Safety and effectiveness of a portable external automatic defibrillator-pacemaker

Area of Science:

• Cardiology
• Biomedical Engineering
• Emergency Medicine

Background:

• Sudden cardiac death (SCD) is a significant public health concern.
• Early resuscitation is crucial for improving survival rates from SCD.
• Ventricular fibrillation is the most common arrhythmia in out-of-hospital cardiac arrest.

Purpose of the Study:

• To evaluate the decision-making capabilities of a novel portable automatic defibrillator-pacing machine.
• To assess the efficacy and safety of a tongue-abdominal pathway for ECG sensing and current delivery.
• To determine the reliability of the device in simulated and clinical settings.

Main Methods:

• The device's decision-making logic was tested using simulated ECG signals and recorded arrhythmias.
• The tongue-abdominal pathway was evaluated in 15 patients undergoing elective cardioversion.
• Electrode sites and enzyme release (CPK, CPKMB) were assessed post-cardioversion.

Main Results:

• The device demonstrated 95% consistency in decision-making over repeated trials.
• Automatic pacing occurred reliably during asystole.
• The tongue-abdominal pathway provided adequate ECG recordings, though low-amplitude signals (<0.35 mV) were missed. A manual override is available.
• Inappropriate defibrillation occurred in 50% of supraventricular and ventricular tachycardia recordings, but required specific patient conditions and operator inaction.

Conclusions:

• The portable defibrillator shows promise for community use by emergency services and trained laymen.
• The tongue-abdominal pathway is effective for ECG sensing and current delivery.
• The device's automatic mode has safety features, but a manual override is essential for certain arrhythmias and low-amplitude signals.