Humans ; Torsades de Pointes

Although amiodarone is generally regarded as safe with a low incidence of associated arrhythmias, torsade de pointes (TdP) has been observed usually in the presence of predisposing factors. We report a case of amiodarone-induced TdP after long-term administration of a low dose of oral amiodarone in the absence of predisposing factors.
Amiodarone ; Arrhythmias, Cardiac ; Incidence ; Torsades de Pointes

No abstract available.
Magnesium Sulfate* ; Magnesium* ; Torsades de Pointes*

Torsades de pointes (TdP) is a rare complication of a complete atrioventricular block with QT prolongation. Additional risk factors, such as hypokalemia, may increase the risk of TdP during atrioventricular (AV) block. We experienced a case of TdP, caused by a complete heart block and hypokalemia, which was successfully treated by implanting a permanent pacemaker and correction of the electrolyte imbalance.
Atrioventricular Block* ; Heart Block ; Hypokalemia* ; Risk Factors ; Torsades de Pointes*

No abstract available.
Humans ; Long QT Syndrome ; Postoperative Period ; Torsades de Pointes

Electrocardiography ; Female ; Humans ; Syncope/etiology* ; Torsades de Pointes/etiology*

Diagnosis, Differential ; Electrocardiography ; Humans ; Tachycardia, Ventricular ; Torsades de Pointes

Terfenadine is widely used because of nonsedating effect. But It could rarely provoke a potentially lethal ventricular tachyarrhythmia. Recently, we experienced two cases of torsades de pointes(TDP) of occurred after combined use of terfenadine and ketoconazole in usual dose. In one case, 31-yr-old female presented palpitation and recurrent syncope of sudden onset after ingestion of terfenadine 60mg and ketoconzole 200mg 5 times. On attack, ECG showed a polymorphic ventricular tachycardia, and after attack, showed prolongation of QT interval and TU wave changes. Her laboratory findings were not contributory. TDP was controlled with MgSO4 and isoproterenol infusion. Then, QT interval was normalized and no further episode occurred. In the other case, 32-yr-old female presented palpitation and recurrent syncope of sudden onset after ingestion of terfenadine 60mg and ketoconzole 200mg 5 times. ECG showed prolongation of QT interval and TU wave changes. Her laboratory findings were not contributory. TDP was controlled with MgSO4 and isoproterenol infusion. Then, QT interval was normalized and no further episode occurred.
Eating ; Electrocardiography ; Female ; Humans ; Isoproterenol ; Ketoconazole* ; Syncope ; Tachycardia ; Tachycardia, Ventricular ; Terfenadine* ; Torsades de Pointes*

Anesthesiologists are faced with a growing number of patients in need of cardiac pacing with symptoms of increasing complexity. Because intraoperative pacemaker malfunction can lead to sudden death, it is important for the anesthesiologists to possessthe information necessary to evaluate and treat such patients. On the other hand, torsade de pointes, a particular form of life-threatening polymorphic ventricular tachycardia, is known to be elicited in patients with cardiac pacemakers in the setting of abnormally long QT intervals, decreased heart rate and severe electrolyte disturbances, notably hypokalemia. We herein report a case of intraoperative torsade de pointes that was triggered by pacemaker malfunction-induced bradycardia in a patient with a VVI-type cardiac pacemaker, whose serum potassium and magnesium level were low preoperatively. (Korean J Anesthesiol 1999; 37: 164~167)
Bradycardia ; Death, Sudden ; Hand ; Heart Rate ; Humans ; Hypokalemia ; Magnesium ; Potassium ; Tachycardia, Ventricular ; Torsades de Pointes*

BACKGROUNDTorsade de pointes (TdP) is a form of polymorphic ventricular tachycardia featuring prolonged QT intervals. Female gender is associated with an increased risk of TdP. However, the causes of the sex difference in risk are poorly understood. Recently, transmural dispersion of repolarization (TDR) has been implicated in the genesis of TdP. Consequently, we compared TdP incidence and TDR between male and female rabbit hearts in order to investigate the mechanism of sex difference in TdP risk in rabbits in vitro.

METHODSBy means of monophasic action potential recording techniques, the monophasic action potential of the epicardium, midmyocardium, and endocardium were simultaneously recorded using specially designed plunge-needle electrodes placed across the left ventricular free wall of both female (n = 8) and male (n = 8) rabbit hearts purfused by the Langendorff method. TdP was induced by bradycardia, d-sotalol, and low-K+, Mg2+ Tyrode solution.

RESULTSTDR measurements in all three myocardial layers of male and female rabbit hearts were (18 +/- 2) ms and (21 +/- 2) ms, respectively (n = 8, P > 0.05). After perfusion with d-sotalol, the 90% monophasic action potential duration was prolonged in both male and female rabbits. TDR in male and female rabbit hearts increased to (29 +/- 2) ms and (61 +/- 2) ms, respectively, a difference that is significant. Eight female rabbit hearts had early afterdepolarization and 7 of them developed TdP. Seven male rabbit hearts had early after depolarization, but only one of these hearts developed TdP.

CONCLUSIONGreater TDR may play an important role in the higher incidence of TdP in female rabbit hearts.

Action Potentials ; Animals ; Electrocardiography ; Female ; Male ; Rabbits ; Risk ; Sex Characteristics ; Sotalol ; Torsades de Pointes ; etiology ; physiopathology