Sustained Ventricular Tachycardia as a Harbinger of Cardiac Amyloidosis.

BACKGROUND Cardiac amyloidosis is an infiltrative cardiomyopathy caused by the extracellular deposition of insoluble precursor protein amyloid fibrils. These depositions of protein amyloid fibrils are found on the atria and ventricles and can cause a wide array of arrhythmias; however, sustained ventricular arrhythmias are quite uncommon. CASE REPORT A 71-year-old man with a history of hypertension developed a sudden onset of shortness of breath, profuse diaphoresis, lightheadedness, and presyncope. Upon emergency medical services' arrival, an initial electrocardiogram revealed wide complex tachycardia with a heart rate of 220 to 230 beats per min. He was subsequently given, in succession, magnesium, adenosine, and amiodarone with no change in heart rate or rhythm. Due to ongoing symptoms of diaphoresis and the development of dyspnea, he underwent direct current cardioversion and was converted from ventricular tachycardia to atrial fibrillation at controlled rates. A transthoracic echocardiogram and cardiac magnetic resonance imaging showed features suspicious for cardiac amyloidosis. A subsequent 99m technetium pyrophosphate single-photon emission computerized tomography scan revealed a grade 3 visual uptake and a heart-to-contralateral lung ratio of 1.92, consistent with transthyretin amyloidosis. The patient was treated with tafamidis and an implantable cardioverter-defibrillator for secondary prevention of ventricular arrhythmia. CONCLUSIONS This case highlights the need to consider cardiac amyloidosis in the differential diagnoses of patients with persistent ventricular arrhythmia and no prior history of heart disease.

Acquired tracheoesophageal fistula status post laryngeal neoplasm resection.

A tracheoesophageal fistula (TEF), albeit rare, can be a life-threatening condition that requires prompt identification and treatment. Pulmonary contamination and restriction of proper nutrition are common, unfortunate consequences of untreated TEFs and are often the causes of mortality in this population. In our patient, a history of laryngeal malignancy along with symptoms of chest pain and cough with ingestion of liquids, even without evidence of aspiration pneumonia, appropriately prompted investigation for potential TEF. Initial imaging through barium swallow identified the TEF, and the patient underwent treatment with endoclips by endoscopy with bronchoscopic assistance.

Keeping NAION visual loss: discriminating urgent versus emergent visual loss in an elderly female.

A 72-year-old woman presented with sudden, monocular vision loss and a temporal headache without eye pain. Examination revealed complete loss of vision in the right eye in bilateral superior visual fields and hyperaemic oedema with haemorrhages of the optic disc. She had significant vasculopathic risk factors, including age greater than 50 years, hypertension, recent coronary artery bypass graft and hyperlipidaemia. Atypical features were investigated, including simultaneous vision changes in contralateral eye, prodrome, jaw claudication, scalp tenderness and headache. The patient indicated persistent temporal headaches since the onset of the visual changes, prompting investigation with temporal biopsy and inflammatory markers with initiation of steroids. Diagnostic studies excluded inflammatory disease and retinal vascular thrombosis. The patient was diagnosed with non-arteritic anterior ischaemic optic neuropathy (NAION) and the steroids were tapered off. At 6 months, the patient has maintained altitudinal visual loss, but her central vision in the affected eye has remained 20/25.

Haemorrhagic stroke or hyperglycaemia?

A 56-year-old woman with no medical history was admitted with acute onset hemiballistic-choreiform movements of right extremity. On admission, her serum glucose and osmolality were elevated. Her glycosylated haemoblobin (HbA1c) was 17.9 with average blood sugars of 467 mg/dL. A CT scan of the brain revealed unilateral hyperintensities in the basal ganglia. A complete stroke work-up, including MRI and MR angiography of brain was otherwise unrevealing. Subcutaneous insulin was instituted, which led to complete resolution of her symptoms within 48 h of hospital admission. She was readmitted 4 weeks after her initial discharge for similar, but less severe, symptoms. This time her HbA1c was 13.9 with an average blood sugar of 352 mg/dL. A repeat MRI demonstrated a persistent abnormal signal within the left basal ganglia without infarct. She was started on subcutaneous insulin. Her symptoms improved but did not resolve. Haloperidol and gabapentin were initiated and she was again discharged after stabilisation to a rehabilitation centre as per physiotherapy recommendations.

Spatially and temporally resolved single-cell exocytosis utilizing individually addressable carbon microelectrode arrays.

We report the fabrication and characterization of carbon microelectrode arrays (MEAs) and their application to spatially and temporally resolve neurotransmitter release from single pheochromocytoma (PC12) cells. The carbon MEAs are composed of individually addressable 2.5-mum-radius microdisks embedded in glass. The fabrication involves pulling a multibarrel glass capillary containing a single carbon fiber in each barrel into a sharp tip, followed by beveling the electrode tip to form an array (10-20 microm) of carbon microdisks. This simple fabrication procedure eliminates the need for complicated wiring of the independent electrodes, thus allowing preparation of high-density individually addressable microelectrodes. The carbon MEAs have been characterized using scanning electron microscopy, steady-state and fast-scan voltammetry, and numerical simulations. Amperometric results show that subcellular heterogeneity in single-cell exocytosis can be electrochemically detected with MEAs. These ultrasmall electrochemical probes are suitable for detecting fast chemical events in tight spaces, as well as for developing multifunctional electrochemical microsensors.