Five-year follow-up of left ventricular diastolic function in systemic sclerosis patients: Determinants of mortality and disease progression

Objectives

In systemic sclerosis (SSc), left ventricular diastolic dysfunction reflects primary myocardial involvement of the disease. We aimed to assess the abnormalities of the diastolic function, analyze the characteristics of the disease progression, and investigate the prognostic value of diastolic dysfunction in SSc patients.

Patients and methods

A total of 34 SSc patients (57 ± 12 years, 31 female) were involved in the study. The following traditional or tissue Doppler parameters of left ventricular diastolic function were obtained: E/A, lateral E?, E/E?, left ventricular mass index (LVM index), and maximal left atrial (LA) volume index. Measurements were repeated after 5.5 years.

Results

At baseline, diastolic dysfunction was found in 62% of the SSc patients. Follow-up time was 5.4 ± 1.2 years. A total of 6 patients died of heart failure. In univariate Cox regression analysis, age (HR = 1.08, p < 0.05), LVM index (HR = 1.07, p < 0.01), lateral E? (HR = 1.57, p = 0.05), and LA volume index (HR = 1.11, p < 0.01) were predictors of survival. During the follow-up, significant increase in LA volume index (27.5 ± 9.7 vs. 35.4 ± 10.6 cm³/m², p < 0.001) and E/E? was found (7.6 ± 2.5 vs. 8.7 ± 3.8, p < 0.05) while E? did not change (9.6 ± 2.6 vs. 9.2 ± 1.9 cm/s, NS). The increase in LA volume index showed positive correlation (r = 0.46, p < 0.05) while the decrease in E? values showed negative correlation (r = −0.54, p < 0.01) with the duration of the SSc.

Conclusion

In SSc patients, left ventricular diastolic dysfunction is highly prevalent and is associated with increased risk of mortality. Our data suggest that in the advanced phase of the disease, the myocardial fibrotic processes burns out while the increase of the filling pressure progresses continuously.     

Muscle‐specific kinase antibodies: A novel cause of peripheral nerve hyperexcitability?

Introduction: Antibodies that target the postsynaptic neuromuscular junction (NMJ) protein, muscle‐specific kinase (MuSK), have been associated with myasthenia gravis (MG), often with cramps and fasciculations, after administration of acetylcholinesterase inhibitors (AChE‐I). Methods: In this report, 2 patients are described with elevated MuSK antibodies and evidence of peripheral nerve hyperexcitability (PNH) unrelated to AChE‐I medication. Results: Patient 1 presented with facial neuromyotonia and fasciculations, without overt weakness. EMG studies demonstrated myokymic discharges in facial muscles, with bursts of discharges after voluntary activation, and widespread fasciculation potentials in limb muscles. Patient 2 presented with bulbar weakness and fasciculations in the tongue and limbs, initially diagnosed as bulbar‐onset amyotrophic lateral sclerosis. Subsequent investigation identified the presence of MuSK antibodies. Conclusions: We hypothesize that MuSK antibodies may induce these phenotypes through disruptive actions at the NMJ, in particular the binding of acetylcholinesterase (AChE) to MuSK via its collagen Q (ColQ) tail, producing a reduction in synaptic AChE activity. Muscle Nerve 48:819–823, 2013     

Ultrasound diagnosis of bony nerve entrapment: Case series and literature review

Introduction: Nerve entrapment due to osseous callus formation is a rare complication after bone fracture. Electrodiagnostic studies and routine radiographic imaging often fail to demonstrate the pathology. The diagnosis is difficult and is often made incidentally upon surgical exploration. Nerve ultrasonography has not been used routinely to assess such lesions. Methods: We report 5 cases of nerve entrapment in osseous callus after fractures that occurred in 2011 and 2012. The diagnosis was made by ultrasound (US). We then performed a review of the relevant literature. Conclusions: US is becoming an invaluable tool for diagnosing peripheral nerve entrapments. The current cases suggest that nerve US should be strongly considered as an adjunctive diagnostic tool for nerve palsies developing after trauma. Muscle Nerve 48 : 445–450, 2013     

Lack of efficacy of high-dose verapamil in preventing brain damage in baboons and pigs after prolonged partial cerebral ischemia

There has been mounting speculation that calcium antagonists may be useful in reducing or preventing brain damage after cardiopulmonary resuscitation. To test the clinical usefulness of these agents in averting such damage, high-dose verapamil was administered to baboons and pigs after partial cerebral ischemia for varying periods of time. In Group A baboons and pigs, the major aortic branches supplying the carotid and vertebral circulations were clamped for periods ranging from 15 to 150 minutes, and neurological recovery was observed. In Group B, verapamil hydrochloride 0.7 mg/kg was given by intravenous infusion after similar periods of arterial occlusion. The administration of verapamil did not lead to any clinically improved neurological outcome. The use of verapamil after prolonged periods of partial cerebral ischemia did not improve neurological recovery in baboons and pigs.