System and method for real-time simulation of patient-specific cardiac electrophysiology including the effect of the electrical conduction system of the heart

#The present invention relates to simulating cardiac electrophysiology of a patient, and more particularly to patient-specific simulation of cardiac electrophysiology of a patient including the effect of the electrical conduction system of the heart for planning or guidance of electrophysiology interventions.

#The prevalence of heart rhythm disease is increasing in Western countries. While primary treatments are based on drugs, minimally invasive electrophysiology (EP) therapies are becoming effective enough to be considered as viable alternatives. For example, the use of ablative therapies is increasing for treatment of cardiac arrhythmias, such as atrial fibrillation or ventricular tachycardia, while Cardiac Resynchronization Therapy (CRT) is becoming a treatment of choice for heart failure patients. However, these therapies require thorough patient selection and complex planning, and their long term efficacy is still sub-optimal. Accordingly, tools and techniques to improve patient selection, therapy planning, and interventional guidance are desirable.

#Computational models for real-time simulation of cardiac EP could be used for intra-operatory guidance and optimization of an EP intervention, as well as for reducing the duration of such procedures and thus reducing patient stress, especially in the case of invasive procedures. Unfortunately, a trade-off between model accuracy and computational cost is still a challenge, and no solution has been proposed to realize real-time modeling of the patient-specific electrophysiology including the electrical conduction system of the heart.

#FIG. 1 illustrates the electrophysiological conduction system of the heart;

#FIG. 2 illustrates a method for simulating patient-specific cardiac EP including the effect of the Purkinje system according to an embodiment of the present invention;

#FIG. 3 illustrates a method of modeling the effect of the Purkinje network of a patient according to an embodiment of the present invention;

#The present invention relates to patient-specific simulation of cardiac electrophysiology (EP) including the effect of the electrical conduction system of the heart using medical imaging data of a patient. Embodiments of the present invention are described herein to give a visual understanding of the methods for patient-specific modeling and electrophysiology simulation using medical imaging data. A digital image is often composed of digital representations of one or more objects (or shapes). The digital representation of an object is often described herein in terms of identifying and manipulating the objects. Such manipulations are virtual manipulations accomplished in the memory or other circuitry/hardware of a computer system. Accordingly, is to be understood that embodiments of the present invention may be performed within a computer system using data stored within the computer system.

#FIG. 1 illustrates the electrical conduction system of the heart. As shown in FIG. 1, the electrical conduction system of the heart is composed of several elements including: sinoatrial node 102, atrioventricular node 104, His bundle 106, and Purkinje fibers 108. In normal physiological conditions, the electrical pulse is spontaneously generated in the sinoatrial node 102—the natural pacemaker—localized at the junction of the superior vena cava with the right atrium. As the electrical wave propagates towards the atrioventricular node 104, the electrical wave depolarizes the atrial myocytes, which contract and pump the blood to the ventricles. After depolarization of the atria, the action potential reaches the atrioventricular (AV) node 104, localized in the lower part of the right atrium on the fibrous atrioventricular ring. The electrical impulse is then stopped for a few milliseconds to synchronize the heart. This “pause” is fundamental as it enables the atria to fully contract and completely pump the blood into the ventricles. Fibrous tissue separates the musculature of atria and ventricula, the only connection being the muscular bundle of His 106 departing from the AV node 104. After crossing the atrioventricular junction, the bundle of His 106 splits (usually in two branches) at the summit of the ventricular septum. The left bundle branch 110 is a series of fascicles spreading over the septum of the left ventricle and connecting with ordinary myocardial fibers. The right bundle branch 112 tends to remain a bundle until it reaches the anterior papillary muscle, where it splits in fascicles spreading over the right ventricle myocardium. The tree-like terminal branchings of the left and right bundles 110 and 112 are called Purkinje fibers 108 and extend subendocardially up to ⅓ or ½ of the ventricular thickness.

#The His-Purkinje system is involved in abnormal excitation patterns that may lead to arrhythmias. Examples of this phenomenon include left or right branch blocks that cause delayed ventricle contraction, bundle branch reentry that is associated with tachycardia, and subendocardial focal activity considered to be of Purkinje origin that may result in tachycardia or fibrillation. Since the His-Purkinje system plays such an important role in both normal ventricular excitation and life threatening ventricular arrhythmias, modeling of the His-Purkinje system is important for a realistic ventricle model of the heart.