A FAMILIAL SYNDROME OF CARDIAC MYXOMAS, MYXOID NEUROFIBROMATA, CUTANEOUS PIGMENTED LESIONS, AND ENDOCRINE ABNORMALITIES

Abstract A family syndrome of cardiac myxomas, myxoid neurofibromata, cutaneous pigmented lesions, and endocrine abnormalities is described. Three cases from a family of four are presented. All had cutaneous pigmented lesions. The mother had left and right atrial myxomata, her daughter a left ventricular myxoma, subcutaneous myxoid neurofibromata, and mammary fibroadenosis, and her son has no evidence of cardiac myxoma. Elevated circulating levels of insulin-like growth factors in the one family member tested raises the possibility of abnormal stimulation of somatic growth and may be linked to development of soft tissue neoplasms in these patients.     

Independent folding of autolytic fragments of thermolysin and their domain-like properties

High molecular weight autolysis products from thermolysin have been isolated and identified. The primary fragments correspond to residues 1 to 187–204 (21kD) and residues 187–204 to 316 (12kD), respectively. The fragments are both capable of independent refolding upon removal of denaturant. On the basis of these results, we suggest that the first step in the unfolding pathway of thermolysin involves unfolding of an interdomain region and domain separation. Bound calcium ions at sites 1, 2 and 4 play a major role in protecting the protein against both autolysis and unfolding, probably by stabilizing the interdomain region and enhancing domain-domain interactions.     

Symptoms and correlates of anabolic-androgenic steroid dependence

Forty-nine male weight lifters, all users of anabolic-androgenic steroids (AASs), completed an anonymous, self-administered questionnaire to investigate addictive patterns of use. At least one DSM-III-R symptom of dependence was reported by 94% of the sample. Three or more symptoms, consistent with a diagnosis of dependence, were reported by 57%. Dependent users (n=28) could be distinguished from non-dependent users (n=21) by their use of larger doses, more cycles of use, more dissatisfaction with body size, and more aggressive symptoms. Multiple regression analysis revealed that dosage and dissatisfaction with body size were the best predictors of dependent use. Patterns of other substances used, although not predictive of AAS dependence, revealed very low cigarette use and at the same time high alcohol consumption. These data support the notion that AASs are addicting, and suggest that dissatisfaction with body size may lead to dependent patterns of use. The implications for both prevention and treatment are discussed.     

Heart rate increment analysis is not effective for sleep-disordered breathing screening in patients with chronic heart failure

Frequency domain analysis of heart rate variation has been suggested as an effective screening tool for sleep-disordered breathing (SDB) in the general population. The aim of this study was to assess this method in patients with chronic congestive heart failure (CHF). We included prospectively 84 patients with stable CHF, left ventricular ejection fraction (LVEF) <45% and sinus rhythm. The patients underwent polygraphy to measure the apnoea/hypopnoea index (AHI) and simultaneous Holter electrocardiogram monitoring to measure the power spectral density of the very low frequency component of the heart rate increment, expressed as the percentage of total power spectral density [% very low frequency increment (%VLFI)]. %VLFI could be determined in 54 patients (mean age, 52.8 ± 12.3 years; LVEF, 33.5 ± 9.8%). SDB defined as AHI ≥15 h⁻¹ was diagnosed in 57.4% of patients. Percent VLFI was not correlated with AHI ( r  =   0.12). Receiver-operating characteristic curves constructed using various AHI cut-offs (5–30 h⁻¹) failed to identify a %VLFI cut-off associated with SDB. The 2.4% VLFI cut-off recommended for the general population of patients with suspected SDB had low specificity (35%) and low positive and negative predictive values (35% and 54%, respectively). Heart rate increment analysis has several limitations in CHF patients and cannot be recommended as an SDB screening tool in the CHF population.     

