1/40. inflammation of the cardiac conduction system in a case of hyperthyroidism.A 37-year-old female showed signs of hyperthyroidism 2 weeks before death after a partial thyroidectomy was carried out 15 years previously. An examination 3 days before death revealed a normal blood cell count, an increased level of thyroidal hormones, sinus tachycardia and a high blood pressure of 170/90 mm Hg. A hyperthyroidism was diagnosed and therapy with carbimazol (2 x 10 mg) was started but 2 days later fever and chill occurred and before death short phases of unconsciousness and dyspnoea. The autopsy findings showed an interstitial inflammation of the AV-node, the His-bundle and its branches which can correlate with typical ECG changes in hyperthyroidism.- - - - - - - - - - ranking = 1keywords = sinus (Clic here for more details about this article) |
2/40. Laboratory confirmation of scopolamine co-intoxication in patients using tainted heroin.BACKGROUND: First described in 1995, at least 325 patients with a history of heroin use have since required emergency medical evaluation in several eastern US cities, because of an anticholinergic toxidrome following use of heroin. This co-intoxication has been alleged to result from an atropine-like compound. We report the clinical findings and laboratory analysis of one of several individuals who presented to our Emergency Department during this epidemic. CASE REPORT: A 23-year-old male was one of 3 patients brought to the Emergency Department due to agitated behavior after insufflating heroin. Following physical and chemical restraint, vital signs were pulse 134 bpm, BP 160/90 mm Hg, RR 24/min, and T 37.3 degrees C. physical examination was remarkable for dilated pupils 8-9 mm without nystagmus, along with dry mouth, decreased bowel sounds, and flushed dry skin. A bladder catheter was placed and 500 mL of urine was obtained. Electrocardiogram revealed sinus tachycardia only. Additional sedation was required for 12 hours until normal mental status returned. A small sample of the "heroin" used was obtained and analyzed. Scopolamine was confirmed by gas chromatography-mass spectrometry. Further evidence of scopolamine intoxication was supported by identifying scopolamine in the urine of this patient. CONCLUSION: gas chromatography-mass spectrometry revealed scopolamine to be the cause of anticholinergic findings in a patient following use of tainted heroin. It is unclear whether scopolamine is an adulterant or contaminant in this heroin. patients with anticholinergic findings following use of heroin may be co-intoxicated with scopolamine.- - - - - - - - - - ranking = 1keywords = sinus (Clic here for more details about this article) |
3/40. Electrophysiologic findings of a patient with inappropriate sinus tachycardia cured by selective radiofrequency catheter ablation.Radiofrequency catheter ablation (RFCA) for inappropriate sinus tachycardia (IST) is associated with a high recurrence rate and sometimes requires pacemaker implantation, especially after extensive ablation. We report a patient with drug-refractory IST who was successfully treated by selective RFCA to the 2 earliest activation sites. During tachycardia, the earliest atrial activation preceded the surface P wave by 50 ms or more, whereas it was only 27 ms for the rest of the right atrium after ablation. Our patient had the longest activation period during tachycardia among the reported patients. In IST patients, a longer activation time at the site of the earliest atrial activation may imply that the abnormality is confined to a small area within the sinus node and may predict the efficacy of selective RFCA.- - - - - - - - - - ranking = 6keywords = sinus (Clic here for more details about this article) |
4/40. Evidence of sinoatrial block as a curative mechanism in radiofrequency current ablation of inappropriate sinus tachycardia.Inappropriate sinus tachycardia is a nonparoxysmal tachycardia characterized by high resting heart rates and a disproportionate response to activity. Sinus node modification with radiofrequency current has been used successfully as treatment for this arrhythmia. However, the electrophysiologic mechanisms leading to successful modification are not yet fully elucidated. We report a case of a patient with drug-resistant inappropriate sinus tachycardia in whom successful treatment of the arrhythmia was achieved by documented sinoatrial exit block induced by radiofrequency current applications.- - - - - - - - - - ranking = 6keywords = sinus (Clic here for more details about this article) |
5/40. theophylline toxicokinetics in premature newborns.BACKGROUND: While cytochrome P4501A2 is the primary pathway for theophylline (aminophylline ethylenediamine) metabolism in adults, it is developmentally immature in the newborn. OBJECTIVE: To report the developmental differences in theophylline toxicokinetics of neonates. DESIGN: Case series. Three premature neonates received inadvertent intravenous overdoses of theophylline for apnea of prematurity while in newborn intensive care. Maximum serum concentrations ranged from 55 to 123 mg/L. theophylline-derived caffeine levels plateaued at 8.4 to 13 mg/L and did not decline during the sampling period. All newborns experienced sinus tachycardia and agitation. Sequential theophylline and caffeine serum levels were obtained periodically for 62 to 100 hours. In contrast to older children and adults, in whom theophylline disposition follows zero-order kinetics at high concentrations, a monoexponential function best described theophylline elimination in the premature newborn, with half-lives ranging from 24.7 to 36.5 hours and estimated clearance from 0.02 to 0.05 L/kg per hour. These values are consistent with those previously reported in neonates. All patients were treated with supportive care without invasive procedures. No seizures or apparent sequelae occurred. CONCLUSION: Developmental differences in the balance between nonrenal (ie, metabolic) and renal elimination pathways produce the unique toxicokinetics of theophylline in the neonate.- - - - - - - - - - ranking = 1keywords = sinus (Clic here for more details about this article) |
