Fasciculation electromechanical latency is prolonged in amyotrophic lateral sclerosis.

OBJECTIVE: In amyotrophic lateral sclerosis (ALS), motor neurons become hyperexcitable and spontaneously discharge electrical impulses causing fasciculations. These can be detected by two noninvasive methods: high-density surface electromyography (HDSEMG) and muscle ultrasonography (MUS). We combined these methods simultaneously to explore the electromechanical properties of fasciculations, seeking a novel biomarker of disease. METHODS: Twelve ALS patients and thirteen healthy participants each provided up to 24 minutes of recordings from the right biceps brachii (BB) and gastrocnemius medialis (GM). Two automated algorithms (Surface Potential Quantification Engine and a Gaussian mixture model) were applied to HDSEMG and MUS data to identify correlated electromechanical fasciculation events. RESULTS: We identified 4,197 correlated electromechanical fasciculation events. HDSEMG reliably detected electromechanical events up to 30 mm below the skin surface with an inverse correlation between amplitude and depth in ALS muscles. Compared to Healthy-GM muscles (mean = 79.8 ms), electromechanical latency was prolonged in ALS-GM (mean = 108.8 ms; p = 0.0458) and ALS-BB (mean = 112.0 ms; p = 0.0128) muscles. Electromechanical latency did not correlate with disease duration, symptom burden, sum muscle power score or fasciculation frequency. CONCLUSIONS: Prolonged fasciculation electromechanical latency indicates impairment of the excitation-contraction coupling mechanism, warranting further exploration as a potential novel biomarker of disease in ALS. SIGNIFICANCE: This study points to an electromechanical defect within the muscles of ALS patients.

Hemodynamically unstable pericardial effusion in the Intensive Cardiac Unit: prospective study.

The authors have conducted a prospective investigation on 15 patients with hemodynamically unstable pericardial effusion (main criteria: echocardiographic signs of various degrees of right ventricular diastolic collapse and clinical instability) hospitalized in the Intensive Cardiac Unit (1.97% of all patients) for one year and have compared the results with literature data. The causes of pericardial effusion were neoplasms, infections, rupture of heart of aorta and hypothyroidism. Investigation revealed the most frequent findings: symptoms (dyspnea, retrosternal pain, loading intolerance, nonproductive cough), clinical signs (soft heart sounds, changes in pulmonal findings, fever, jugular venous distention, tachycardia, arterial hypotension and hepatomegaly), laboratory changes (elevated erythrocyte sedimentation rate, leukocytosis), ECG changes (ST-T abnormality, microvoltage, tachycardia) and chest X-rays changes (enlarged cardiac silhouette, pleural effusion). Echocardiography found an average width of pericardial effusion of 2.5 cm (+/- 1.2), frequently thickened pericardium and changes in heart motions. The most used drugs in therapy were indomethacin, antibiotics, analgesics and corticosteroids. In three patients pericardiocentesis, and in two pericardiectomy were performed. Two patients died, 13 patients were discharged from the ICU with an improved health condition. Literature data on this condition are either lacking, or differ from the above findings.

Meningitis and endocarditis caused by group B streptococcus in a human immunodeficiency virus (HIV) infected patient.

We present a case of meningitis and endocarditis caused by Streptococcus agalactiae (group B streptococcus) in an adult patient with human immunodeficiency virus (HIV) infection. To our knowledge, only four other cases of meningitis, none of which had concomitant endocarditis, have been reported so far. A 45-year-old homosexual patient presented with fever, confusion, and signs of meningeal irritation. Streptococcus agalactiae was cultured from the blood, urine, and cerebrospinal fluid (CSF). Diagnosis of meningitis caused by streptococcus agalactiae was made. On day 35, a heart murmur was noticed, and patient developed cardiac decompensation. Echocardiography revealed vegetations on the mitral and aortic valve. After nine weeks of antibiotic treatment, the patient was discharged from the hospital in good general condition, with improved CSF and echocardiographic findings.

How long can an escalation of dose override tolerance to the hypotensive efficacy of nitroglycerin infusion in coronary care patients.

Tolerance to nitroglycerin infusion (NG) can be overridden by dose escalation. The aim of this study was to define for how long it can be done for hypotensive efficacy of NG, in a coronary care setting. A prospective trial with an intra-individual therapeutic comparison was performed in 60 patients with acute myocardial infarction or unstable angina. Initial efficacy of NG was confirmed by a 10% blood pressure decrease (measured by cuff). Seventy-two-hour NG infusion was interrupted, for 30 minutes, every 12 hours. If blood pressure increased by 10% after infusion interruption, the infusion was continued at the previous rate. If blood pressure did not increase (detected tolerance--weakened efficacy of NG), the dose was increased until pressure decreased by 10% and the infusion was continued at the new dose. Failure to achieve hypotensive response, despite a 5-fold dose increase, indicated onset of resistance--completely lost hypotensive efficacy of NG. The majority of patients (49 out of 55) who developed tolerance, developed it during the first 36 hours, while the majority of those who developed resistance (33 out of 40), developed it within 60 hours of the infusion. Tolerance was overridden by dose escalation in 41 out of 55 patients, which was repeated in 31 patients. Complete restoration of NG action was possible over 24 hours in half the patients, and over 48 hours in one third of the patients. Three out of 34 patients who developed tolerance before the 13th hour did not develop resistance during the following 60 hours of dose up-titration. The conclusion is that tolerance to NG can be overridden by dose escalation in the majority of patients for a significant period of time, which is useful in clinical practice.

