Cardiac rhythm in atrial isomerism

Area of Science:

• Cardiology
• Pediatric Cardiology
• Electrophysiology

Background:

• Atrial isomerism is a complex congenital heart defect.
• Electrocardiographic findings in atrial isomerism are not fully understood.
• Understanding cardiac rhythm in these patients is crucial for management.

Purpose of the Study:

• To analyze electrocardiographic findings in patients with left and right atrial isomerism.
• To determine the incidence and significance of arrhythmias in atrial isomerism.
• To correlate electrocardiographic abnormalities with anatomical defects and patient outcomes.

Main Methods:

• Retrospective review of standard electrocardiograms from 126 patients with atrial isomerism.
• Analysis of rhythm, P-wave axis, and atrioventricular (AV) block.
• Correlation with associated cardiac anomalies and outcomes.

Main Results:

• Sinus rhythm was common in right isomerism (58/59) but less so in left isomerism (49/67).
• Complete AV block was more frequent in left isomerism with AV septal defects (5/45 vs. 0/47).
• P-wave axis shifts were observed, and ambulatory monitoring revealed infrequent sinus rhythm.

Conclusions:

• Atrial isomerism frequently presents with electrocardiographic abnormalities, including rhythm disturbances.
• Despite frequent findings, significant arrhythmias are uncommon and do not appear to affect prognosis.
• Patient outcomes are primarily determined by associated anatomical abnormalities, not arrhythmias.