Relationship Between Serum Potassium Concentration and Risk of Recurrent Ventricular Tachycardia or Ventricular Fibrillation

INTRODUCTION: Electrolyte abnormalities are considered a correctable cause of a life-threatening ventricular arrhythmia according to American Heart Association/American College of Cardiology Practice Guidelines, and ventricular tachycardia or ventricular fibrillation in the setting of an electrolyte abnormality is considered a class III indication for defibrillator implantation. However, there are little data to support this recommendation. The purpose of this study was to determine the risk of a recurrent sustained ventricular arrhythmia in patients with a low serum potassium concentration at the time of an initial episode of a sustained ventricular arrhythmia. METHODS AND RESULTS: One hundred sixty-nine consecutive patients who presented with a sustained ventricular arrhythmia and a serum potassium concentration determined on the day of the arrhythmia underwent defibrillator implantation. All patients had structural heart disease and left ventricular ejection fraction of 0.32+/-0.15. On the day of the index arrhythmia, 30% of the patients had a serum potassium concentration <3.5 or >5.0 mEq/L, including 7% who had a serum potassium concentration <3.0 or >6.0 mEq/L. For the entire cohort of patients, freedom from a recurrent sustained ventricular arrhythmia was 18% at 5 years and was not significantly different among patients with a serum potassium concentration <3.5 mEq/L (23%), between 3.5 and 5.0 mEq/L (16%), and >5.0 mEq/L (5%; P = 0.1). CONCLUSION: The results of the present study suggest that patients with structural heart disease and an abnormal serum potassium concentration at the time of an initial episode of sustained ventricular tachycardia or ventricular fibrillation are at high risk for a recurrent ventricular arrhythmia; therefore, implantable defibrillator therapy may be reasonable.     

Perspectives on phantom boarder symptom

Phantom boarder symptom (PBS) is a hallucinatory and delusional syndrome that tends to occur in the elderly, in which the patient imagines that someone uninvited is living in their home. This article provides an overview of the historical background that has led to the current focus on PBS as a single symptom, from its classification as late paraphrenia to its being recognized as a type of misidentification, and discusses classification problems and PBS subclassifications. In addition, the results of our own investigation of PBS, which focused on PBS in senile dementia, support the findings of previous studies, such as the absence of a relationship between dementia severity and the occurrence of delusion. The discussion therefore focuses on the psychosocial factors that serve as the mechanism of PBS onset, and directions and possibilities for therapy are suggested.     

Effects of High-frequency Current on Pacemakers during Endoscopic Gastric Surgery: Experimental Study

Abstract: This study examined the effects of high-frequency current on pacemakers. Pacemakers were implanted in mongrel dogs, gastric mucosal resection was performed endoscopically using monopolar and bipolar snares, and the times for resection and magnitude of interference current (IC) in the myocardial electrodes were compared. The time for resection was 9.56±2.87 seconds with a monopolar snare and 0.82±0.13 seconds with a bipolar snare (p<0.01). The magnitude of the IC was 0.59±0.26 mV with a monopolar snare and 0.26±0.12 mV with a bipolar snare (p<0.01). The times required for resection and the magnitude of the IC using a bipolar snare in the coagulation mode at an output of approximately 12 W were 1.97±0.65 seconds and 0.03±0.02 mV, respectively, and those in the cutting mode were 1.68±0.50 seconds and 0.07±0.04 mV, respectively. The magnitude of the IC was significantly less (p<0.01), but the time required for resection was longer in the coagulation mode. No abnormalities were noted in the pacemaker mode in any of the 10 pacemakers examined after mucosal resection with high-frequency current at an output of 300 W. These results suggest that endoscopic therapy using high-frequency current can be performed more safely with a bipolar snare than with a monopolar snare in patients with pacemakers. In addition, the selection of the endoscope mode is considered to be important. (Dig Endosc 1999; 11: 150–157)     

Solitary psoas muscle metastasis after radical nephrectomy for renal cell carcinoma

Skeletal muscle is a very rare location for the metastasis of renal cell carcinoma (RCC) and only one case of solitary metastasis to the psoas muscle has been reported. We present a 63-year-old male patient with late recurrence (14 years) after left side radical nephrectomy for RCC. He first visited Chikushi Hospital, Fukuoka University, Japan in January 2000 for a postoperative follow-up because he had shifted residence to the area. Follow-up was by abdominal computed tomography (CT) and chest X-ray. In December 2001, a CT scan showed a 1.5 cm enhanced mass in the right psoas muscle without any other metastasis. The mass was resected that month and histological study showed RCC metastasis.     

