Frequency and Output-Dependent Change in Conduction Over Slow Pathways in a Patient with Sustained Ventricular Tachycardia Unrelated to Coronary Artery Disease

In a patient with sustained ventricular tachycardia, we obtained two different paced QRS morphologies from a single pacing site. In one QRS morphology the stimulus to the QRS complex was long, 150 msec, and in the other it was 100 msec. At the paced cycle length of 600 msec and the stimulus output of 4 V, one QRS morphology with the stimulus to the onset of QRS activation (St-QRS) interval of 150 msec was observed. At the paced cycle length of 400 msec, the other QRS morphology with a St-QRS interval of 100 msec was observed alternatively with the former. At the paced cycle length of 353 msec or 316 msec, the latter with a shorter St-QRS interval was exclusively observed. When the stimulus output was increased from 4 to 10 V, keeping with the paced cycle length at 400 msec, the St-QRS interval was shortened from 100 to 80 msec. For the two QRS morphologies with two St-QRS intervals, two slowly conducting pathways would be responsible. The site of the block in the faster pathway must be located at the proximity of the pacing site and the conduction at a shorter paced cycle length would be explained by "supernormal conduction."     

THE IMPACT OF DIABETES MELLITUS ON THE PROGNOSIS OF ALCOHOLICS

In this study, the mortality of clinically treated Japanesealcoholics with diabetes mellitus was analysed. Fifty-one diabeticalcoholics without liver cirrhosis (DM), 23 diabetic and cirrhoticalcoholics (DM LC), 44 cirrhotic alcoholics without diabetes(LC), and 354 alcoholics without either complication (AL) admittedto the National Institute on Alcoholism in 1985 were studied.Thirty-seven diabetics required insulin treatment, and 12 oralhypoglycemic agents. The 4.4-year survival and drinking statusafter discharge were studied in 1990. Stepwise logistic regressionanalysis showed that the estimated odds for death increased8.10, 4.38, 3.70, and 3.27 times for the subjects with the alcoholmisuse after discharge, DM, DM LC, and LC, respectively. The4.4-year survival rate of alcoholics who continued misusingalcohol was much lower in DM (26%, P < 0.0005) and LC (35%,P < 0.0001) than in AL (73%). The survival rate of thosewho stopped misusing alcohol was significantly higher in DM(90%, P < 0.0001), LC (88%, P < 0.0001) and AL (94%, P< 0.0005) than those who continued misusing alcohol. Therewas no significant difference in the survival rate between thealcoholics with DM LC who continued misusing alcohol (50%) andthose who stopped misusing alcohol (73%). In the dead patients,56% of DM died unexpectedly or suddenly, whereas 71% of LC diedof liver failure after hospitalization. These results suggestthat diabetic alcoholics should be intensively educated forabstinence.     

Signet-ring cell carcinoma of the prostate effectively treated with maximal androgen blockade

Primary signet-ring cell carcinoma (SRCC) of the prostate is very rare and has a poor prognosis, even when treated with aggressive therapy. We report herein a case of a 72-year-old man with prostatic SRCC. The patient had a tumor that extended directly to the rectum. Maximal androgen blockade was started and 20 months later, the patient was alive without evidence of recurrence. The present case of prostatic SRCC responded well to medical therapy, however, tumors can recur after a long period of time. Therefore, adjuvant therapy is recommended.     

Electroanatomical Mapping‐Guided Endocardial and Epicardial Ablation of Sustained Ventricular Tachycardia Originating From Alcohol Septal Ablation‐Induced Scar in a Patient With Hypertrophic Obstructive Cardiomyopathy

Ventricular Tachycardia After Alcohol Septal Ablation. A 76‐year‐old female developed 2 different ventricular tachycardias (VTs) 5 years after alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy. VT#1 was a small macroreentry at the anterior border of the low‐voltage zone, suggesting the ASA‐scar and eliminated by endocardial ablation at a site recording fractionated potentials covering the mid‐diastolic and presystolic periods. VT#2 was a focal VT and eliminated by epicardial cryoablation at the basal posterior left ventricle, suggesting the posterior border of the ASA‐scar. Using the electroanatomical mapping, we demonstrated that the mechanism of the VTs was reentry at the edge of the ASA‐scar. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1296‐1299, November 2010)     

Comparative study of the stability of the folding intermediates of the calcium-binding lysozymes

Unfolding profiles of two calcium-binding lysozymes, equine milk lysozyme and pigeon egg-white lysozyme, were obtained by circular dichroism and proton NMR measurements. Equine lysozyme unfolds through a stable molten globule intermediate. The molten globule of equine lysozyme was characterized as more ordered than that of bovine α-lactalbumin. On the other hand, pigeon lysozyme unfolds by a two-state mechanism and the intermediate could not be observed in guanidine or thermal unfolding, the same as with conventional non-calcium-binding lysozymes. Thus, from the point of view of the unfolding profile, equine lysozyme belongs to the group of α-lactalbumin, but pigeon lysozyme belongs to the conventional lysozyme group.     

