A case of inefficient defibrillation during thoracotomy

Area of Science:

• Cardiology
• Medical Devices
• Thoracic Surgery

Background:

• Implantable cardioverter defibrillators (ICDs) are crucial for managing life-threatening ventricular arrhythmias.
• Intraoperative management during device implantation requires careful consideration of patient physiology.
• Thoracotomy, a surgical approach involving chest incision, can alter intrathoracic dynamics.

Observation:

• A case of intraoperative ventricular fibrillation occurred during an epicardial lead implant procedure.
• The ventricular fibrillation was refractory to a 35-J shock delivered by the patient's ICD.
• Iatrogenic pneumothorax was induced during the thoracotomy for lead placement.

Findings:

• The induced pneumothorax likely caused a temporary increase in intrathoracic impedance.
• This impedance change is hypothesized to have elevated the defibrillation threshold.
• The elevated threshold resulted in the ineffective termination of ventricular fibrillation by the ICD shock.

Implications:

• Clinicians should be aware of potential changes in intrathoracic impedance during thoracotomy in patients with ICDs.
• Altered impedance may necessitate adjustments in defibrillation strategies or energy levels.
• This case underscores the importance of monitoring and managing intrathoracic conditions during ICD procedures involving thoracotomy.