Despite significant improvement in the management of patients with implantable cardioverter-defibrillators (ICDs), many patients still receive ICD shocks in the community and present to emergency departments. These urgent admissions are poorly described in the wider literature.

To describe the characteristics of emergency presentations for ICD shocks.

From November 2011 to November 2014, all patients admitted to the cardiac emergency department of Lille University Hospital for ICD shock(s) were prospectively enrolled. Patient characteristics, investigation results, and details of electrical activities from ICD interrogation were recorded at presentation.

In total, 109 emergency presentations for ICD shocks were recorded in 90 patients (85% male; 57±16 years; ischemic cardiomyopathy: 49%; LVEF 34±13%; secondary prevention: 68%). Overall, 83 (76%) were provoked by an appropriate index shock (AS), and 26 (24%) by an inappropriate index shock (IS). The majority of patients received multiples shocks (AS: 60%, IS: 81%). Of the 83 presentations for AS, 66 (80%) were triggered by monomorphic VTs and 43 (52%) were caused by electrical storms. The main reasons for IS were atrial fibrillation or flutter (62%) and sinus node tachycardia (19%). Overall, hospitalization was required in 82 cases (75%), with a median length of stay of 7 days [4–11]. Following presentation, the following measures were taken: change in ICD programming (45%), loading dose of amiodarone (33%), increase of β-blockers dosage (32%), VT ablation (18%), reintervention on the ICD system (6%).

Emergency presentations for ICD shocks remain frequent, and are caused by appropriate ICD therapies in 3 out of 4 cases. These admissions place a considerable burden on emergency and cardiology departments. Evidence-based strategies capable of reducing the incidence of emergency presentations for ICD shocks in the community should be more widely implemented.