heart, lung & circulation
-
Heart, lung & circulation · Sep 2015
Vascular Dilation, Tachycardia, and Increased Inotropy Occur Sequentially with Increasing Epinephrine Dose Rate, Plasma and Myocardial Concentrations, and cAMP.
While epinephrine infusion is widely used in critical care for inotropic support, there is no direct method to detect the onset and measure the magnitude of this response. We hypothesised that surrogate measurements, such as heart rate and vascular tone, may indicate if the plasma and tissue concentrations of epinephrine and cAMP are in a range sufficient to increase myocardial contractility. ⋯ The dose response of epinephrine is distinct for vascular tone, HR and contractility. The need for higher doses to see cardiac effects is likely due to the threshold for drug accumulation in tissue. Successful inotropic support with epinephrine cannot be achieved unless the infusion is sufficient to raise the heart rate.
-
Heart, lung & circulation · Sep 2015
Clinical Trial Observational StudyUtility of Routine Exercise Stress Testing among Intermediate Risk Chest Pain Patients Attending an Emergency Department.
To assess the utility of routine exercise stress testing (EST) in patients at intermediate risk of acute coronary syndrome (ACS) according to the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (HFA/CSANZ) guidelines. ⋯ EST stratifies intermediate risk patients to a near zero short-term risk of ACS. However, the overall yield of EST within this group of patients is extremely low. Intermediate risk patients with normal zero and six hour biomarkers have a very low probability of ACS, and over half of these patients ultimately diagnosed with ACS in this group were deemed unsuitable for EST anyway. Future research should focus on the identification of patients who do not require EST and the inclusion of routine EST within the HFA/CSANZ guidelines should be reconsidered.
-
Heart, lung & circulation · Sep 2015
Levosimendan Improves Neurological Outcome in a Swine Model of Asphyxial Cardiac Arrest.
In asphyxial cardiac arrest, the severe hypoxic stress complicates the resuscitation efforts and results in poor neurological outcomes. Our aim was to assess the effects of levosimendan on a swine model of asphyxial cardiac arrest. ⋯ The addition of levosimendan to adrenaline improved coronary perfusion pressure immediately after the onset of cardiopulmonary resuscitation and resulted in better 24-hour neurological outcome.
-
Heart, lung & circulation · Aug 2015
Multicenter Study Clinical TrialCharacteristics and Outcomes of MI Patients with and without Chest Pain: A Cohort Study.
There are conflicting data on patient characteristics and outcomes of myocardial infarction (MI) patients presenting with and without the symptom of chest pain. ⋯ Characteristics differed between patients with and without chest pain. However, the symptom of chest pain was not associated with survival.