1H-n.m.r. studies on cross-relaxation phenomena in bovine mercaptalbumin (BMA) solution and partially hydrolyzed bovine plasma albumin (BPA*) gel

Bovine plasma albumin Fr. V(BPA) contains small amounts of proteolytic enzyme which catalyzes a very limited cleavage of BPA in the F-form near pH 3.8, resulting in the formation of partially hydrolyzed BPA(BPA*). BPA* had a tendency to form a transparent gel at pD 4.0 (pD range of the F-form) above 7%. Highly purified proteolytic enzyme-free bovine mercaptalbumin (BMA) was in a transparent solution at pD 4.0 even at 12.4%. after 5 days incubation at 35°. Cross-relaxation times (T_IS) between irradiated protein protons and observed protons, such as side chain and water protons, were studied on BMA solution and BPA*-gel. T_IS values of BMA solution, obtained by the saturation transfer (SATUR) and inversion recovery (INVER) methods, were a single kind of T_IS for each side chain. Those of BPA*-gel by the SATUR method indicated the presence of two kinds of T_IS, that is, short and long T_IS values for each side chain. However, those by the INVER method showed a single kind of T_IS for each side chain, corresponding to the long T_IS value by the SATUR method. The short T_IS values of BPA*-gel, observed by the SATUR method, may be due to immobile joint parts of fibrous BPA* aggregates. T_IS values from protein to water protons (T_IS(HDO)) in BPA*-gel, obtained by the INVER method, were far shorter than those in BMA solution, indicating a large amount of hydration of BPA* and rapid exchange between bound and bulk water in the gel state.     

Dual colour fluorescein analysis of peripheral blood T cells in auto-immune chronic active hepatitis

Both CD4 and CD8 T cells are subdivided into two phenotypically distinct sublineages via another two T cell markers, Leu-8 and CD11b antigens. The proportions of these four T cell subsets, CD4+Leu8+, CD4+Leu8-, CD8+11b+ and CD8+11b-, were studied in patients with auto-immune chronic active hepatitis (CAH) and compared with disease controls (hepatitis B surface antigen positive chronic active hepatitis) and healthy controls. We found that the proportion of CD4+Leu8+ cells was significantly reduced compared with controls (P less than 0.01), whereas those of the other cells were almost identical in all 3 groups. The absolute number of these CD4+Leu8+ cells was also lower than that of controls (P less than 0.01). Thus, the present study suggests that a reduced number of CD4+Leu8+ cells is associated with the aberrant immune response in auto-immune CAH.     

Dyschromatosis symmetrica hereditaria associated with neurological disorders

Dyschromatosis symmetrica hereditaria (DSH) is a pigmentary genodermatosis of autosomal dominant inheritance caused by a mutation of adenosine deaminase acting on the RNA 1 gene (ADAR1). It is characterized by a mixture of hyper‐ and hypopigmented macules on the back of the hands and feet. The pathomechanism by which the ADAR1 gene mutation induces DSH has not been clarified yet. We experienced an 11‐year‐old male DSH patient associated with dystonia, mental deterioration and brain calcification, who had a mutation of p.G1007R in the ADAR1 gene. This mutation had already been reported in a patient with similar neurological symptoms by Tojo et al. Additionally, a patient with DSH associated with torsion dystonia was reported by Patrizi et al., but gene analysis was not carried out. Only three cases with neurological disorders have been reported, although more than 50 mutations of the ADAR1 gene causing DSH have been reported and none of them had any neurological symptoms. Therefore, we suggest that neurological disorders rarely develop in DSH.     

Discrimination between His-bundle and the Right Bundle Branch during Electrophysiologic Studies

Background: The purpose of this study was to identify the His-bundle (HB) versus right bundle branch (RBB) during electrophysiologic studies, using the V3 phenomenon, and to compare the timing of HB versus RBB potentials of sinus cycles (His-ventricular [H-V] interval).
Methods: The study enrolled 16 patients without structural heart disease, who underwent electrophysiologic studies during which the H-V interval was within normal limits and the V3 phenomenon was induced during recordings of the HB and the RBB potentials by a multi-electrode catheter. The recording site of the earliest HB potential just before the V3 phenomenon was defined as the branching portion of His bundle (HBBP), the site immediately proximal to the HBBP as the HB, and the site immediately distal to the HBBP as the RBB.
Results: The HBBP was identified in all patients. In all cases but one patient, the H-V interval measured at the HB adjacent to the HBBP was ≥35 ms. However, in 12 patients, the H-V interval measured at the RBB adjacent to the HBBP was also ≥35 ms.
Conclusions: The electrophysiologic identification of HB versus RBB by simultaneous recordings of HB and RBB potentials during induction of the V3 phenomenon was feasible. When the discrimination between HB and RBB was based on the measurement of the H-V interval, the proximal portion of the RBB was frequently misidentified as the HB.