Novel ventricular tachyarrhythmia detection enhancement detects undertreated life-threatening arrhythmias

Ventricular arrhythmia detection for contemporary Biotronik and Abbott implantable cardioverter defibrillators with markedly prolonged detection in Biotronik devices

BACKGROUND

Implantable cardioverter defibrillators (ICDs) are typically programed with both ventricular tachycardia (VT) and ventricular fibrillation (VF) treatment zones. Biotronik and Abbott ICDs do not increment the VT counter when the tachycardia accelerates to the VF zone, which could result in a prolonged delay in tachycardia detection.

METHODS

Patients with Biotronik and Abbott ICDs receiving care at Veterans Affairs facilities in Northern California were identified. Patient information and device tracings for patients with any ICD therapies were examined to assess for possible delayed tachycardia detection.

RESULTS

Among 52 patients with Biotronik ICDs, 8 (15%) experienced appropriate ICD therapy over a median follow-up of 29 months. Among 68 patients with Abbott ICDs, 26 (38%) experienced appropriate ICD therapy over a median follow-up of 83 months. Three of the patients with Biotronik ICDs who received appropriate therapy experienced a delay in VT/VF detection due to the tachycardia rate oscillating between the VT and VF treatment zones (longest 31.2 s on detection), compared with four of the patients with Abbott ICDs (longest 4.1 s on the detection and 8 s on redetect). One of the patients with a Biotronik ICD experienced recurrent syncope associated with delayed detection and another died on the day of delayed detection. One of the patients with an Abbott ICD experienced syncope.

CONCLUSIONS

Because contemporary Biotronik and Abbott ICDs freeze the VT counters when tachycardia is in the VF zone, ICD therapies can be markedly delayed when the tachycardia oscillates between the VT and VF zone.

Inappropriate ventricular fibrillation annotation and defibrillator discharge despite the same tachycardia cycle length in ventricular tachycardia-1 zone in an Abbott defibrillator - What is the mechanism?

Newer devices incorporate advanced algorithms to have more accurate delivery of implantable cardioverter-defibrillator (ICD) therapy. Newer models of Abbott Implantable cardioverter-defibrillators like Gallant and Entrant have a new ventricular fibrillation (VF) therapy assurance algorithm. This algorithm has a proven role in avoiding under-detection of VF where some of the smaller electrograms are under-sensed. We report a case of ventricular fibrillation therapy assurance (VFTA) algorithm malfunction in a 48-year-old lady having single chamber Entrant Implantable cardioverter-defibrillator, where the patient received inappropriate therapies. The VFTA algorithm eventually had to be turned off.

The Gallant™ system heart rhythm management device: making a connection

Implantable cardiac defibrillators have revolutionized the way we prevent sudden cardiac death via arrhythmias. The addition of cardiac resynchronization pacing to defibrillators has broadened that treatment to include patients with heart failure and reduced ejection fraction. As with all technology, new devices and platforms expand the capabilities and interface with patients across the world. This review discusses the evolution from the initial modalities and methods of communication of implantable devices up to the most recent advances in implantable defibrillators and their integration into patient lives and clinical practice. This review is focused on the integration of Bluetooth communication into modern healthcare with the Gallant™ family of devices, the first branded launch by Abbott Laboratories.