6/40. A case of thyrotoxicosis with pancytopenia.We report a 49-year-old man with primary hyperthyroidism who presented with pancytopenia. The patient presented with leg edema, sinus tachycardia, cardiomegaly, and pleural effusions, all from congestive heart failure. Laboratory data showed pancytopenia and primary hyperthyroidism; echocardiogram showed diffuse hyperkinesis of the left ventricular wall and right ventricular overloading. The bone marrow was moderately hypercellular and compatible with arrested hematopoiesis. pancytopenia and heart failure improved after administration of methimazole and diuretics. However, high levels of thyroid hormone recurred with pancytopenia 4 months after admission. Therefore, subtotal thyroidectomy was performed, and the levels of thyroid hormones and peripheral blood cell counts have remained normal. pancytopenia may be caused by hyperthyroidism.- - - - - - - - - - ranking = 1keywords = sinus (Clic here for more details about this article) |
7/40. clenbuterol ingestion causing prolonged tachycardia, hypokalemia, and hypophosphatemia with confirmation by quantitative levels.BACKGROUND: clenbuterol is a long acting beta2-adrenergic agonist used in the treatment of pulmonary disorders. Acute clenbuterol toxicity resembles that of other beta2-adrenergic agonists. Most previously reported cases of clenbuterol toxicity describe patients who ate livestock illicitly treated with clenbuterol. CASE REPORT: We report a case of human clenbuterol toxicity confirmed and correlated with qualitative and quantitative serum clenbuterol assays. This poisoned patient, a 28-year-old woman, developed sustained sinus tachycardia at 140/min, hypokalemia (2.4 mEq/L, 2.4 mmol/L), hypophosphatemia (0.9 mg/dL, 0.29 mmol/L), and hypomagnesemia (1.52 mg/dL, 0.76 mmol/L) after ingesting a reportedly small quantity of clenbuterol. The patient received repeated doses of metoprolol to treat her cardiovascular stimulation and potassium chloride to treat her hypokalemia. She remained symptomatic for more than 20 hours after the ingestion. Analysis by enzyme-linked immunosorbent assay and liquid chromatography/mass spectrometry revealed a serum clenbuterol concentration of 2.93 mcg/L 3 hours after the ingestion and an undetectable serum concentration 20 hours after ingestion. It is noteworthy that at a serum concentration below the limit of detection by liquid chromatography/mass spectrometry, the patient remained symptomatic. Acute clenbuterol toxicity is rarely reported following illicit use in humans, and this is the first such case to provide confirmatory toxicological analysis.- - - - - - - - - - ranking = 1keywords = sinus (Clic here for more details about this article) |
8/40. Lactic acidosis associated with the usual theophylline dose in a patient with asthma.Metabolic and electrolyte abnormalities, including hypokalemia, hyperglycemia and lactic acidosis, are associated with theophylline overdose. However, we report an unusual case of sinus tachycardia, lactic acidosis, hypokalemia and hyperglycemia associated with the usual theophylline dose in a patient with asthma. The theophylline dose was 200 mg orally twice daily. Three hours after administration of the third dose, the patient experienced palpitation. An electrocardiogram showed a sinus tachycardia. Arterial blood gas analysis revealed a mixed metabolic acidosis and respiratory alkalosis. serum lactate level was 51 mmol/L (normal 0.7-2.1 mmol/L). biochemistry results were sodium 136 mEq/L, chloride 99 mEq/L, potassium 1.9 mEq/L and glucose 204 mg/dL. Our case suggests that a possibility of theophylline-associated metabolic abnormalities should be considered when an asthmatic patient given the usual theophylline dose presents with lactic acidosis, hypokalemia and hyperglycemia of unknown etiology.- - - - - - - - - - ranking = 2keywords = sinus (Clic here for more details about this article) |
9/40. Right diaphragm paralysis following cardiac radiofrequency catheter ablation for inappropriate sinus tachycardia.We describe a case of permanent right diaphragm paralysis following a radiofrequency cardiac ablation procedure. The relationship between the procedure and the phrenic nerve lesion is discussed with respect to the possible pathogenetic mechanisms. Radiofrequency current used in cardiac electrophysiology may cause serious thoracic nerve injuries. Means to avoid this complication are pointed out.- - - - - - - - - - ranking = 4keywords = sinus (Clic here for more details about this article) |
10/40. Radiofrequency catheter ablation using non-contact mapping for inappropriate sinus tachycardia.INTRODUCTION: In this report we describe our experience using non-contact mapping for radiofrequency ablation in patients with inappropriate sinus tachycardia. methods AND RESULTS: Two female patients with persistent complaints of palpitations and documented inappropriate sinus tachycardia with failed medical management underwent radiofrequency ablation using non-contact mapping. Non-contact mapping provided a continuous determination of the site of earliest breakthrough, facilitating the delivery and the assessment of the results of each radiofrequency application. CONCLUSION: Non-contact mapping is an effective mapping modality in the interventional treatment of inappropriate sinus tachycardia.- - - - - - - - - - ranking = 7keywords = sinus (Clic here for more details about this article) |
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