Method and apparatus for predicting acute response to cardiac resynchronization therapy

A method for predicting acute responses to cardiac resynchronization therapy, the method comprising:

• (a) measuring an intrinsic QRS complex (WB) during an intrinsic systolic cycle as a first interval;
• (b) measuring a stimulated QRS complex (WS) during a stimulated systolic cycle as a second interval;
• the stimulated QRS complex (WS) being measured during ventricular stimulation at a short atrioventricular delay (AVD);
• (c) comparing the percent change in duration between the first interval and the second interval against a pre-determined threshold value between 10 and 25 percent of the change in duration between the first interval and the second interval;
• and
• (d) classifying an acute response type of at least one selected stimulation site according to the percent change in duration between the first interval and the second interval.

A method for predicting acute responses to cardiac resynchronization therapy, the method comprising:

• (a) measuring a first interval during an intrinsic systolic cycle over more than one atrioventricular delay;
• (b) measuring a second interval during a stimulated systolic cycle over each of the atrioventricular delays;
• and
• (c) determining the percent change in duration between the first interval and the second interval for each of the atrioventricular delays;
• and
• (d) classifying an acute response type of at least one selected stimulation site according to variations in the percent change in duration between the first interval and the second interval across each of the atrioventricular delays.

An apparatus for predicting acute responses to cardiac resynchronization therapy, the apparatus comprising:

• (a) an electrocardiographic device being configured to measure a first interval during an intrinsic systolic cycle and a second interval during a stimulated systolic cycle over more than one atrioventricular delay;
• and
• (b) a controller being configured to determine the percent change in duration between the first interval and the second interval for each of the atrioventricular delays;
• the controller further being configured to classify an acute response type of at least one selected stimulation site according to variations in the percent change in duration between the first interval and the second interval across each of the atrioventricular delays.

An apparatus for predicting acute responses to cardiac resynchronization therapy, the apparatus comprising:

• (a) an electrocardiography means being configured to measure a first interval during an intrinsic systolic cycle and a second interval during a stimulated systolic cycle over more than one atrioventricular delay;
• and
• (b) a controlling means being configured to determine the percent change in duration between the first interval and the second interval for each of the atrioventricular delays;
• the controlling means further being configured to classify an acute response type of at least one selected stimulation site according to variations in the percent change in duration between the first interval and the second interval across each of the atrioventricular delays.