Prevalence of fever in patients undergoing left atrial ablation of atrial fibrillation guided by barium esophagraphy.

BACKGROUND: Real-time esophageal imaging is critical in avoiding esophageal injury. However, the safety of esophageal imaging with barium has not been specifically explored. METHODS: Three hundred seventy consecutive patients underwent left atrial (LA) ablation of atrial fibrillation (AF) under conscious sedation. One hundred eighty-five patients (50%) underwent the ablation procedure with, and 185 patients (50%) underwent the procedure without administration of barium. Fever, as a surrogate for aspiration, was defined as a maximal temperature >or=100 degrees F within the first 24 hours following the ablation procedure. RESULTS: Thirty of the 370 patients (8%) developed fever within 24 hours after LA ablation. The prevalence of fever was 9% (17/185) among patients who received barium and 7% (13/185) among those who did not receive barium (P = 0.6). Evaluation revealed the following causes of fever in 14 of the 30 patients (47%) with no difference in prevalence between the 2 groups: pericarditis, venous thromboembolism, hematoma, and infiltrate on chest radiography. Multivariate analysis failed to reveal any factors associated with development of fever. None of the patients experienced serious complications such as respiratory failure or atrioesophageal fistula. CONCLUSIONS: Fever may occur in approximately 10% of patients undergoing LA ablation of AF. Administration of barium is not associated with fever or other complications such as aspiration pneumonia. Real-time imaging of the esophagus with barium administration in conjunction with conscious sedation appears to be safe.

Radiofrequency catheter ablation of chronic atrial fibrillation guided by complex electrograms.

BACKGROUND: Radiofrequency catheter ablation of atrial fibrillation (AF) guided by complex fractionated atrial electrograms has been reported to eliminate AF in a large proportion of patients. However, only a small number of patients with chronic AF have been included in previous studies. METHODS AND RESULTS: In 100 patients (mean age, 57+/-11 years) with chronic AF, radiofrequency ablation was performed to target complex fractionated atrial electrograms at the pulmonary vein ostial and antral areas, various regions of the left atrium, and the coronary sinus until AF terminated or all identified complex fractionated atrial electrograms were eliminated. Ablation sites consisted of > or = 1 pulmonary vein in 46% of patients; the left atrial septum, roof, or anterior wall in all; and the coronary sinus in 55%. During 14+/-7 months of follow-up after a single ablation procedure, 33% of patients were in sinus rhythm without antiarrhythmic drugs, 38% had AF, 17% had both AF and atrial flutter, 9% had persistent atrial flutter, and 3% had paroxysmal AF on antiarrhythmic drugs. A second ablation procedure was performed in 44% of patients. Pulmonary vein tachycardia was found in all patients in both previously targeted and nontargeted pulmonary veins. There were multiple macroreentrant circuits in the majority of patients with atrial flutter. At 13+/-7 months after the last ablation procedure, 57% of patients were in sinus rhythm without antiarrhythmic drugs, 32% had persistent AF, 6% had paroxysmal AF, and 5% had atrial flutter. CONCLUSIONS: Modest short-term efficacy is achievable with radiofrequency ablation of chronic AF guided by complex fractionated atrial electrograms, but only after a second ablation procedure in > 40% of patients. Rapid activity in the pulmonary veins and multiple macroreentrant circuits are common mechanisms of recurrent atrial arrhythmias.

Twenty-one episodes of peritonitis in a continuous ambulatory peritoneal dialysis patient: What is the root cause?

A 51-year-old female, with non-alcoholic liver cirrhosis, portal hypertension, type 2 diabetes mellitus, autosomal dominant polycystic kidney disease with a clipped cerebral aneurysm and chronic kidney disease stage 5 was on continuous ambulatory peritoneal dialysis (CAPD) for 6.5 years elsewhere. She came for opinion on continuation of CAPD as she had 21 episodes of peritonitis in 76 months. Her blood pressure was 80/50 mmHg. She was on haemodialysis with a temporary central access for 2 weeks. She had no abdominal tenderness, and exit site looked normal. Fluid was negative for Mycobacterium tuberculosis. Laparoscopically, we replaced the catheter with a new swan-neck Tenckhoff double-cuff catheter through a different exit site in the same sitting. Catheter-tip biofilm culture isolated Enterococcus casseliflavus. Peritoneal sampling biopsy showed evidence of fibrosis. She has adequate ultrafiltration and is currently on automated peritoneal dialysis for 5 months.

