DATE OF PROCEDURE: MM/DD/YYYY
PROCEDURES PERFORMED:
1. Comprehensive electrophysiologic study with programmed stimulation and induction of arrhythmia with cannulation of the coronary sinus.
2. Detailed mapping of the tachycardia focus.
3. Radiofrequency catheter ablation for typical atrioventricular nodal reentry tachycardia.
4. Programmed stimulation after intravenous drug infusion with isoproterenol.
SURGEON: John Doe, MD
PROCEDURE IN DETAIL: The patient was brought to the electrophysiology laboratory in a fasting state. The patient was prepped and draped in the usual sterile fashion. Lidocaine 1% was used for local anesthesia, and fentanyl and Versed were administered in divided doses using the conscious sedation protocol. The 8 French and 7 French sheaths were placed in the right femoral vein, two 7 French sheaths were placed in the left femoral vein, and a 7 French sheath was attempted to be placed in the right internal jugular vein. The guidewire could be inserted into the right internal jugular vein but could not be advanced into the right atrium. Contrast, 20 mL, was injected revealing anomalous drainage of the subclavian vein. A decision to forego right internal jugular vein cannulation was made and an extra 7 French sheath was placed in the left femoral vein using the modified Seldinger technique. Through the groin sheaths, a Cordis Webster deflectable decapolar catheter was positioned in the coronary sinus, a fixed curve Bard quadripolar catheter was positioned in the atrioventricular junction, a fixed curve Bard quadripolar catheter was positioned in the high right atrium and right ventricular apex under fluoroscopic guidance. The patient’s coronary sinus was extremely large. Thresholds were measured.
The baseline rhythm was normal sinus. The following conduction intervals were recorded including the basic cycle length of 1024 milliseconds, a PR interval of 150 milliseconds, QRS duration of 120 milliseconds, a QT interval of 441 milliseconds, an AH interval of 88 milliseconds, and a HV interval of 46 milliseconds. Atrial pacing to assess sinus node function was performed. The longest corrected sinus node recovery time was 242 milliseconds at a pacing cycle length of 600 milliseconds. Atrial pacing was performed to assess AV node function. AV Wenckebach occurred at a pacing cycle length of 430 milliseconds. Single premature stimuli were delivered in the atrium. The effective refractory period of the AV node was 400 milliseconds at pacing cycle length of 600 milliseconds and the effective refractory period of the atrium was 240 milliseconds at a pacing cycle length of 600 milliseconds. There was no AH jump at the baseline state. Ventricular pacing was performed. VA conduction was present and concentric. VA Wenckebach occurred at a pacing cycle length of 420 milliseconds. Single premature stimuli were delivered in the ventricle. VA conduction was decremental. The effective refractory period of the AV node in the retrograde direction was 360 milliseconds at 600 milliseconds and the effective refractory period of the ventricle was 260 milliseconds at 600 milliseconds.
Because there was no SVT induced at the baseline state, isoproterenol at 1 mcg and then 2 mcg per minute was infused. After a resultant increase in heart rate, programmed stimulation was performed. At a cycle length of 500 milliseconds and a coupling interval of 250 milliseconds, a 100 millisecond AH jump was recorded. Double premature stimuli were delivered in the atrium at a cycle length of 500 milliseconds and a coupling interval of 320, 260 milliseconds. Supraventricular tachycardia was induced at a cycle length of 410 milliseconds. PVCs were delivered spanning systole and diastole. PVCs that were synchronous to His bundle depolarization were analyzed. These PVCs did not delay or pre-excite the atrium. Ventricular pacing was performed during tachycardia. The tachycardia was entrained. With termination of ventricular pacing, the response was VA and VA. During tachycardia, the VA time measured 16 milliseconds. All these maneuvers confirmed the diagnosis to be typical AV nodal reentry tachycardia. The tachycardia was terminated with overdrive ventricular pacing. The tachycardia was reproducibly inducible with an AH jump using double premature stimuli in the atrium. The tachycardia was also induced with burst atrial pacing at 310 milliseconds. A decision to proceed with radiofrequency catheter ablation was made.
The 8 French sheath was replaced with an SR0 long sheath under fluoroscopic guidance. Through this long sheath, an EPT large curve 4 mm mapping and ablation catheter was positioned in the slow pathway area of the AV node. Detailed mapping of the slow pathway region was performed. Radiofrequency energy was delivered at appropriate sites for 20 seconds with a maximum power of 50 watts, temperature of 60 degrees for 20 seconds. If junctional rhythm was not seen, RF energy delivery was discontinued. In this fashion, four RF lesions were administered. The first two lesions did not elicit junctional rhythm. The latter two lesions elicited junctional rhythm and RF energy was delivered for a total of 60 seconds each. There was no heart block seen during RF energy delivery. The patient tolerated radiofrequency ablation well.
The catheter was withdrawn from the ablation site. Isoproterenol at 1 mcg and then 2 mcg per minute was infused. Programmed stimulation was performed after ablation. VA Wenckebach occurred at a pacing cycle length of 310 milliseconds. AV Wenckebach occurred at a pacing cycle length of 330 milliseconds. Single and double premature stimuli were delivered in the atrium. A single echo beat was elicited with a long escape junctional beat to follow. Isoproterenol was discontinued and programmed stimulation was performed. There were no inducible arrhythmias at the end of the procedure. The AH interval measured 100 milliseconds. The HV interval measured 40 milliseconds. The catheters and sheaths were removed and direct pressure was applied to obtain hemostasis. The patient tolerated the procedure well without complications and was sent to the holding area in stable condition.
PROCEDURE FINDINGS:
1. Normal sinus node function.
2. Normal atrial function.
3. Abnormal AV node function with dual pathways in the AV node and inducible typical AV nodal reentry tachycardia.
4. Normal His-Purkinje function.
5. Normal ventricular function.
6. Anomalous drainage of the superior vena cava into the right atrium.
RESULTS: Successful radiofrequency catheter ablation with slow pathway of the AV node to treat typical AV nodal reentry tachycardia.
