Abstract: The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).

Abstract: Assessing symptomatic and asymptomatic physiologic changes due to chronic heart failure involves apparatus and methods for gauging degradation and possible improvement using automated measurement of inter-ventricular conduction time, both alone and in combination with other automated physiologic tests. Conduction times increase due to the greater distance a wavefront must traverse as a heart enlarges. Analysis of conduction time can be used to verify the occurrence of cardiac remodeling due to heart failure as well as beneficial reverse remodeling due to successful heart failure therapy delivery. Patient activity level(s) and presence/increase in pulmonary fluids can also be used to automatically determine changes in heart failure status and/or predict hospitalization. Conduction time is monitored between electrodes positioned in the left and right ventricles of the heart via endocardial or epicardial electrodes.

Abstract: Assessing symptomatic and asymptomatic physiologic changes due to chronic heart failure involves apparatus and methods for gauging degradation and possible improvement using automated measurement of inter-ventricular conduction time, both alone and in combination with other automated physiologic tests. Conduction times increase due to the greater distance a wavefront must traverse as a heart enlarges. Analysis of conduction time can be used to verify the occurrence of cardiac remodeling due to heart failure as well as beneficial reverse remodeling due to successful heart failure therapy delivery. Patient activity level(s) and presence/increase in pulmonary fluids can also be used to automatically determine changes in heart failure status and/or predict hospitalization. Conduction time is monitored between electrodes positioned in the left and right ventricles of the heart via endocardial or epicardial electrodes.

Abstract: Assessing symptomatic and asymptomatic physiologic changes due to chronic heart failure involves apparatus and methods for gauging degradation and possible improvement using automated measurement of inter-ventricular conduction time, both alone and in combination with other automated physiologic tests. Conduction times increase due to the greater distance a wavefront must traverse as a heart enlarges. Analysis of conduction time can be used to verify the occurrence of cardiac remodeling due to heart failure as well as beneficial reverse remodeling due to successful heart failure therapy delivery. Patient activity level(s) and presence/increase in pulmonary fluids can also be used to automatically determine changes in heart failure status and/or predict hospitalization. Conduction time is monitored between electrodes positioned in the left and right ventricles of the heart via endocardial or epicardial electrodes.

Abstract: The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).

Abstract: The invention provides methods and apparatus for determining in a non-tracking pacing mode (e.g., DDI/R, VVI/R) whether a ventricular pacing stimulus is capturing a paced ventricle, including some or all of the following aspects. For example, increasing a ventricular pacing rate a nominal amount to an overdrive pacing rate higher than a most recent heart rate and evaluating a conduction interval from a first pacing ventricle to a second sensing ventricle and then continuing to monitor the underlying rate to ensure that a threshold testing pacing rate will not exceed a predetermined minimum interval and providing pacing stimulation to the first ventricle and sensing the second ventricle to determine whether the pacing stimulation to the first ventricle was one of sub-threshold and supra-threshold. The methods and apparatus are especially useful in conjunction with ensuring actual delivery of a ventricular pacing regime (e.g., cardiac resynchronization therapy or “CRT”).

Abstract: Assessing symptomatic and asymptomatic physiologic changes due to chronic heart failure involves apparatus and methods for gauging degradation and possible improvement using automated measurement of inter-ventricular conduction time, both alone and in combination with other automated physiologic tests. Conduction times increase due to the greater distance a wavefront must traverse as a heart enlarges. Analysis of conduction time can be used to verify the occurrence of cardiac remodeling due to heart failure as well as beneficial reverse remodeling due to successful heart failure therapy delivery. Patient activity level(s) and presence/increase in pulmonary fluids can also be used to automatically determine changes in heart failure status and/or predict hospitalization. Conduction time is monitored between electrodes positioned in the left and right ventricles of the heart via endocardial or epicardial electrodes.