[Acute renal failure in heart transplantation]. / Akutno zatajenje bubrega u transplantaciji srca.

In this study the incidence and the development of acute renal failure (ARF) in heart transplant recipients is presented. Among the thirteen heart transplant recipients eight of them developed oliguric or nonoliguric ARF. Besides the known factors such as actual condition of the patient, kidney function, peri and post-operative compromised circulation, our results demonstrate the significance of postoperative cyclosporin concentration in combination with the use of other drugs. The results also show the importance of the way cyclosporin has been administrated. The parenteral route of appliance is connected with the greater risk of higher drug concentration in the plasma than the peroral one. In connection with this is the higher incidence of adverse reactions to cyclosporin given parenterally. In addition to ranitidine and captopril, which have been mentioned earlier, the findings of our study indicate that greater attention has to be paid to the treatment with ketoconazol given in combination with cyclosporin, since it results in decreased cyclosporin clearance. Other nephrotoxic drugs like amphotericin also increase the possibility of renal lesions. The incidence of acute renal failure in this group of patients is high. Our data suggest that the reasons for the development of ARF are multifactorial. These data further suggest that a reasonable way to solve nonoliguric form of acute renal failure is to maintain the "internal balance" and that it is not necessary to perform extracorporeal elimination of nitrogen substances, if there are no additional complications (i.e. gastrointestinal bleeding).(ABSTRACT TRUNCATED AT 250 WORDS)

A dynamical model for the separation of secondary resistance from tolerance to nitroglycerin infusion.

A dynamic model for the estimation of a residual hypotensive efficacy of nitroglycerin (NG) infusion was constructed to distinguish secondary resistance from tolerance to NG, as lost vs weakened efficiency. The model was tested by individual comparison in 82 of 92 patients with acute myocardial infarction or unstable angina. Ten patients were excluded from the study protocol due to complications that required therapy modification. NG infusion (20 micrograms/ml) efficiency was initially confirmed by a 10% decrease in the mean brachial artery (cuff) blood pressure. The infusion (63 hours mean duration) was discontinued every 12 hours for 30 minutes and pressure changes were analyzed. If NG hypotensive efficacy was maintained (as proved by at least 10% pressure increase), infusion was carried on using the initial dose. Lack of 10% pressure increase after 30-minute infusion discontinuity (tolerance) indicated the need for an increase in the NG dose until 10% pressure decrease (not below 105/60) was obtained. Lack of 10% pressure decrease, with a 5-fold increase in NG dose (up to 320 micrograms/ml), was considered to be a sign of secondary resistance. There were no proceeding complications and tolerance was found in 72 patients. Beside tolerance, secondary resistance was simultaneously present in 16 patients, while the NG efficacy was restored by dose increase in the remaining 78% of tolerant patients. "Paradoxical" pressure decrease was noted in 12 tolerant patients after the infusion interruption, while "paradoxical" pressure increase was observed in 3 resistant patients during the infusion acceleration.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler evaluation of prosthetic mitral valves.

For the evaluation of patients with prosthetic heart valves Doppler echocardiography is superior over other noninvasive techniques because it allows quantitative assessment of valve function. As a noninvasive method Doppler is safe, easily repeatable and provides haemodynamic data that closely correlate with parameters obtained by invasive procedures (Sagar et al., 1986: Simpson et al., 1986; Wilkins et al., 1986; Gibbs, 1987). The purpose of our study was to evaluate Doppler characteristics of mechanical and tissue mitral prostheses; Starr-Edwards, Björk-Shiley, Hall-Medtronic and Hancock in patients with clinically normal valve function.

Can prazosin be used in the treatment of refractory heart failure only on the basis of clinical monitoring?

25 patients are presented with chronic cardiomyopathy (NYHA class IV), who were refractory to conventional digitalis and diuretics treatment which was administered over at least 3 weeks. The patients were split in 2 groups: the first group consisted of 10 patients who were haemodynamically monitored while being administered nitroprusside for 24 hours. After the treatment, the cardiac index significantly increased (by 36%), left ventricular filling pressure decreased (by 48%), and systemic vascular resistance fell (by 47%). The second group, consisting of 15 patients, was administered prazosin in addition to conventional treatment. The effects of prazosin were clinically monitored. After 3 weeks of continual prazosin treatment, the clinical condition of 12 patients was improved to NYHA class II whereas the condition of the other 3 was improved only to NYHA class III. During further treatment this improvement was maintained. The effects of the treatment can be easily followed and assessed on the basis of clinical features, so that other, more complex methods of follow-up are not required. The results of our study show that patients with refractory heart failure can be safely administered prazosin without previous assessment of haemodynamic parameters.