Abstract: An exemplary method includes detecting ventricular fibrillation, delivering a low voltage cardiac stimulus, determining whether the low voltage cardiac stimulus terminated the ventricular fibrillation, and delivering a higher voltage cardiac stimulus if the low voltage cardiac stimulus did not terminate the ventricular fibrillation. In one example, the delivering the low voltage cardiac stimulus occurs within approximately 10 event intervals from the detected onset of ventricular fibrillation; otherwise, delivery of an appropriate higher voltage cardiac stimulus occurs. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Embodiments of the present invention are directed to implanted systems, and methods for use therewith, that can monitor a cardiac condition. Pressure in sensed in a left chamber of the heart and a right chamber of the heart. A pressure differential is determined between the sensed pressure in the left chamber and the sensed pressure in the right chamber. A cardiac condition is monitored based on the pressure differential. By determining pressure differentials, as opposed to absolute pressures, calibrations/adjustments for changes in weather, altitude or similar pressure affecting factors are not necessary, since the pressure in the left and right chambers should both be equally affected by such changes. Accordingly, with embodiments of the present invention, an external (i.e., non-implanted) pressure sensor is not needed for measuring ambient pressure.