Radiofrequency Ablation for Typical Atrial Flutter in Dextroversion With PLSVC and IVC Interruption

Figures

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  Figure 1. Electrocardiograms Before and After the Ablation Procedure (A) Recorded upon admission, showing typical AFL, with reversed limb leads and mirror-image precordial leads. (B) Recorded after successful ablation, showing typical sinus rhythm, with reversed limb leads and mirror-image precordial leads. (C) Recorded after successful ablation, showing typical sinus rhythm. Under standard lead placement, Q waves in leads I and aVL and q waves in leads V5 and V6 are clearly visible, which are typical features of dextroversion. AFL = atrial flutter.

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  Figure 2. Preoperative Transthoracic Echocardiography Preoperative transthoracic echocardiography showing complex cardiac anatomy: (A) A4C showing the valves, (B) A4C showing the margin of the coronary sinus (CS), (C) A3C showing the valves, (D) long-axis view of the CS showing significant dilation, (E) subxiphoid view shows hepatic vein drainage into the right atrium, (F) the superior vena cava long-axis view showing CS long-axis. These findings confirmed dextroversion and PLSVC, which were critical for procedural planning. A3C = apical three-chamber view; A4C = apical four-chamber view; CS = coronary sinus; PLSVC = persistent left superior vena cava.

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  Figure 3. Preoperative Chest X-Ray The chest X-ray shows the cardiac apex pointing to the right, confirming dextroversion. The heart is located in the right hemithorax, while the trachea remains in the midline.

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  Figure 4. Abdominal CT The abdominal CT shows visceral anomalies, including a short pancreas with an absent tail and an irregularly shaped spleen on the left side. CT = computed tomography.

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  Figure 5. The Inferior Vena Cava CTA Preoperative CECT scans revealing multiple anatomical anomalies. (A) Three-dimensional reconstruction of superior vena cava CTA. The persistent left superior vena cava () drains into the right atrium (). The right brachiocephalic vein () and left brachiocephalic vein () drain into the persistent left superior vena cava (). Aorta (). (B) Coronal view showing the cardiac apex pointing to the right, with the liver on the right and spleen on the left, confirming dextroversion with situs solitus. Persistent left superior vena cava (). Hepatic veins (arrow) are shown draining directly into the right atrium (). Aorta (). (C) The interrupted inferior vena cava () continues as the azygos vein, draining into the persistent left superior vena cava (), located near the aorta (). (D) The PLSVC () is shown draining into the right atrium (). (E) The IVC () is positioned to the left of the aorta (). CTA = computed tomography angiography; IVC = inferior vena cava; PLSVC = persistent left superior vena cava.

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  Figure 6. Intraprocedural Electrophysiological Model and Ablation (A) The 3D model of the right atrium confirms clockwise atrial flutter around the tricuspid annulus and identifies the location of the His bundle potential. (B) Pacing from the coronary sinus after ablation verifies the bidirectional block, with an S-A interval of 157 ms, confirming the successful termination of the flutter circuit. S-A = stimulus-to-atrial. (C) Caudal view of the ablation line.

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  Figure 7. Three-Year Long-Term Follow-Up Electrocardiogram This figure shows the patient's follow-up ECG 3 years after the ablation procedure to evaluate the long-term efficacy of the treatment. The ECG result shows that the patient maintained a stable sinus rhythm, confirming that the conduction block established in the critical isthmus by the ablation procedure provided long-term rhythm control for the patient. ECG = electrocardiogram.

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  Visual Summary. A Tailored Ablation Strategy for Complex Anatomy Part 1: Preprocedural imaging and diagnosis. Three images illustrating the diagnostic challenge: (Left) coronary computed tomography angiography (CTA) reconstruction highlights the complex vascular anomalies, including the persistent left superior vena cava (PLSVC) and interrupted inferior vena cava (IVC). (Middle) 12-lead Electrocardiogram (ECG) shows typical atrial flutter (AFL) waves. (Right) Axial CT scan confirms the dextroversion (dextrocardia with situs solitus), showing the heart positioned in the right hemithorax. Part 2: Intraprocedural mapping and ablation. Intracardiac electrograms and 3D electroanatomical mapping (via left subclavian access) confirm a clockwise atrial flutter circuit. The ablation line (red dots) targets the critical isthmus between the hepatic vein orifice and the tricuspid annulus. Part 3: Postprocedural outcome. Follow-up 12-lead ECG demonstrates the successful restoration and maintenance of normal sinus rhythm, which persisted throughout the 3-year follow-up.