Effect of mental challenge induced by movie clips on action potential duration in normal human subjects independent of heart rate.

Background: Mental stress and emotion have long been associated with ventricular arrhythmias and sudden death in animal models and humans. The effect of mental challenge on ventricular action potential duration (APD) in conscious healthy humans has not been reported.

Methods And Results: Activation recovery intervals measured from unipolar electrograms as a surrogate for APD (n=19) were recorded from right and left ventricular endocardium during steady-state pacing, whilst subjects watched an emotionally charged film clip.

Automatic image-based retrospective gating of interventional cardiac X-ray images.

Gating of X-ray fluoroscopy images is required for catheter reconstruction for registration of pre-procedural images with fluoroscopy for guidance and biophysical modelling. We propose a novel and clinically useful retrospective method for automatic image-based cardiac and respiratory motion gating. The technique is based on tracking and statistical analysis of the shape of the coronary sinus catheter.