Ana Bernardes

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.

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.

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.

Veia cava superior esquerda persistente – Um acesso vascular sem limitações

A veia cava superior esquerda persistente (VCSEP) é a malformação venosa congénita torácica mais frequente e o seu diagnóstico costuma ser incidental. Casos clínicos demonstrativos de implantação de pacemakers de dupla câmara (DDD), cardioversores desfibrilhadores implantáveis e sistemas de ressincronização cardíaca através desse acesso venoso foram já descritos na literatura. Contudo, na grande maioria dos casos apresentados o posicionamento do eletrocater (ECT) ventricular direito (ECT-VD) ficou restrito ao apéx do ventrículo direito (VD). Até ao momento estão descritos na literatura apenas quatro casos de posicionamento do ECT VD no trato de saída do VD através da VCSEP. Os autores apresentam o caso de uma doente do sexo feminino, de 79 anos, com diagnóstico de síncope e bloqueio de ramo esquerdo proposta para implantação de pacemaker DDD. Durante o procedimento obteve-se acesso venoso pela veia cefálica esquerda, verificou-se que o ECT progredia à esquerda da coluna vertebral, sugestivo da presença de VCSEP. Através desse acesso foi possível implantar sequencialmente o ECT-VD no trato de saída do VD e o ECT auricular no apêndice auricular direito, ambos com sistema de fixação ativa (Figura 1).Persistent left superior vena cava (PLSVC) is the most common thoracic congenital malformation and its diagnosis usually occurs by chance. Demonstrative clinical cases of dual-chamber (DDD) pacemaker implantation, implantable cardioverter defibrillators and cardiac resynchronization systems through PLSVC access have already been described in the literature. However, in most of the cases presented, the positioning of the lead in the right ventricle (RV) was restricted to the RV apex. To date, the literature reports only four cases of RV lead positioning in the right ventricular outflow tract (RVOT) via the PLSVC. The authors present the case of a 79-year-old female patient, diagnosed with syncope and left branch bundle block, in whom implantation of a DDD pacemaker was proposed. During the procedure, venous access was obtained via the left cephalic vein, and the lead was found to progress to the left of the spinal column, suggesting the presence of PLSVC. Through this access,

Active fixation coronary sinus lead extraction – A safe procedure

© 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier Espana, S.L.U. All rights reserved.

Twiddler's syndrome, a rare cause of pacemaker malfunction

© 2015 Sociedade Portuguesa de Cardiologia. Published by Elsevier Espana, S.L.U. All rights reserved.

Implantação de CRT‐D através de veia cava superior esquerda persistente

Persistence of the left superior vena cava is rare, being found in 0.3--2% of the general population, and shows considerable anatomical variability. We report the case of a 64-year-old man with idiopathic dilated cardiomyopathy, admitted electively for implantation of a cardiac resynchronization therapy defibrillator. Access was achieved via the left cephalic vein, but the lead was seen to advance to the left of the spinal column. Contrast injection revealed a persistent left superior vena cava draining into the right atrium close to the coronary sinus ostium. On encountering this congenital defect, many operators immediately decide to use special techniques, particularly for biventricular devices; some adopt a right approach to facilitate catheter manipulation, others use a hybrid technique (right and left in the same procedure), and some implant the right ventricular lead in the left ventricle. However, these techniques can be rather complex and carry an increased risk of infection and vascular injury, especially with a bilateral approach. Therefore, since according to various authors and our own experience conventional

Ablação epicárdica para prevenção da fibrilhação ventricular em doente com síndrome de Brugada

We present the case of a 60-year-old woman with Brugada syndrome, permanent type 1 electrocardiographic pattern, who had previously received an implantable cardioverter-defibrillator. She suffered frequent syncopal episodes and multiple appropriate shocks (around five per month) due to polymorphic ventricular tachycardia/ventricular fibrillation, refractory to quinidine therapy. Combined epicardial and endocardial electroanatomical mapping was performed with a view to substrate ablation. An area of abnormal fractionated electrograms, lasting up to 370 ms and up to 216 ms after the end of the surface QRS, was identified in the epicardium in the lower anterior part of the right ventricular outflow tract. Extensive epicardial ablation of this area, which eliminated the fractionated electrograms, led to the disappearance of the Brugada electrocardiographic pattern six weeks after ablation. Despite discontinuation of quinidine, no further ventricular arrhythmias occurred during follow-up, which is still of short duration.