Radiofrequency Catheter Ablation of Parasystole Originating from the Inferior Vena Cava

A 76‐year‐old man with a history of atrial septal defect repair underwent radiofrequency (RF) ablation of typical atrial flutter. During electrophysiological study, incessant sharp potentials were recorded, originating from the ostium of the inferior vena cava (IVC), and dissociated from atrial activity. During sinus rhythm, these potentials propagated to the atria and caused premature complexes when falling beyond the atrial refractory period. Electro‐anatomical mapping revealed the presence of the earliest potential in the postero‐lateral ostium of the IVC, propagating to the septal region. After RF isolation of the IVC, the patient has remained arrhythmia‐free over a 5‐year follow‐up. (PACE 2010; e62–e64)     

Neurally Mediated Syncope as a Cause of Syncope in Patients with Brugada Electrocardiogram

Neurally Mediated Syncope in Brugada Syndrome. Introduction: Patients with type 1 Brugada electrocardiogram (ECG) and an episode of syncope are diagnosed as symptomatic Brugada syndrome; however, all episodes of syncope may not be due to ventricular tachyarrhythmia. Methods and Results: Forty‐six patients with type 1 Brugada ECG (all males, 51 ± 13 years, 29 spontaneous, 17 Ic‐drug induced), 20 healthy control subjects (all males, 35 ± 11 years), and 15 patients with suspected neurally mediated syncope (NMS; 9 males, 54 ± 22 years) underwent the head‐up tilt (HUT) test. During the HUT test, 12‐lead ECGs were recorded in all patients, and the heart rate variability was investigated in some patients. Sixteen (35%) of 46 patients with Brugada ECG, 2 (10%) of 20 control subjects, and 10 (67%) of 15 patients with suspected NMS showed positive responses to the HUT test. Although no significant differences were observed in HUT‐positive rate among Brugada patients with documented VT (7/14; 50%), syncope (5/19; 26%) and asymptomatic patients (4/13; 31%), the HUT‐positive rate was significantly higher in patients with documented VT (50%) and those with VT or no symptoms (11/27, 41%) compared to that in control subjects (10%) (P < 0.05). Augmentation of ST‐segment amplitude (≥0.05 mV) in leads V1‐V3 was observed in 11 (69%) of 16 HUT‐positive patients with Brugada ECG during vasovagal responses, and was associated with augmentation of parasympathetic tone following sympathetic withdrawal. Conclusion: Thirty‐five percent of patients with Brugada ECG showed vasovagal responses during the HUT test, suggesting that some Brugada patients have impaired balance of autonomic nervous system, which may relate to their syncopal episodes. (J Cardiovasc Electrophysiol, Vol. 21, pp. 186‐192, February 2010)     

Iatrogenically Induced Intractable Atrioventricular Reentrant Tachycardia After Verapamil and Catheter Ablation in a Patient with Wolff-Parkinson-White Syndrome and Idiopathic Dilated Cardiomyopathy

ln a patient with WPW syndrome and idiopathic dilated cardiomyopathy, intractable atrioventricular reentrant tachycardia (AVRT) was iatrogenically induced. QRS without preexcitation, caused by junctional escape beats after verapamil or unidirectional antegrade block of accessory pathway after catheter ablation, established frequent AVRT attack.     

Dynamic Relationship Between the Q-aT Interval and Heart Rate in Patients with Long QT Syndrome During 24-Hour Holter ECG Monitoring

The purpose of this study was to investigate the dynamic relationship between heart rate and the Q-aT interval (the interval from the Q wave to the T wave apex) in patients with long QT syndrome. The QT to heart rate relation is useful for evaluating abnormalities of the ventricular repolarization, but its clinical application to the long QT syndrome requires accurate computer aided measurement of the QT interval and the sampling of a large number of beats. Therefore, the Q-aT interval was used on the basis of some reports that the heart rate dependency of the QT interval was concentrated in the Q-aT interval. Recent advances in the computer technology have allowed analysis of the relationship between the Q-aT and RR intervals on Holter ECG recordings. However, in addition to a prolonged QT interval, most patients with long QT syndrome have bizarre and variable T waves and the influence of this T wave morphology on the Q-aT to heart rate relation has not been clarified. We investigated the dynamic relationship between the Q-aT interval and heart rate in 10 patients with long QT syndrome and 11 control subjects using our original computer algorithm for the analysis of 24-hour Holter ECG recordings. The patients showed morphological T wave changes associated with heart rate changes during Holter recordings and these affected the Q-aT interval. The patients showed the following characteristics in the relationship between the major T wave peak and the RR interval: (1) a modestly decreased correlation between Q-aT and RR than in the control subjects (a median r value of 0.87 vs 0.93; P = 0.001); and (2) a steeper Q-aT/RR slope than in controls (a median slope of 0.24 vs 0.16; P < 0.05). Abnormal and variable T wave morphology in the long QT patients was closely related to a modestly decreased correlation between Q-aT and RR than in the control subjects. The steep Q-aT/RR slope might reflect unstable repolarization of the ventricle, which could act as a substrate for ventricular tachyarrhythmias.     

