Cardiopulmonary functional status assessment via heart rate response detection by implantable cardiac device
First Claim
Patent Images
1. A cardiac device, comprising:
- one or more sensing channels for generating intra-cardiac electrogram signals;
a controller for detecting intrinsic cardiac activity and measuring an intrinsic heart rate from the electrogram signals;
an activity level sensor interfaced to the controller for measuring a parameter related to a patient'"'"'s level of physical activity;
wherein the controller is programmed to construct a historical record of activity level versus heart rate, referred to as a heart rate response profile;
wherein the controller is programmed to compute a heart rate response slope from the heart rate response profile, defined as the ratio of an incremental change in intrinsic rate to an incremental change in measured activity level;
wherein the controller is programmed to collect periodic maximum heart rates over time and derive a maximum intrinsic heart rate parameter therefrom indicative of the maximum heart rate the patient is able to attain;
a pacing channel for pacing a cardiac chamber, wherein the controller is programmed to control the delivery of pacing pulses in accordance with a programmed mode; and
,wherein the controller is programmed to switch to a rate-adaptive pacing mode if both the heart rate response slope and maximum intrinsic heart rate parameters have decreased below respective predefined limit values.
1 Assignment
0 Petitions
Accused Products
Abstract
An implantable cardiac device is configured and programmed to assess a patient'"'"'s cardiopulmonary function by evaluating the patient'"'"'s heart rate response. Such evaluation may be performed by computing a heart rate response slope, defined as the ratio of an incremental change in intrinsic heart rate to an incremental change in measured activity level. The heart rate response slope may then be compared with a normal range to assess the patient'"'"'s functional status.
-
Citations
18 Claims
-
1. A cardiac device, comprising:
-
one or more sensing channels for generating intra-cardiac electrogram signals; a controller for detecting intrinsic cardiac activity and measuring an intrinsic heart rate from the electrogram signals; an activity level sensor interfaced to the controller for measuring a parameter related to a patient'"'"'s level of physical activity; wherein the controller is programmed to construct a historical record of activity level versus heart rate, referred to as a heart rate response profile; wherein the controller is programmed to compute a heart rate response slope from the heart rate response profile, defined as the ratio of an incremental change in intrinsic rate to an incremental change in measured activity level; wherein the controller is programmed to collect periodic maximum heart rates over time and derive a maximum intrinsic heart rate parameter therefrom indicative of the maximum heart rate the patient is able to attain; a pacing channel for pacing a cardiac chamber, wherein the controller is programmed to control the delivery of pacing pulses in accordance with a programmed mode; and
,wherein the controller is programmed to switch to a rate-adaptive pacing mode if both the heart rate response slope and maximum intrinsic heart rate parameters have decreased below respective predefined limit values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for operating a cardiac device, comprising:
-
generating intra-cardiac electrogram signals and measuring an intrinsic heart rate from the electrogram signals; measuring a parameter related to a patient'"'"'s level of physical activity;
constructing a historical record of activity level versus heart rate, referred to as a heart rate response profilemonitoring a patient'"'"'s cardiopulmonary functional status by computing a heart rate response slope from the heart rate response profile, defined as the ratio of an incremental change in intrinsic rate to an incremental change in measured activity level; collecting periodic maximum heart rates over time and deriving a maximum intrinsic heart rate parameter from the collected periodic maximum heart rates that reflects the maximum intrinsic heart rate that the patient is able to attain over a defined period of time; pacing a cardiac chamber in accordance with a programmed mode; and
,switching to a rate-adaptive pacing mode if both the heart rate response slope and maximum intrinsic heart rate parameters have decreased below respective predefined limit values. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification