Internal Cardioversion of Chronic Atrial Fibrillation in Patients

Transvenous internal cardioversion of chronic AF using a right atrium (RA) coronary sinus (CS) vector requires more energy than cardioversion of paroxysmal AF. Chronic AF is not terminated in 25% of patients using biphasic shocks up to 10 J. We therefore evaluated efficacy, safety, and tolerability of internal cardioversion using a "unipolar' configuration (RA to skin patch) and biphasic shocks in patients with long-lasting AF and different heart disease. In each patient, biphasic R have synchronous shocks were delivered between a large defibrillating surface area electrode in the RA and a skin patch in the left prepectoral position. Defibrillation protocol started with a test shock of 0.4 J. Shocks were repeated and increased until termination of AF or a maximum of 34 J. Sedation was used when the patient described the shock as painful. This study included 11 patients with a mean age of 67 ± 8 years (range 56–83). AF duration was ± 1 month in all patients with a mean duration of 11 ± 11 months (range 2–36). Underlying heart disease was present in all patients and the mean left atrial dimension was 43 ± 9 mm (range 26–57). AF was terminated in 10 of 11 patients (91 %) with a mean delivered energy of the successful shocks of 18.7 ± 8.7 J (median energy 16.9 J; range 7.3–32.5) and a mean leading edge voltage of 564 ± 129 V. The mean shock impedance at the defibrillation threshold was 71 ± 13 Ω, (range 59–103). A total of 131 shocks were delivered without any complication and proarrhythmia episodes. We conclude that low energy "unipolar" internal cardioversion is a simple, safe, and effective technique for termination of chronic AF in patients with heart disease. The procedure is often tolerated under light sedation.     

Extracorporeal photochemotherapy induces apoptosis of infiltrating lymphoid cells in patients with mycosis fungoides in early stages. A quantitative histological study

Extracorporeal photochemotherapy (ExP) is a well-tolerated new form of chemoimmunotherapy, which is considered to be effective for cutaneous T-cell lymphoma (CTCL) and the treatment of choice for Sézary syndrome. Improvements have also been seen in patients with non-erythrodermic mycosis fungoides (MF) in the early stages, even when tumour cells are not detectable in the peripheral blood. In this study, we used ExP as a monotherapy in seven patients who had early stage (Ib) MF, and who were no longer responsive to or had contraindications for other therapies. We observed a clinical improvement in the disease after 12 months of treatment: one patient showed a complete response, five a partial response, and one remained stable. In each patient we compared skin biopsies of large plaque lesions before and after the treatment. We undertook a histological evaluation of the infiltrate. The lymphoid cell proliferation and death rates were quantified using the following parameters: lymphoid cell density (LCD), Ki67+ lymphoid cell nuclei percentage (Ki67+ Lcn percentage), and apoptotic index (AI). Significant decreases in the lymphoid cell infiltrate and in cell proliferation, and a significant increase in AI were observed after therapy. The mean LCD decreased from 187 ± 33 to 34 ± 17·7, Ki67+ Lcn mean percentage decreased from 16·9 ± 3·9 to 4·9 ± 2·4, and the AI mean value increased from 0·05 ± 0·03 to 2·41 ± 1·54. Our results suggest a role for apoptosis in the improvement of the skin lesions and are in line with some reports on the mode of action of ExP. Although the way in which ExP works needs to be clarified further, it does seem to stimulate a CD8+ cell-mediated anticlonotypic activity against circulating pathogenic clones. Furthermore, a release of tumour necrosis factor α (TNF-α) by circulating monocytes has been demonstrated after ExP. Both are known to induce cell death by apoptosis.     

Transthoracic Sensor for Noninvasive Assessment of Left Ventricular Contractility: Validation in A Minipig Model of Chronic Heart Failure

Background: Invasively measured left ventricular (LV) dP/dt is the accepted standard for measuring acute and chronic directional changes in LV contractility. Recently, we developed a noninvasive force sensor based on an accelerometer positioned on the chest, which measures the vibrations generated by isovolumic myocardial contraction. The aim of this paper was to compare noninvasive (accelerometer) versus invasive (LV dP/dt) indices of myocardial contractility in a chronic minipig model of pacing‐induced heart failure (HF). Comparative assessment was performed both at rest and following dobutamine infusion. Methods: In adult male minipigs (n = 6), LV contractility was simultaneously assessed both invasively (LV dP/dt, Millar catheter) and noninvasively (accelerometer) at rest and following dobutamine (up to 7.5 mcg/kg/min), both before and after development of HF by pacing the LV at 180 beats/min for 3 weeks. Results: Invasive and noninvasive assessments were obtained in 24 conditions (12 at rest and 12 after dobutamine infusion). Sensor‐based cardiac force changes were significantly related to positive peak LV dP/dt_max changes following dobutamine infusion both in normal (r = 0.88, P < 0.001) and failing heart (r = 0.89, P < 0.001). The force‐frequency relation showed a tight correlation between invasive and noninvasive assessment (r = 0.68, P = 0.02). Conclusions: The force‐frequency relation can be assessed noninvasively by a transthoracic sensor based on an accelerometer. The method can efficiently detect the development of resting dysfunction and the contractile reserve at different HF steps, with potential for wearable HF monitoring. (PACE 2010; 795–803)     

Relationship between fasting insulin and cardiovascular risk factors is already present in young men: the Verona Young Men Atherosclerosis Risk Factors Study

The associations between fasting plasma insulin concentration and risk factors for cardiovascular diseases were examined in 979 18-year-old men participating in the Verona Young Men Atherosclerosis Risk Factors Study, a cross-sectional population-based study. Body mass index (BMI), waist-to-hip ratio (WHR), plasma triglycerides and uric acid concentrations, and blood pressure values significantly increased, and the high-density lipoprotein (HDL)–total cholesterol ratio decreased, across quartiles of fasting insulin. Total and low-density lipoprotein cholesterol concentrations did not change significantly with the increase in fasting insulin levels. After adjustment for BMI, WHR, smoking, alcohol intake and physical activity, only plasma triglycerides significantly increased across insulin quartiles (F =7.1; P <0.001). However, systolic blood pressure and uric acid were close to statistical significance (P =0.06–0.07). Multiple linear regression analysis confirmed that plasma insulin was independently correlated with plasma triglycerides and, to a lesser extent, with blood pressure and uric acid concentration. This analysis pointed out that BMI was a stronger independent predictor of all cardiovascular disease risk factors than fasting insulin. When subjects were categorized according to the number of metabolic and haemodynamic disorders occurring within the same individual, subjects with multiple disorders (i.e. three or four) had higher plasma insulin levels than those with none or few disorders, even after adjusting for BMI, WHR and behavioural variables (F =4.0; P <0.01). These results indicate that hyperinsulinaemia is already associated with a cluster of cardiovascular disease risk factors in young adulthood, the strongest independent association being with plasma triglycerides.