EP0906055A1 - Dispositif de detection et d'evaluation du niveau de shunts intracardiaques - Google Patents

Dispositif de detection et d'evaluation du niveau de shunts intracardiaques

Info

Publication number
EP0906055A1
EP0906055A1 EP97925223A EP97925223A EP0906055A1 EP 0906055 A1 EP0906055 A1 EP 0906055A1 EP 97925223 A EP97925223 A EP 97925223A EP 97925223 A EP97925223 A EP 97925223A EP 0906055 A1 EP0906055 A1 EP 0906055A1
Authority
EP
European Patent Office
Prior art keywords
shunt
thermodilution
curve
heart
magnitude
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP97925223A
Other languages
German (de)
English (en)
Inventor
Jiri Endrys
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0906055A1 publication Critical patent/EP0906055A1/fr
Pending legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
    • A61B5/026—Measuring blood flow
    • A61B5/0275—Measuring blood flow using tracers, e.g. dye dilution
    • A61B5/028—Measuring blood flow using tracers, e.g. dye dilution by thermo-dilution

Definitions

  • the present invention relates to an apparatus for detecting and determining the magnitude of intracardiac shunts by the use of thermodilution. Description of related art.
  • Intracardiac shunts are today normally detected by computing blood samples from different sites within the heart The differences m oxygen saturation indicate wether a shunt exists or not The method is also not particularly sensitive and is also prone to measurement errors, especially in patients with atrial septal defect .
  • SU-A-1109124 describes a method for diagnosing of mtracardial blood shunt defects by introduction of a hypertonic sodium chloride solution into the high pressure heart chamber with subsequent registration of the moment at which it reaches the heart chamber with a lower pressure
  • the electric blood resistance m the chamber with the lower pressure is measured before and after the introduction of the hypertonic sodium chloride solution and m the event of an electric blood resistance in the heart chamber, as compared with the initial resistance, a heart defect with pathological mtracardial blood shunt is diagnosed.
  • the present invention solves the problems noted above and provides an apparatus for detecting and determining the magnitude of intracardiac shunts by the use of thermodilution
  • two thermodilution curves are measured from different parts of the heart.
  • the presence of an intracardiac shunt is detected by comparing the shapes of the measured thermodilution curves with the shape of thermodilution curves obtained from a heart without a shunt. If the compared shapes do not correspond to each other it indicates that an intracardiac shunt exists.
  • To determine the magnitude of an intracardiac shunt the areas under the measured thermodilution curves are calculated.
  • thermodilution is one of several different: techniques to determine cardiac output, but one advantage is that thermodilution is a rather simple and precise method.
  • Thermodilution is one common form of indicator dilution used to obtain cardiac output.
  • a thermodilution catheter is placed e.g. in the right part of the heart so that an injection port of the catheter is in the right atrium and a thermistor on the catheter is located downstream in the pulmonary artery.
  • a bolus of cold saline is injected into the right atrium through the injection port where it mixes with the blood and produces a temperature change which is detected by the thermistor. From this, a thermodilution curve can be plotted, and the shape of the curve depends on the flow rate.
  • the apparatus for detecting and determining the magnitude: of intracardiac shunts by the use of thermodilution accordin ⁇ t to the present invention comprises means for measuring the temperature changes of the blood as a function of time for providing of two different thermodilution curves obtained from different parts of the heart. Then the thermodilution curves are digitized by a digitizing means, e.g. an A/D-converter. The digitized thermodilution curves are then stored in a memory unit connected to the digitizing means.
  • the apparatus according to the present invention also comprises a comparison unit connected to the memory unit for comparing of the shapes of the measured thermodilution curves with the shapes of thermodilution curves obtained from a heart without a shunt.
