Method and apparatus for treating diastolic heart failure
Methods and systems for treating patients with diastolic heart failure (DHF) are disclosed which include slowing a patient's heart rate below its intrinsic rate, and controlling the rate using cardiac pacing therapy to improve LV filling and cardiac output. In certain embodiments, a pacing treatment rate may be determined by adjusting an adaptive rate by an amount determined by evaluating one or more patient parameters.
1. A method of treating a patient responsive to a diagnosis of diastolic heart failure (DHF), the method comprising:
causing the patient's heart rate to decrease below the patient's intrinsic heart rate;
sensing the patient's level of exercise and level of left ventricular afterload;
determining an adaptive heart rate R 0 as a function of the patients level of exercise;
determining a rate adjustment R A as a function of the patient's level of ventricular afterload;
adjusting the adaptive rate, R 0 , by the rate adjustment, R A , to provide exercise responsive pacing at a treatment rate, R T , corresponding to a desired level of left ventricular afterload;
and delivering cardiac pacing therapy to the patient at the treatment rate.
2. The method of claim 1 wherein determining the rate adjustment, R A , comprises determining the rate adjustment as a function of aortic impedance.
3. The method of claim 1 wherein determining the adaptive rate, R 0 , comprises deriving the adaptive rate from an activity sensor.
4. The method of claim 1 wherein determining the adaptive rate, R 0 , comprises deriving the adaptive rate from a physiologic sensor.
5. The method of claim 1 wherein R A is a function of R 0 .
6. The method of claim 1 comprising triggering application of the rate adjustment, R A , when the patient's level of left ventricular afterload crosses a predetermined threshold.
7. The method of claim 1 wherein determining R T comprises subtracting R A from R 0 .