Stromal cell-derived factor-1α improves infarcted heart function through angiogenesis in mice

BACKGROUND: Local delivery of stromal cell-derived factor-1alpha (SDF-1) has been demonstrated to improve hind limb ischemia through enhanced neovascularization in animals. It was hypothesized that local administration of SDF-1 also contributes to neovascularization of ischemic heart. METHOD: Acute myocardial infarction was created by left coronary artery ligation in C57BL/6J mice. Immediately after infarction induction, mice were treated by injection directly into the center of ischemic myocardium either with saline (control group) or SDF-1 (SDF-1 group). Cardiac function was measured on echocardiogram 2 and 4 weeks after infarction. On week 4 mice were killed to evaluate infarction size and capillary vessel density. To determine the contribution of bone marrow cells to angiogenesis, the same procedures were performed on C57BL/6J chimeric mice reconstituted with green fluorescent protein-positive bone marrow cells. RESULTS: Fractional shortening was greater in the SDF-1 group at 4 weeks (0.31 +/- 0.06% vs 0.23 +/- 0.03%, P = 0.037). The infarct area was smaller in the SDF-1 group compared to the control group (9.31 +/- 2.76% vs 18.07 +/- 5.69%, P = 0.028). Green fluorescent protein-positive cells accumulated predominantly at the peri-infarction site, and were located with the capillary vessels. Capillary vessel density was significantly increased in the SDF-1 group (13.08 +/- 4.11 vessels/mm(2) vs 34.50 +/- 7.59 vessels/mm(2), P = 0.014). CONCLUSIONS: SDF-1 protects against deterioration of cardiac function after acute myocardial infarction by promoting angiogenesis. The safety and long-term prognosis of this treatment remains to be determined.     

Electrophysiologic Evaluation of Asymptomatic Patients with the Wolff-Parkinson-White Pattern

In the past 4 years, 34 asymptomatic patients with the Wolff-Parkinson-White (WPW) pattern underwent electrophysiologic study. The effective refractory period (ERP) of antegrade conduction over the accessory pathway was 288 +/- 29 msec. In three asymptomatic patients (9%), the antegrade ERP of the accessory pathway was shorter than 250 msec. The antegrade ERP of the accessory pathway became shorter than 250 msec in an additional 12 of 22 (55%) patients after isoproterenol administration. Nineteen (56%) of the asymptomatic patients showed the absence of retrograde conduction over the accessory pathway even after isoproterenol administration. The rate of induction of orthodromic reciprocating tachycardia in the asymptomatic WPW patients was 15% (5/34), which was significantly lower than that in the symptomatic patients. These data suggest that in the asymptomatic patients, the absence of retrograde conduction over the accessory pathway is the reason they remained asymptomatic, free of reciprocating tachycardia. However, even in the asymptomatic patients, some had the accessory pathway in which antegrade ERP was shorter than 250 msec. They may result in rapid ventricular conduction over the accessory pathway when atrial fibrillation develops.     

Experimental Study About Removal of the Implanted Tined Polyurethane Ventricular Lead by Radiofrequency Waves Through the Lead

Polyurethane pacemaker leads are widely used nowadays. However, only a few studies have been done to investigate the fixation mechanism of polyurethane leads. To elucidate how pacemaker leads are fixed at the early phase after implantation, polyurethane-insulated tined ventricular leads were implanted in seven mongrel dogs. One to 4 months later, tips of the leads were anchored among the trabeculae and the distal part of the leads were encapsulated by whitish fibrous tissue. It was found that not organized thrombi, but cell reaction with various stages of inflammatory cells was responsible for forming the fibrous tissue. We attempted to remove the lead by delivering radiofrequency wave through the lead. However, no lead could be removed.     

FK506 promotes liver regeneration by suppressing natural killer cell activity

We examined the mechanism of promotion of liver regeneration by tacrolimus hydrate (FK506), a potent immunosuppressant, after partial hepatectomy. The administration of FK506 significantly increased the bromodeoxyuridine (BrdU) labelling index at 36 and 48 h after 70% hepatectomy compared with the placebo group. Using the same model, we examined the effect of FK506 on the expression of hepatocyte growth factor (HGF) and transforming growth factor-β1 (TGF-β1) and found no changes in HGF and TGF-β1 mRNA expression in the liver or in the HGF protein concentration in plasma. We found that pretreatment with FK506 markedly reduced the activity and number of liver-resident natural killer (NK) cells at the time of partial hepatectomy. Our observations suggest that the promotion of liver regeneration by FK506 may be attributable to a reduction in the number of liver-resident NK cells and to inhibition of their activity.     

Prognosis of the middle-aged and aged patients with obstructive sleep apnea syndrome

Abstract The long-term natural course of obstructive sleep apnea syndrome (OSAS) is studied in order to determine whether severity of nocturnal oxygen desaturation associated with apnea/hypopnea, body mass index (BMI), and hypertension influence survival in young (<40 years), middle-aged (40–64 years), and aged (65 years) using a questionnaire survey. One hundred and forty-eight patients with OSAS aged 17–78 years (136 men, 12 women, mean 52.0±12.3 yean), who were diagnosed by standard polysomnography (PSG) between 1983 and 1993, participated in the study. The survey revealed 15 deaths and 101 survivors; 32 subjects could not be located. The survival rate was 71.4% (95% confidence interval:55.6–87.2%). The survival rate in patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (87.6%). In the young group, only one death (a 19–year-old woman) occurred unexpectedly during sleep. The patient showed an apnea/hypopnea index (AHI) of 33 per h and the length of time that the nocturnal oxygen saturation (SaO₂) fell below 90% (time of SaO₂ < 90%) of 205 min. The survival rate in middle-aged patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (79.2 vs 91.0%), but this pattern was not seen among the aged. Time of SaO₂ <90% was significantly longer in the middle-aged patients than in the aged patients, but AHI did not differ between the two groups. Moreover, it was significantly correlated with AHI in middle-aged patients, but not in the aged patients. The survival rate was significantly lower in patients with hypertension than in the patients without such complications in the middle-aged group (57.9 vs 90.4%). Cox proportional-hazard regression model including age, hypertension, BMI, AHI, lowest SaO₂, and time of SaO₂ <90% showed that hypertension was only significantly associated with lower survival rate in total group and middle-aged patients, but not in the young or aged patients. The prognosis in patients with OSAS may differ among the generations. The prognosis in the middle-aged population may depend on the role of OSAS on the complications of hypertension or severity of oxygen desaturation, but not on AHI only.