  • the apparatus thus also comprises a calculation means connected to the correction unit for calculation in the first place of the areas under the thermodilution curves.
  • the calculation means calculates, in dependance of the type of shunt, a left - to - right shunt or a right - to - left shunt, and in dependance of the type of heart defect, an atrial septal defect, ASD, a ventricular septal defect, VSD, or a patent ductus arteriosus, PDA, different combinations of cardiac outputs to finally determine the magnitude of the shunt.
  • the apparatus By using the apparatus according to the present invention one provides an accurate and reliable way to detect and determine the magnitude of intracardiac shunts .
  • the magnitude of intracardiac shunts is the most important parameter in deciding for surgical treatment of a heart .
  • Fig. 1 is a schematic sectional view of a human heart
  • Fig. 2 is a plot of a thermodilution curve obtained for a heart without a shunt
  • Fig. 3 is a plot of a thermodilution curve obtained for a heart with a left to right shunt (L-R shunt) ;
  • Fig. 4 is a plot of a thermodilution curve obtained for a heart with a right to left shunt (R-L shunt) ; and Fig. 5 is a schematic block diagram of an apparatus according to the present invention.
  • FIG 1 there is disclosed a schematic sectional view of a human heart.
  • the heart is partitioned in a right half and a left half.
  • the right half of the heart comprises the right ventricle RV, and the right atrium, RA.
  • the left half of the heart comprises the left ventricle, LV, and the left atrium, LA.
  • IVC inferior vena cava
  • PA pulmonary artery
  • the pulmonary vein, PV leads to the left atrium, LA, and the aorta, AO, leads the blood to "the rest of the body”.
  • Atrial septal defect ASD
  • ventricular septal defect VSD
  • RV right ventricule
  • LV left ventricule
  • PDA patent ductus arteriosus
  • the shunts are partitioned in L-R shunt, a left to right shunt (abnormal connection from the left to the right half of the heart) and R-L shunt, a right to left shunt (abnormal connection from the right to the left half of the heart) .
  • thermodilution technique The principle upon which the thermodilution technique is based is that the change of heat of a substance is related to its mass and specific heat for a given change in temperature. For a static system, if two substances at different temperatures are mixed, the resulting temperature of the mixture will fall between the starting temperatures of the two substances. If the mass of one substance is unknown, it can be determined by equating at equilibrium the change on heat of the two substances and calculating the unknown mass from the resulting equation. When this principle is applied to a system of continuous flow, as in the heart and vasculature, a small amount of relatively cool substance (e.g.
  • thermodilution curve the thermodilution curve
  • Fig. 2 is a plot of thermodilution curve 10 obtained for a heart without a shunt, i.e. a healthy heart.
  • the rising part of the curve indicates the cooling of the blood and the decay of the curve indicates the subsequent heating of the blood.
  • Tie curve is characterized by an exponential decay.
  • Fig. 3 is a plot of a thermodilution curve 20 obtained for a heart with a left - to - right shunt (L-R shunt) , i.e. an abnormal connection from the left to the right half of the heart. If the curves of fig. 2 and fig. 3 are compared to each other it is apparent that the downslope of the curve m figure 3 follows another exponential track after a certain point, S in figure 3 where this point is situated at 56% of the peak value of the curve 20.
  • L-R shunt left - to - right shunt
  • Fig. 4 is a plot of a thermodiluition curve 30 obtained for a heart with a right - to - left shunt (R-L shunt) , i.e. an abnormal connection from the right to the left half of the heart .
  • This curve is recorded from a patient with an atrial septal defect, ASD, i.e. a hole m the wall between the right atrium, RA, (see fig. 1) and the left atrium, LA.
  • ASD atrial septal defect
  • RA right atrium
  • LA left atrium
  • thermodilution curve a catheter is inserted e.g. into a large vein and passed along the vein toward e.g. the right heart and through the right part of the heart to a short distance beyond.
  • the catheter has an orifice cut to the outside of the catheter and liquid is injected at this orifice into the bloodstream from the far end of the catheter.