Risk of thromboembolic events after percutaneous left atrial radiofrequency ablation of atrial fibrillation.

BACKGROUND: In patients with atrial fibrillation (AF), the risk of thromboembolic events (TEs) is variable and is influenced by the presence and number of comorbid conditions. The effect of percutaneous left atrial radiofrequency ablation (LARFA) of AF on the risk of TEs is unclear. METHODS AND RESULTS: LARFA was performed in 755 consecutive patients with paroxysmal (n = 490) or chronic (n = 265) AF. Four hundred eleven patients (56%) had > or = 1 risk factor for stroke. All patients were anticoagulated with warfarin for > or = 3 months after LARFA. A TE occurred in 7 patients (0.9%) within 2 weeks of LARFA. A late TE occurred 6 to 10 months after ablation in 2 patients (0.2%), 1 of whom still had AF, despite therapeutic anticoagulation in both. Among 522 patients who remained in sinus rhythm after LARFA, warfarin was discontinued in 79% of 256 patients without risk factors and in 68% of 266 patients with > or = 1 risk factor. Patients older than 65 years or with a history of stroke were more likely to remain anticoagulated despite a successful outcome from LARFA. None of the patients in whom anticoagulation was discontinued had a TE during 25 +/- 8 months of follow-up. CONCLUSIONS: The risk of a TE after LARFA is 1.1%, with most events occurring within 2 weeks after the procedure. Discontinuation of anticoagulant therapy appears to be safe after successful LARFA, both in patients without risk factors for stroke and in patients with risk factors other than age > 65 years and history of stroke. Sufficient safety data are as yet unavailable to support discontinuation of anticoagulation in patients older than 65 years or with a history of stroke.

A tailored approach to catheter ablation of paroxysmal atrial fibrillation.

BACKGROUND: Because the genesis of atrial fibrillation (AF) is multifactorial and variable, an ablation strategy that involves pulmonary vein isolation and/or a particular set of ablation lines may not be equally effective or efficient in all patients with AF. A tailored strategy that targets initiators and drivers of AF is a possible alternative to a standardized lesion set. METHODS AND RESULTS: Catheter ablation was performed in 153 consecutive patients (mean age, 56+/-11 years) with symptomatic paroxysmal AF with the use of an 8-mm tip radiofrequency ablation catheter. The esophagus was visualized with barium. The pulmonary veins and left atrium were mapped during spontaneous or induced AF. Arrhythmogenic pulmonary veins were isolated or encircled. If AF was still present or inducible, complex electrograms in the left atrium, coronary sinus, and superior vena cava were targeted for ablation. The end point of ablation was absence of frequent atrial ectopy and spontaneous AF during isoproterenol infusion and noninducibility of AF. Routine energy applications near the esophagus were avoided. During follow-up, left atrial flutter developed in 19% of patients and was still present in 10% at >12 weeks of follow-up. A repeat ablation procedure was performed in 18% of patients. During a mean follow-up of 11+/-4 months, 77% of patients were free from AF and/or atrial flutter without antiarrhythmic drug therapy. Pericardial tamponade or transient neurological events occurred in 2% of procedures. CONCLUSIONS: A tailored ablation strategy that only targets triggers and drivers of AF is feasible and eliminates paroxysmal AF in approximately 80% of patients.

Echocardiography induced tachycardia in a patient with a minute ventilation rate responsive pacemaker.

We report a case of a 57 year-old man with a minute ventilation rate-response pacemaker and an inappropriate increase in his heart rate during a transthoracic echocardiography study. The increase in heart rate was due to interference between echocardiography and minute ventilation sensor. This was confirmed by a repeat echocardiogram, which reproduced the same effect and turning off the minute ventilation sensor stopped the tachycardia. We suggest that deactivating the minute ventilation sensor would avoid this interaction and electrophysiologists should be aware of this unusual electromagnetic interference phenomenon.

