Ventricular Tachycardia in Fabry Disease Detected in a 50-Year-Old Woman during 14-Day Continuous Cardiac Monitoring

Fabry disease is an X-linked lysosomal storage disorder. Female carriers were long thought to be asymptomatic; however, research has revealed the opposite. Cardiac conditions are the chief causes of death in women with Fabry disease. Although ventricular tachycardia has been reported in male patients with Fabry disease, it is not thought to be a frequent finding in females. We describe the case of a 50-year-old woman in whom we used 14-day continuous electrocardiographic monitoring to identify nonsustained ventricular tachycardia, after electrocardiograms and 24-hour Holter monitoring failed to detect the arrhythmia. A permanent implantable cardioverter-defibrillator relieved the patient's symptoms. We discuss why this case supports the need for more extensive electrophysiologic evaluation in women who have Fabry disease.

Inappropriate implantable cardioverter-defibrillator shocks attributed to alternating-current leak in a swimming pool

Implantable cardioverter-defibrillators (ICDs) are the standard of care for preventing sudden cardiac death in patients who are predisposed to malignant ventricular arrhythmias. Causes of inappropriate ICD shock include equipment malfunction, improper arrhythmia evaluation, misinterpretation of myopotentials, and electromagnetic interference. As the number of implanted ICDs has increased, other contributors to inappropriate therapy have become known, such as minimal electrical current leaks that mimic ventricular fibrillation. We present the case of a 63-year-old man with a biventricular ICD who received 2 inappropriate shocks, probably attributable to alternating-current leaks in a swimming pool. In addition, we discuss ICD sensitivity and offer recommendations to avoid similar occurrences.

Unexpected embolization of Teflon pledget in the left main stem during: a Bentall operation

We report the case of an 83-year-old man in whom acute left ventricular failure with ventricular arrhythmic storm developed during a Bentall operation. During re-exploration of the annular and coronary ostial anastomoses, no abnormality was seen, and none of the common sequelae of aortic root replacement was evident. The application of retrograde cardioplegia yielded a Teflon pledget that had migrated into the distal part of the left main stem. The pledget was removed, the anastomoses were reestablished, and the patient recovered uneventfully. This case suggests that left ostial anastomosis re-exploration should be carefully considered when no other cause of coronary insufficiency is obvious, and that retrograde cardioplegia may be useful to detect embolization in the left coronary system.

Heterogeneity of left ventricular signal characteristics in response to acute vagal stimulation during ventricular fibrillation in dogs

Studies have shown that long-term vagal stimulation is protective against ventricular fibrillation; however, the effects of acute vagal stimulation during ventricular fibrillation in the normal heart have not been investigated. We examined the effects of acute vagal stimulation on ventricular fibrillation in a canine model. In 4 dogs, we induced 30-second periods of ventricular fibrillation by means of intraventricular pacing. During 2 of the 4 periods of fibrillation that we analyzed, vagal stimulation was delivered through electrodes in the caudal ends of the vagus nerves. Noncontact unipolar electrograms were recorded from 3 ventricular regions: the basal septum, apical septum, and lateral free wall. We then computed the most frequent cycle length, mean organization index, and mean electrogram amplitude for each region. During fibrillation, vagal stimulation shortened the most frequent cycle lengths in the basal septum (P=0.02) and apical septum (P=0.0001), but not in the lateral wall (P=0.46). In addition, vagal stimulation significantly reduced the mean organization indices in the apical septum (P <0.001) and lateral wall (P <0.001), but not in the basal septum (P=0.19). Furthermore, vagal stimulation raised the mean electrogram amplitude in the basal septum (P <0.01) but lowered it substantially in the apical septum (P=0.00005) and lateral wall (P=0.00003). We conclude that vagal stimulation acutely affects the characteristics of ventricular fibrillation in canine myocardium in a spatially heterogeneous manner. This nonuniformity of response may have implications with regard to manipulating the autonomic system as a means of modifying the substrate for ventricular dysrhythmias.