The purpose of this study is to determine the clinical usefulness of measuring the heart's
pumping ability by measuring the Peripheral Pulse Volume (PPV).
Peripheral Pulse Volume (PPV) is the change in the volume of a limb that occurs when blood
passes through the limb. The limb also acts as an electrical conductor whose electrical
impedence changes with limb geometry and volume. Each time the heart beats, the volume of
the limb segment changes, and therefore its electrical impedence changes. A plethysmograph
can be used to measure volume changes of a part of the body by producing a plethysmographic
waveform. Selectively capturing a number of these plethysmographic wave forms with
acceptable noise levels and averaging them using the EKG as a reference-timing signal
generate a highly reproducible pulse volume signal. Signal averaged pulse volume
measurement will be obtained non-invasively from the lower extremities of patient
volunteers. A disposal non-occluding electrical monitoring strap will be applied to the
calf of each patient. Changes in the calf's size/volume caused by changes in the patient's
cardiac output and calf blood flow will result in electrical impedance changes. These
changes will be recorded by an analog admittance plethysmograph attached to the lower
extremity strap. The analog plethysmograph is coupled to a digital computer for signal
enhancement and measurement.
- Coronary care unit patients with indwelling right heart (Swan Ganz) catheters with or
without intraaortic balloon assist pumping devices.
- Congestive Heart Failure patients on and off various therapeutic inotropic agents
with or without indwelling heart catheters
- Cardiac catheterization laboratory patients undergoing prophylactic IABP in the
presence of left main or diffuse unstable CAD
- Chronic renal failure patients undergoing hemodialysis.
- Peripheral Vascular Disease patients
- Patients undergoing Tilt Table Testing
- Any patients undergoing right heart catheterization Exclusion criteria -- Non