CUTANEOUS B-CELL LYMPHOMA CONSISTING OF LARGE CLEAVED CELLS WITH MULTILOBATED NUCLEI

A 65-year-old man was seen at the Ushioda Hospital in Au-gust 1989, because of a 1-month history of a tumor on the scalp. The tumor was excised and the diagnosis was malig-nant lymphoma. The patient was then referred to our de-partment in September 1989. Several nut-sized lymph nodes wvepa-b and m-fepa for 2 months. Since then, the patient has been free of disease up to the time of writing, July 1992, a period of 2.5 years. Biopsy samples taken from the tumor on the scalp showed a monomorphous infiltrate of large lymphoid cells throughout the entire dermis and subcutis, with a definite clear zone (Fig.1). A high-power view showed diffuse large lymphoid cell infiltration. Numerous mitotic figures were also seen. The lymphoid cells had multilobated nuclei and distinct nucleoli (Fig. 2). Monoclonal antibodies such as Leui (CD5), Leu2a (CD8), Leu3a (CD4), Leu4 (CD3), MT-1 (CD43), Leu14 (CD22), LN1 (CDw75), and Leu26 (CD20), and polyclonal antibodies such as anti-kappa, anti-lambda, anti-IgG, anti-lgA, anti-IgM, and anti-lgD were purchased from commercial sources. Optimal dilutions of the monoclonal antibodies and heteroantisera were assessed beforehand by titration on suitable tissue samples. The antigens recognized by the monoclonal anti-bodies and heteroantisera were investigated by either the avidin-biotin peroxidase complex (ABC) method on cryostat sections or the peroxidase-antiperoxidase complex (PAP) method on paraffin sections, as described elsewhere.¹ The immunologic properties of the infiltrating cells were determined using skin biopsied in August 1989, and October 1989. Large lymphoid cells, which formed the major popu-lation of infiltrating cells, were positive for CD20, CD22, and HLA-DR and negative for CD3, CD4, CD43, and CD45RO. From these findings the patient was diagnosed as hav-ing primary cutaneous B-cell lymphoma, diffuse large non-cleaved cell type, as classified by the Working Formulation.²     

Hydrophilic bile salts and liposomes inhibit hydrophobic bile salt-induced release of glycoprotein by guinea-pig gall-bladder

Abstract Bile salts can be cytotoxic to mucosal surfaces, because of their detergent properties. This is not normally seen under physiological circumstances in the gall-bladder. To further study normal mucosal defence mechanisms, the present study was performed to examine the effects of liposomes and hydrophilic bile salts on hydrophobic bile salt-induced release of radiolabelled glycoproteins from explants of guinea-pig gall-bladder. Glycoprotein release was correlated with the degree of hydrophobicity of bile salts, as determined by the retention factor in reversed-phase high-performance liquid chromatography. Hydrophobic bile salt-induced release of glycoproteins was reduced by liposomes and hydrophilic bile salts. The inhibitory effect of liposomes was directly related to the degree of saturation of their fatty acyl chains, and that of hydrophilic bile salts was related to the degree of hydrophilicity. These findings suggest that vesicles and hydrophilic bile salts may play a cytoprotective role against membrane damage passively caused by hydrophobic bile salts in the biliary system, and that such damage may occur according to the quantitative and qualitative imbalance among these factors.     

Reversibility of organic anion-induced cholestasis: Association with compensatory hypersecretion of biliary phospholipid and protein in the dog

Abstract The effect of a concomitant infusion of organic anions, structurally related phthaleins, on bile flow was studied in anaesthetized dogs. A combination of rose bengal and sulfobromophthalein was found to uniquely and synergistically produce an acute, reversible form of intrahepatic cholestasis (< 10% of control level). This phenomenon was not observed with the administration of those individual organic anions at concentrations previously associated with the induction of intrahepatic cholestasis. The infusion of either a micelle forming bile salt, sodium taurocholate, or a non-micelle forming bile salt, sodium dehydrocholate, rapidly reversed the intrahepatic cholestasis (within 20 min after bile salt infusion). During the choleretic phase immediately following the bile salt infusion, a transient but marked hypersecretion, a disproportionately increased output in relation to that of bile acids, of biliary phospholipid (176% of control level by taurocholate and 138% of control level by dehydrocholate), and an even more striking amount of biliary protein hypersecretion were observed (392% of control level by taurocholate and 357% of control leverl by dehydrocholate). Although the significance of these new post-cholestatic observations requires clarification, it is suggested that the intrahepatic cholestasis induced by organic anions reflects a reversible defect in the mechanism(s) involved in transcellular transport.     

An estimation of human bile metastability: Clinical application of a sensitive cholesterol crystal growth assay

The formation of cholesterol monohydrate crystal initiates cholesterol gallstone formation. The nucleation time (NT), a light microscopy method, is used currently to estimate human bile metastability. Recently, a cholesterol crystal growth (CCG) assay utilizing photometric turbidity to quantitate cholesterol crystallization was developed using model bile systems. The object of this study was to determine whether this novel CCG assay was applicable to the quantitative assessment of native human bile metastability. Human gall-bladder bile samples were collected from patients undergoing cholecystectomy. There were five patients with cholesterol gallstone and five stone-free patients. A significant correlation between the onset time measured by the CCG assay and the NT observed by light microscopy was found in our modified assay condition where interference by bilirubin was negligible (P < 0.01). Also, the growth rate measured by the CCG assay significantly correlated with the NT (P < 0.05). These results indicate that the CCG assay is applicable to quantitative assessment of human bile metastability reflected by cholesterol crystal nucleation and that the cholesterol crystal growth is also conveniently estimated by this method.