  • Disposed in the catheter is one or two thermistors, placed at different places along the catheter.
  • thermo-probe or thermo-probes
  • First curve Injection of cold saline into right atrium (RA) or Superior vena cava (SVC) or Infenor vena cava (IVC) .
  • Second curve Injection of cold saline into the left ventricle (LV) .
  • Patent ductus arteriosus or cornary A-V fistula
  • PDA left ventricle
  • Thermo - probes 1st in the descending aorta (DA) - measures PBF; 2nd in the pulmonary artery (PA) - measures L-R. 2.2.
  • Ventricular septal defect (VSD) First curve: Injection of cold saline into the right atrium (RA) .
  • Second curve Injection of cold saline into the left ventricle (LV) .
  • L-R shunt is calulated as the ratio:
  • First curve Injection of cold saline into the left ventricular (LV) .
  • Second curve Injection of cold saline into the right atrium (FA) or superior vena cava (SVC) or infenor vena cava (IVC) .
  • Thermo - probe in the aorta (AO) - measures R-L.
  • R-L shunt is calculated as the ratio;
  • PBF SBF - R-L (all m L/min)
  • a R , Area of 2nd curve
  • a SB ⁇ Area of 1st curve.
  • FIG 5 there is disclosed a schematic block diagram of an apparatus 40 according to the present invention.
  • the apparatus 40 comprises a means 42 for measuring the temperature of the blood as a function of time
  • the measuring means 42 receives thermo - probe - input from the thermo - probe (probes) m the catheter.
  • the measuring means 42 must be able to receive two different thermo - probe - signals simultaneously if the catheter has two thermo - probes.
  • the measuring means 42 outputs an analog signal, m the form of a thermodilution curve (see fig 2-4) , to a digitizing means 44 for digitizing the thermodilution curve (or curves) .
  • the apparatus 40 also comprises a memory unit 46 connected to the digitizing means 44 for storing the digitized thermodilution curve
  • the memory unit 46 is constructed to store at least two digitized thermodilution curves, because the information contained in two thermodilution is needed to be able to both detect and determine the magnitude of mfracardiac shunts
  • a comparison unit 48 is connected to the memory unit 46 for comparing of the shapes of the measured thermodilution curves with the shape of thermodilution curves obtained from a heart without a shunt.
  • the apparatus 40 also comprises a correction unit 50 connected to the comparison unit 48 for eliminating the influence of a left to - right shunt (L-R shunt) (see fig. 3) on the thermodilution curve. If a left - to - right shunt exists m the heart the downslope of the curve 20 follows another exponential track after a certain point, S in fig 3 where this point is situated at 56% of the peak value of the curve 20
  • the correction unit 50 uses extrapolation for correction of the curve for the shunt flow. Two points are chosen on the thermodilution curve (see fig.
  • a calculation means 52 is connected for calculation in the first place of the areas under the measured thermodilution curves and, when the shunt is a left - to - right shunt, for calculation in the second place of the cardiac output of the right half of the heart, CO R , and (of the cardiac output of the left half of the heart, C0 L , and the magnitude of the left - to - right shunt) or the magnitude of the left - to - right shunt.
  • the calculation unit in the second place calculates the cardiac output in the left half of the heart, C0 L , and the magnitude of the right - to - left shunt .
  • the left - to - right shunt is defined as:
  • the magnitude of the shunt is often expressed in percent, namely:
  • the magnitude of the different shunts can also be calculated as
  • a SBF Area of SBF curve .
  • the apparatus 40 also comprises a display unit 54 connected to the calculation means 52 and to the memory unit 46
  • the display unit 54 displayes plots of the measured thermodilution curves and the magnitade of the intracardiac shunt .
  • the digitizing means 44 can be a conventional A/D- converter 44.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Physics & Mathematics (AREA)
  • Cardiology (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Hematology (AREA)
  • Physiology (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Surgical Instruments (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
  • Display Devices Of Pinball Game Machines (AREA)

