Clinical experience with a new detection algorithm for differentiation of supraventricular from ventricular tachycardia in a dual-chamber defibrillator

INTRODUCTION: Inadequate therapy for supraventricular tachyarrhythmias (SVT) is a frequent problem of implantable cardioverter defibrillators (ICD). Dual-chamber ICDs have been developed to improve discrimination of SVT from ventricular tachycardia (VT). We investigated the positive predictivity, sensitivity, and specificity of a new algorithm, the SMART detection trade mark algorithm, incorporated in the Phylax AV (Biotronik) dual-chamber ICD. METHODS AND RESULTS: Two hundred nine patients (185 men, age 64 +/- 11 years) received a Phylax AV ICD with SMART detection trade mark activated. In 138 of these patients, 1,245 sustained tachycardia episodes with a detailed electrogram were stored in the device during a follow-up period of 10 +/- 6 months. Episodes were correctly classified as ventricular fibrillation (VF, n = 178) in 52 patients, VT (n = 641) in 98 patients, and SVT (n = 385) in 48 patients by the algorithm. Forty-one true SVT episodes (3.3%) were misclassified as VT: atrial fibrillation (n = 7) and flutter (n = 1), sinus tachycardia (n = 12), and other SVT (n = 21). The positive predictivity for VF/VT was 94.5% (95% CI 92.7-95.8) uncorrected and 94.5% (95% CI 92.9-95.8%) corrected with the generalized equation estimation (GEE) method. The positive predictivity for SVT was 100%. The specificity was 88.9% (95% CI 85.6-91.6%) uncorrected and 89.0% (95% CI 85.6-91.6%) corrected with the GEE method with a sensitivity of 100%. CONCLUSION: The SMART detection trade mark algorithm was safe and reliable for the detection of all ventricular tachycardias. Although its specificity was high, it should be improved with regard to SVT to avoid inappropriate ICD therapies.     

Treatment and prophylaxis of infected forms and complications of pancreatic necrosis with the use of regional intraarterial infusion

The aim of the investigation was to study the variants of the course of sterile and infected pancreatonecrosis, the character of the developing complications depending on the state of organic blood circulation in the pancreas and the influence of its correction upon the outcomes of the disease. The material of examination and treatment of 121 patients with pancreatonecrosis was analyzed. Complex treatment of 51 of the patients included the method of regional intraarterial infusion. Celiacography and CT with the intraarterial contrast reinforcement have revealed that in 35 (68.6%) patients there were symptoms of "perfusion block" of the pancreas of different degrees which was due to spasm, thrombosis of the vessels and impairment of the regional microcirculation. Differentiated approach to the composition of the infusate resulted in arrest of phenomena of "perfusion block" of the pancreas in 24 out of 35 patients. As a whole, using this method allowed to reduce the number of purulent complications, primary open operations and reoperations. Lethality in the group with infusion was 9.8%.     

Clinical manifestation of hypertension in citizens of siege Leningrad (1941-1944). Retrospective analysis of archive materials

AIM: To characterize peculiarities of arterial hypertension course in citizens of sieged Leningrad. MATERIALS AND METHODS: 2000 case records of hypertensive patients treated in 6 hospitals of sieged Leningrad have been analysed. RESULTS: Arterial hypertension (AH) was verified as the basic disease in 69 cases. Of them, only 47 patients were eligible for analysis. Mean age of the patients was 45 years. AH duration before hospitalization was less than 1 year in 35% of the cases. Hypertensive crises, hypertensive angiopathy, cerebral atherosclerosis, cardiac hypertrophy were documented in 25, 15, 15 and 64% of the cases, respectively. In hospital, no specific antihypertensive therapy was given. At the discharge, systolic blood pressure decreased significantly, diastolic blood pressure decreased insignificantly. CONCLUSION: Clinical data evidence for rapid affection of target organs in hypertensive subjects exposed to unfavourable conditions of the war time.     

Changes in the urogenital organs in traumatic strictures of the urethra

The urogenital tract has been examined in 35 patients who required 3 or more years of therapy. A range of studies revealed a short urethral stricture in 11, long urethral stricture in 26, megalocystis in 6, domicile urinary bladder in 2 and bladder diverticulosis in 6 patients. Simple and diuretic excretory urography showed normal bilateral renal function in 5, moderately impaired function in 14 and severe loss of function in 6 patients. Single-kidney functional impairment was seen in 10 patients. Over 504 of patients showed prolonged urographic retention of urine in the pelvis and ureter. Bilateral ureterohydronephrosis was found in 3 and unilateral one in 3 patients. Descending, ascending and micturitional urethrocystography revealed urinary reflux into the prostate (n = 13), seminiferous ducts (n = 3), seminal vesicles (n = 4) and ureters (n = 4). Vasovesiculographic sizes and shapes of the seminal vesicles were normal in 2 patients while the vesicles were uni- or bilaterally dilated or constricted in other patients. The treatment was operative in 34 patients. Histological examination of scars and resected tissues showed fibrous sclerotic lesions in the prostate and suppurative inflammatory and fibrous lesions in seminal vesicular walls. With long treatment of urethral strictures, micturition disorders were superimposed by reflux of infected urine into the prostate, seminal vesicles and ureters, inducing inflammation and functional abnormalities; these caused shrinkage and compression of the posterior urethra, bladder cervix, intramural and prevesical ureteral segments, resulting in chronic renal failure. An early and radical plastic operation on the urethra may prevent the mentioned disorders.     

Inhibition of caffeine contractures of slow rat muscles by urea and its derivatives

Contractures induced by rapid cooling of rat soleus muscles in the presence of low concentrations of caffeine (2–3 mmol.1^–1) have been studied. Urea, methylurea and 1,3-dimethylurea inhibit reversibly these contractures as well as caffeine contractures (20 mmol.1^–1, 30°C) but do not affect twitches. This finding leads support to the idea of the existence of differentmechanisms activating contraction in response to caffeine action or deplorization.