Conventional catheter ablation of cardiac arrhythmias is associated with radiation risks for patients and laboratory personnel. However, nonfluoroscopic catheter guidance may increase the risk for ...inadvertent cardiac injury. A novel radiofrequency ablation catheter capable of real-time tissue-tip contact force measurements may compensate for nonfluoroscopic safety issues.
To investigate the feasibility of contact force-controlled zero-fluoroscopy catheter ablation.
In 30 patients (including 12 pediatric patients), zero-fluoroscopy catheter ablation of right-sided (right atrium, n = 20; right ventricle, n = 2) and left atrial (n = 8) arrhythmias was attempted. Inclusion criteria were symptomatic suspected atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, focal right atrial and ventricular arrhythmias, and lone atrial fibrillation. A novel irrigated-tip catheter with an integrated contact force sensor was used for nonfluoroscopic 3-dimensional electroanatomical mapping and radiofrequency ablation. Transseptal access was gained under transesophageal guidance for ablation of left-sided arrhythmias.
Procedural success without fluoroscopy was achieved in 29 of the 30 patients (97%). In 1 patient, endocardial nonfluoroscopic ablation failed because of an epicardial accessory pathway within a coronary sinus aneurysm. Mean total contact force and amplitude of force undulations were kept below 50 g during mapping and below 40 g during ablation to prevent contact force peaks (>100 g). Apart from a transient second-degree type I atrioventricular block, no complications occurred. The mean procedure time was 2.8 ± 0.9 hours. There were no arrhythmia recurrences during a mean follow-up of 6.2 ± 4.2 months.
Contact force-controlled zero-fluoroscopy catheter ablation is generally feasible in right-sided and left atrial cardiac arrhythmias.
Objective Right ventricular–pulmonary arterial coupling is an important determinant in the development of right ventricular failure. The purpose of our study was to assess right ventricular–pulmonary ...arterial coupling in children and adolescents with dilatation of the right ventricle after repair of tetralogy of Fallot. Methods Right ventricular–pulmonary arterial coupling was quantified as the ratio of pulmonary arterial elastance (an index of arterial load) and right ventricular end-systolic elastance (an index of contractility) using pressure-volume loops with conductance catheters at the baseline level and during dobutamine infusion. Results A total of 24 patients (mean age, 16.7 ± 7.0 years) after tetralogy of Fallot repair were enrolled in the present study. End-systolic elastance showed an appropriate increase under inotropic stimulation from 0.24 ± 0.18 to 0.47 ± 0.39 mm Hg/mL/m2 ( P < .01). Simultaneously, the arterial elastance increased from 0.50 ± 0.28 to 0.72 ± 0.48 mm Hg/mL/m2 ( P < .01). Right ventricular–pulmonary arterial coupling was impaired at rest and did not improve significantly under dobutamine stress in the entire study population (arterial elastance/end-systolic elastance decreased from 3.0 ± 2.8 to 2.7 ± 3.1; P = .70). Patients with transannular patch repair (n = 11) showed significant uncoupling in response to dobutamine (arterial elastance/end-systolic elastance increased from 2.0 ± 0.8 to 3.7 ± 4.1), and coupling even improved with dobutamine in patients who had undergone a transatrial approach (arterial elastance/end-systolic elastance decreased from 1.6 ± 1.0 to 0.9 ± 0.6; P = .04). Conclusions Our study demonstrated that right ventricular–pulmonary arterial coupling is impaired in patients with tetralogy of Fallot and is mainly affected by the surgical strategy used at the primary repair. These results elucidate the emerging role of ventricular-arterial interactions as a contributing mechanism for deterioration in right ventricular performance and impaired response to inotropic drugs in patients with tetralogy of Fallot.
We report a simple valve repair for severe pulmonary incompetence in a 25-year-old patient. The patient had been operated on twice before for ventricular septal defect and coarctation of the aorta. ...The first operation consisted of pulmonary artery banding and coarctectomy and end-to-end anastomosis at 4 months, followed by debanding and transinfundibular ventricular septal defect closure at 6 years of age. Massive pulmonary incompetence was due to destruction of one valve cusp with the right ventricular outflow tract and pulmonary artery dilated secondarily. Repair consisted of pulmonary valve bicuspidization and right ventricular remodelling.
Multicystic encephalomalacia (ME) usually results from severe hypoxic-ischemic brain damage occurring during the late third trimester of gestation and birth. We report on a case of congenital ME due ...to a congenital anomaly of the aortic origin of brachiocephalic vessels resulting in subclavian steal syndrome. A 5-day-old term neonate presented with microcephaly and overlapping cranial sutures. Both arms were developed normally. Magnetic resonance imaging of the brain showed extensive bilateral supratentorial ME. Color duplex sonography of the aortic arch and the intracranial and extracranial vessels revealed a stenosis at the origin of the left common carotid artery and atresia of the origin of the left subclavian artery resulting in left-sided subclavian steal syndrome and retrograde perfusion of the basilar artery. Total cerebral blood flow volume was reduced to 22 mL/min. Severely reduced cerebral blood flow volume resulted from left carotid artery stenosis and atresia of the origin of the left subclavian artery with consecutive subclavian steal. Infratentorial brain structures and the left arm remained intact, but supratentorial brain structures were severely affected with ME.
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