Atrial fibrillation with a very rapid ventricular response as the first clinical arrhythmia in a 76-year-old man

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 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.

Wolff-Parkinson-White syndrome in the elderly: clinical and electrophysiological findings

BACKGROUND

Screening for Wolff-Parkinson-White (WPW) syndrome is recommended in children and young adults. The aim of this study was to evaluate the clinical and electrophysiological characteristics of patent WPW syndrome in subjects > or =60 years of age.

METHODS

Four-hundred and fifty-nine consecutive patients with WPW syndrome, aged 8-80 years, were recruited; 32 (7%) of these patients were > or =60 years of age. The clinical, electrophysiological and therapeutic data for these patients were evaluated.

RESULTS

Sixteen men and 16 women, aged 60-81 years (67+/-4.5), were admitted for resuscitated sudden death (1), rapid atrial fibrillation (4), syncope (4), or junctional tachycardia (13); 10 patients were asymptomatic (10). Left lateral bundles of Kent were detected more frequently in patients over 60 years (56%) than in those<60 years of age (40.5%). Reciprocal tachycardia was induced in 58% of subjects<60 years of age and 53% of those > or =60 years old (difference not significant); atrial fibrillation was more frequent in subjects > or =60 years of age (37.5% vs. 19%) (p<0.05). The incidence of malignant forms of WPW syndrome was identical in older and younger subjects. Ablation of the accessory pathway was indicated 18 times; effective ablation of a left bundle of Kent required a second intervention more often in patients > or =60 years of age (22% vs. 5%) (p<0.05).

CONCLUSION

WPW syndrome is not uncommon in subjects over 60 years of age (7%). Left lateral accessory pathways, that have similar conduction properties to those in much younger subjects, are common. Ablation of the bundle of Kent is often difficult but is indicated in symptomatic subjects or those with more serious forms of WPW syndrome.