Ventricular arrhythmias following transcatheter pulmonary valve replacement with the harmony TPV25 device.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) with the Harmony valve (Medtronic, Inc.) was recently approved to treat postoperative native outflow tract pulmonary regurgitation. While the 22 mm Harmony valve Early Feasibility Study demonstrated ventricular tachycardia (VT) in only 5% of patients, little is known about ventricular arrhythmias after TPVR with the larger 25 mm valve (TPV25). METHODS: A single center review was performed of patients with TPV25 implant from 2020 to 2021. Demographic, cardiac, procedural, and postimplant cardiac telemetry data were collected and compared between patients who did and did not have peri-implant ventricular arrhythmia. RESULTS: Thirty patients underwent TPV25 at a median age of 30 years. On postimplant telemetry, VT events were documented in 12 patients (40%); 11 nonsustained VT (NSVT) (median 3 episodes per patient and 6 beats per episode, maximum 157 episodes) and 1 sustained VT (3%), with Torsades de Pointes secondary to a short coupled premature ventricular contraction (PVC). VT events were associated with annular valve positioning (p < 0.001) and increased postimplant PVC burden (p < 0.0001), but there was no association between VT and other demongraphic, historical, or procedural factors. The frequency of NSVT events fell from 3/h from 0 to 12 h postimplant to 0.5/hr from 12 to 24 h (p < 0.001). CONCLUSION: VT occurred commonly (40%) in the first 24 h after TPV25 implant, with self-limited NSVT in 11 of 12 patients and 1 patient with cardiac arrest secondary to Torsades de Pointes. VT only occurred with annular valve positioning. Larger, longer-term studies are needed to determine risk factors for and natural history of post-TPVR VT.

[Cardiac arrest due to torsades de pointes ventricular tachycardia in a patient with Lyme carditis].

A 45-year-old female presented with third degree atrioventricular block and was diagnosed with Lyme carditis. Despite appropriate antibiotic treatment and continuous ventricular pacing, she suffered sudden cardiac arrest due to torsades de pointes ventricular tachycardia. Although rare, severe and potentially fatal ventricular tachyarrhythmias can occur in patients with Lyme borreliosis.

Nontraditional placement of an implantable cardioverter-defibrillator in a heterotaxy patient after the completion of total cavopulmonary connection.

A 15-year-old boy with heterotaxy syndrome developed a prolonged QT interval and intractable torsade de pointes after the administration of sodium channel blockers for atrial tachyarrhythmia. Although this situation called for the placement of an implantable cardioverter-defibrillator, a conventional transvenous approach was not available since the patient had previously undergone a nonfenestrated extracardiac total cavopulmonary connection. We were urged to carry out the surgical placement of an epicardial lead for an implantable cardioverter-defibrillator using a single coil transvenous shock lead through re-do midline sternotomy. Here we describe the details of this nontraditional surgical procedure for the placement of a lead for an implantable cardioverter-defibrillator in a case without venous access into the heart.

Amiodarone-induced torsade de pointes in a patient with wolff-Parkinson-White syndrome.

Amiodarone is generally regarded to have a high safety profile with a low incidence of arrhythmias. However, there have been reports of torsades de pointes under certain conditions, such as electrolyte imbalance or concomitant antiarrhythmic therapy. We describe a case of amiodarone-induced torsade de pointes early after initiation of intravenous amiodarone in the setting of T-wave alternans.

Abolition of Torsade de Pointes after radiofrequency catheter ablation at right ventricular outflow tract.

Radiofrequency (RF) catheter ablation was tried to treat a patient with syncope, perhaps due to polymorphic ventricular tachycardia (VT) of Torsade de Pointes (TdP) type which was documented by Holter monitoring. Electrophysiological study showed that the isolated ventricular extrasystoles (VEs) that initiated TdP were exactly replicated by pace mapping at the septal site of the right ventricular outflow tract. Performance of RF ablation at this site abolished the TdP and episodes of syncope with no requirement for antiarrhythmic agents for 3 years, whereas isolated VEs persisted. Although it is difficult to mention whether RF ablation was successful or not in this case, this procedure should be considered as a potentially curative approach to the TdP, when the arrhythmogenic focus can be fixed and identified as in this case.