Induction of atrial fibrillation with adenosine during a transesophageal electrophysiology study to risk stratify a patient with asymptomatic ventricular preexcitation.

An asymptomatic adolescent male athlete was incidentally found to have ventricular preexcitation on electrocardiogram during a sports preparticipation physical. A transesophageal electrophysiology study (TEEPS) was performed after an exercise stress test failed to delineate the patient's risk of sudden cardiac death. The TEEPS was favored in this case over a transvenous electrophysiology study due to reduced invasiveness. The goal of the TEEPS was to place the patient into atrial fibrillation (AFib) and evaluate the shortest preexcited RR interval during AFib, thereby assessing the risk of his accessory pathway. Conventional pacing modalities were unable to induce AFib. During atrial burst pacing, adenosine was then administered, which successfully induced AFib. This case highlights adenosine's potential to induce atrial fibrillation during transesophageal electrophysiology studies when atrial pacing alone was unable to do so.

Atrial fibrillation induction by transesophageal electrophysiology studies in patients with asymptomatic ventricular preexcitation.

OBJECTIVE: Ventricular preexcitation is a conduction abnormality caused by an accessory pathway bridging the atria and ventricles. If the accessory pathway conducts rapidly during atrial fibrillation (AFib), sudden death may result. The purpose of this study was to determine the ability of transesophageal electrophysiology studies (TEEPS) to induce AFib in pediatric patients with asymptomatic ventricular preexcitation (aVPE). DESIGN: A retrospective review of patients with aVPE who had a TEEPS was conducted. Inclusion criteria were evidence of ventricular preexcitation on electrocardiogram; age <18 years; and no history of tachycardia, palpitations, or syncope. Data gathered included age, weight, height, form of sedation, and TEEPS results. If AFib was induced, patients were classified as at risk of sudden death if the shortest preexcited RR interval during AFib was <250 ms or no risk if ≥ 250 ms. RESULTS: A total of 26 patients met the inclusion criteria, with average age of 11.9 years, weight of 48.9 kg, and height of 149.2 cm. During the procedure, nine patients underwent conscious sedation (34.6%), and 17 underwent general anesthesia (65.4%). AFib was induced in 23 patients (88.5%), of whom 17 (73.9%) had no risk and six (26.1%) had risk. No statistical differences were noted in age, weight, height, or form of sedation when comparisons were made between AFib induction and no AFib induction. CONCLUSIONS: TEEPS induced AFib in 88.5% of patients. Age, weight, height, and form of sedation had no effect upon AFib inducibility. TEEPS is an effective modality to induce AFib in pediatric patients with aVPE.

Induction of left ventricular fascicular tachycardia with transesophageal pacing in a toddler.

J.V. is a 3(1/2)-year-old patient with left ventricular fascicular ventricular tachycardia that had been well controlled on verapamil for 3 years. He was taken for a transesophageal electrophysiology study prior to discontinuing medication in an attempt to induce his tachycardia. We report the use of transesophageal electrophysiology study as a noninvasive method to induce left ventricular fascicular ventricular tachycardia in a toddler.

Graded blood pressure reduction in hypertensive outpatients associated with use of a device to assist with slow breathing.

To study the effects of device-guided breathing on office systolic blood pressure (SBP), five centers randomized 149 untrained hypertensives (50% male, age 59+/-10 years, baseline blood pressure 150+/-9/86+/-9 mm Hg, 77% taking drug therapy). One half received a device to guide slow breathing; all received a home blood pressure monitor and only simple, written instructions. The changes in office SBP (adjusted for office-to-home difference in baseline SBP and accumulated time spent in slow breathing, guided and measured by the device) were significantly (p<0.001 for trend) correlated with accumulated time spent in slow breathing. Greater decreases in SBP (-15.0+/-1.8 vs. -7.3+/-1.9 mm Hg) were observed for those who spent more (vs. less) than 180 minutes over 8 weeks in slow breathing, as well as those who just monitored their blood pressure at home (-9.2+/-1.6 mm Hg). Thus, even without training, hypertensive patients who receive a device to guide slow breathing significantly lowered their office SBP if the total time spent in slow breathing over 8 weeks exceeded a "threshold" value of 180 minutes.