Left ventricular stimulation in treatment of heart failure

SEARCH FOR AN ALTERNATIVE TREATMENT: The concept of stimulating the ventricle to improve heart function in patients with severe heart failure is an old one, but the first published series was reported about 10 years ago and provided encouraging results that lead to numerous other studies. A PROMISING TECHNIQUE: Excepting a few patients with a long PR, stimulation of the right ventricle is ineffective or even deleterious. Stimulation of the lateral region of the left ventricle has produced some undeniably favorable and sometimes even spectacular improvement in hemodynamic performances. Permanent stimulation of both ventricles or the left ventricle produces an overall clinical improvement in patients with severe heart failure (NYHA III or IV) and major left intraventricular conduction disorders (QRS > 140 ms). These results have been recently confirmed in a prospective randomized trial. CAREFUL OPEN QUESTIONS: There is no fully satisfactory explanation for the improvement which, it is important to note, does not occur in all patients. A more homogeneous contraction of the left ventricle certainly plays a fundamental role. Resynchronization of the two ventricles with dual stimulation is more complex and costly and remains to be evaluated. One crucial question is currently being examined: what is the effect of stimulation on the high mortality in these patients?     

Urinary stability of carboxycyclophosphamide and carboxyifosfamide, two major metabolites of the anticancer drugs cyclophosphamide and ifosfamide

Phosphorus-31 nuclear magnetic resonance spectroscopy was used to evaluate the stability of carboxycyclophosphamide (CXCP) and carboxyifosfamide (CXIF) in human urine at pH 7.0 and 5.5 at 25°, 8°, −20°, and −80 °C. At 25 °C and pH 7.0, CXCP and CXIF are relatively stable (≈10% degradation in 24 h). In contrast, they are much less stable at pH 5.5 (≈80% degradation of CXIF and ≈50% degradation of CXCP in 24 h). The rate of degradation of CXCP and CXIF was a function of the storage temperature of the urine samples but, even at −80 °C, was not negligible: ≈30% degradation for CXCP irrespective of pH and ≈40% and 50% degradation for CXIF at pH 7.0 and 5.5, respectively, after storage for 6 months. CXCP was more stable than CXIF at either pH (7.0 or 5.5) and at all storage temperatures (8°, −20°, or −80 °C) of the urine samples. CXCP and CXIF were more stable at pH 7.0 than at pH 5.5, although this difference fell with decreasing temperatures to be almost negligible at −80 °C. To ensure a true estimate of CXCP and CXIF levels, urine samples must be frozen and stored at −80 °C within a few hours of micturition. CXCP and CXIF assays should also be carried out within 2 months and 1 month of storage, respectively. Received: 13 July 1996 / Accepted: 20 January 1997     

Direct coronary stenting without balloon predilation of lesions requiring long stents: immediate and 6-month results of a multicenter prospective registry.

To assess the outcomes of direct coronary stenting (DS) using long stents and examine predictive factors of DS failure, this prospective multicenter registry included 128 consecutive patients who underwent the implantation of stents >or= 18 mm in length without balloon predilation for de novo coronary artery stenoses. Mean lesion and stent lengths were 20.7 +/- 5.4 and 21.4 +/- 3.8 mm, respectively. Rates of DS success, lesion success, and primary success were 82%, 99%, and 97.7%, respectively. At 6 months, rates of MACE and TVR were 12.5% and 6.3%, respectively. In multivariate analysis, factors predictive of DS failure vs. DS success were presence of calcifications (78% vs. 45%; P = 0.004) and reference vessel diameter (2.77 +/- 0.4 vs. 3.13 +/- 0.42 mm; P = 0.0002). DS of complex lesions with stents >or= 18 mm in length was performed safely and with a high success rate. This strategy was less successful in the treatment of small vessels and in presence of calcifications.     

Impact of Direct Transcatheter Aortic Valve Replacement Without Balloon Aortic Valvuloplasty on Procedural and Clinical Outcomes: Insights From the FRANCE TAVI Registry

Objectives

This study sought to describe the current practices and compare outcomes according to the use of balloon aortic valvuloplasty (BAV) or not during transcatheter aortic valve replacement (TAVR).

Left auricular hypertrophy in aortic stenosis in adults

Left atrial hypertrophy (LAH) was noted from the electrocardiograms of 72 of 98 adult patients (81%) who underwent hemodynamic evaluation of calcified aortostenosis (CAS). The relations between LAH and clinical, echographic and hemodynamic findings are specified. The frequency of LAH was not higher in cases of a history of hypertension, angina pectoris, lipothymia or exercise-induced syncope. In contrast, dyspnea was more frequently associated with LAH (84%) than not (17%). An approximately linear relation was seen between LAH and the mean pulmonary capillary pressure, the mean rate of circumferential decrease (RCF), the coefficient of muscle rigidity (ks of Mirsky), the left ventricular mass (LVM) and the left ventricle-aorta gradient. LAH is, therefore, a frequent sign in patients presenting CAS. Its origin is multifactorial, with a predominance of increased mean capillary pressure in cases of clinical signs of poor safety.     

Electrophysiological effects of intravenous magnesium sulfate in man

Magnesium salts have been used for many years to correct a wide variety of arrhythmias. A few experimental studies have been devoted to their electrophysiological effects, but these remain poorly documented in man, hence this study. An electrophysiological investigation was conducted in 24 patients before, and immediately after a bolus intravenous injection of magnesium sulphate in doses of 1.5 g to 12 patients (group I) and 3 g to 12 other patients (group II), followed by a continuous infusion at the rate of 1 mg/min. The drug had no influence on heart rate, duration of QRS, QT and QTc intervals and ventricular refractory period. A small, but statistically significant prolongation of HV (from 57 to 59 ms, p less than 0.05) was observed in group II. Analysis of the results in group I revealed a moderate but significant prolongation of the PR and AH intervals. The electrophysiological effects were distinctly more pronounced in group II patients, with significant prolongation of: PR and AH intervals, effective refractory period of the right atrium and AV node, Wenckebach's point, corrected sinus node recovery time and sinoatrial conduction time. These results demonstrate that magnesium sulphate principally acts on the sinus node, the AV node and the atrium, suggesting a blocking effect on calcium channels.     

An OxPLORE Initiative Evaluating Children’s Surgery Resources Worldwide: A Cross-sectional Implementation of the OReCS Document

World Journal of Surgery - The Global Initiative for Children's Surgery (GICS) group produced the Optimal Resources for Children’s Surgery (OReCS) document in 2019, listing standards of...