Thirty years of blackouts: a case report of swallow syncope.

Deglutition syncope has been demonstrated in isolated case reports, the first being described over 50 years ago. It is thought to be caused by a hypersensitive vagotonic reflex in response to esophageal dilation after swallowing. It can cause syncope due to complete atrioventricular (AV) block and acute reduction of cardiac output. Although rare, its lethality is worthy of discussion, as early recognition can offer complete treatment with placement of a pacemaker. A 54-year-old man presented with 30 years of lightheadedness and syncope, followed by disorientation and tremors, after eating sandwiches or drinking carbonated beverages. He initially was evaluated by a neurologist. Work-up included cardiac 2D transthoracic echocardiogram, electroencephalogram, swallow stud, pulmonary function tests, electrocardiogram, and cardiac stress testing. All tests were within normal limits, and it was determined that he was suffering from convulsive syncope and deglutition syncope. Referral to the cardiac electrophysiology department with tilt-table testing accompanied by swallow evaluation was then recommended. The tests demonstrated marked vagal response resulting in sinus bradycardia with second-degree AV block and pauses up to 3.5 seconds. Patient experienced near syncope. A rate-responsive, dual-chamber Boston Scientific pacemaker with DDDR programming was implanted. Patient has remained asymptomatic at follow-up.

The impact of vagotonic, adrenergic, and random type of paroxysmal atrial fibrillation on left atrial ablation outcomes.

BACKGROUND: Accumulating data have shown that the autonomic nervous system is strongly implicated in the genesis of atrial fibrillation (AF). The aim of this study was to assess the efficacy of a single ablation procedure in patients with vagotonic, adrenergic and random type of paroxysmal AF. METHODS AND RESULTS: The clinical records of consecutive patients with symptomatic, drug-refractory paroxysmal AF who underwent pulmonary vein antral isolation were analysed. The study population consisted of 104 patients (64 males, mean age 57.9 ± 10.9 years) with paroxysmal AF. Based on AF triggers, patients were classified in those with vagotonic (31.7%), adrenergic (17.3%) and random AF (51%). Subjects with adrenergic and random AF tended to be older (p: 0.104) and displayed a higher incidence of hypertension (p: 0.088) compared with those with vagotonic AF. Following a mean follow-up period of 14.7 ± 7.4 months, 74 patients were free from arrhythmia recurrence (71.2%). Late arrhythmia recurrence (>3 months from the index procedure) occurred in 33.3%, 16.7% and 30.2% of patients with vagotonic, adrenergic and random AF, respectively (p: 0.434). Cox regression analysis showed that early AF recurrence [hazard ratio (HR) 15.76; 95% confidence interval (CI) 5.456-45.566, p: <0.001], left atrial volume (HR 0.969; 95% CI 0.942-0.996, p: 0.025) and statin use (HR 6.828; 95% CI 2.078-22.437 p: 0.002) were independent predictors of late arrhythmia recurrence. CONCLUSIONS: In this study cohort, the type of paroxysmal AF was not associated with arrhythmia recurrence following left atrial ablation.