Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature

Abstract

Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore.

Keywords: Asia; Singapore; cardiac arrest; subcutaneous implantable cardioverter defibrillators; ventricular arrhythmias.

Fig. 1

Patient 1: Screening ECGs in the (a) lying down position and (b) sitting position. The QRS complex in (a) fits the pink template, confirming the patient’s suitability for subcutaneous implantable cardioverter defibrillator implantation.

Fig. 2

Illustration shows the correct positioning of the pulse generator and electrode of the subcutaneous implantable cardioverter defibrillator (S-ICD). The S-ICD pulse generator should be just lateral to the cardiac apex, in the mid-axillary line. A: distal electrode ring; B: proximal electrode ring; CAN: pulse generator. (Illustration used with permission from Boston Scientific.)

Fig. 3

Tracing during defibrillation threshold testing shows successful defibrillation following induction of ventricular fibrillation (VF) using 50 Hz alternating current stimulation.

Fig. 4

(a) Posteroanterior and (b) lateral radiographs show satisfactory placement of the pulse generator of the subcutaneous implantable cardioverter defibrillator (S-ICD). The S-ICD lead travels to the inferior edge of the xiphisternum, then takes a superior course along the left parasternal margin.