Introduction: The defibrillator vest (LifeVest®) is an option for treating patients at risk for ventricular tachycardia (VT) or ventricular fibrillation (VF) due to underlying cardiac pathology, especially during their evaluation for ICD implantation. Patients wear the LifeVest externally. The device can detect abnormal cardiac rhythms and deliver shocks to terminate these rhythms. Patients have the option to actively inhibit shock delivery.
Methods: From June 2010 to September 2012, 42 patients (pts) (38 males; age 48?14 y) were managed with the LifeVest. Indications were: Newly diagnosed myocarditis (MYC): 24 pts (57%), other forms of dilated cardiomyopathy (DCM): 9 (21%) pts, status post (s/p) ICD explantation (EXPL) for device infection: 4 pts (10%), markedly lowered LV ejection fraction (LVEF) and acute myocardial infarction (CHD): 2 pts (5%), ion channel disorder (GEN): 1 pt (2%), and others (OTH): 2 pts (5%). By echocardiography, the LVEF was below 15% in 10.8%, between 16 and 25% in 45.9%, between 26 and 35% in 13.5%, and above 35% in 29.7% of patients.
Results: Patients wore the LifeVest for an average of 23 hours per day over a mean period of 83 days. In 32 pts (76%), a total number of 276 events were detected.
In one patient who was hemodynamically compromised due to VT, the arrhythmia was successfully terminated by shock delivery. Another patient actively withheld therapy delivery when the LifeVest detected VT until emergency medical personnel arrived. One patient inhibited shock delivery throughout a 55 second episode of atrial fibrillation with rapid conduction. The other events were shorter than 15 seconds (detection window) or artifacts.
Out of the cohort of 42 pts, 18 (43%) received an ICD. In 5 pts (12%), CRT-D (cardiac resynchronization defibrillators) were implanted. Two pts (5%) received dual chamber and 11 pts (26%) single chamber ICDs. In 24 pts (57%), ICD implantation was waved after further assessment of the underlying cardiac pathology. Four pts s/p ICD infection underwent ICD reimplantation, leaving 14 pts (37%) for de novo ICD implantation.
Conclusions: After a mean treatment duration of 83 days with the LifeVest in this population with a high risk of malignant cardiac arrhythmias, only 43% (n=18) required an ICD. Our data show that the LifeVest is useful for bridging before ICD implantation. It is safe and economical.