Implantation of cardioverter defibrillators with minimal fluoroscopy using a three-dimensional navigation system: a feasibility study.

AIMS: Fluoroscopy is necessary to implant cardioverter defibrillators using the conventional approach. Modern electroanatomic navigation systems allow the visualization of multiple catheters and, as they are capable of rendering precise geometrical reconstructions of cardiac chambers, have been used for fluoroscopy-free electrophysiological procedures. The aim of our study was to assess the feasibility of non-fluoroscopic implants using a three-dimensional navigation system. METHODS AND RESULTS: The NavX system was used to create the virtual anatomies of heart chambers and thoracic veins. Defibrillator leads were placed at stable positions using exclusively the electrical and anatomical information provided by the navigator. A single fluoroscopy shot confirmed final lead positions. Thirty-five consecutive patients had 30 single-chamber and 5 dual-chamber defibrillators implanted. Cardiac chambers geometries were developed in 10 ± 4.3 min. Ventricular and atrial leads were implanted, with suitable positions and electrical parameters being achieved, in 18 ± 22 and 16 ± 9 min, respectively. The final confirmatory shot was the only fluoroscopy needed in 31 (89%) cases. Two patients needed fluoroscopy-guided relocation of the ventricular lead due to high defibrillation threshold and a breakdown of the active-fixation mechanism, respectively. In one patient the ventricular lead was totally extracted and reimplanted because a loop has formed in the vena cava, and one patient required fluoroscopy-guided subclavian puncture. In five cases (16%), the position of the proximal defibrillation coil was minimally modified with fluoroscopy due to incomplete geometric reconstruction of the superior vena cava. CONCLUSION: Fluoroscopy-free defibrillators implantation is feasible using a navigation system. Suitable placement of the proximal coil is a critical stage and requires a reliable and complete reconstruction of the superior vena cava.

Feasibility and safety of pulmonary vein isolation by high-power short-duration radiofrequency application: short-term results of the POWER-FAST PILOT study.

PURPOSE: Pulmonary vein (PV) isolation (PVI) by point-by-point radiofrequency application (PPRF) results in longer procedures than that achieved by single-shot ablation techniques. In addition, it is associated with significant risk of oesophageal injury. The POWER-FAST pilot study evaluated the feasibility and safety of PVI by high-power short-duration (HPSD) PPRF. METHODS: HPSD PPRF around the PVs was done in 48 consecutive patients with atrial fibrillation. Fifty watts was delivered until a predefined lesion index value was reached (LSI ≥ 5 or Abl-I ≥ 350) and 60 W during 7-10 s in the first 18 and last 30 patients, respectively. A control group of 47 consecutive patients who had undergone PVI before the HPSD group with conventional PPRF (30 W for 30 s) was included for reference. Echocardiography and oesophageal endoscopy was performed shortly after ablation in all patients. RESULTS: PVI of all targeted veins was achieved in 98% and 100% of patients of the conventional and HPSD groups, respectively (p = 0.59). Total radiofrequency time was 34 ± 11, 24 ± 8, and 15 ± 5 min in groups 30 W, 50 W, and 60 W (p < 0.001). Audible steam pops occurred in 4 out of 48 (8%) patients in the HPSD group, accounting for 4 (0.08%) out of 5 269 HPSD radiofrequency applications. No patient in the HPSD group developed pericardial effusion. The incidence of oesophageal lesions was 28%, 22%, and 0% in groups 30 W, 50 W, and 60 W, respectively (p = 0.007) CONCLUSIONS: PVI can be achieved with HPSD PPRF in most patients. This approach appears safe and associated with low risk of esophageal damage.

What is behind radiofrequency delivery at the cavo-tricuspid isthmus?

Catheter-based ablation of isthmus-dependent common atrial flutter results in very high success rates and almost no complications. However, bidirectional conduction block through the isthmus may be challenging in a small percentage of patients regarding the use of high power and high temperature settings during radiofrequency delivery. Anatomical and physiological circumstances may be the reason for such difficulties to achieve bidirectional block at the cavo-tricuspid isthmus. However, in the present case we show edema formation after multiple shots of radiofrequency delivery at the cavo-tricuspid isthmus, which complicates the achievement of bidirectional conduction block.

Sudden cardiac arrest as first symptom of a benign cardiac tumor growth / Muerte súbita como primer síntoma de crecimiento de tumor cardíaco benigno

Abstract Primary cardiac tumors are rare, especially in the pediatric age. Most of them are benign in the sense they are not invasive. However, benign tumors maintain the potential for serious illness related to significant hemodynamic compromise or life-threatening dysrhythmias. We present the case of an infant with an initial diagnosis of cardiac rhabdomyoma who suffered ventricular arrhythmia and cardiac arrest. He suffered irreversible severe neurologic sequelae, due to his prolonged cardiopulmonary arrest and was finally diagnosed of cardiac fibroma. Good arrhythmia control was obtained after an extensive partial surgical resection of the tumor. This case highlights the importance of arrhythmia burden in this condition. A correct diagnosis based essentially in different imaging modalities and closer clinical and rhythm follow up could have avoided this ominous event.

Resumen Los tumores cardíacos primarios son raros, especialmente en la edad pediátrica. La mayoría de ellos son benignos, en el sentido de que no son invasivos. Sin embargo, los tumores benignos tienen el potencial para producir enfermedades graves que pueden causar compromiso hemodinámico significativo o arritmias potencialmente letales. Se presenta el caso de un niño con un diagnóstico inicial de rabdomioma cardíaco, quien sufrió una arritmia ventricular y una parada cardíaca. Tuvo secuelas neurológicas severas irreversibles debido al tiempo prolongado en parada cardiorrespiratoria y se le diagnosticó finalmente fibroma cardíaco. Se obtuvo un buen control de las arritmias después de una extensa resección parcial del tumor. Este caso pretende subrayar la importancia del riesgo de aparición de arritmias en esta situación. El diagnóstico correcto basado fundamentalmente en el uso de distintas modalidades de imagen y el seguimiento clínico y arritmológico, podrían haber evitado este desenlace fatal.

What is behind radiofrequency delivery at the cavo-tricuspid isthmus? / ¿Qué sucede en el istmo cavo-tricuspídeo durante la ablación con radiofrecuencia?

Catheter-based ablation of isthmus-dependent common atrial flutter results in very high success rates and almost no complications. However, bidirectional conduction block through the isthmus may be challenging in a small percentage of patients regarding the use of high power and high temperature settings during radiofrequency delivery. Anatomical and physiological circumstances may be the reason for such difficulties to achieve bidirectional block at the cavo-tricuspid isthmus. However, in the present case we show edema formation after multiple shots of radiofrequency delivery at the cavo-tricuspid isthmus, which complicates the achievement of bidirectional conduction block.

La ablación con catéter del flutter de tipo común dependiente del istmo es un procedimiento con elevada tasa de éxito y rara vez complicaciones. Sin embargo, en un pequeño porcentaje de casos puede resultar complicado conseguir el objetivo de bloquear bidireccionalmente el istmo durante el procedimiento de ablación a pesar de incrementar la potencia y temperatura del catéter de radiofrecuencia. Las características anatómicas y fisiológicas del istmo cavo-tricuspídeo pueden ocasionar dificultades en la consecución del bloqueo bidireccional. Sin embargo, en el presente caso mostramos cómo la propia aplicación de radiofrecuencia puede ocasionar edema importante tras múltiples aplicaciones con las consiguientes dificultades para conseguir el bloqueo bidireccional del istmo.