Isolated Disruption of the Right Coronary Artery Following a Steam Pop during Cavotricuspid Linear Ablation with a Contact Force Catheter

A 70‐year‐old woman with persistent atrial fibrillation underwent pulmonary vein isolation and linear ablation with a contact sensor catheter. During cavotricuspid isthmus ablation, a steam pop resulted in cardiac tamponade, and the patient developed severe hypotension despite successful pericardial puncture and minimal residual pericardial effusion. Right coronary artery angiography revealed extravasal contrast medium accumulation posterior of the Crux Cordis. Emergent cardiac surgery confirmed isolated disruption of the artery in the absence of additional heart perforation. Although contact sensor catheters may reduce complications, steam pops can still occur and result in dramatic complications.     

Long-Term Intrinsic Pacemaker Function in Patients Paced for Sinus Node Deficiency After Cardiac Transplantation

Fifteen cardiac transplant recipients requiring permanent pacing (AAJ, n = 9; VVI, n = 6; rate responsive devices, n = 11) for postoperative sinus node (SN) insufficiency underwent evaluation of long-term SN function 240 to 1,461 days after transplantation. The intrinsic rhythm at the time of discharge was sinus in 7 patients; functional escape in 6 patients; and pacemaker dependent in 2 patients. At follow-up, 5 patients had regained regular sinus rhythm, accounting for a total of 11 patients in sinus rhythm while 4 patients were in functional bradycardia. The SN recovery time as determined by the permanent pacemaker was normal (< 1,500 msec) in only 1/8 patients in whom it was determined, although 4 of these 8 patients were temporarily overriding the pacemaker during ambulatory monitoring. Patients with pathological SN recovery times included 3 patients with late return of sinus rhythm and 4 patients who had recovered normal sinus rhythm before their discharge from the hospital. Three patients developed late symptoms despite apparent early normalization and underwent delayed pacemaker implantations on postoperative days 35, 52, and 225, respectively. We conclude that, in patients requiring pacemaker implantation after cardiac transplantation, normalization of SN function cannot be inferred from just return of sinus rhythm, regardless of whether it occurs early or late. These findings may have implications when a pacemaker exchange or explanation is being considered.     

Therapy of Cardiac Device Pocket Infections with Vacuum‐Assisted Wound Closure—Long‐Term Follow‐Up

Background: Cardiac device infections are serious complications that require aggressive treatment strategies, including interventional or surgical lead extraction. Methods: Here we describe the long‐time follow‐up of vacuum‐assisted closure (V.A.C.) treatment in five patients with local cardiac device infection (LDI). In these patients the device was removed, the electrodes were shortened, and a V.A.C. treatment was applied. The primary endpoint was defined as time to re‐LDI. Results: Three patients had LDI of a pacemaker pocket, whereas two presented with an infection of their ICD pocket. The V.A.C. treatment was applied for 34.4 ± 17.9 days. The mean hospitalization time was 38.6 ± 19.2 days. The follow‐up period was assessed for 34.6 ± 19.2 months. Only one patient developed re‐LDI, 69 days after removal of the device. The other four patients did not show any signs of reinfection during the follow‐up period. None of the five patients sustained serious adverse events. Conclusions: V.A.C. treatment may be an option for selected patients with LDI who refuse a laser‐guided lead extraction or surgical removal of the electrodes as the primary therapy. (PACE 2012; 35:1217–1221)     

New Evidence that AV Node Slow Pathway Conduction Directly Influences Fast Pathway Function

Interaction Between the Slow and Fast Pathway. Introduction: Shortening of the AV node fast pathway effective refractory period (ERP) following successful slow pathway ablation may be a nonspecific effect of energy application at the AV junction or may be due to elimination of a direct effect of slow pathway conduction on the fast pathway.
Methods and Results: Twenty-six consecutive patients (20 women and 6 men; mean age 45 ± 3 years) with typical AV nodal reentrant tachycardia who underwent successful slow pathway ablation (defined as complete elimination of dual AV node physiology) were studied. The fast pathway ERP (at a drive train cycle length of 600 msec) was determined prior to ablation (baseline) and following unsuccessful and successful ablation attempts. Successful slow pathway ablation shortened the fast pathway ERP significantly (317 ± 9 msec; P < 0.001) compared to baseline (386 ± 12 msec), whereas unsuccessful ablations bad no effect (376 ± 11 msec). Sinus cycle length, the AH interval, and blood pressure were unchanged following successful ablation. Shortening of the fast pathway ERP did not correlate with the number of energy applications or with two measures of the proximity between the slow and the fast pathway.
Conclusion: These results support the hypothesis that shortening of the fast pathway ERP following slow pathway ablation is due to elimination of a direct effect of slow pathway conduction on fast pathway function rather than a nonspecific effect of repeated energy delivery at the AV junction.     

