A rule-based method for predicting the electrical activation of the heart with cardiac resynchronization therapy from non-invasive clinical data

Fig. 1. Six electrophysiology models were investigated with the inclusion of scar, functional block in the anterior or posterior regions of the LV, slow septal conduction, and fast endocardial conduction used to determine the importance of these factors in accurately simulating the electrical propagation across the ventricles.

Fig. 2. RV pacing with a six-fold increase in the ventricular endocardium was simulated for the 14CMR cases, with the electrical activation time normalized as a percentage of the QRS duration. The latest activated site is highlighted with a white dot.

Fig. 3. The simulated local activation time normalized as a percentage of the QRS duration (LAT) was compared against the clinical LAT for each of the measured sites in the coronary sinus venous branches for the model with fast endocardial conduction.

Fig. 4. Simulations were run for the 14 CMR cases, with a basic model, inclusion of scar (for cases 9–14), slow septum, fast endocardial conduction, anterior or posterior functional block. Boxplots of the (a) temporal error, (b) distance error, and (c) conduction velocities are shown for each model. The conduction velocities which are between the physiologically plausible range (0.07–0.75 m/s) are highlighted in green.

Fig. 5. (a) CT images were acquired for 4 CRT upgrade patients and were automatically segmented using the Philips model based tool. (b) The EAM from Ensite NavX (white) was mapped to the coronary sinus semi-automatically segmented from the CT images (black). (c) The electrical activation across the ventricles from RV pacing was simulated. (d) The EAM local activation times were mapped onto the model (spheres) and the RMS distance error of the mapped EAM sites onto the models is stated for each case. (e) The LAT as a percentage of the QRS duration was compared between the clinical measurements and the model simulations with a six-fold increased conduction velocity in the ventricular endocardium.

Fig. 6. Simulations were run for the 4 CT cases, with a basic model, slow septum, fast endocardial conduction, anterior or posterior functional block. Boxplots of the (a) temporal error, (b) distance error, and (c) conduction velocities are shown for each model. The conduction velocities which are between the physiologically plausible range (0.07–0.75 m/s) are highlighted in green.