Acute delayed gastric emptying after ablation of atrial fibrillation: treatment with botulinum toxin injection

Catheter Ablation in the Treatment of Atrial Fibrillation

Catheter ablation (CA) of the pulmonary veins for atrial fibrillation (AF) is growing exponentially and is the most commonly performed electrophysiologic procedure. Initial descriptions focused on CA for paroxysmal AF, and now more recently expanded in application to persistent AF and those with comorbid heart failure. Efforts to improve success have and continue to address issues such as pulmonary vein "reconnection" following ablation through different ablative energy modalities, and the use of a "hybrid" surgical/endocardial combined approach in persistent forms of AF. Technologic advances as well are concurrently seeking to improve safety, particularly regarding the incidence of atrio-esophageal fistula in this seemingly ever-growing ablation population.

Botulinum Toxin A Improves Symptoms of Gastroparesis

BACKGROUND AND AIMS

Pyloric injections of botulinum toxin A (BoNT/A) have shown benefit in open-label studies for patients with gastroparesis but not in randomized trials. We sought to examine the effectiveness of BoNT/A injections in a prospective open-label trial of patients with gastroparesis to assess specific symptom improvements over the course of 6 months. We also wanted to determine if specific biochemical measures including creatinine kinase, lactate dehydrogenase, aldolase, and C-reactive protein suggesting muscular injection could be used to predict successful response to pyloric injections of BoNT/A.

METHODS

Patients with gastroparesis undergoing pyloric BoNT/A injections for the treatment of symptomatic gastroparesis were enrolled. The patients completed the Gastroparesis Cardinal Symptom Index (GCSI) at the initial encounter and at 1, 3, and 6 months. Blood samples were collected before and 1 h after BoNT/A therapy.

RESULTS

We enrolled 34 patients for serum analysis of which 25 patients were available for symptom follow-up. Sixty-four percent of patients had an improvement in symptoms at 1 month. Patients with improved GCSI total score at 1 month had an improvement in most individual symptoms evaluated. For patients that improved at 1 month, this improvement often extended up to 6 months (p = 0.04). Serum measures studied did not correlate with clinical outcomes.

CONCLUSIONS

BoNT/A therapy to the pylorus provided symptomatic improvement at 1 month in 64% of patients. For those patients initially responding, the improvement can last out to 6 months. The biochemical markers did not serve to predict the outcome of injections.

Botulinum Toxin Injection for Treatment of Gastroparesis

Refractory gastroparesis is among the most difficult therapeutic challenges in gastroenterology. Pyloric dysfunction has been described in a subset of patients with gastroparesis, prompting experimentation with botulinum toxin injections into the pylorus, which is relatively safe and has been successfully used in other gastrointestinal disorders. However, causality between pyloric dysfunction and symptoms of gastroparesis has never been demonstrated. Although several open-label studies showed initial promise, 2 randomized clinical trials failed to elicit a difference in clinical outcomes in botulinum toxin versus placebo. Based on current evidence, further use of botulinum toxin for gastroparesis is discouraged outside of a research trial.

Upper gastrointestinal complications following ablation therapy for atrial fibrillation

BACKGROUND

Following ablation therapy for cardiac arrhythmias, patients may develop upper gastrointestinal (UGI) symptoms. The vagus nerve is close to the atria and may be affected by ablating energy.

AIM

To identify structural or functional complications in UGI tract following ablation for atrial fibrillation (AF) and clinical outcomes and association with vagal dysfunction.

METHODS

Using natural language processing of electronic medical records and an AF ablation database of 5380 patients treated during 17 years, we identified 40 patients with UGI complications. We evaluated vagal dysfunction by electrocardiogram (ECG) showing lack of sinus arrhythmia (variation in R-R interval by ≥120 milliseconds, in presence of normal sinus P waves and constant P-R interval).

KEY RESULTS

Among 40 patients: (A) eight had structural GI complications confirmed by diagnostic tests: seven with esophageal ulcer/erosions and no signs of UGI bleeding and one developed esophagopericardial fistula (and survived with treatment); (B) 15 had functional UGI complications confirmed by objective motility tests. Nine had newly developed symptoms and six had aggravated symptoms; and (C) the remaining 17 had GI symptoms without relevant diagnostic results. Most UGI issues resolved spontaneously or with conservative treatment. However, 2 died several weeks after ablation procedure; cause of death was suspected atrioesophageal fistula or esophageal rupture. Vagal dysfunction persisted for 3 months in 13 and was transient in 8.

CONCLUSIONS/INFERENCES

Although most GI issues resolved spontaneously, there should be a high index of clinical suspicion in patients with persistent symptoms. Vagal dysfunction may serve as a marker of more extensive tissue damage.

Effect of atrial fibrillation ablation on gastric motility: the atrial fibrillation gut study

BACKGROUND

Collateral damage to the vagal nerve and the upper gastrointestinal (UGI) system during atrial fibrillation ablation has not been systematically evaluated.

METHODS AND RESULTS

We performed a prospective, observational study assessing the effect of atrial fibrillation ablation on the function of the vagus nerve/UGI system. All patients underwent esophageal manometry, gastric emptying study, and sham-feeding test (corresponding to esophageal, gastric, and small intestinal function evaluation, respectively) before ablation (baseline) and subsequently at 24 hours, 90 days, and 180 days after the procedure. In addition, UGI symptom assessment using the patient assessment of upper gastrointestinal disorders-symptom severity index (PAGI-SYM) questionnaire was performed at baseline and during each of the subsequent evaluations. Of the 27 patients enrolled in the study, 9 (33%) patients had abnormal UGI function at baseline; defined as at least one of the 3 abnormal tests. At 24 hours after the radiofrequency catheter ablation, 20 (74%) patients had at least 1 new abnormality on the UGI function tests (P<0.001). New onset esophageal dysmotility, delayed gastric emptying time, and abnormal sham-feeding tests were observed in 13 (48%), 13 (48%), and 9 (33%) patients, respectively. Mean PAGI-SYM scores increased from 7.78±6.6 at baseline to 15.56±13.4 (P=0.002) at 24 hours. New onset abnormalities persisted in 9 (33%) patients at 3 months and normalized in all patients at 6 months.

CONCLUSIONS

Atrial fibrillation ablation results in functional impairment of the UGI system, including the esophagus, stomach, and small intestine. This impairment is transient and is probably mediated by the injury to the components of the vagal nerve.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique Identifier: NCT01396356.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.