Medtronic Device: ICD Field: Therapy

Theoritical features / Basic concepts

Shock therapie Anti-tachycardia Pacing   SHOCK THERAPIES Shock therapies ICD were originally invented to terminate malignant ventricular arrhythmias using DC shocks. Cardioversion is the delivery of a DC shock synchronized to the rising edge of the R wave of the electrocardiogram to terminate a supraventricular or a ventricular tachyarrhythmia, whereas defibrillation is the delivery of an unsynchronized DC shock to terminate VF. During VF, the instability and low voltage of the ventricular EGM sometimes precludes the synchronization of ICD shocks. Medtronic ICDs systematically seek to synchronize the shock delivery, including in the VF zone. Several shock characteristics are programmable, including vector, amplitude and number of shocks delivered. Shock waveform: early defibrillators...

Medtronic paths associated with this specificity

Patient implanted with a single-chamber ICD (Protecta VR) for ischemic cardiomyopathy and hospitalized for several syncopal episodes with electrical shocks; this tracing shows a control episode of the "normal" functioning of an ICD with correct detection of ventricular fibrillation and successful treatment by a maximum electrical shock

Same patient as in the previous tracing; second episode of syncopal ventricular arrhythmia; this tracing allows focusing on the functioning of the post-shock phase following an electrical shock.

Patient with severe ischemic cardiomyopathy implanted with a CRT device (Viva XT CRT-D) hospitalized for syncope and several electrical shocks; this tracing allows focusing on the management of patients with a high defibrillation "threshold".

Patient implanted with a single-chamber ICD (EnTrust VR) for ischemic cardiomyopathy; palpitations and recording of several episodes of ventricular arrhythmia detected in the VF zone; this tracing allows focusing on the interest of anti-tachycardia pacing in the VF zone.

Same patient as the previous tracing.

Patient implanted with a single-chamber ICD (Entrust VR) for dilated cardiomyopathy; tachycardia episodes detected in the VT zone; this tracing allows discussing the value of anti-tachycardia pacing in the VT zone.

Patient implanted with dual-chamber ICD (Entrust DR) for ischemic cardiomyopathy; consultation for electrical shock.

Patient implanted with a triple-chamber ICD (Protecta XT CRT-D) for ischemic cardiomyopathy; the recorded episode shows the limitations of the programming of a low-amplitude shock in the VT zone.