Giuseppe Francavilla

Novel Electrocardiographic Parameters of Altered Repolarization in Uncomplicated Overweight and Obesity

In addition to well‐known electrocardiographic measurements, as QT, QT dispersion, and QT apex dispersion, new parameters such as Tpeak‐Tend, Tpeak‐Tend dispersion, and Tpeak‐Tend/QT ratio have been recently introduced as indexes of increased arrhythmic risk. The aim of the present study was to test, in overweight and obese subjects not affected by conditions of comorbidity, the aforementioned markers of ventricular repolarization. We studied 60 athletic subjects with normal body weight (21 females and 39 males, BMI between 19 and 24, mean BMI 22.0 ± 2.0 kg/m2, aged 14–64 years, mean age 32 ± 13.59) and 60 sedentary and overweight/obese subjects (34 overweight and 26 obese, 22 females, and 38 males, BMI between 26 and 55, mean BMI 30.7 ± 5.7 kg/m2, aged 14–64, mean age 38 ± 14.49). Each subject underwent anthropometric measurements and a 12‐lead electrocardiogram, from which the following different parameters were calculated: QT, corrected QT, QT dispersion, QT apex dispersion, Tpeak‐Tend, Tpeak‐Tend dispersion and Tpeak‐Tend/QT ratio were calculated. The aforementioned repolarization markers resulted, respectively: 340.2 ± 25.1, 373.8 ± 25.9, 29 ± 16.2, 23.5 ± 14.6, 87.3 ± 12.8, 26.5 ± 16.8, and 0.22 ± 0.03 ms in control subjects and 362.5 ± 28.5, 397.4 ± 35.4, 34.5 ± 16.8, 30.7 ± 16.3, 90.5 ± 15.2, 27 ± 17.1, and 0.22 ± 0.04 ms in overweight/obese subjects. Neither uncomplicated obesity nor overweight were associated with a statistically significant difference in QT dispersion, QT apex dispersion, Tpeak‐Tend, Tpeak‐Tend dispersion, and Tpeak‐Tend/QT ratio; QT and corrected QT were the only parameters that showed statistically significant variations between normal weight and overweight/obese subjects.

Behavior of repolarization variables during exercise test in the athlete's heart.

Background: T peak–T end, QT peak/QT ratio and T peak–T end/QT ratio are markers able to test myocardial repolarization homogeneity, their increase has been related to a higher risk of ventricular tachyarrhythmias. These parameters have not yet been studied in left ventricular hypertrophy due to training. Aim of the research was to test the behavior of these variables in the athletes heart during exercise.

Red Cell Filterability and Erythrocyte Membrane Microviscosity During Ticlopidine Treatment

The effects of 10 days treatment with 500 mg/day ticlopidine on the filterability of red blood cells in suspension and on the microviscosity of the red blood cell membrane was evaluated in 11 patients with vascular atherosclerosis. The results show ticlopidine to be effective in influencing the rheological measures of red cell filterability and membrane microviscosity: filterability was increased and microviscosity was decreased. Ticlopidine also decreased the extent of fluorescence polarization. These results are discussed regarding possible mechanisms of action of ticlopidine.

EFFECT OF MESOGLYCAN ON MACRORHEOLOGIC AND MICRORHEOLOGIC PARAMETERS

Abstract Whole blood filtration, mean erythrocyte aggregation, and erythrocyte membrane fluidity were examined in 10 patients with vascular atherosclerotic disease (VAD) and in 15 VAD patients with noninsulin-dependent diabetes mellitus (NIDDM) treated with mesoglycan (100 mg orally twice a day) for 30 days. The red cell membrane transverse fluidity gradient was evaluated in the VAD subjects, and the red cell membrane protein lateral mobility was measured in the VAD subjects with NIDDM. In both groups, mesoglycan treatment was responsible for an increase in erythrocyte membrane fluidity. This finding, which reflects an improvement in the dynamic properties of red cell membrane, assumes particular significance because this microrheologic parameter is always altered in VAD subjects, with or without NIDDM.

Age- and sex-based reference ranges for non-invasive ventricular repolarisation parameters

Some electrocardiographic parameters are able to assess indirectly ventricular repolarisation homogeneity. It is consequently essential to discriminate between normal and abnormal values in clinical decision‐making. Considering there is still not a consensus about normal cut‐off values, the aim of this study was to document reference intervals in all age groups of a healthy population, providing for age‐ and sex‐percentile tables, which can be used easily and quickly in clinical practice.

Effect of nimodipine on rheologic parameters in patients with chronic cerebrovascular disease

Abstract Sixteen patients with chronic cerebrovascular disease were treated with a monotherapeutic regimen of nimodipine 30 mg orally three times a day. At baseline and after 45 and 90 days of therapy, the patients whole blood filterability, erythrocyte membrane fluidity, red blood cell membrane protein lateral mobility, and red blood cell Ca 2+ content (total and cytosolic) were evaluated. After 45 days, an increase in whole blood filterability and a decrease in the cytosolic red cell Ca 2+ content was seen. At the end of treatment, whole blood filterability, erythrocyte membrane fluidity, and red cell membrane protein lateral mobility had increased, compared with baseline values, while the total and cytosolic red cell Ca 2+ content had significantly decreased. These findings demonstrate that nimodipine not only influences red blood cell calcium but also acts on the macro- and microrheologic patterns.

Vascular atherosclerotic disease: evaluation of the whole-blood f ilterability and red cell membrane microrheological pattern after intravenous administration of a single dose of pentoxifylline

A study was carried out in 10 patients with vascular atherosclerotic disease to investigate the effects of a single dose of 300 mg pentoxifylline, given by intravenous infusion over 30 minutes, on various macrorheological and microrheological parameters. Measurements were made at baseline, at the end of the intravenous infusion and again 30 minutes later, of whole-blood filterability, erythrocyte membrane fluidity (using pyrene as probe) and transverse fluidity gradient (using fluorescent fatty acids as probes). The results showed that there was a significant variation in whole-blood filterability and the red cell membrane fluidity gradient after pentoxifylline. No difference, however, was noted for the membrane fluidity. These data suggest, therefore, that pentoxifylline plays a role in affecting the red cell membrane microrheological pattern.

Hemorheologic profile of hyperlipidemic patients treated with gemfibrozil

Abstract We measured the plasma lipid levels and the macrorheologic (whole-blood, plasma, and serum viscosity levels; fibrinogen; hematocrit; mean erythrocyte aggregation; and whole-blood filterability) and microrheologic (erythrocyte membrane fluidity and red cell membrane protein lateral mobility) determinants in a group of 19 hyperlipidemic patients (Fredricksons classification phenotype IIa, 12 patients; phenotype IV, 4; phenotype IIb, 3) at baseline and after 45 and 90 days of treatment with gemfibrozil (900 mg orally once a day). At baseline we noted statistically significant increases in plasma viscosity level, fibrinogen, and mean erythrocyte aggregation, as well as a statistically significant decrease in whole-blood filterability, erythrocyte membrane fluidity, and red cell membrane protein lateral mobility in hyperlipidemic patients compared with healthy subjects. The gemfibrozil treatment provided a statistically significant decrease of the plasma lipid levels, but had little effect on the hemorheologic profile.