Heart Rate Variability in Patients with Familial Amyloid Polyneuropathy

The purpose of this study was to evaluate heart rate variability (HRV) in patients with familial amyloid polyneuropathy (FAP) using the time- and frequency-domain analysis. The study population consisted of 19 patients with FAP, and 19 age and sex matched normal volunteers. The 24-hour Holter recordings of all subjects in sinus rhythm and off medication were analyzed. Five time-domain indices of HRV were computed. The frequency component of HRV was calculated by fast Fourier transform analysis of the RR intervals. The power spectrum of the low frequency (LF) between 0.04–0.15 Hz and high frequency (HF) between 0.15–0.40 Hz and the LF/HF ratio was calculated. Global measures of HRV including the standard deviation of the mean of RR intervals (SDNN) and the standard deviation of 5-minute mean RR intervals (SDANN) were decreased in patients with FAP. Specific vagal influences on HRV including the proportion of RR intervals more than 50 milliseconds different (pNN50) and the HF power on spectral analysis were less in patients with FAP. LF power and LF/HF ratio were more decreased in patients with FAP at the advanced stage than at the early stage. In conclusion, HRV was significantly decreased in patients with FAP at the early stage, and sympathetic activity was more decreased in patients at the advanced stage. These findings suggest that the decrease of the HRV is an indicator of this disease and the power spectral analysis of the HRV is beneficial in assessing the severity of the autonomic dysfunction.     

Hepatic HCV-RNA as a predictor of outcome after interferon therapy in patients with chronic hepatitis C

Measurement of serum HCV-RNA is a useful index for evaluating the antiviral effect of interferon therapy in chronic hepatitis C. In the present study, we investigated whether the detection of hepatic HCV-RNA after interferon treatment, using a polymerase chain reaction assay, predicted long-term response to therapy in patients with chronic hepatitis C. Thirty-three patients underwent liver biopsies before and after interferon therapy. Histology and clinical courses were compared after treatment. Before therapy, serum and hepatic HCV-RNA was detected in specimens from 32 (97%) and 33 (100%) patients, respectively. Serum HCV-RNA became undetectable in samples from 22 (67%) patients; however, in 10 of these patients (45%), serum HCV-RNA levels relapsed after therapy. Hepatic HCV-RNA became undetectable in 14 patients after therapy and the serum aminotransferase concentration remained within normal limits during and following (24–92 weeks) therapy in 12 of these patients (86%). All 11 patients with detectable hepatic HCV-RNA also had serum HCV-RNA and elevated aminotransferase concentrations refractory to therapy. The absence of hepatic HCV-RNA at the end of interferon treatment thus predicted a long-term complete response to therapy with a sensitivity of 100%, a specificity of 90% and an accuracy of 94%. We conclude that hepatic rather than serum HCV-RNA is a more useful index for the prediction of the long-term efficacy of interferon therapy.     

Stromal Cell‐Derived Factor 1α Induces Accumulation of Intraveneously Administered Marrow‐Derived Stromal Cells in the Partially Obstructed Rat Bladder

Objectives: We investigated the time course of the stromal cell‐derived factor 1α (SDF1α) expression and behavior of intravenously administered bone marrow‐derived stromal (BMS) cells in the urinary bladder of partial bladder outlet obstruction (PBOO) rats. Methods: Study 1: Recombinant SDF1α or saline was directly injected into the bladder wall of female rats followed by intravenous administration of BMS cells isolated from green fluorescent protein (GFP) transgenic rats. The bladder was examined with immunohistochemistry to determine whether SDF1α would enhance migration of BMS cells to the bladder. Study 2: Following surgery of PBOO or sham in female rats, bladders were removed on days 1–14, and expression of hypoxia inducible factor 1α (HIF1α) and SDF1α were examined with real‐time polymerase chain reaction (PCR) to determine if PBOO preferentially increased their expression. Study 3: Female rats underwent PBOO or sham surgery followed by intravenous administration of GFP‐positive BMS cells. Bladders were examined with immunohistochemistry on days 1–14 to determine whether BMS cells preferentially accumulated in the bladder. Results: BMS cells were accumulated in the injection site of SDF1α but not saline in the bladder. SDF1α and HIF1α increased at day 1 after PBOO compared to sham. More BMS cells accumulated in the bladder of PBOO on day 1, and some BMS cells expressed smooth muscle phenotypes by day 14. Conclusion: SDF1α induced with ischemia/hypoxia due to PBOO is implicated in the accumulation of BMS cells in the bladder and regeneration of the bladder for PBOO.     

Double ventricular responses during extrastimulation of atrioventricular nodal reentrant tachycardia

In patients with dual atrioventricular (AV) nodal pathways,double ventricular responses to a single atrial depolarizationhave been shown to occur, but virtually only during a trialpacing in sinus rhythm. We report on a patient with a slow-fastform of AV nodal reentrant tachycardia who exhibited doubleventricular responses following extrastimulation during AV nodalreentrant tachycardia. The phenomenon of double ventricularresponses during the tachycardia was demonstrated by ex trastimulationfrom the proximal coronary sinus. Retrograde unidirectionalblock in the slow pathway, and an anterograde effective refractoryperiod that was shorter in the fast pathway than that in theslow pathway, are suggested.     

Class IC Antiarrhythmic Drugs, Flecainide and Pilsicainide, Produce ST Segment Elevation Simulating Inferior Myocardial Ischemia

ST Elevation with Flecainide and Pilsicainide . Flecainide and pilsicainide, Class IC antiarrhythmic drugs with slow kinetics, were administered to a 64-year-old man experiencing ventricular tachycardia. Both drugs suppressed the arrhythmia, but caused ST segment elevation in leads II, III, and aVF. No evidence of ischemic heart disease was detected. Withdrawal of the drugs eliminated the ST change. Because these drugs frequently are used to treat tachyarrhythmias in patients who may present with chest pain, this rare ECG manifestation of Class IC drugs should he recognized to avoid misdiagnosis of acute interior myocardial infarction.