Early Diagnosis of Diastolic Dysfunction and Reliability of DSE in Detecting Stress Diastolic Dysfunction
Condition: Diastolic Dysfunction
Study type: Interventional

Summary: 
      The heart becoming "stiff" due to increased fibrous tissue or decreased elasticity of the
      heart tissue is one of the earliest changes caused by heart failure. These changes can be
      detected by simple non-invasive echocardiogram techniques. However, these techniques usually
      detect the increased "stiffness" of the heart only after it has progressed to a significant
      extent. The investigators hypothesize that if they stress the heart using a Dobutamine
      infusion and measure the filling pressure using echocardiogram, it will provide them with
      tools to identify these changes earlier.
    

Detailed description: 
      The heart becoming "stiff" due to increased fibrous tissue or decreased elasticity of the
      heart tissue is one of the earliest changes caused by heart failure. These changes can be
      detected by simple non-invasive echocardiogram techniques. However, these techniques usually
      detect the increased "stiffness" of the heart only after it has progressed to a significant
      extent. The investigators hypothesize that if they stress the heart using a Dobutamine
      infusion and measure the filling pressure using echocardiogram, it will provide them with
      tools to identify these changes earlier.

      The investigators are planning to include people have normal heart function. It is standard
      procedure to measure cardiac pressure during catheterization. Simultaneously, the
      investigators will infuse Dobutamine (standard drug used for chemical stress testing, DSE).
      This drug increases the heart rate and mimics exercise in normal humans who are unable to
      exercise for various reasons. The investigators would continue to monitor the pressure inside
      the heart as they infuse Dobutamine and see of there is an increase in filling pressure. The
      investigators will correlate the invasive pressures with their echo derived measurements.

      The investigators plan to include 25 veterans in this study. For each individual the study
      would increase the amount of time they will spend in the Catheterization Lab from 30 to 120
      minutes. The entire procedure will be monitored by Advanced Cardiac Life Support (ACLS)
      certified nurses and doctors.
    

Intervention name(s): Dobutamine stress echo (DSE); Atropine bolus
Intervention type(s): Drug; Drug
Intervention description(s): Dobutamine intravenous infusion would be undertaken starting at 10 micro-grams/kg per minute in three minute intervals increased to 20, 30, 40 or 50 micro-grams/kg per minute or to a peak heart rate response of at least 85% age predicted maximum heart rate.; If at the end of the Dobutamine protocol, there is inadequate heart rate response, intravenous atropine boluses of 0.5 milligrams (maximum 1.0 mg) would be used as needed to achieve a heart rate of at least 85% of age predicted maximum heart rate.
Other intervention name(s): Dobutamine hydrochloride; Atropine sulfate
Intervention MeSH terms: Atropine; Dobutamine
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention