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Biomedical subjects

Lee A Biblo

Publications and source records attributed to Lee A Biblo.

9 recordsLinked to original sources
PubMed2004

Preservation of the anterior fat pad paradoxically decreases the incidence of postoperative atrial fibrillation in humans.

OBJECTIVES: The goal of this study was to determine if parasympathetic nerves in the anterior fat pad (FP) can be stimulated at the time of coronary artery bypass surgery (CABG), and if dissection of this FP decreases the incidence of postoperative atrial fibrillation (AF). BACKGROUND: The human anterior epicardial FP contains parasympathetic ganglia and is often dissected during CABG. Changes in parasympathetic tone influence the incidence of AF. METHODS: Fifty-five patients undergoing CABG were randomized to anterior FP preservation (group A) or dissection (group B). Nerve stimulation was applied to the FP before and after surgery. Sinus cycle length (CL) was measured during stimulation. The incidence of postoperative AF was recorded. RESULTS: Of the 55 patients enrolled, 26 patients were randomized to group A, and 29 patients were randomized to group B. In all of the 55 patients, the FP was identified before initiating cardiopulmonary bypass by CL prolongation with stimulation (865.5 +/- 147.9 ms vs. 957.9 +/- 155.1 ms, baseline vs. stimulation, p < 0.001). In group A, stimulation at the conclusion of surgery increased sinus CL (801.8 +/- 166.4 ms vs. 890.9 +/- 178.2 ms, baseline vs. stimulation, p < 0.001). In group B, repeat stimulation failed to increase sinus CL (853.6 +/- 201.6 ms vs. 841.4 +/- 198.4 ms, baseline vs. stimulation, p = NS). The incidence of postoperative AF in group A (7%) was significantly less than that in group B (37%) (p < 0.01). CONCLUSIONS: This is the first study demonstrating that direct stimulation of the human anterior epicardial FP slows sinus CL. This parasympathetic effect is eliminated with FP dissection. Preservation of the human anterior epicardial FP during CABG decreases incidence of postoperative AF.

Adipose Tissue↗
PubMed2004

Relation between the AH interval and the ablation site in patients with atrioventricular nodal reentrant tachycardia.

The determinants of slow pathway conduction in patients with AV nodal reentrant tachycardia (AVNRT) are still unknown, and great differences in the AH interval during slow pathway conduction are observed between patients. In 35 patients with typical AVNRT who underwent successful slow pathway ablation (defined as complete elimination of dual pathway physiology), the A2H2 interval at the "jump" during programmed atrial stimulation and the AH interval during AVNRT (as a reflection of slow pathway conduction time) and the fluoroscopic distance between the successful ablation site and the His-bundle recording site and between the coronary sinus ostium (CSO) and the His-bundle recording site were determined. The mean (+/- SEM) AH interval during slow pathway conduction was 323 +/- 12 ms with programmed stimulation and 310 +/- 10 ms during AVNRT. The mean number of energy applications was 8 +/- 1 (range 1-21). The mean distances between (1) the successful ablation site and the His bundle recording site and (2) between the CSO and the His-bundle recording site were 24 +/- 1 and 28 +/- 1 mm in the RAO and 23 +/- 1 and 28 +/- 1 mm in the LAO projections, respectively. The AH interval during slow pathway conduction correlated significantly with the distance between the successful ablation site and the His-bundle (P < 0.001) but not with the distance between CSO and His-bundle recording site. There is a significant correlation between the AH interval during slow pathway conduction and the distance of the successful ablation site from the His bundle. This relationship (1) suggests that, in addition to functional factors, anatomic factors influence slow pathway conduction and (2) may be helpful in determining the initial energy application site during slow pathway ablation.

Adolescent↗
PubMed2004

Migration of an inferior vena cava filter to the right ventricle and literature review.

Migration of an inferior vena cava (IVC) filter to the heart after placement is an extremely rare complication. The case of a 42-year-old man who presented with ventricular arrhythmia and tricuspid valve regurgitation, and underwent open heart surgery to extract an IVC filter from the right ventricle 12 days after infrarenal IVC filter placement, is reported.

