Temporary pacemaker treatment in open heart surgery: pre- to postoperative changes in the electrogram...

Area of Science:

• Cardiology
• Cardiac Surgery
• Biomedical Engineering

Background:

• Temporary pacemaker treatment is crucial for patients undergoing cardiac surgery.
• Right ventricular electrogram parameters, including amplitude and maximum derivatives, are vital for pacemaker function.
• Hypothermia is commonly used during cardiac surgery.

Purpose of the Study:

• To investigate changes in right ventricular electrogram amplitudes (AMAX, UMAX) and maximum derivatives (DMAX, SMAX) during temporary pacemaker treatment in cardiac surgery patients.
• To assess the impact of the pre- to postoperative phase on these electrogram parameters.
• To determine if these changes could lead to pacemaker malfunction.

Main Methods:

• Thirty-three patients undergoing cardiac surgery under general hypothermia were studied.
• Right ventricular electrogram parameters (AMAX, UMAX, DMAX, SMAX) were measured preoperatively and postoperatively.
• A paired comparison was conducted on 29 patients using standard electrodes.

Main Results:

• Significant reductions in AMAX, UMAX, DMAX, and SMAX were observed postoperatively compared to preoperative values (p < 0.001).
• The most substantial decrease in electrogram amplitudes and derivatives occurred within the first 24 hours.
• These reduced electrogram values in four patients led to pacemaker demand failure.

Conclusions:

• Cardiac surgery, particularly under hypothermia, leads to a significant decline in right ventricular electrogram parameters.
• The observed electrogram changes may be insufficient for temporary pacemaker inhibition, increasing the risk of demand failure.
• Close monitoring of pacemaker function is essential in the postoperative period following cardiac surgery.