Abstract: A cardiovascular electrode catheter for use in arrhythmia ablation procedures has a dumbbell-shaped large-tip electrode having an annular recess or indentation. The annular recess divides the electrode into a ball-shaped distal portion and a generally cylindrical proximal portion. Both the distal and proximal portions of the electrode have a diameter substantially the same as that of the catheter body. The recess enables the electrode to grip the mitral or tricuspid annulus or the atrial or ventricular myocardial wall to improve ablation procedures.

Abstract: A cardiovascular electrode catheter for use in arrhythmia ablation procedures has a dumbbell-shaped large-tip electrode having an annular recess or indentation. The annular recess divides the electrode into a ball-shaped distal portion and a generally cylindrical proximal portion. Both the distal and proximal portions of the electrode have a diameter substantially the same as that of the catheter body. The recess enables the electrode to grip the mitral or tricuspid annulus or the atrial or ventricular myocardial wall to improve ablation procedures.

Abstract: A system for aborting the dual pathway tachycardias in a heart comprising the syndrome of paroxysmal supraventricular tachycardia (due generally to atrioventricular nodal reentry or atrioventricular reentry using an anomalous atrioventricular connection for retrograde conduction) by sensing cardiac impulses and, with respect to each sensed cardiac impulse, determining if such sensed cardiac impulse is an inciting cardiac impulse, a cardiac impulse which occurs at a time with respect to the last received cardiac impulse which falls within a predetermined echo zone and which will result in the initiation of a dual pathway tachycardia, and inducing an aborting cardiac impulse in response to a sensed inciting cardiac impulse in the cardiac muscle at a time within the predetermined aborting zone for aborting the initiation of the dual pathway tachycardia.