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QRS Complex and Ventricular Depolarization

Marks rapid ventricular depolarization, primarily driven by the His-Purkinje system. The complex's duration is critical for assessing bundle branch block.
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The statement of the theorem

Define the ventricular depolarization process by the change in transmembrane potential ΔV(r,t)=Vmax−Vrest\Delta V(\mathbf{r}, t) = V_{max} - V_{rest}. The QRS complex is modeled by the rapid propagation of the electrical wavefront E(r,t)\mathbf{E}(\mathbf{r}, t) through the ventricular myocardium Ωvent\Omega_{vent}. The governing equation for the potential change is: \n∂V∂t=12κ∇2V−vcond⋅∇V+Istim/Cm\frac{\partial V}{\partial t} = \frac{1}{2\kappa} \nabla^2 V - \mathbf{v}_{cond} \cdot \nabla V + I_{stim} / C_m \nWhere κ\kappa is the tissue conductivity and CmC_m is the membrane capacitance. The complex's duration ΔtQRS\Delta t_{QRS} is inversely proportional to the maximum conduction velocity vmax\mathbf{v}_{max} in the His-Purkinje system: ΔtQRS∝1/vmax\Delta t_{QRS} \propto 1 / \mathbf{v}_{max}.