Method and apparatus for developing a vectorcardiograph in an implantable medical device

A method of developing a vectorcardiogram projected onto at least one of reference sagittal, horizontal, and frontal planes of the body employing a cardiac implantable medical device comprising:

• implanting a first pair of vectorcardiogram sense electrodes in the body to define a first internal lead vector having a first vector orientation in relation to the reference sagittal, horizontal, and frontal planes of the body;
• coupling the first pair of vectorcardiogram sense electrodes to the implantable medical device;
• sensing a first PQRST electrogram of the heart across the first internal lead vector;
• implanting a second pair of vectorcardiogram sense electrodes in the body to define a second internal lead vector having a second vector orientation in relation to the reference sagittal, horizontal, and frontal planes of the body;
• coupling the second pair of vectorcardiogram sense electrodes to the implantable medical device;
• sensing a second PQRST electrogram of the heart across the second internal lead sector;
• deriving the orientation and magnitude of the wave front of at least one of the P-wave, QRS wave and T-wave over the time of occurrence of the first sensed PQRST electrogram as a first one of an x-axis vector projected into the reference sagittal plane as a sagittal vectorcardiogram, a y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram;
• and
• deriving the orientation and magnitude of the wave front of at least one of the P-wave, QRS wave and T-wave over the time of occurrence of the second sensed PQRST electrogram as a second one of an x-axis vector projected into the reference sagittal plane as a sagittal vectorcardiogram, a
• y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram.

A method of developing an xyz-vectorcardiogram projected into three dimensional space in spatial reference to at least one of reference sagittal, horizontal, and frontal planes of the body employing an implantable medical device, comprising:

• implanting a pair of vectorcardiogram sense electrodes in the body to define an internal lead vector having a vector orientation in relation to the reference sagittal, horizontal, and frontal planes of the body;
• coupling the a pair of vectorcardiogram sense electrodes to the implantable medical device;
• sensing the PQRST electrogram of the heart across the internal lead vector;
• and
• deriving the orientation and magnitude of the wave front of at least one of the P-wave, QRS wave and T-wave of the sensed PQRST electrogram over the time of occurrence of the sensed PQRST electrogram as an xyz-vectorcardiogram projected into three-dimensional space in reference to at least one of reference sagittal, horizontal, and frontal planes of the body.

A cardiac implantable medical device that develops a vectorcardiogram projected onto at least one of reference sagittal, horizontal, and frontal planes of the body comprising:

• a pair of vectorcardiogram sense electrodes adapted to be implanted in the body to define an internal lead vector having a vector orientation In relation to the reference sagittal, horizontal, and frontal planes of the body;
• means for sensing the PQRST electrogram of the heart across the internal lead vector;
• and
• means for deriving the orientation and magnitude of the wave front of at least one of the P-wave;
• QRS wave and T-wave of the sensed PQRST electrogram over the time of occurrence of the sensed PQRST electrogram as at least one of an x-axis vector projected into:
• the reference sagittal plane as a sagittal vectorcardiogram, a y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram.

A cardiac implantable medical device that develops a vectorcardiogram projected onto at least one of reference sagittal, horizontal, and frontal planes of the body comprising:

• a first pair of vectorcardiogram sense electrodes adapted to be implanted within the body defining a first internal lead vector having a first vector orientation in relation to the reference sagittal, horizontal, and frontal planes of the body;
• first sensing means for sensing a first PQRST electrogram of the heart across the first internal lead vector;
• a second pair of vectorcardiogram sense electrodes adapted to be implanted within the body defining a second internal lead vector having a second vector orientation in relation to the reference sagittal, horizontal, and frontal planes of the body;
• second sensing means for sensing a second PQRST electrogram of the heart across the second internal lead vector;
• means for deriving the orientation and magnitude of the wave front of at least one of the P-wave, ORS wave and T-wave over the time of occurrence of the first sense PQRST electrogram a first one of an x-axis vector projected Into the reference sagittal plane as a sagittal vectorcardiogram, a y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram;
• and
• means for deriving the orientation and magnitude of the wave front of at least one of the P-wave, QRS wave and T-wave over the time of occurrence of the second sensed PQRST electrogram as a second one of an x-axis vector projected into the reference sagittal plane as a sagittal vectorcardiogram, a y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram.

