João de Sousa

Triple-site pacing for cardiac resynchronization in permanent atrial fibrillation – Acute phase results from a prospective observational study

INTRODUCTION AND AIM Multi-site pacing is emerging as a new method for improving response to cardiac resynchronization therapy (CRT), but has been little studied, especially in patients with atrial fibrillation. We aimed to assess the effects of triple-site (Tri-V) vs. biventricular (Bi-V) pacing on hemodynamics and QRS duration. METHODS This was a prospective observational study of patients with permanent atrial fibrillation and ejection fraction <40% undergoing CRT implantation (n=40). One right ventricular (RV) lead was implanted in the apex and another in the right ventricular outflow tract (RVOT) septal wall. A left ventricular (LV) lead was implanted in a conventional venous epicardial position. Cardiac output (using the FloTrac™ Vigileo™ system), mean QRS and ejection fraction were calculated. RESULTS Mean cardiac output was 4.81±0.97 l/min with Tri-V, 4.68±0.94 l/min with RVOT septal and LV pacing, and 4.68±0.94 l/min with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV). Mean pre-implantation QRS was 170±25 ms, 123±18 ms with Tri-V, 141±25 ms with RVOT septal pacing and LV pacing and 145±19 with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV and pre-implantation). Mean ejection fraction was significantly higher with Tri-V (30±11%) vs. Bi-V pacing (28±12% with RVOT septal and LV pacing and 28±11 with RV apical and LV pacing) and pre-implantation (25±8%). CONCLUSION Tri-V pacing produced higher cardiac output and shorter QRS duration than Bi-V pacing. This may have a significant impact on the future of CRT.

Electrical storm induced by H1N1 A influenza infection

Pandemic H1N1 influenza A virus is spreading worldwide. We report a case of electrical storm during H1N1 influenza A infection in a patient with congenital long-QT syndrome (LQTS) that was previously stable on beta-blocker therapy. Possible causes for the association of A flu and LQTS recurrent ventricular arrhythmias are discussed.

Triple-site pacing for cardiac resynchronization in permanent atrial fibrillation: follow-up results from a prospective observational study

Aims Cardiac Resynchronization Therapy (CRT) is associated with a particularly high non-response rate in patients with atrial fibrillation (AF). We aimed to assess the effectiveness of triple-site (Tri-V) pacing CRT in this population. Methods and results Prospective observational study of patients with permanent AF who underwent CRT implantation with an additional right ventricle lead in the outflow tract septal wall. After implantation, programming mode (Tri-V or biventricular pacing) was selected based on cardiac output determination. Patients were classified as responders if NYHA class was reduced by at least one level and echocardiographic ejection fraction (EF) increased ≥ 10%, and as super-responders if in NYHA class I and EF ≥ 50%. Forty patients (93% male, mean age 72 ± 10 years) were included. Thirty-three were programmed in Tri-V. The following results pertain to this subgroup. At baseline, 58% were in NYHA class III and 36% NYHA class II. At 1 year follow-up, Minnesota QoL score was reduced (36 ± 23 vs. 8 ± 6; P = 0.001) and the 6MWT distance improved (384 ± 120 m to 462 ± 87 m, P = 0.003). Mean EF increased (26% ± 8 vs. 39 ± 10; P < 0.001 at 6 months and 41 ± 10; P < 0.001 at 12 months). Responder rate was 59% at 6 months and 79% at 12 months. Super-responder rate was 9% at 6 months and 16% at 12 months. One year survival free from heart failure hospitalization was 87.9%. Conclusion Tri-V CRT yielded higher response and super-response rates than usually reported for CRT in patients with permanent AF using clinical and remodeling criteria.

Overcoming a subclavian complete occlusion: Simple single lead extraction by the subclavian vein allowing implantation of two new leads and upgrade to CRT-P with multi-site pacing.

Central venous obstruction following pacemaker implantation is not uncommon, and can prove challenging in the case of system upgrade. We report a case of DDDR to CRT-P (with multi-site pacing) upgrade, where a subclavian occlusion was overcome resorting to an atrial lead extraction (using only a locking stylet). This allowed regaining of the venous access with subsequent implantation of not just one, but two new leads and subsequent successful upgrade.

Nova mutação na síndroma de QT Longo em doente com diagnóstico prévio de epilepsia

Congenital long QT syndrome (LQTS) can present as syncope or seizures, secondary to polymorphic ventricular tachycardia, mimicking a primary seizure disorder. In patients treated with an implantable cardioverter-defibrillator (ICD), the recurrence of arrhythmias with subsequent frequent therapeutic shocks may cause adverse reactions, which can be psychogenic. We report the case of a 22-year-old woman with syncope and seizures who was diagnosed in childhood as epileptic and in whom LQTS was diagnosed only in adulthood. Beta-blocker therapy failed and an ICD was implanted. However, as arrhythmias persisted, left cardiac sympathetic denervation was performed. After surgery, three-month follow-up showed a significant reduction in arrhythmias. The genetic study identified a heterozygous mutation, c.1817 C>T p.S606F, on the KCNH2 gene that has not previously been reported in the literature. We also report the rare occurrence of an electrical storm in the course of H1N1 infection. This case illustrates the difficulties in the diagnosis and treatment of LQTS. The possibility of a common genetic basis for arrhythmic diseases and epilepsy is discussed.

Ripple mapping: Initial multicenter experience of an intuitive approach to overcoming the limitations of 3D activation mapping

Ripple mapping (RM) displays electrograms as moving bars over a three‐dimensional surface displaying bipolar voltage, and has shown in a single‐center series to be effective for atrial tachycardia (AT) mapping without annotation of local activation time or window‐of‐interest assignment. We tested the reproducibility of these findings in operators naïve to RM, using it for the first time in postablation AT.

Expanding the functional role of miRNAs in the establishment of permanent atrial fibrillation.

a University Hospital Santa Maria, Department of Cardiology, Lisbon Academic Medical Centre, CCUL, Lisbon University, Lisbon, Portugal b Programme for Advanced Medical Education, Fundação Calouste Gulbenkian, Ministry of Health and Foundation for Science and Technology, Lisbon, Portugal c Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal d University Hospital Santa Maria, Department of Cardiothoracic Surgery, Lisbon Academic Medical Centre, CCUL, Lisbon University, Lisbon, Portugal

Trombosis intracardiaca estéril asociada a electrodo de marcapasos

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Persistent left superior vena cava : a vascular access without limitations

© 2018 Sociedade Portuguesa de Cardiologia. Published by Elsevier Espana, S.L.U. All rights reserved.

Taquicardia mediada por via Mahaim

We present the case of a previously healthy 42-year-old man who attended the emergency department due to a sudden onset of rapid and regular palpitations. The ECG showed 190 bpm, wide QRS with left bundle branch block tachycardia. He was started on amiodarone with progression to 230 bpm, wide QRS tachycardia with multiple morphologies, followed by spontaneous conversion to sinus rhythm, normal PR interval and rS pattern in LIII. The echocardiogram was negative for structural heart disease. The electrophysiological study demonstrated the presence of an accessory pathway with anterograde decremental conduction and no retrograde conduction. Both episodes of clinical tachycardia were induced. A diagnosis of Mahaim fiber-mediated antidromic atrioventricular reentrant tachycardia and pre-excited atrial fibrillation was made. Mapping was performed with detection of an M potential (His-like) at the lateral region of the tricuspid ring followed by radiofrequency ablation with immediate success criteria. Post-ablation there was a change to a qR pattern in LIII. At 12-months follow-up there was no recurrence of the tachycardia.