High-Density Circumferential Pulmonary Vein Mapping with a 20-Pole Expandable Circular Mapping Catheter

The differentiation of pulmonary vein (PV) electrograms from atrial far-field signals during PV isolation (PVI) for atrial fibrillation (AF) may be difficult. In addition, owing to highly variable PV ostial sizes, current fixed-diameter circular PV mapping catheters may not yield optimal electrograms. We evaluated an expandable, circular 15–25 mm diameter, 20-pole mapping catheter for PV mapping during sustained AF in 25 patients. After selective PV angiography to define the ostial position and size, the catheter was introduced into each PV and withdrawn to the most stable proximal position, with optimal wall contact ensured by progressive loop expansion. At each PV ostium, electrograms recorded at high resolution (HR) were compared with those recorded at a resolution similar to that of a standard 10-pole Lasso catheter. After PVI performed during ongoing AF, the presence of residual far-field potentials (FFP) under both set-ups was compared. We mapped 97 PV, including 4 pairs with common ostia. In the HR recordings, the PV potentials had greater amplitude (0.5 ± 0.1 vs 0.3 ± 0.1 mV, P = 0.001) and fragmentation, whereas left atrial FFP were minimized. After successful isolation of all PV, FFP were observed in 33% of left superior and 28% of left inferior PV on the HR recordings, compared to 66% and 61%, respectively under normal resolution. Catheter stability and optimal wall contact, in combination with HR electrograms can optimize circumferential PV mapping during AF and improve the discrimination of FFP postablation.     

Incidence and Prevention of Cardiac Tamponade Complicating Ablation for Atrial Fibrillation

Cardiac tamponade complicating catheter ablation of atrial fibrillation (AF) occurs in approximately 1% of pulmonary vein isolation (PVI), and up to 6% of linear ablation procedures. We reviewed 348 consecutive AF ablation (including repeat) procedures over 1 year, which all included PVI, with additional linear lesions at the mitral isthmus in 73%, and cavotricuspid isthmus (CTI) in 76%. An irrigated-tip ablation catheter was used, with power limited to 25–35 W for PVI and 45–60 W for linear lesions. Tamponade occurred in seven men and three women (2.9% of the population) during the creation of linear ablation lesions. Mechanical perforations occurred in two patients, and "popping" during radiofrequency (RF) energy delivery at the mitral isthmus in six, and at the CTI in two patients. Peak RF power was significantly higher in patients with than without tamponade (53 ± 4 W vs 48 ± 7 W; P = 0.02), and was greater than 48 W in all cases of "popping." In the following year, RF power for linear ablation was limited to ≤42 W. Among 398 procedures, tamponade occurred in four patients (1.0%; P = 0.047 vs first year), three from "popping" and one from mechanical trauma. Procedural success rate remained the same despite reduction of power. Risk of tamponade was highest during linear ablation, mainly associated with high energy delivery and "popping." Reducing the energy limited, though did not eliminate this complication.     

Percutaneous transhepatic catheterization of the portal venous system

During recent years, percutaneous transhepatic catheterization of the portal venous system has become the most accurate procedure for investigation of the portal system. The procedure can be performed under local analgesia, is relatively simple, and complications are rare. The success rate is high, approximately 90%, especially when the liver hilum is localized by ultrasonography prior to catheterization. The free portal pressure can be measured. Selective catheterization of all portal tributaries can be performed. The indications are: portography in patients with cirrhosis of the liver and portal hypertension for delineation of collateral vein systems including gastro-oesophageal varices; visualization of veins that may be used for portosystemic shunt operations; postoperative control of shunt patency; diagnosis of portal and hepatic vein thrombosis; localization of stenosis in the portal vein system; pre-operative evaluation of patients with tumours in the biliary tract and pancreas; obliteration of bleeding oesophageal varices; and verification and localization of endocrine pancreatic tumours making curative resection possible. Further, transhepatic catheterization of the portal system may be used in research on the development of portal hypertension, collateral veins, variceal bleeding, and for haemodynamic, metabolic and pharmacologic studies in the gastrointestinal tract.     

Clinicopathological correlates of CD56 expression in multiple myeloma: a unique entity?

Summary. Prior studies have suggested that loss of plasma cell CD 5 6 expression in multiple myeloma defines a unique patient subset and that CD56 expression reliably discriminates between monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). We conducted a study of 68 untreated patients with MM from a single institution to define the clinicopathological correlates of CD56 expression. We find CD56 expression in 55% of MM. Lack of CD56 expression does not define a unique clinicopathological or prognostic entity in MM. Strong CD 5 6 expression can also be found in MGUS and does not help to distinguish from MM.