Trends in the use of implantable cardioverter defibrillators in Australia: a 10-year nationwide study from 2000-2009.

BACKGROUND: Implantable cardioverter defibrillators (ICD) have been demonstrated to reduce mortality in survivors of life-threatening arrhythmias (secondary prevention) and in patients at increased risk of sudden cardiac death (primary prevention). Other nations have reported significant increases in ICD use in recent years. AIM: To investigate Australian nationwide trends of ICD procedures over a 10-year period (2000-2009). METHODS: A retrospective analysis of the Australian Institute of Health and Welfare's National Hospital Morbidity Database was performed to determine the annual number of ICD implantation and replacement procedures between 2000 and 2009. Rates were calculated using Australian Bureau of Statistics data on the annual estimated population. Time trends in the yearly procedure number and rate were analysed using negative binomial regression models with comparisons made by age and sex. RESULTS: The number of new ICD implantations increased from 708 to 3198 procedures between 2000 and 2009. Replacement procedures increased from 290 to 1378. The implantation rate (per million) increased from 37.0 to 145.6 and the replacement rate from 15.1 to 62.7. When rates were adjusted for age and sex, the implantation rate increased annually by 15.8% and the replacement rate by 16.6% (P < 0.0001). Procedures occurred most commonly in men (implantations: 80.1%; replacements: 78.0%) between ages 70-79. CONCLUSIONS: ICD procedures increased significantly in Australia between 2000-2009. Despite these increases, other studies have suggested ICD devices are currently under-utilised. During the study period, males accounted for the majority of ICD procedures. While there are numerous reasons for this, it is not known if device under-use is more common in females.

HIV and Long QT syndrome--cause or coincidence.

The Long QT syndrome is a disorder characterized by abnormalities of cardiac repolarisation, resulting in a propensity to polymorphic ventricular tachycardia (torsades de pointes) and sudden cardiac death. It remains unclear whether cardiac involvement with the HIV virus itself can cause QT prolongation. We report a case of a HIV infected young female presenting with recurrent syncope due to torsades de pointes.

Monomorphic ventricular tachycardia related to Wolff-Parkinson-White surgery.

Monomorphic ventricular tachycardia (MVT) is well described in patients who have had a ventricular scar due to repair of congenital heart disease. A 54-year-old woman presented with MVT 20 years after WPW surgery for a left-sided accessory pathway. The circuit was mapped to an area at the base of the left ventricle consistent with the incision described in the operation report. Entrainment confirmed the re-entrant circuit. Successful radiofrequency ablation was performed in a zone of slowed conduction consistent with the circuit isthmus. Any iatrogenic ventricular scar may form the substrate for MVT and be treated with standard electrophysiology techniques.