Flow-occluding method for the diagnosis of heart conditions
First Claim
1. A method for analyzing the biomechanical behaviour of a subject'"'"'s cardiac muscle and for diagnosing its pathological conditions which comprises:
- introducing a pressure sensor into one of the subject'"'"'s ventricles;
positioning a balloon inflation valve in the discharge port of said ventricle;
closing said valve during at least one cycle of systolic or diastolic pressure;
recording the pressure values derived from the sensor during said cycle;
plotting said values in relation to time; and
mathematically analysing said plotted values and deriving at least one parameter indicative of the condition of the cardiac muscle from the shape of the curve representing the variations of said values during said cycle by interpreting said curve as a theoretical pressure-function (P) varying in time (t) with changes of ventricular volume (V) according to a phenomenological model equation;
space="preserve" listing-type="equation">P(V,t)=B(V)t.sup.y e.sup.-xtwherein B is a factor corresponding to the influence of the cardiac muscle size, y represents a first parameter indicative of the excitation-contraction delay, and x represents a second parameter indicative of the inotropic characteristic of the muscle; and
computing the x and y parameters which most closely fit the curve.
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Abstract
A method for analyzing the biomechanical behavior of the cardiac muscle and for diagnosing pathological conditions of the heart. The apparatus measures and records the rise and fall of intra-ventricular isovolumetric pressure monitored by a transducer installed at the tip of a cardiac catheter. The pressure versus time recordings during both the systolic and diastolic phases are mathematically analyzed, and two parameters indicative of the biomechanical conditions of the muscle are derived. The parameters are then plotted against each other on a map in which diagnostic zones of various normal and pathological heart conditions are delineated. The cardiac catheter is fitted with a balloon inflation valve used to close the aortic port during a single heartbeat in order to override the aortic valve and maintain the isovolumetric condition during contraction and relaxation of the cardiac muscle organ.
63 Citations
9 Claims
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1. A method for analyzing the biomechanical behaviour of a subject'"'"'s cardiac muscle and for diagnosing its pathological conditions which comprises:
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introducing a pressure sensor into one of the subject'"'"'s ventricles; positioning a balloon inflation valve in the discharge port of said ventricle; closing said valve during at least one cycle of systolic or diastolic pressure; recording the pressure values derived from the sensor during said cycle; plotting said values in relation to time; and mathematically analysing said plotted values and deriving at least one parameter indicative of the condition of the cardiac muscle from the shape of the curve representing the variations of said values during said cycle by interpreting said curve as a theoretical pressure-function (P) varying in time (t) with changes of ventricular volume (V) according to a phenomenological model equation;
space="preserve" listing-type="equation">P(V,t)=B(V)t.sup.y e.sup.-xtwherein B is a factor corresponding to the influence of the cardiac muscle size, y represents a first parameter indicative of the excitation-contraction delay, and x represents a second parameter indicative of the inotropic characteristic of the muscle; and
computing the x and y parameters which most closely fit the curve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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