Sensitivity Analysis of Single Beat Left Ventricular Elastance Estimation by Chen Method.

INTRODUCTION: Left ventricular (LV) end-systolic elastance (Ees) can be estimated using single-beat (Ees(sb)) Chen method, employing systolic and diastolic arm-cuff pressures, stroke volume (SV), ejection fraction and estimated normalized ventricular elastance at arterial end-diastole. This work aims to conduct a sensitivity analysis of Chen formula to verify its reliability and applicability in clinical scenario. METHODS: Starting from a baseline condition, we evaluated the sensitivity of Ees(sb) to the parameters contained in the formula. Moreover, a mathematical model of the cardiovascular system was used to evaluate the sensitivity of Ees(sb) to end-diastolic LV elastance (Eed), Ees, arterial systemic resistance (Ras) and heart rate (HR). RESULTS: In accordance with Ees definition, Ees(sb) increases by increasing aortic pressure and pre-ejection time, reaching the highest value for a pre-ejection time = 40 ms, and then decreases. In contrast with Ees definition, Ees(sb) increases (from 3.21 mmHg/mL to 12.15 mmHg/mL) by increasing the LV end-systolic volume and decreases by increasing the SV. In the majority of the analysis with the mathematical model, Ees was underestimated using the Chen method: by increasing Ees (from 0.5 to 2.5 mmHg/mL), Ees(sb) passes only from 0.56 to 1.54 mmHg/mL. Ees(sb) increases for higher Eed (from 1.03 to 2.33 mmHg/mL). Finally, Ees(sb) decreases (increases) for HR < 50 bpm (< 50 bpm), and for Ras < 1100 mmHg/gcm4 (> 1100 mmHg/gcm4). CONCLUSION: Unexpectedly Ees(sb) increases for higher LV end-systolic volume and decreases for higher SV. These results contrast with Ees definition, which is the ratio between the LV end-systolic pressure and the LV end-systolic volume. Moreover, Ees(sb) is influenced by cardiocirculatory parameters such as LV Eed, HR, Ras, ejection time, and pre-ejection time. Finally, Ees(sb) computed with the model output often underestimates model Ees.

Update on distal deep venous thrombosis. Reports of a multicenter study.

AIM: No study of strong methodology could be found to resolve the controversy of optimal treatment of distal deep venous thrombosis (DDVT). Some inconclusive evidence exists on two approaches to care: anticoagulants and compression therapy or compression therapy and Duplex scanning monitoring. Different studies report propagation to popliteal vein in 8% of patients without anticoagulant treatment, while a complete thrombus resolution within 4 weeks occurred in 20% of patients. We report data of a study conducted in patients affected by DDVT and treated with nadroparin administered once daily in association with compression therapy. METHODS: One hundred and ten patients with DDVT of the gastrocnemius or tibial veins, assessed by Duplex scanning, were enrolled in 8 clinical centres of the Lazio Region. At baseline, patient demographics, medical history (including risk factors for DDVT), circumferences of both calves and ankles, and a VAS-pain scale were recorded. At 7 and 28 days from baseline, patients were re-assessed by Duplex scanning, calves and ankles circumferences and VAS-pain were measured, and the patients were asked about possible side effects. RESULTS: At the end of the study period, no propagation to the popliteal vein was observed, and no side effects were reported. Overall, the calf circumference in the affected leg significantly decreased from baseline (38.1 cm) to week 1 (37.1 cm), and to week 4 (35.7 cm). Also the VAS-pain scores significantly decreased during the study - the observed means were 58.4, 30.7, and 12.7 at the three visits, respectively. The percentage of partial recanalization of tibial DVT at 7 days was lower than gastrocnemius DVT (31.6% vs. 59.8%) whereas the percentage of total recanalization at 28 days was comparable (52.6% vs. 59.8%). Complete recanalization occurred in 56.4% of all patients. CONCLUSION: Our study suggests that anticoagulant treatment, associated with compression therapy, is safe and causes clinical improvement (as assessed by calf measurements) and pain relief. Overall complete resolution (56.4%) is significantly higher than in untreated patients (20%). Such results, together with the already reported higher satisfaction of patients for the once-daily administration regimen, should be considered as a viable option for the treatment of DDVT.

[Essential arterial hypertension and Leriche-Fontaine stage II obliterating vascular disease of the lower limbs. A new pharmacological approach with ketanserin]. / Ipertensione arteriosa essenziale e vasculopatia degli arti inferiori ad evoluzione obliterante al II stadio di Leriche e Fontaine. Un nuovo approccio farmacologico con ketanserina.

The efficacy of ketanserin treatment (40 mg daily for 90 days) was evaluated in 88 patients with arterial hypertension combined with Leriche-Fontaine stage II obliterating arterial disease of the lower limbs. Already after one month's treatment satisfactory control of blood pressure was achieved and maintained during the following months. In parallel with pressure control, an obvious improvement of functional and instrumental parameters of arterial disease was observed (walking distance, Winsor index). The drug was well tolerated, so that treatment had never to be withdrawn.