How sex affects the sinus rhythm heartbeat

Area of Science:

• Cardiology
• Electrophysiology
• Atrial Electrophysiology

Background:

• Growing evidence highlights sex-specific differences in atrial fibrillation (AF) epidemiology and pathophysiology.
• However, sex-based differences in atrial electrophysiological properties during sinus rhythm (SR) remain largely unexplored.

Purpose of the Study:

• To investigate sex-based regional differences in atrial electrophysiological properties during SR.
• Focus areas included the right atrium (RA), left atrium (LA), Bachmann's Bundle (BB), and pulmonary vein region (PVA).

Main Methods:

• Intra-operative, high-resolution mapping during SR in 53 matched female and male participants without AF history.
• Measurements included conduction block (CB), continuous conduction delay and block (cCDCB), conduction velocities (CV), total atrial activation times (TAT), unipolar potential voltages, and low voltage areas (LVA).

Main Results:

• Females showed significantly lower unipolar potential voltages and slower CV in the RA and BB compared to males.
• Females exhibited more LVAs, CB, and cCDCB lines, with longer CB and cCDCB lines specifically in the RA (P < 0.05).

Conclusions:

• Significant sex-based differences exist in atrial electrophysiological properties during SR, particularly in the RA and to a lesser extent in the BB.
• Females present with increased areas of conduction disorders and low voltage potentials in the RA and BB.
• Further research is needed to determine if these electrophysiological differences contribute to sex-based variations in arrhythmia susceptibility, such as AF.