3-dimensional mapping and radiofrequency ablation of atrial flutter in a patient with interrupted inferior vena cava.

The presence of isolated interrupted inferior vena cava (IVC) is very rare. Though the occurrence of typical atrial flutter in this setting has recently been described, the use of 3-dimensional activation mapping to aid the management of such patients has not yet been described. We report the successful ablation of this arrhythmia in a 63-year-old woman using the superior route through the internal jugular vein with the help of a mapping system.

Association of decreased glomerular filtration rate with racial differences in survival after acute myocardial infarction.

BACKGROUND AND OBJECTIVES: African-American race and decreased kidney function have been associated with higher mortality after acute myocardial infarction (AMI). However, whether there are racial differences in the prevalence or prognostic importance of renal insufficiency in AMI is unknown. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: Among 1847 AMI patients enrolled in the multicenter Prospective Registry Evaluating Myocardial Infarction Event and Recovery (PREMIER) study, estimated glomerular filtration rate (eGFR) was used to stratify prognosis and to examine potential interactions among eGFR, race, and mortality. Multivariable proportional hazards regression was used to examine the effect of race and eGFR on 3.5-year all-cause mortality. RESULTS: Race and eGFR were significantly associated with mortality. After adjustment for eGFR alone, differences in mortality by race were substantially attenuated (unadjusted hazard ratio [HR] for African Americans=1.56 [95% confidence interval {CI}=1.2 to 2.1]; eGFR-adjusted HR=1.32 [95% CI=0.99 to 1.75]). A similar magnitude of attenuation in racial differences in survival was observed after adjustment for all covariates except eGFR (HR=1.29 [95% CI=0.96 to 1.72]). A final model adjusting for all covariates only slightly attenuated the association further. No interaction between race and eGFR was detected. CONCLUSIONS: Renal insufficiency, which may represent chronic kidney disease, is a prognostically important comorbidity in African Americans after AMI. However, the effect of decreased eGFR on mortality is comparable between races, suggesting that preventing renal insufficiency in African Americans could be an important target to reduce racial disparities in post-AMI survival.

Randomized evaluation of right atrial ablation after left atrial ablation of complex fractionated atrial electrograms for long-lasting persistent atrial fibrillation.

BACKGROUND: With electrogram-guided radiofrequency ablation (RFA) of long-lasting persistent atrial fibrillation (AF), the best results have been reported when complex fractionated electrograms (CFAEs) in both the left (LA) and right (RA) atria were targeted. However, many studies have reported excellent outcomes from RFA of long-lasting persistent AF with the use of other ablation strategies that were limited to the LA. The incremental value of RFA of RA CFAEs is yet to be defined. METHODS AND RESULTS: In 85 patients with long-lasting persistent AF (age=59+/-10 years), RFA was directed at CFAEs in the LA and coronary sinus until AF terminated (19) or all identified LA CFAEs were eliminated. Sixty-six patients who remained in AF were randomly assigned to cardioversion and no further RFA (n=33) or to RFA of RA CFAEs (n=33). RA sites consisted of the crista terminalis (69%), septum (38%), superior vena cava (28%), coronary sinus ostium (22%), and the base of the appendage (31%). AF terminated in 1 (3%) of 33 patients during RA RFA. At 17+/-6 months after a single ablation procedure, 74% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Rates of freedom from AF were similar in the patients randomized to no RFA in the RA (24%) and those randomized to RFA of RA CFAEs (30%, P=0.8). The ablation procedure was repeated in 26 patients (31%) for AF (n=22) or atrial flutter (n=4). At 16+/-7 months after the final procedure, 89% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Among the randomized patients, the proportion of patients who remained in sinus rhythm was similar in patients who did not undergo RFA of RA CFAEs (52%) and those who did (58%, P=0.6). CONCLUSIONS: After RFA of CFAEs in the LA and coronary sinus, ablation of CFAEs in the RA provides little or no increment in efficacy among patients with long-lasting persistent AF.