Counter

Medtronic Device: ICD Field: Counter

Medtronic paths associated with this specificity

Primary implantation of a dual-chamber ICD (Evera XT DR) in a patient with ischemic cardiomyopathy; at the end of the procedure, induction of ventricular arrhythmia by low amplitude electrical shock on the T wave; a single VF zone with a 270 ms limit was programmed (initial detection counter: 12/16); this tracing corresponds to the induction procedure and allows focusing on the functioning of the VF probabilistic counter.

Patient implanted with a single-chamber ICD (Protecta XT VR) for Brugada syndrome; hospitalization for syncope and electrical shock with VF tracing stored in the device memory allowing to focus on the functioning of the VF counter.

Patient implanted with a single-chamber ICD (Virtuoso II VR) for hypertrophic cardiomyopathy; syncope during exertion requiring 2 electrical shocks (35 Joules), the second enabling to terminate the arrhythmia; the analyzed tracing allows focusing on the functioning of the redetection counter.

Patient implanted with a dual-chamber ICD (Virtuoso DR) for ischemic cardiomyopathy and hospitalized following the occurrence of several electrical shocks without prior symptoms; this tracing suggests the advantage of increasing the number of intervals required for initial detection to 30/40 beats in order to reduce the risk of inappropriate therapies.

Patient implanted with a single-chamber ICD (Visia AF XT VR) for ischemic cardiomyopathy; multiple episodes of NSVT stored in the device memory; an episode with electrical shock; this tracing suggests the advantage of programming the initial counter at 30/40 in order to reduce the occurrence of appropriate but avoidable therapies.

This patient presented multiple episodes of non-sustained ventricular tachycardia stored in the memory of the device and defined by the occurrence of at least 5 consecutive intervals in one of the detection zones without any of the initial counters being filled (VT or VF). For a same patient, the greater the number of required intervals (30/40 versus 9/12), the higher the probability of recording an episode of non-sustained ventricular tachycardia.

Patient implanted with a dual-chamber ICD (Evera XT DR) for ischemic cardiomyopathy with multiple episodes of paroxysmal atrial fibrillation; 2 detection zones were programmed with a VT zone between 350 and 270 ms; the analyzed episode was diagnosed as SVT/AF by the device; the objective of this tracing is to highlight the value of the VT counter to avoid inappropriate therapies during an episode of AF.

Patient implanted with a dual-chamber ICD (Evera XT DR) for right ventricular arrhythmogenic dysplasia with multiple episodes of ventricular tachycardia; 3 detection zones were programmed with a VT zone between 360 and 300 ms; the analyzed episode was diagnosed as VT by the device; the purpose of this tracing is to highlight the need to properly program the lower limit of the VT zone.

Patient implanted with a single-chamber ICD (Virtuoso II VR) for ischemic cardiomyopathy; 3 zones were programmed (VT between 360 to 300 ms, FVT between 300 and 260 ms, VF encompassing the FVT zone from 300 ms onward); the FVT zone is programmed via VF with an initial counter at 18/24; episode classified as FVT stored in the device memory which allows highlighting the specificities of the functioning of this fast VT zone.

Patient implanted with a triple-chamber ICD (Viva Quad CRT-D) for ischemic cardiomyopathy. A VF episode via the combined counter was stored in the device memory. The number of intervals in the VF zone for initial detection was programmed to 30/40. This tracing allows focusing on the value of a combined counter in order to avoid delaying the detection of an arrhythmia at the limit of the detection zone.