Method and apparatus for verifying bradycardia/asystole episodes via detection of under-sensed events

A method comprising:

• sensing a cardiac signal of a patient via a first electrode and a second electrode of an insertable cardiac monitor subcutaneously implanted within the patient, the insertable cardiac monitor having a length, a width, and a depth, wherein the length is greater than the width and the width is greater than the depth;
• comparing an amplitude of the cardiac signal to a primary threshold;
• detecting an R-wave based on the comparison of the amplitude of the cardiac signal to the primary threshold;
• detecting an asystole based on a comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the primary threshold;
• in response to detecting the asystole, comparing the amplitude of the cardiac signal subsequent to the detected R-wave to a secondary threshold;
• and
• determining whether the detection of the asystole is false based on the comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the secondary threshold.

A system comprising:

• an external programmer;
• and
• an insertable cardiac monitor configured for subcutaneous implantation within a patient, the insertable cardiac monitor having a length, a width, and a depth, wherein the length is greater than the width and the width is greater than the depth, the insertable cardiac monitor comprising:
• a first electrode located at distal end of the insertable cardiac monitor;
• a second electrode located at a proximal end of the insertable cardiac monitor;
• circuitry comprising a processer, the circuitry configured to:
• sense a cardiac signal of the patient via the first electrode and the second electrode;
• compare an amplitude of the cardiac signal to a primary threshold;
• detect an R-wave based on the comparison of the amplitude of the cardiac signal to the primary threshold;
• detect an asystole based on a comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the primary threshold;
• in response to detecting the asystole, compare the amplitude of the cardiac signal subsequent to the detected R-wave to a secondary threshold;
• and
• determine whether the detection of the asystole is false based on the comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the secondary threshold.

An insertable cardiac monitor configured for subcutaneous implantation within a patient, the insertable cardiac monitor having a length, a width, and a depth, wherein the length is greater than the width and the width is greater than the depth, the insertable cardiac monitor comprising:

• a first electrode located at distal end of the insertable cardiac monitor;
• a second electrode located at a proximal end of the insertable cardiac monitor;
• circuitry comprising a processer, the circuitry configured to:
• sense a cardiac signal of the patient via the first electrode and the second electrode;
• compare an amplitude of the cardiac signal to a primary threshold;
• detect an R-wave based on the comparison of the amplitude of the cardiac signal to the primary threshold;
• and
• detect an asystole based on a comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the primary threshold;
• means for, in response to detecting the asystole, comparing the amplitude of the cardiac signal subsequent to the detected R-wave to a secondary threshold;
• and
• means for determining whether the detection of the asystole is false based on the comparison of the amplitude of the cardiac signal subsequent to the detected R-wave to the secondary threshold.