Unexpected Discharge from an Implanted Automatic Defibrillator

The occurrence of inappropriate discharge from an implanted cardioverter-defibrillator is reported. The device was triggered by an episode of induced nonsustained ventricular tachycardia, and the shock was delivered 10 sec after spontaneous termination of the arrhythmia.
This observation demonstrates that unexpected discharges from an implanted cardiaverter/defibrillator can occur while the patient is asymptomatic. In order to avoid such an adverse effect, improvement of the detection system of the device is advisable.     

Knowledge of residual curarization: an Italian survey

Background: The use of neuromuscular blocking agents (NMBAs) is widespread in anesthetic practice; little is known about the current use of these drugs in Italy. This survey was conducted to obtain information about the most commonly used clinical tests and the train‐of‐four (TOF) ratios that are considered as being reliable for assessing recovery from neuromuscular blockade at the end of anesthesia and the estimated occurrence rates of post‐operative paralysis in Italian hospitals. Methods: The questionnaire was given to Italian anesthesiologists attending the 62nd National Congress of the Italian Society of Anesthesia, Analgesia and Intensive Therapy. Collected data were stratified by age and the total number of surgical procedures performed in the hospitals concerned. Results: Seven hundred and fifty‐four correctly compiled questionnaires were collected (response rate 88.7%). Seventy three percent of the respondents only used clinical tests for monitoring the level of neuromuscular blockade. The main clinical tests cited for the evaluation of residual paralysis were keeping the head lifted up for 5 s, protruding the tongue and opening the eyes. TOF was used by 35% of the respondents on a routine basis. Only 24% of the interviewed anesthesiologists reported that before extubation, a TOF ratio of at least 0.9 should be reached. Conclusions: Most Italian anesthetists assess the recovery from neuromuscular blockade only by clinical signs. There is poor awareness about the inability of such techniques to indicate even a significant amount of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of NMBAs.     

Peptide-urea interaction

The excess enthalpies of the ternary aqueous solutions containing urea and the glycyl-glycine, glycyl-L-alanine, L-alanyl-L-alanine and sarcosyl-sarcosine diketopiperazines respectively have been determined. A weak but favourable enthalpic contribution to the interaction between these solutes is found. The difference between “strong” and “weak” interactions in aqueous solutions of non-electrolytes is stressed and the role of water in the weak, non-specific interactions, is discussed. The consequence of the weakness of the urea-peptide interactions on the binding of urea to the proteins is also briefly discussed.     

Hypertrophic cardiomyopathy: Is a left ventricular outflow tract gradient a major prognostic determinant?

The relationship of left ventricular outflow tract gradientas well as of clinical, ECG and haemodynamic data to presentingfeatures and prognosis was evaluated in 125 consecutive patientswith hypertropic cardiomyopathy, 79 men and 46 women (mean age:34±7 years) studied between January 1970 and December1985.Most clinical, ECG and haemodynamic findings were similarin the 44 patients (35%) with a pressure gradient (30mmHg) andin the 81 patients (65%) without. Those with obstruction hadgreater ECG voltage S V, and R V5; however, higher grade ventriculararrhythmias were more common in patients without obstruction.During a mean follow-up period of 7.6±4.5 years (range2-18 years), death from a cardiac cause occurred in 28 patients(21 died suddenly) and was significantly less common in patientswith a pressure gradient than in those without (11% vs 28%,P=0039). Univariate analysis of survival curves showed thatthe most powerful predictors of a poor prognosis were ejection fraction (P=0.0001), mean pulmonary artery pressure (P=0.0001),dyspnoea (P=0.001), left ventricular end-diastolicpressure (P=0.002),complex ventricular arrhythmias (P=0.029) and severe mitralregurgitation (P=0.037). Using multivariate analysis, a decreasedejection fraction (P=0.006) and a raised mean pulmonary arterypressure (P=0.022) were the only independent prognostic determinants.Thus,the presence of a left ventricular outflow tract gradient doesnot seem of adverse prognostic significance. Risk factor characterizationin patients with hypertrophic cardiomyopathv may be improvedby assessment of ventricular arrhythmias in the context of leftventricular function     

Early systolic closure in malformed aortic valve

Three cases are presented in whom early systolic closure ofthe aortic valve, in the absence of other conditions usuallyassociated with this echocardiographic finding, is related toan abnormality of the aortic valve. In such a situation theearly systolic closure of the valve should be considered a reboundeffect. For the occurrence of this effect, two conditions arenecessary: (1) the malformed valve does not open completelywith a sudden arrest of the opening motion; (2) the valvulartissue must possess some degree of elasticity.