Static lung volumes and airway resistance reference values in healthy adults

Background and objective: The assessment of static lung volumes and airway resistance is a frequently performed diagnostic procedure and considered as an important tool in medical surveillance to detect pulmonary diseases. The objectives of the study are to establish reference equations for body plethysmographic parameters in a representative adult population across a wide age range and to compare the normative values from this sample with previous ones. Methods: Body plethysmography was applied in 1809 participants (885 males) of a cross‐sectional, population‐based survey (Study of Health in Pomerania). Individuals with cardiopulmonary disorders and/or a pack‐year smoking history >10 years and participants with a body mass index >30 kg/m² were excluded. In total, 686 healthy individuals (275 males) aged 25–85 years were assessed. Results: Prediction equations for both genders were established by quantile regression analysis taking into account the influence of age, height and weight. Conclusions: The study provides a novel set of prediction equations for static lung volumes and airway resistance obtained using body plethysmography. Compared with our findings, existing equations underestimated some normal values. The results emphasize the need for up‐to‐date reference equations.     

A novel isotonic‐balanced electrolyte solution with 1% glucose for perioperative fluid management in children‐ an animal experimental preauthorization study

Background: The recommendations for perioperative maintenance fluid in children have been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations (1–2.5% instead of 5%) to avoid hyponatremia or hyperglycemia. Objective: The objective of this prospective animal study was to determine the margin of safety of a novel isotonic‐balanced electrolyte solution with 1% glucose (BS‐G1) in comparison with normal saline with 1% glucose (NS‐G1) in the case of accidental hyperhydration with a focus on acid–base electrolyte balance, glucose concentration, osmolality and intracranial pressure in piglets. Methods: Ten piglets (bodyweight 11.8 ± 1.8 kg) were randomly assigned to receive either 100 ml·kg^?1 of BS‐G1 or NS‐G1 within one hour. Before, during and after fluid administration, electrolytes, lactate, hemoglobin, hematocrit, glucose, osmolality and acid–base parameters were measured. Results: Unlike BS‐G1, administration of NS‐G1 produced mild hyperchloremic acidosis (base excess BS‐G1 vs NS‐G1, baseline 1.9 ± 1.7 vs 2.9 ± 0.9 mmol·l^?1, study end 0.2 ± 1.7 vs ?2.7 ± 0.5 mmol·l^?1, P < 0.05, chloride BS‐G1 vs NS‐G1 baseline 102.4 ± 3.4 vs 102.0 ± 0.7 mmol·l^?1, study end 103.4 ± 1.8 vs 109.0 ± 1.4 mmol·l^?1P < 0.05). The addition of 1% glucose led to moderate hyperglycemia (P < 0.05) with a concomitant increase in serum osmolality in both groups (P < 0.05). Conclusion: Both solutions showed a wide margin of safety in the case of accidental hyperhydration with less acid–base electrolyte changes when using BS‐G1. This novel solution could therefore enhance patient’s safety within the scope of perioperative volume management.     

Acucise endopyelotomy: A technique with limited efficacy for primary ureteropelvic junction obstruction in adults

AIM: To retrospectively evaluate the ef fi cacy of Acucise endopyelotomy in a series of patients with primary ureteropelvic junction obstruction (UPJO). METHODS: Twenty-four patients with a symptomatic primary UPJO underwent Acucise endopyelotomy. Patients with high-grade hydronephrosis and/or poor renal function were excluded. Patients were followed by ultrasound imaging, intravenous urography, diuretic renography, and clinical review. RESULTS: The overall success rate was 58% (14/24 patients), with a median follow up of 32 months. Of the ten patients in whom Acucise endopyelotomy failed, seven underwent open pyeloplasty, one required nephrectomy, and two received a permanent ureteral stent. A poor outcome was noted in patients without perioperative extravasation. CONCLUSIONS: Our experience with Acucise endopyelotomy indicates that the success rate is lower than initially reported. Larger studies are needed to clarify the role of Acucise endopyelotomy in comparison with other techniques.     

Bufuralol metabolism in human liver: a sensitive probe for the debrisoquine-type polymorphism of drug oxidation

The genetically controlled polymorphism causing decreased metabolism of debrisoquine is closely related to that of the metabolism of bufuralol and numerous other drugs and has important clinical consequences. A sensitive in vitro assay was developed which quantifies the production of 1'-hydroxy-bufuralol (carbinol) from bufuralol in human liver microsomes. Initial formation rates of carbinol suggested Michaelis-Menten kinetics with an apparent KM of 61 and 171 mumol l-1 and Vmax of 3.2 and 5.8 nmol mg-1 microsomal protein h-1 in two human liver samples. The Vmax in microsomes of thirty-two liver samples was 4.2 +/- 1.0 (SD) nmol carbinol mg-1 protein h-1. Metabolism of debrisoquine in vivo, as expressed by the 'metabolic ratio' of debrisoquine over 4-OH debrisoquine correlated (r = -0.65, P less than 0.01; n = 18) with carbinol production rate in microsomes in vitro. Microsomes of one individual identified as poor metabolizer of debrisoquine in vivo showed reduction of carbinol formation to 1.97 nmol mg-1 h-1. Mixing his microsomes with those of an extensive metabolizer resulted in additive formation of carbinol excluding mediation of the defect by a soluble inhibitor. These data support the concept of a primary defect in microsomal oxidation of bufuralol. The described assay offers a sensitive tool to investigate the molecular mechanism of the 'debrisoquine polymorphism'.