Acute massive rise in the capture threshold: successful management with long-term oral prednisolone.
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Aged↗
Biomedical subjects
Hyung-Wook Park
Publications and source records attributed to Hyung-Wook Park.
Ketanserin, a 5-HT2 antagonist, directly inhibits the ATP-sensitive potassium channel in mouse ventricular myocytes.
The effects of ketanserin, a 5-HT2 antagonist, on the ATP-sensitive K+ (K(ATP)) channels were studied in mouse ventricular myocytes using patch clamp technique. Under the whole-cell voltage clamp conditions, ketanserin (1-100 microM) reversibly inhibited pinacidil-induced K(ATP) current in a concentration-dependent fashion with a Ki value of 9.36 microM and the Hill coefficient was 0.67. This inhibition was developed even with the presence of 5-hydroxytryptamine (100 microM) in the bath. Prazosin, a selective alpha1-antagonist, also failed to mimic the effect of ketanserin. Ketanserin did not affect the channel activity in inside-out configuration under the ATP-free internal solution. Furthermore, ketanserin applied to the external solution did not affect the pinacidil-induced channel activity in the cell-attached patches, but did inhibit it when applied into the pipette. These results suggest that the inhibitory action of ketanserin observed in this study was probably due to a direct action on the K(ATP) channel rather than to an action through the 5-HT2 receptor or alpha1-adrenoceptor blockade, and that the antiarrhythmic activity of ketanserin against cardiac arrhythmias induced in the ischemic/reperfused heart is at least in part attributable to its inhibition of the K(ATP) channel.
Adenosine Triphosphate↗
Multiple pacing lead-induced superior vena cava syndrome: successful treatment by balloon angioplasty.
Pacemaker-induced SVC syndrome. The superior vena cava (SVC) syndrome is an uncommon but sometimes serious complication associated with permanently implanted pacemakers. The mechanical stress associated with pacemaker wires may lead to vessel wall inflammation, fibrosis, thrombus formation, and, ultimately, venous stenosis and occlusion. The surgical treatment of pacemaker-related SVC syndrome requires thoracotomy and may result in significant morbidity. The long-term effects on the pacemaker electrodes, due to compression between the stent and the wall of the vein, remain unknown. We describe a case in which balloon venoplasty successfully resolved the SVC syndrome. The patient has remained symptom-free and with normal pacemaker function for 6 months.
Angioplasty, Balloon↗
Disseminated intravascular coagulation as a complication of radiofrequency catheter ablation of atrial fibrillation.
Since Haissaguerre and his colleagues demonstrated the importance of the pulmonary veins in the generation of atrial fibrillation (AF) in 1998, a variety of different ablative interventions have been performed to eliminate AF. Various complications related to catheterization, ablation itself including pulmonary vein stenosis, pericardial effusion, stroke, and atrioesophageal fistula have been reported. Disseminated intravascular coagulation (DIC) is a systemic syndrome characterized by enhanced activation of coagulation with some intravascular fibrin formation and deposition. This is the first report, to our knowledge, of a patient whose condition was complicated by DIC after segmental ostial isolation of pulmonary veins for persistent AF. The patient has completely recovered from the DIC by hemodialysis, administration of blood constituents for 15 days.
Aged↗
Clinical characteristics of hypervagotonic sinus node dysfunction.
BACKGROUND: Sinus node dysfunction (SND) is caused not only by intrinsic sinus node disease, but also by the extrinsic factors. Among the extrinsic factors, autonomic imbalance is most common. Symptomatic SND usually requires permanent pacemaker therapy. However, the clinical characteristics and patient response to medical therapy for hypervagotonic SND have not been properly clarified. MATERIALS AND METHODS: Thirty two patients (14 men, 18 women, 51 +/- 14 years) with hypervagotonic SND were included in this study, but those patients who had taken calcium antagonists, beta-blockers or other antiarrhythmic drugs were excluded. Hypervagotonic SND was diagnosed if the abnormal electrophysiologic properties of the sinus node were normalized after the administration of atropine (0.04 mg/kg). RESULTS: The presenting arrhythmias were 16 cases of sinus bradycardia (50.0%), 12 of sinus pause (37.5%), 3 of sinoatrial block (9.4%) and 1 of tachy-bradycardia (3.1%). Nine (28.1%) patients had hypertension, 7 (21.9%) smoked, 2 (6.3%) had diabetes mellitus, and 1 (3.1%) had hypercholesterolemia. Among the patients, 3 had no remarkable symptoms, 13 had dizziness, 7 had syncope, 3 had weakness and 6 had shortness of breath. Twenty five (78.1%) patients were treated with theophylline, 1 patient with tachy-bradycardia syndrome was treated with digoxin and propafenone, and 6 (18.8%) were treated with no medication. During the 43 +/- 28 month follow-up, 25 patients remained asymptomatic, but 6 who took no medication developed mild dizziness. One patient needed permanent pacemaker implantation owing to recurrent syncope despite of theophylline treatment. CONCLUSION: These results show that hypervagotonic SND has a benign course and most of the patients can be managed safely without implanting a pacemaker. (Ed note: I like the abstract. It is short and direct, as it should be.)
Dizziness↗
Detection of rhinovirus in turbinate epithelial cells of chronic sinusitis.
BACKGROUND: In contrast to the well-established association of rhinovirus (RV) with acute sinusitis, little is known about the role of RV infections in the pathogenesis of chronic sinusitis. Therefore, we assayed the nasal cavity mucosae of chronic sinusitis patients lacking signs of acute viral infection for the presence of RV. METHODS: Nasal lavage fluids and turbinate epithelial cells from 39 sinusitis patients and 27 control subjects were tested. Turbinate epithelial cells were collected using a Rhino-probe mucosal curette. Picornavirus was assayed by an initial reverse-transcription polymerase chain reaction (PCR), and picornavirus-positive samples were assayed by nested reverse-transcription PCR to detect RV. RESULTS: All lavage fluids from both groups, as well as control epithelial cells, were negative for picornavirus. In contrast, 8 of 39 (21%) epithelial cell samples from sinusitis patients were positive for picornavirus. RV-specific nested-PCR revealed that all eight of these samples were positive for RV. CONCLUSION: The detection of RV in the turbinate epithelial cells of chronic sinusitis patients suggests that RV may be important in the pathogenesis of chronic sinusitis.
Adult↗