DETECTING IMPAIRED HEART MECHANICAL PERFORMANCE AND APPARATUS THEREFOR

• US 3,776,221 A
• Filed: 04/02/1971
• Issued: 12/04/1973
• Est. Priority Date: 04/02/1971
• Status: Expired due to Term

• Current Assignee: Kevin M. Mcintyre
• Original Assignee: Kevin M. Mcintyre
• Inventors: McIntyre, Kevin M.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/130,572
• Time in Patent Office: 977 Days
• Field of Search: 128/2.5A,2.5E,2.5F,2.5G,2.5M,2.5N,2.5P,2.5Q,2.5R,2.5T,2.05
• US Class Current: 600/485
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

A pressure-sensitive device contacts the skin of a patient near an artery noninvasively to provide a signal representative of systemic arterial blood pressure both before and after a Valsalva Manoeuvre. This blood pressure signal is differentiated, and the changes in amplitude before and after the Valsalva Manoeuvre detected to indicate potential left ventricle failure when the change is less than a predetermined value. Signals representative of pulse pressure, the mean systemic arterial blood pressure, heart rate and left ventricular ejection time are also provided to facilitate detection of impaired mechanical performance of the heart.

Claims

1. A method of detecting mechanical heart impairment which method includes the steps of, noninvasively providing a blood pressure signal representative of blood pressure by placing pressure sensitive means in contact with the skin of a patient near an artery, differentiating said blood pressure signal, subjecting said patient whose blood pressure is characterized by said pressure signal to a heart straining manoeuvre, detecting the change in the amplitude of the differentiated pressure signal after said manoeuvre from its amplitude before said manoeuvre, and determining a probable mechanical impairment of the heart when said change is less than a predetermined value.

2. A method of detecting mechanical heart impairment in accordance with claim 1 wherein said heart straining manoeuvre is a Valsalva manoeuvre and said signal representative of blood pressure is representative of systemic arterial blood pressure.

3. A method of detecting mechanical heart impairment in accordance with claim 2 wherein said Valsalva manoeuvre is involuntarily induced in said patient.

4. A method of detecting mechanical heart impairment in accordance with claim 1 and further including the steps of providing signals representative of systemic peak pressure, systemic mean pressure, heart rate, and left ventrical ejection time both before and after said manoeuvre and sensing the differences between respective signals before and after said manoeuvre.

5. A method of detecting mechanical heart impairment in accordance with claim 1 which method includes the steps of, recording the differentiated blood pressure signal so that its peak amplitude before said manoeuvre is between a baseline and predetermined control line and observing the amplitude of said differentiated blood pressure signal immediately after said manoeuvre relative to a predetermined normal limit line spaced from said control line to determine potential mechanical impairment when the peak amplitude after said manoeuvre is between the control line and the acceptable level line, mechanical heart impairment when then below said control line and no mechanical impairment when above said acceptable level line.

6. Apparatus for practicing the method of claim 1 comprising, pressure sensitive means responsive to said blood pressure for providing said blood pressure signal, means for differentiating said blood pressure signal to provide a differentiated pressure signal representative of the time derivative of said blood pressure, means for detecting the change in the amplitude of the differentiated pressure signal after said manoeuvre from its amplitude before said manoeuvre including means for recording said differentiated pressure signal before and after said manoeuvre to provide an indication of the changes in the differentiated pressure signal before and after said manoeuvre, and meaNs for determining a probable mechanical impairment of the heart when said change is less than a predetermined value.

7. Apparatus in accordance with claim 6 and further comprising means responsive to said blood pressure signal for deriving signals representative of heart rate, pulse pressure and peak pressure, and means responsive to said differentiated pressure signal, said heart rate, said pulse pressure and said peak pressure for providing an indication of mechanical heart impairment.