This study suggests that the autonomic nervous system plays an important role in both the initiation and termination of PAF. Furthermore, the time of PAF onset influences the autonomic tone at the initiation and termination of PAF.

We experienced a long-term survival case of primary cardiac lymphoma (PCL) demonstrating ventricular tachycardia (VT) as an initial sign, which was related to localized myocardial damage by lymphoma cells. A 70-year-old woman with sustained VT was admitted to the Kofu Municipal Hospital. VT ceased with the administration of disopyramide intravenously. The origin of the VT was the free wall of the right ventricular outflow tract (RVOT) as observed by electrocardiography on admission. A solitary mass in the free wall of the RVOT was found by echocardiography, chest computed tomographic scanning and magnetic resonance imaging. There was no evidence of extracardiac involvement. The patient was histologically diagnosed as PCL by endomyocardial biopsy. Chemotherapy started immediately after the diagnosis and the mass showed a marked reduction in size. After 8 cycles of chemotherapy, radiotherapy was performed. Pericardial thickness in the free wall of the RVOT developed without severe side effects. Complete remission has been maintained for 30 months after the initial diagnosis, and no recurrence and arrhythmias have been detected during the follow-up period. It was demonstrated that rapid diagnosis and chemotherapy followed by radiotherapy for PCL achieved better survival.

We investigated the nonuniform effects of autonomic nerve stimulation of the effective refractory period (ERP) of the right atrium in the anesthetized dog. Stimulation of the discrete intracardiac sympathetic nerves to the sinoatrial (SA) nodal region uniformly shortened ERPs at three sites in the right atrium after administration of atropine. Right ansa subclavia (RS) stimulation similarly shortened ERPs in the absence of atropine. Stimulation of the discrete intracardiac parasympathetic nerves to the SA nodal region (SAP stimulation) shortened ERPs of the right atrium in a nonuniform manner. Simultaneous RS and SAP stimulation additively shortened ERPs at each site and decreased sinus rate much more than SAP stimulation alone. Shortening of ERP induced by SAP stimulation was greater than that induced by RS stimulation at similar absolute changes in heart rate. These results suggest that simultaneous activation of sympathetic and parasympathetic nerves nonuniformly shortens the ERP in the right atrium as the algebraic sum of the individual responses to each stimulation. However, parasympathetics exert the principal neural control over atrial ERP.

One rapid shot of the tissue adhesive can block a vessel 0.6 cm or less in diameter with fast flow velocity, and a vessel up to 1.2 cm in diameter with slow flow velocity. Fast blood flows in a larger diameter vessel and slow injection of the tissue adhesive may result in fragmentation. This model of the varix was useful for assessing the effect of tissue adhesive used to treat gastric varices.

The -5 C/T polymorphism of platelet glycoprotein (GP) Ib alpha is a major determinant of the level of GP Ib/V/IX complex surface expression. We investigated the frequency of this polymorphism among Asian populations. The gene frequencies of cytosine (C) in this polymorphism were 0.283 and 0.219 in Japanese and Korean populations respectively. The C allele is linked with human platelet antigen (HPA)-2a and smaller types of variable number of tandem repeats (VNTR). A novel allele, C-HPA-2a-D of VNTR, was found. No association was observed between these alleles and coronary artery disease in this case-control study. The clinical relevance of this polymorphism in the thrombotic status remains undetermined.

Stimulation of discrete intracardiac sympathetic nerves to the SA (SAS stimulation) or AV nodal region (AVS stimulation) increased the heart rate or de creased AV conduction time and caused an AV junctional rhythm, respectively, in anesthetized dogs treated with atropine. Topical application of tetrodotoxin (TTX) at the SAS or AVS stimulation locus totally inhibited the response to each stimulation, whereas each TTX treatment slightly attenuated the chronotropic response to the right ansa stimulation by 23 ± 7.7% and the dromotropic response to the left ansa stimula tion by 7 ± 7.5%. TTX abolished AVS stimulation-induced one. Before atropine, topical application of hexamethonium at the locus for stimulation of intracardiac para sympathetic nerves to the SA (SAP stimulation) or AV nodal region (AVP stimula tion) abolished almost totally negative chronotropic responses to SAP and cervi cal vagus stimulation or negative dromotropic responses to AVP and cervical vagus sti mulation, respectively. These results demonstrate that activation of a very small population of intracardiac sympathetic nerves to target cells is enough to induce posi tive chronotropic and dromotropic responses in the heart in situ, and that SA and AV nodal pacemaker activity and AV conductivity are controlled multi-directionally by in tracardiac sympathetic nerves in contrast with parasympathetic ones.Activation of both right and left sympathetic nerves to the heart increases heart rate, short ens atrioventricular (AV) conduction time (AVCT), and increases myocardial contractile force (1, 2). Right sided sympathetic projec tions exert more pronounced effects on rate (2-4), whereas left sided sympathetic projec tions predominantly modulate AV conduction (5-8). The more peripherally located the point of electrical activation of cardiac sym pathetic nerves, the more distinct the effects on control of regional cardiac function (2, 9). Projections of extracardiac sympathetic effer ents to automatic, conductile and contractile tissues of the dog heart are parallel, but dis tinct (10). Recently, we have found that sti mulation of the intracardiac sympathetic nerve fibers to the SA (SAS stimulation) and AV nodal regions (AVS stimulation) results in selective positive chronotropic and dromotro pic responses, respectively, in the atropine treated dog heart (11). There are loci for SAS and AVS stimulation, i.e., the right atrial side of junctions of the right pulmonary veins and

Our results suggest that sympathetic activity can reduce transmural dispersion of repolarization under autonomic control in the canine heart under baseline conditions.

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