A case of ventricular premature contractions with multiple morphologies reproduced by a single ventricular extrastimulus with different coupling intervals

; Introduction: A 22-year-old male with no prior cardiovascular history presented with frequent symptomatic ventricular premature contractions (VPCs) with multiple QRS morphologies despite bisoprolol treatment. Results: The coupling intervals progressively increased from VPC1 to VPC3, and VPC2 was the most frequent (VPC1: 9.3%, VPC2: 30.2%, VPC3: 0.5%). The earliest activation site was identified at the left-right coronary cusp junction. Single ventricular extrastimuli with variable coupling intervals from this site successfully reproduced QRS morphologies identical to VPC 1-3. Conclusion: The findings revealed the utility of unique pace-mapping technique in cases of VPCs with multiple morphologies.