Abstract

L'invention concerne un dispositif (40) de détection et d'évaluation du niveau de shunts intracardiaques sur la base de la thermodilution. Deux courbes de thermodilution sont établies à partir de mesures effectuées sur différentes parties du coeur. On décèle la présence d'un shunt intracardiaque en comparant (48) la forme de courbes établies pour les mesures de thermodilution et celle de courbes de thermodilution qui correspondent à un coeur sans shunt. La détermination du niveau d'un shunt intracardiaque suppose une évaluation (52) des domaines situés au-dessous des courbes établies pour les mesures de thermodilution: on utilise les données qui correspondent à ces zones pour évaluer (52) le débit cardiaque et, ensuite, le niveau du shunt.
EP97925223A 1996-06-17 1997-06-16 Dispositif de detection et d'evaluation du niveau de shunts intracardiaques Pending EP0906055A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE9602388A SE9602388D0 (sv) 1996-06-17 1996-06-17 An apparatus for detecting and determining the magnitude of intracardiac shunts
SE9602388 1996-06-17
PCT/IB1997/000751 WO1997048334A1 (fr) 1996-06-17 1997-06-16 Dispositif de detection et d'evaluation du niveau de shunts intracardiaques

Publications (1)

Publication Number Publication Date
EP0906055A1 true EP0906055A1 (fr) 1999-04-07

Family

ID=20403039

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97925223A Pending EP0906055A1 (fr) 1996-06-17 1997-06-16 Dispositif de detection et d'evaluation du niveau de shunts intracardiaques

Country Status (4)

Country Link
EP (1) EP0906055A1 (fr)
JP (1) JP2000512864A (fr)
SE (1) SE9602388D0 (fr)
WO (1) WO1997048334A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005007592A1 (de) * 2005-02-18 2006-08-24 Pulsion Medical Systems Ag Vorrichtung zur Bestimmung kardiopulmonaler Volumina und Flüsse eines Lebewesens
CZ303304B6 (cs) * 2010-10-08 2012-07-25 Štásek@Josef Zarízení k provádení merení intrakardiálních zkratu a chlopenních regurgitací

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3726269A (en) * 1971-11-24 1973-04-10 W Webster Cardiovascular catheter for thermal dilution measurement
US4417588A (en) * 1982-03-22 1983-11-29 Critikon, Inc. Apparatus and method for initiating cardiac output computations
US5595181A (en) * 1994-03-24 1997-01-21 Hubbard; A. Robert System for providing cardiac output and shunt quantitation

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9748334A1 *

Also Published As

Publication number Publication date
JP2000512864A (ja) 2000-10-03
SE9602388D0 (sv) 1996-06-17
WO1997048334A1 (fr) 1997-12-24

Similar Documents

Publication Publication Date Title
JP3242655B2 (ja) 血液循環の充満状態を測定するための装置
Forrester et al. Thermodilution cardiac output determination with a single flow-directed catheter
Groszmann et al. Wedged and free hepatic venous pressure measured with a balloon catheter
CA2356254C (fr) Appareil, systeme informatique et programme informatique permettant de determiner un parametre cardio-vasculaire
US4819655A (en) Injectateless thermal cardiac output determination method and apparatus
US4798211A (en) Diagnostic methods and apparatus employing monitoring of myocardial ischemia
EP1935334B1 (fr) Appareil de surveillance d'un patient pour déterminer un paramètre représentant un compartiment du volume intrathoracique d'un patient
US5595181A (en) System for providing cardiac output and shunt quantitation
US4901734A (en) Dual-thermistor thermodilution catheter
Böck et al. Cardiac output measurement using femoral artery thermodilution in patients
US20120165689A1 (en) Catheter with common guide wire and indicator lumen
US6746408B2 (en) Method of blood flow measurement in arterio-venous hemodialysis shunts by indicator dilution
JPS62231619A (ja) 心筋虚血を検出するための方法および装置
US7549965B2 (en) Compensation method for thermodilution catheter having an injectate induced thermal effect in a blood flow measurement
WO1997048334A1 (fr) Dispositif de detection et d'evaluation du niveau de shunts intracardiaques
WO2009049872A1 (fr) Procédé et dispositif de mesures de dilution d'indicateur
Vliers et al. Choice of detection site for the determination of cardiac output by thermal dilution: the injection-thermistor-catheter
David Hillis et al. Measurements of left‐to‐right intracardiac shunting in adults: Oximetric versus indicator dilution techniques
Silove et al. Thermal dilution measurement of pulmonary and systemic blood flow in secundum atrial septal defect, and transposition of great arteries with intact interventricular septum
WO1997048335A1 (fr) Appareil de detection et d'evaluation du niveau de flux de regurgitation dans une valvule cardiaque
Bourdillon et al. Saline conductivity method for measuring cardiac output simplified
Alpert et al. Thermodilution Qp/Qs: an indicator dilution method
Feneley Measurement of cardiac output and shunts
Paulsen et al. Continuous registration of blood velocity and cardiac output with a hot-film anemometer probe, mounted on a Swan-Ganz thermodilution catheter
JP2779401B2 (ja) 肺毛細血管圧測定用肺動脈カテーテル

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 19990118

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE