Patent ID: 8521282

Claim:
A heart stimulation system comprising: an electrode lead configured to be placed inside a coronary sinus of a heart as a coronary sinus lead comprising at least one stimulation electrode and an ultrasonic transducer configured to measure a velocity of blood flow across a mitral valve of said heart when said ultrasonic transducer is situated in the coronary sinus or a cardiac vein when in its implanted state; a stimulation pulse generator configured to generate electric stimulation pulses wherein said stimulation pulse generator is connected to said electrode lead that is configured to deliver said electric stimulation pulses to at least one chamber of a heart via said at least one stimulation electrode; memory; an ultrasonic transducer control unit wherein the ultrasonic transducer control unit is configured to excite the ultrasonic transducer with a pulse duration of approximately 1 to 5 microseconds; generate high frequency pulses of 3 to 9 pulses within 100 ms to 300 ms that begins with a left atrial excitation or contraction, or left atrial event and generate high frequency pulses only within a measurement period of 5 to 10 minutes a day; apply a time window in which to receive a reflected ultrasound signal by said ultrasonic transducer wherein the time window is arranged in chronological relation to an emission each of said high frequency ultrasonic pulses wherein said time window comprises a duration of an expected time of flight between emission of said ultrasonic pulse and a time when a reflected ultrasound signal is expected to return and evaluate only that part of the reflected ultrasound signal within said time window; and, a control unit that is connected to said memory, said stimulation pulse generator and said ultrasonic transducer via said ultrasonic transducer control unit wherein said ultrasonic transducer control unit is configured to provide a flow velocity output signal to the control unit that reflects said velocity of blood flow and wherein said control unit is configured to process said flow velocity output signal to optimize an atrioventricular delay AVD through measurement of said velocity of blood flow across said mitral valve after said left atrial event and vary the atrioventricular delay AVD for a few beats each and to determine an optimal AVD value and create separate tables in said memory for different event types, including atrial paced and sensed events and store the optimal AVD value in said separate tables based on said event types, together with the heart rate under which the optimal AVD value was determined and trigger right and left ventricular stimulation pulses when no intrinsic excitation of said heart occurs in a predetermined period and when said velocity of blood flow is below a threshold value with said optimal AVD obtained from said memory based on a current heart rate.