| 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. ( info) |
12/76. 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. ( info) |
| 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. ( info) |
14/76. Unusual Wenckebach upper rate response of an atrial-based DDD pacemaker. We describe in this report an unusual form of Wenckebach upper rate response produced by a DDD pulse generator with atrial-based lower rate timing. The pacemaker maintained the programmed upper and lower rate intervals at the expense of a prolonged atrial paced-ventricular paced AV interval. This form of upper rate behavior eliminated the longer cycle (containing the unsensed P wave) that occurs at the end of the pacemaker Wenckebach sequence during traditional DDD pacing with ventricular-based lower rate timing. ( info) |
15/76. Tachycardiomyopathy: a diagnosis not to be missed. The prognosis of dilated cardiomyopathy is generally poor. In the vast majority of cases the cause of the ventricular dysfunction is irreversible but occasionally potentially curable causes are identified. Tachycardiomyopathy is a rare and potentially treatable cause of heart failure. A patient with a particularly severe case who had an excellent outcome is presented. ( info) |
16/76. 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. ( info) |
17/76. Combined epicardial-endocardial approach to ablation of inappropriate sinus tachycardia. A combined epicardial-endocardial approach to ablation of inappropriate sinus tachycardia in a highly symptomatic patient who failed to respond to medical therapy and endocardial ablation is described. The anatomy and physiology of the sinus node is discussed, providing a basis for performing this procedure. This case provides an additional therapeutic option for a condition that often is difficult to manage. ( info) |
18/76. Isolated anomalous origin of the right pulmonary artery from the ascending aorta (so-called "hemitruncus"): diagnosis and complex management in a newborn. We report a case of an anomalous origin of the right pulmonary artery (RPA) from the ascending aorta diagnosed at echocardiography at 13 days of age. The diagnostic clue was relieved in the suprasternal and parasternal high short-axis views, showing aorto-RPA continuity with a systolic flow in the left pulmonary artery and a systo-diastolic flow in the RPA. At 34 days of age the infant was submitted to surgery during which a direct end-to-lateral anastomosis without conduit interposition was performed. During the short-term follow-up the patient developed RPA stenosis at the anastomosis site and underwent percutaneous stent implantation. ( info) |
19/76. Nontraumatic localized dehiscence of the proximal ascending aorta through an aortic valve commissure. Acute dissection of the ascending aorta is a life-threatening condition that requires timely recognition and management. Here we describe an unusual variant of acute dissection involving a localized tear in the proximal ascending aorta through the commissure of the left and noncoronary cusps of the aortic valve causing aortic regurgitation. ( info) |
20/76. hypoglycemia after albuterol overdose in a pediatric patient. albuterol overdose can lead to tachycardia, hypotension, tremor, hypokalemia, and hyperglycemia in children. hypoglycemia had been previously reported in only one child. We describe a 3-year-old boy who ingested high-dose albuterol in this report. On arrival to the emergency department, the child was agitated and had noticeable restlessness, sinus tachycardia, mild hypokalemia (3.2 mEq/L), and hyperglycemia (187 mg/dL). Activated charcoal and intravenous hydration were given, and electrocardiogram monitoring was performed. Sinus tachycardia resolved within 4 to 6 hours. hypoglycemia (45 mg/dL) was identified 4 hours after admission. The child recovered uneventfully within 24 hours with glucose replacement. This case suggests that hypoglycemia could be a late complication of acute albuterol overdose; thus, the period of observation should be extended in these cases. ( info) |