Wolff-Parkinson-White pattern on alternate beats: What is the mechanism?

The Holter electrocardiogram from an asymptomatic man shows intermittent preexcitation. At the lowest rates all the QRS complexes display a WPW pattern. As the rate increases, preexcitation fails to occur and all the QRS complexes become persistently narrow. With a further increase in sinus rate the WPW occurs on alternate beats and this alternation is maintained for a while. A careful analysis of the accessory pathway conduction in relation to sinus-cycle length and morphology of the prior beat strongly supports the supernormal conduction through the Kent bundle associated with linking as the key mechanism underlying the preexcitation on alternate beats.

Assessment of implant position after total knee arthroplasty by dual-energy computed tomography.

BACKGROUND: Correct alignment of prosthetic components is the most important factor for the success of total knee arthroplasty (TKA). Dual-energy computed tomography (DECT) may be a reliable method in determining implant position after TKA. PURPOSE: To evaluate the accuracy and reproducibility of DECT in determining implant position after TKA. MATERIAL AND METHODS: Institutional review board approval was obtained. Forty-five patients (age 75.2 ± 6.4 years) prospectively underwent TKA at our institution between May and December 2012. DECT was performed 1 year after surgery, using an alignment similar to a standing position and generating images at an extrapolated energy of 120 kVp, in order to reduce metal artifacts. Implant position was evaluated by two independent readers. Intra- and inter-observer agreements were calculated. DECT measurements on implant position were compared with the preoperative planning based on radiographs. Additional clinical and DECT findings were taken into account. RESULTS: Metal artifact reduction was judged satisfactory in all cases. Regarding implant position assessed with DECT, good to excellent intra-observer (k: 0.74-0.87 and k: 0.75-0.88, respectively), and inter-observer agreement (k: 0.72-0.82) were found. In the comparison with preoperative planning, the widest limits of agreement were within 3.9° for the sagittal orientation of tibial component. A single patient with postoperative knee pain and stiffness had periprosthetic osteopenia, quadriceps femoris tendon calcifications, articular effusion, and excessive intrarotation of the femoral component. CONCLUSION: DECT is an accurate and reproducible tool for determining implant position after TKA.

Alert-LDL-2: adherence to guidelines and goals attainment in the treatment of diabetic patients with dyslipidemia.

BACKGROUND: Type 2 diabetes mellitus is associated with a cluster of lipid and apolipoprotein abnormalities which increase the risk for atherosclerotic cardiovascular disease. The aim of this study was to evaluate the adherence to guidelines-oriented dyslipidemia treatment in diabetic patients and to assess the efficacy of a territorial goal-oriented program. METHODS: One thousand seventy-one diabetic patients at very high cardiovascular risk were enrolled in this prospective study. They performed a clinical-laboratory follow-up program, received lifestyle recommendations and optimization of their antihyperlipidemic therapies. At the beginning and the 3-month follow-up visit, LDL-c data were collected, and further therapies were prescribed to the patients that did not reach the target. After 12 month follow-up, LDL-c data were collected again. RESULTS: Diabetic patients significantly improved mean LDL cholesterol levels during one-year follow-up (LDLc mean value 135 mg/dL at baseline, 60 mg/dL at the end of the study), obtaining a greater reduction compared to non-diabetic patients participating in the same program. Accordingly, the percentage of patients that reached the lipid target was significantly higher in diabetic patients after 3-months and 12- follow-ups (P<0.05). Diabetic patients assuming statins, both in monotherapy and in combination with ezetimibe, increased during the follow-up (74.1% at the enrolment vs. 88.2% one year later). GLP1ra-treated patients achieved the greatest reduction in cholesterol levels compared to baseline. CONCLUSIONS: The results of the study recommend encouraging strategies and appropriate treatments to achieve a targeted lipid profile in diabetic patients at very high cardiovascular risk.

ALERT-LDL: adherence to guidelines in the treatment of patients with dyslipidemia.

The association between LDL-c levels and cardiovascular outcomes suggests tailoring lipid-lowering therapies according to total cardiovascular risk. We aimed to evaluate the adherence to guidelines-oriented dyslipidaemia's treatment in an outpatient population referring to ARCA cardiologists, and assess the efficacy of treatment's optimization for each specific level of risk. Three thousand seventy-five patients enrolled in this prospective study were classified according to cardiovascular risk category, and their therapies were optimized. At the beginning and the 3 month follow-up visit, LDL-c data were collected, and further therapies were prescribed to the patients that did not reach the target. A significant LDL-c reduction was observed in all subgroups at different cardiovascular risk at the end of the study (p < 0.05). The number of patients assuming statins, both in monotherapy and in combination with ezetimibe, increased during the follow-up (63% at the enrollment vs 89% after 12 months). At the enrollment, only 1.4% of patients were treated with PCSK-9 inhibitors while after 12 months the percentage increased both in high (5.8%) and very high-risk (18.4%) patients. At the beginning of the study, only 698/3075 patients (22.7%) reached lipid targets. At the end of the study, carried out by the referring cardiologists in the pertaining healthcare districts and specifically aimed to control the lipid profile, the percentage of patients on target increased in all risk categories (68.5%). Our results suggest carefully implementing measures that encourage outpatients and their cardiologists to achieve the targeted lipid profile according to cardiovascular risk.

Implant positioning in TKA: comparison between conventional and patient-specific instrumentation.

The number of total knee arthroplasty (TKA) procedures continuously increases, with good to excellent results. In the last few years, new surgical techniques have been developed to improve prosthesis positioning. In this context, patient-specific instrumentation is included. The goal of this study was to compare the perioperative parameters and the spatial positioning of prosthetic components in TKA procedures performed with patient-specific instrumentation vs traditional TKA. In this prospective comparative randomized study, 15 patients underwent TKA with 3-dimensional magnetic resonance imaging (MRI) preoperative planning (patient-specific instrumentation group) and 15 patients underwent traditional TKA (non-patient-specific instrumentation group). All patients underwent postoperative computed tomography (CT) examination. In the patient-specific instrumentation group, preoperative data planning regarding femoral and tibial bone resection was correlated with intraoperative measurements. Surgical time, length of hospitalization, and intraoperative and postoperative bleeding were compared between the 2 groups. Positioning of implants on postoperative CT was assessed for both groups. Data planned with 3-dimensional MRI regarding the depth of bone cuts showed good to excellent correlation with intraoperative measurements. The patient-specific instrumentation group showed better perioperative outcomes and good correlation between the spatial positioning of prosthetic components planned preoperatively and that seen on postoperative CT. Less variability was found in the patient-specific instrumentation group than in the non-patient-specific instrumentation group in spatial orientation of prosthetic components. Preoperative planning with 3-dimensional MRI in TKA has a better perioperative outcome compared with the traditional method. Use of patient-specific instrumentation can also improve the spatial positioning of both prosthetic components.