Biomedical subjects

John D Murphy

Publications and source records attributed to John D Murphy.

5 recordsLinked to original sources

PubMed2006

Fontan completion in infants.

BACKGROUND: Since the implementation of the Fontan procedure, several clinical factors have been linked to outcome. A study of the outcome after Fontan completion was undertaken with particular attention to the influence of age and cardiac diagnosis. METHODS: Review of all patients (n = 107) undergoing Fontan completion between January 1998 and July 2005 to identify predictors of outcome: early death, prolonged effusions, and prolonged hospital stay. RESULTS: Median age was 13 months (range, 11 to 35) and median weight was 9.4 kgs (6.7 to 15.1). Hypoplastic left heart syndrome was present in 61 patients, and stage I Norwood was the initial palliation in 69. An interim superior cavopulmonary connection was performed in all. A lateral tunnel was used, and a deliberate right to left shunt was created in 99 patients. Mean transpulmonary gradient and pulmonary artery pressure were 5.7 +/- 1.5 mm Hg and 11.6 +/- 2.2 mm Hg, respectively. Median time to extubation was 5 hours (range, 2.5 to 184). Median duration of pleural effusion was 3 days (1 to 58) and was greater or equal to 14 days in 13 patients (12%). Overall mortality was 4.5% (5 of 107). Variables associated with poor outcome included associated noncardiac diagnosis (p < 0.05), elevated transpulmonary gradient (p = 0.03), and pulmonary artery pressure (p < 0.02). Hypoplastic left heart syndrome was the only variable associated with prolonged effusive complications. CONCLUSIONS: Fontan completion can be performed with good results in the first year of life independent of anatomic diagnosis. Significant noncardiac pathology, and a higher pulmonary artery pressure were predictive of worse outcome. Hypoplastic left heart syndrome was associated with prolonged effusions.

Abnormalities, Multiple↗

PubMed2006

Transthoracic percutaneous access for electroanatomic mapping and catheter ablation of atrial tachycardia in patients with a lateral tunnel Fontan.

BACKGROUND: The incidence of atrial tachycardia following Fontan surgery is high, but access to the pulmonary venous atrium, a frequent site of arrhythmia origin, is limited. OBJECTIVES: The purpose of this study is to report our results with a novel transthoracic percutaneous technique that provides direct access to the pulmonary venous atrium for electrophysiologic procedures. METHODS: Six transthoracic ablation procedures were performed in five patients (age 1.2-17 years, weight 9.2-68.4 kg) with a lateral tunnel Fontan. Under biplane fluoroscopy, a percutaneous needle was advanced at the selected intercostal space toward the pulmonary venous atrium. Once access was confirmed, a sheath was placed over a wire and a Navistar CARTO catheter advanced for mapping and ablation. Additional catheters were placed in the baffle and esophagus for pacing and reference. Atrial tachycardia was induced, electroanatomic mapping performed, and candidate areas tested with entrainment techniques. Radiofrequency ablation was performed and success defined as the inability to reinduce tachycardia using the initiating protocol. RESULTS: All tachycardias were ablated. Procedure time ranged from 3.7 to 4.9 hours, and fluoroscopy time ranged from 31 to 70 minutes. Hospital stay was 2 days. One patient had a pneumothorax and two had a hemothorax that was drained. Tachycardia recurred in one patient at 3 months. Ablation was repeated successfully. Four patients are free of tachycardia at follow-up ranging from 6 to 29 months. Follow-up is not available for one child. CONCLUSION: Transthoracic percutaneous access provided a direct route to the pulmonary venous atrium for successful mapping and radiofrequency ablation in Fontan patients.

Adolescent↗

PubMed2004

Transthoracic access for cardiac catheterization.

