Can an inappropriate shock from a life vest (LV) cause cardiac damage?

Inappropriate Shocks from Life Vests Can Cause Psychological Distress and Rarely Physical Harm

Inappropriate shocks from a wearable cardioverter defibrillator (life vest) can cause significant psychological distress and in rare cases may induce ventricular arrhythmias, but do not typically cause direct cardiac damage.

Psychological Impact of Inappropriate Shocks

Inappropriate shocks from life vests can have substantial psychological consequences:

• Anxiety (8-63%) and depression (5-41%) are common in patients experiencing inappropriate shocks 1
• Post-traumatic stress disorder may develop, particularly in patients with pre-existing psychological distress 1
• Patients may develop anticipatory shock anxiety and device dependence 1
• Psychological distress can lead to decreased quality of life and social withdrawal 1
• Up to 17.3% of patients discontinue wearing their life vest after experiencing inappropriate shocks 2

Physical Consequences of Inappropriate Shocks

While direct cardiac damage is uncommon, inappropriate shocks can have other physical consequences:

• In rare cases (19 patients in one large study), inappropriate shocks can induce sustained ventricular tachycardia or ventricular fibrillation requiring subsequent appropriate shocks 2
• Physical injuries from falls have been reported in patients receiving inappropriate shocks (30 patients in the same study) 2
• Inappropriate shocks may lead to emergency room visits or hospitalizations 2

Causes of Inappropriate Shocks in Life Vests

Understanding the causes can help prevent inappropriate shocks:

• Tachycardias (48.9%): Including atrial fibrillation (32.2%), supraventricular tachycardia (13%), and non-sustained VT/VF (3.4%) 2
• Motion artifacts (32.7%): Particularly during activities like riding motorcycles, lawnmowers, or tractors 2
• Oversensing of low-level electrical signals (18.4%) 2

Incidence of Inappropriate Shocks

• The inappropriate shock rate for life vests is approximately 2-2.8% according to registry data 3
• In a meta-analysis of wearable cardioverter-defibrillator studies, the incidence of inappropriate therapy was 2 per 100 persons over 3 months 4

Management After an Inappropriate Shock

European and UK guidelines recommend:

• Identify and correct the cause of the inappropriate shock (e.g., programming issues, lead fracture, atrial fibrillation) 1
• Following correction, driving may resume after 1 month in the absence of further symptomatic therapy 1
• Assessment of psychological status and treatment of distress is recommended in patients with recurrent inappropriate shocks (Class I, Level C recommendation) 1

Prevention Strategies

To minimize the risk of inappropriate shocks:

• Proper patient education on correct device use is essential 5
• Patients should be instructed on proper use of response buttons to abort inappropriate shocks, as many patients (47.9%) do not use them or use them improperly (20.2%) 2
• Avoid activities known to trigger motion artifacts when possible 2

Clinical Implications

Healthcare providers should:

• Discuss quality-of-life issues before life vest prescription and during follow-up (Class I, Level C recommendation) 1
• Provide psychological support for patients experiencing inappropriate shocks 1
• Recognize that the psychological impact of inappropriate shocks may be more significant than any physical damage to the heart
• Consider that high levels of pre-implantation concerns may predispose patients to post-implant psychological problems 1

While inappropriate shocks from life vests can cause significant psychological distress and rarely induce arrhythmias, the benefits of potentially life-saving therapy in appropriate patients outweigh these risks. Improved device sensing, rhythm discrimination, and methods to abort inappropriate shocks are needed to enhance patient experience and adherence.