A system for developing an xyz-vector vectorcardiogram of electrical signals of the heart accompanying depolarization and re-polarization of the muscle cells of the heart during a PQRST cardiac cycle employing an implantable medical device comprising:

• an atrial electrode implanted in relation to the one of the right atrium and left atrium;
• a right ventricular electrode implanted in relation to the right ventricle;
• a left ventricular electrode implanted in relation to the left ventricle;
• first sensing means selectively coupled to the atrial electrode and the right ventricular electrode for sensing the electrical signals of the heart along a first internal lead vector and providing a first vector signal;
• second sensing means selectively coupled to the atrial electrode and the left ventricular electrode for sensing the electrical signals of the heart along a second internal lead vector and providing a second vector signal;
• third sensing means selectively coupled to the left ventricular electrode and the right ventricular electrode for sensing the electrical signals of the heart along a third internal lead vector and providing a third vector signal;
• means for developing an xyz-vector of a vectorcardiogram that is related to reference sagittal, horizontal, and frontal planes of the body from one or more of the first, second and third internal lead vector signals;
• and
• means for deriving the orientation and magnitude of a wave front of at least one of the P-wave, QRS wave and T-wave of the sensed PQRST electrogram over the time of occurrence of a sensed PQRST electrogram as at least one of an x-axis vector protected into the reference sagittal plane as a sagittal vectorcardiogram a y-axis vector protected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram.

A method of developing an xyz-vector vectorcardiogram of electoral signals of the heart accompanying depolarization and re-polarization of the muscle cells of the heart during a PQRST cardiac cycle employing an implantable medical device comprising:

• implanting an atrial electrode in relation to the one of the right atrium and left atrium;
• implanting a right ventricular electrode in relation to the right ventricle;
• implanting a left ventricular electrode in relation to the left ventricle;
• sensing the electrical signals of the heart along a first internal lead vector between the atrial electrode and the right ventricular electrode and providing a first internal lead vector signal;
• sensing the electrical signals of the heart along a second internal lead vector between the atrial electrode and the left ventricular electrode and providing a second internal lead vector signal;
• sensing the electrical signals of the heart along a third internal lead vector between the left ventricular electrode and the right ventricular electrode for and providing a third internal lead vector signal;
• developing an xyz-vector of a vectorcardiogram mat is related to reference sagittal, horizontal, and frontal planes of the body from one or mare of the first, second and third internal lead vector signals;
• and
• developing the orientation and magnitude of the wave front of at least one of the P-wave, QRS wave and T-wave of the sensed PQRST electrogram over the time of occurrence of the sensed PQRST electrogram as at least one of an x-axis vector projected into the reference sagittal plane as a sagittal vectorcardiogram, a y-axis vector projected into the reference horizontal plane as a horizontal vectorcardiogram, and a z-axis vector projected into the reference frontal plane as a frontal vectorcardiogram.

A system for developing an internal Xp-vector, Yp-vector and

• Zp-vector electrical signals of the heart accompanying depolarization and re-polarization of the muscle cells of the heart during a cardiac cycle in an implantable medical device capable of communicating with an external medical device, the external medical device capable of developing a reference XE-vector signal, a reference YE-vector signal, and a reference
• ZE-vector signal within a set of orthogonal reference planes defined by a reference XE-vector, a reference E-vector, and a reference ZE-vector, the system comprising:
• first, second, and third electrodes implanted in relation to the heart separated apart from one another such that a first internal lead vector is defined between the first and second electrodes, a second internal lead vector is defined between the first and third electrodes, and a third internal lead vector is defined between the second and third electrodes;
• first sensing means selectively coupled to the first electrode and the second electrode for sensing and amplifying the electrical signals of the heart along the first internal lead vector at a first gain and providing a first vector signal;
• second sensing means selectively coupled to the first electrode and the third electrode for sensing and amplifying the electrical signals of the heart along the second internal lead vector at a second gain and providing a second vector signal;
• third sensing means selectively coupled to the second electrode and the third electrode for sensing and amplifying the electrical signals of the heart along the third internal lead vector at a third gain and providing a third vector signal;
• means for adjusting the first gain to normalize the first vector signal to the reference XE-vector signal to provide the Xp-vector signal;
• means for adjusting the second gain to normalize the second vector signal to the reference YE-vector signal to provide the Yp-vector signal;
• and
• means for adjusting the third gain to normalize the third vector signal to the reference ZE-vector signal to provide the Zp-vector signal.