Re-entry circuit in ventricular tachycardia due to focal fatty-fibrosis in a patient with myotonic dystrophy

A 69-year-old man with a recurrent ventricular tachycardia (VT) was admitted. The patient was diagnosed as myotonic dystrophy type 1 (DM1) and DNA analysis revealed 1,800 CTG-repeat expansion in the myotonic dystrophy protein kinase (DMPK) gene. Ultrasonic cardiogram (UCG), left ventriculogram (LVG) and magnetic resonance imaging (MRI) did not show any abnormal sign including fatty infiltration. But, endomyocardial biopsy obtained from ventricular outflow tract revealed severe fatty infiltration and interstitial fibrosis. Radiofrequency catheter ablation at the biopsy site could eliminate VT, so it was strongly suggested that the re-entry circuit was formed by focal fatty-fibrosis. Careful observation should be continued for a long period.     

Polymorphous ventricular tachycardia due to alpha-blockade

We report a case of polymorphous ventricular tachycardia caused by treatment with the post-synaptic alpha-blocking agent indoramin. This has not been reported with indoramin previously, nor to our knowledge with any other alpha-blocker. This pro-arrhythmic effect appears to be related to its class 3 anti-arrhythmic properties (QT interval prolongation) which is dose dependent, occurring only at large doses.     

Incessant ventricular tachycardia due to subacute thyroiditis

Recent instrumental and technical developments have improved the outcomes of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions. Recently, several cases of PCI in patients with stable coronary artery disease (CAD) using a retrograde approach through the collateral vessels of the CTO have been reported. We herein describe firstly a successful PCI for a CTO lesion using a retrograde approach in the clinical setting of acute coronary syndrome (ACS).     

Life-threatening ventricular tachycardia due to liquorice-induced hypokalaemia

We report on a patient with hypokalaemia and severe ventricular tachycardia of torsades de pointes type which turned out to be caused by an apparent mineralocorticoid excess syndrome associated with liquorice consumption. The patient, a 44-year-old woman, attended the hospital because of irregular heart rhythm and she displayed repeated episodes of life-threatening torsades de pointes ventricular tachycardia. The initial serum potassium was low: 2.3 mmol L-1. The patient was treated with potassium and magnesium infusions, and the dysrhythmias eventually ceased. Endocrinological investigations showed no indication of Cushing's syndrome or hyperaldosteronism. After some time it became clear that the patient had ingested moderately large amounts of liquorice every day for 4 months. After the patient stopped this habit the hypokalaemia and dysrhythmias did not recur and after more than 1 year there are no signs of cardiac illness.     

Recurrent ventricular tachycardia due to pentamidine-induced cardiotoxicity

Although pentamidine isethionate is effective in the treatment of Pneumocystis carinii pneumonia, it frequently causes serious adverse reactions. We report a case of reversible pentamidine-induced cardiotoxicity, characterized electrocardiographically by prolongation of the QT interval, T-wave inversion, and electrical alternans of the U-wave. In addition, the patient had repeated episodes of ventricular tachycardia that culminated in torsades de pointes. Our case re-emphasizes the need for close patient monitoring during pentamidine therapy.     

Refractory symptomatic ventricular tachycardia and ventricular fibrillation in elderly patients

The problem of refractory life-threatening ventricular tachyarrhythmias in elderly patients has not been previously studied. To determine if clinical, anatomic, or electrophysiologic variables and prognosis are significantly different in elderly subjects, 49 elderly (68 to 84 years) and 44 younger (44 to 53 years) survivors of refractory symptomatic ventricular tachycardia and/or ventricular fibrillation secondary to coronary artery disease were studied. Elderly patients displayed more extensive anatomic coronary artery disease, with 80 percent having three-vessel disease in comparison with 30 percent of the younger patients (p less than 0.001). Prior myocardial infarction, heart failure, and cardiomegaly were more common in the elderly group (p less than 0.01, p less than 0.001, and p less than 0.034, respectively), whereas angina was more common in the younger group (p less than 0.001). In 55 percent of the elderly patients and 58 percent of the younger patients, electrophysiologic testing demonstrated inducible sustained ventricular tachycardia that required treatment with an investigative antiarrhythmic drug and/or cardiac surgery, including implantation of an automatic defibrillator. Elderly patients tolerated aggressive evaluation as well as did younger patients, and despite the difference in clinical and anatomic findings, long-term survival curves were similar, although the probability of survival at 20 months was 62 percent in the elderly and 80 percent in the younger patients. This difference in early survival is explained by eight surgical deaths in the elderly group, compared with two in the younger group.     

Electrocardiographic artifact due to a mobile phone mimicking ventricular tachycardia

A case of electrocardiographic artifact due to mobile a phone mimicking ventricular tachycardia was presented. The artifact was discriminated by close scrutiny of ECG and was attributed to a mobile phone because it was simultaneous with mobile phone game.     

Refractory ventricular tachycardia terminated by electric countershock

A case of persistent ventricular tachycardia terminated by alternating current countershock is presented. The importance of electric countershock as a means of controlling refractory ventricular tachycardia in dire situations is discussed.     

Paroxysmal ventricular tachycardia due to interventricular hydatid cyst

A 35-year-old male patient with palpitations and mild lightheadedness was admitted to our clinic. Short-lasting paroxysmal ventricular tachycardia was diagnosed following 12-lead electrocardiography (ECG). A mass that included two-thirds of the interventricular septum and the left ventricular cavity was seen by two-dimensional echocardiography and magnetic resonance imaging (MRI). Specific hemagglutination tests for hydatid cyst were positive. The mass was excised, and the patient had a septoplasty operation to repair the remaining septal defect. He is currently being followed and reports no complaints. No evidence of arrhythmia was noted in 24-hour ambulatory ECG monitoring.     

Paroxysmal fascicular tachycardia and ventricular tachycardia due to mechanical stimulation by a mitral valve prosthesis

Electrophysiologic studies were performed in a woman who had two varieties of paroxysmal wide QRS tachycardia after mitral valve replacement with a Starr-Edwards prosthesis. One tachycardia originated in the left anterior fascicle; QRS complexes were 100 ms wide and resembled right bundle branch block with left posterior fascicular block, and a His bundle potential preceded each QRS by an interval of 20 ms (compared with 50 ms during sinus rhythm). The other tachycardia originated in the left ventricle. Clinical and echocardiographic observations suggested that the tachycardias were caused by mechanical stimulation of the interventricular septum by the mitral prosthesis.