Patients who have undergone Fontan palliation for congenital heart disease have limited access to the pulmonary venous atrium. We describe a transthoracic approach to the pulmonary venous atrium for diagnostic and therapeutic cardiac catheterization. A total of 22 patients ranging in age from 14 months to 25 years and weighing 7-68 kg underwent transthoracic catheterization. With the aid of fluoroscopic and angiographic markers, a 20 gauge needle was inserted into the pulmonary venous atrium. A floppy-tipped wire was inserted, and a 4 Fr sheath was placed, upsized as needed. Access to the pulmonary venous atrium was obtained for all patients. Therapeutic procedures were completed for all patients. Transthoracic access to the pulmonary venous atrium in patients who have undergone a Fontan operation is a reliable and rapid mode of access, allowing for complex therapeutic procedures to be performed in the catheterization laboratory, obviating the need for additional open heart surgery.

Adolescent↗

PubMed2004

Endocardial atrial pacing lead implantation and midterm follow-up in young patients with sinus node dysfunction after the fontan procedure.

The purpose of the study was to investigate the results of endocardial lead implantation, lead performance, and follow-up in young patients after the Fontan procedure. A retrospective study was conducted with patients who had endocardial atrial pacing for SND and intact AVN function after Fontan from two pediatric centers. Patient demographics, pacing, and sensing data of endocardial atrial leads were analyzed at the time of pacemaker implantation and follow-up visits. Fifteen patients (weight 42.6 +/- 35 kg) had transvenous endocardial atrial lead implantation at an average age of 11.4 +/- 6.5 years. Active-fixation leads were used in all patients and steroid elution was present in 12 (80%) patients. Adequate P wave sensing was obtained in patients with sinus rhythm (n = 10); the remaining four patients had junctional rhythm without measurable P waves. Lead failure was not observed in any patient during the follow-up period of 2.9 +/- 2.1 years. The energy threshold at implantation was 1.46 +/- 1.5 microJ, 1.54 +/- 0.75 microJ at 3 months, 0.62 +/- 0.45 microJ at 1 year, 0.72 +/- 0.65 microJ at 2 years, 0.75 +/- 0.55 microJ at 3 years, and 0.8 +/- 0.85 microJ at 5 years postimplant. The lead impedance was 648 +/- 298 omega at implantation, 714 +/- 163 omega at 3 months, 744 +/- 195 omega at 1 year, 734 +/- 198 omega at 2 years, 800 +/- 142 omega at 3 years and 830 +/- 200 omega 5 years postimplant. Anticoagulation therapy (aspirin n = 5, warfarin n = 8) was continued by 13 patients. Complications consisted of a pneumothorax at implantation and a transient ischemic attack in one patient 4 years after pacemaker implant. Endocardial atrial leads offer low energy thresholds and can be implanted relatively safely in Fontan patients.

Adolescent↗

PubMed2003

Hemodynamic profile after the Norwood procedure with right ventricle to pulmonary artery conduit.

BACKGROUND: The balance of systemic, pulmonary, and coronary blood flow after the Norwood operation for hypoplastic left heart syndrome (HLHS) is critical to early survival. We hypothesized that a right ventricle to pulmonary artery conduit (instead of a systemic to pulmonary artery shunt) would result in hemodynamic changes consistent with a more stable balance of systemic, pulmonary, and coronary perfusion. METHODS AND RESULTS: Hemodynamic data were obtained during cardiac catheterization before the hemi-Fontan procedure from 24 patients with HLHS; the first 10 had a Norwood operation with a systemic to pulmonary artery shunt, and the latter 14 had the Norwood operation with a right ventricle to pulmonary artery conduit. Significant differences were present, with the right ventricle to pulmonary artery conduit group having a higher aortic diastolic pressure (55 versus 42 mm Hg), a narrowed systemic pulse pressure (43 versus 64 mm Hg), a lower Qp:Qs (0.92 versus 1.42), a higher coronary perfusion pressure (46 versus 32 mm Hg), and a higher ratio of pulmonary artery diameter to descending aorta diameter (1.51 versus 1.37). CONCLUSIONS: We conclude that, in HLHS after the Norwood operation, the right ventricle to pulmonary artery conduit modification produces hemodynamic changes consistent with improved coronary perfusion and a more favorable distribution of systemic, pulmonary, and coronary blood flow.

Angiography↗