Adult↗
PubMed2002

Identification and characterization of atrioventricular parasympathetic innervation in humans.

INTRODUCTION: We hypothesized that in humans there is an epicardial fat pad from which parasympathetic ganglia supply the AV node. We also hypothesized that the parasympathetic nerves innervating the AV node also innervate the right atrium, and the greatest density of innervation is near the AV nodal fat pad. METHODS AND RESULTS: An epicardial fat pad near the junction of the left atrium and right inferior pulmonary vein was identified during cardiac surgery in seven patients. A ring electrode was used to stimulate this fat pad intraoperatively during sinus rhythm to produce transient complete heart block. Subsequently, temporary epicardial wire electrodes were sutured in pairs on this epicardial fat pad, the high right atrium, and the right ventricle by direct visualization during coronary artery bypass surgery in seven patients. Experiments were performed in the electrophysiology laboratory 1 to 5 days after surgery. Programmed atrial stimulation was performed via an endocardial electrode catheter advanced to the right atrium. The catheter tip electrode was moved in 1-cm concentric zones around the epicardial wires by fluoroscopic guidance. Atrial refractoriness at each catheter site was determined in the presence and absence of parasympathetic nerve stimulation (via the epicardial wires). In all seven patients, an AV nodal fat pad was identified. Fat pad stimulation during and after surgery caused complete heart block but no change in sinus rate. Fat pad stimulation decreased the right atrial effective refractory period at 1 cm (280 +/- 42 msec to 242 +/- 39 msec) and 2 cm (235 +/- 21 msec to 201 +/- 11 msec) from the fat pad (P = 0.04, compared with baseline). No significant change in atrial refractoriness occurred at distances >2 cm. The response to stimulation decreased as the distance from the fat pad increased. CONCLUSION: For the first time in humans, an epicardial fat pad was identified from which parasympathetic nerve fibers selectively innervate the AV node but not the sinoatrial node. Nerves in this fat pad also innervate the surrounding right atrium.

Adipose Tissue↗
PubMed2002

Biventricular pacing for congestive heart failure: early experience in surgical epicardial versus coronary sinus lead placement.

OBJECTIVE: Biventricular pacing (BVP) has recently been introduced for the treatment of refractory congestive heart failure. Coronary sinus lead placement for left ventricular pacing is technically difficult, has a risk of lead dislodgement, and has long procedure times. Surgical epicardial lead placement has the potential advantage of the visual selection of an optimal pacing site, does not need exposure to ionic radiation, and allows lead multiplicity, but it does require a thoracotomy and general anesthesia. We report our early experience of BVP with both modalities. METHODS: BVP was performed in 12 patients with New York Heart Association (NYHA) class IV congestive heart failure (10 men, 2 women). Mean patient age was 68.7 years (range, 41-83 years). Surgical epicardial leads were placed through a 2- to 3-inch incision via a left fourth or fifth intercostal thoracotomy in 4 patients with single lung ventilation under general anesthesia. The other 8 patients underwent transvenous coronary sinus lead placement under conscious sedation. RESULTS: Postoperative NYHA class status improved from class IV to class II in 8 patients and to class III in 3 patients. In 5 of the 8 patients who had undergone follow-up echocardiography with mitral regurgitation, the severity of the mitral regurgitation improved. The mean left ventricular ejection fractions before and after BVP were 18.3% +/- 8.3% and 20.5% +/- 8.0%, respectively (P =.16). Mean fluoroscopy and total procedure times for transvenous lead placement were 77 +/- 19 minutes and 266 +/- 117 minutes, respectively. The mean surgery time for epicardial lead placement was 122 +/- 13 minutes. There were no differences between the 2 methods in pacing threshold or in lead dislodgement. There were no complications related to the surgery or the laboratory procedure. CONCLUSION: In patients with NYHA class IV congestive heart failure, epicardial lead placement through a minithoracotomy for BVP was performed safely with benefits equivalent to those of coronary sinus lead placement and with a shorter procedure time.

Adult↗