Isolated cataplexy in the differential diagnosis of drop attacks: a case of successful clinical diagnosis and treatment.

Drop attacks are sudden spontaneous falls that are not accompanied by alteration of consciousness and are followed by immediate recovery. Cataplexy, which is usually associated with narcolepsy, is one of the causes of drop attacks. We report a patient with the rare condition of cataplexy without associated narcolepsy (isolated cataplexy).

Irrigated radiofrequency catheter ablation guided by electroanatomic mapping for recurrent ventricular tachycardia after myocardial infarction: the multicenter thermocool ventricular tachycardia ablation trial.

Background: Recurrent ventricular tachycardia (VT) is an important cause of mortality and morbidity late after myocardial infarction. With frequent use of implantable cardioverter-defibrillators, these VTs are often poorly defined and not tolerated for mapping, factors previously viewed as relative contraindications to ablation. This observational multicenter study assessed the outcome of VT ablation with a saline-irrigated catheter combined with an electroanatomic mapping system.

Probability density function revisited: improved discrimination of VF using a cycle length corrected PDF.

The probability density function (PDF) describes the fraction of time an electrogram signal spends at the baseline. In normal rhythm the signal is at baseline during the period between electrogram complexes, while in fibrillation the signal exhibits continuous activity and spends little time at baseline. However, time spent at the baseline is dependent on the rate of the rhythm, which limits the ability of the PDF algorithm to discriminate ventricular fibrillation from fast nonfibrillatory rhythms.

Retroperitoneal placement of an ICD generator: a solution for a difficult problem.

A woman experienced multiple episodes of pocket erosion after placement of an implantable cardioverter defibrillator culminating in a pocket infection. The device was placed in a retroperitoneal location, and the patient has not developed further episodes of pocket erosion or infection. Interrogation of the device in this position and its subsequent replacement have been straightforward.

Evaluation of techniques for recognition of ventricular arrhythmias by implanted devices.

Implantable devices that provide antitachycardia and defibrillation capability currently have limited ability to distinguish among different cardiac rhythms. We have investigated three methods of electrogram analysis: rate, irregularity, and amplitude distribution. In 35 episodes in 19 patients, we applied these three algorithms to 15 s recorded passages of ventricular electrograms during supraventricular tachycardia (N = 11), ventricular tachycardia (N = 11), and ventricular fibrillation (N = 13).