Acute Myocardial Infarction after Radiofrequency Catheter Ablation of Typical Atrial Flutter
A 53-yr-old man with persistent atrial flutter () was admitted on August 20th 2012, to undergo radiofrequency catheter ablation. He was given intravenous heparin continuously until 6 hr before the procedure. Transesophageal echocardiogram did not show evidence of intracardiac thrombus two days before the procedure. After obtaining informed consent, he was brought to our electrophysiology laboratory after fasting for 8 hr. Under local anesthesia using lidocaine after sterile draping, two quadripolar electrode catheters (St. Jude Medical, Inc., St. Paul, MN, USA) were positioned to record the activity of the bundle of His and the right ventricular apex. The high right atrium (RA), mid RA, and coronary sinus (CS) were mapped with a deflectable duo-decapolar catheter (St. Jude Medical) (). Intracardiac electrograms were recorded using a Prucka CardioLab™ electrophysiology system (General Electric Health Care System, Inc., Milwaukee, WI, USA). His baseline intracardiac electrogram showed typical counterclockwise atrial flutter (). A 7Fr, 4mm-tip irrigation ablation catheter (St. Jude Medical, Inc., St. Paul, MN, USA) was inserted through an 8Fr, 60 cm-long RAMP sheath (St. Jude Medical, Inc., St. Paul, MN, USA). Radiofrequency current was applied to the posteroseptal side of the cavotricuspid isthmus, with temperature limit of 35℃ and power of 30-35 W (). As atrial flutter persisted after enough ablation, we started making ablation lines at the posterolateral side of the isthmus. Atrial flutter was suddenly terminated while making the first ablation line at the posterolateral side. To ensure successful ablation, radiofrequency energy was delivered six more times. Bidirectional isthmus block was confirmed. During the procedure, the patient complained of chest pain, but we considered it to be related to the ablation itself, because there was no change in the electrocardiogram and because the pain was not severe.\nWhen he returned to the ward, he reported worsening chest pain. We obtained a 12-lead electrocardiogram, which showed ST-segment elevation in leads II, III, aVF, and V5-6 and ST depression in leads I, aVL, and V1-4, suggesting acute myocardial in farction of the inferior wall (). He was immediately brought to the catheterization laboratory. Coronary angiography showed total occlusion at the distal portion of the right coronary artery, which was close to the area of ablation (). We aspirated red thrombi from the artery. After intracoronary injection of abciximab, balloon dilatation with a 3.0×20 mm balloon with a maximum pressure of 10 ATM was done with 20% residual stenosis. His chest pain was immediately relieved. After an hour, the elevated ST segments in leads II, III, aVF, and V5-6 returned to baseline. Cardiac troponin I peaked at 145.92 ng/mL 10 hr later.\nThe patient did not experience chest pain up to the time of discharge. However, approximately 21 hr after the completion of radiofrequency ablation, atrial flutter recurred. As it did not return to sinus rhythm with intravenous amiodarone, and because he developed hypotension 2 hr later, we performed electrical cardioversion with 70 J to achieve sinus conversion. To maintain the sinus rhythm, oral amiodarone 200 mg once daily was prescribed. Five days later, he was discharged without any symptoms as sinus rhythm persisted. After a year, he is still in sinus rhythm and has not experienced any kind of chest pain.