Mechanism of atrial flutter occurring late after orthotopic heart transplantation with atrio-atrial anastomosis

OBJECTIVE: We sought to better define the electrophysiologic mechanism of atrial flutter in patients after heart transplantation. BACKGROUND: Atrial flutter is a recognized problem in the post-cardiac transplant population. The electrophysiologic basis of atrial flutter in this patient population is not completely understood. METHODS: Six patients with cardiac allografts and symptoms related to recurrent atrial flutter underwent diagnostic electrophysiologic study with electroanatomic mapping and radiofrequency catheter ablation. Comparison was made with a control non-transplant population of 11 patients with typical counterclockwise right atrial flutter. RESULTS: In each case, mapping showed typical counterclockwise activation of the donor-derived portion of the right atrium, with concealed entrainment shown upon pacing in the cavotricuspid isthmus (CTI). The anastomotic suture line of the atrio-atrial anastomosis formed the posterior barrier of the reentrant circuit. Ablation of the electrically active, donor-derived portion of the CTI was sufficient to terminate atrial flutter and render it noninducible. Comparison with the control population showed that the electrically active portion of the CTI was significantly shorter in patients with transplant-associated flutter and that ablation was accomplished with the same or fewer radiofrequency lesions. CONCLUSIONS: Atrial flutter in cardiac transplant recipients is a form of typical counterclockwise, isthmus-dependent flutter in which the atrio-atrial anastomotic suture line forms the posterior barrier of the reentrant circuit. Ablation in the donor-derived portion of the CTI is sufficient to create bidirectional conduction block and eliminate this arrhythmia. Ablation or surgical division of the donor CTI at the time of transplantation could prevent this arrhythmia.     

Long-term single procedure efficacy of catheter ablation of atrial fibrillation

Background Two important limitations of the data regarding the outcomes of catheter ablation of atrial fibrillation (AF) are the short-term follow-up used in most published studies and the lack of single-procedure outcomes.Objective The objective was to report the long-term single-procedure outcomes at our center.Materials and methods The patient population was comprised of 200 consecutive patients who underwent ablation (133 men; age 56 ± 11 years). Atrial fibrillation was paroxysmal in 92 (46%). Success was defined as absence of symptomatic AF, off antiarrhythmic drug (AAD) after a single procedure.Results After a follow-up of 26 ± 11 months, the single-procedure long-term success rate was 28% with an additional 7% of patients demonstrating improvement. After including repeat procedures in 64 patients, the overall long-term success rate was 41% with 11% demonstrating improvement. Further subgroup analysis of 48 paroxysmal AF patients considered to be optimal candidates for the procedure, revealed a long-term success rate of 69% with an additional 4% demonstrating improvement. A major complication occurred in 7.9% of patients.Conclusion The results reveal that the long-term single-procedure success rate of catheter ablation of AF in a cohort of patients with predominantly non-paroxysmal AF is less than 40%. The inclusion of redo procedures resulted in an improvement in outcomes. A much higher success rate of 69% was achieved in patients with paroxysmal AF considered to be optimal candidates for this procedure. These results make it clear that further advances in the technique of catheter ablation of AF are needed to improve the safety and efficacy of this procedure. In order to be able to compare outcomes of various techniques in differing patient populations, we urge investigators to report long-term single procedure outcomes.This study was supported by The Norbert and Louise Grunwald Cardiac Arrhythmia Research Fund.     

Value of wireless capsule endoscopy in patients with indeterminate colitis (inflammatory bowel disease type unclassified)

BACKGROUND: Wireless capsule endoscopy (WCE) can identify small bowel mucosal lesions not seen with other imaging modalities. This technique can therefore play an important diagnostic role in the evaluation of patients with inflammatory bowel disease type unclassified (IBDU). We report on a multicentric study whose objective was to evaluate the value of WCE to increase diagnostic accuracy in categorizing IBDU. METHODS: Thirty patients with IBDU and negative serology were included. WCE was performed with a standard Pillcam capsule. Outcome measures were classified as suggestive of Crohn's disease (CD) when -3 ulcerations were present. RESULTS: WCE displayed endoscopic features suggestive for CD in 5 patients. In 6 other patients, WCE was negative, but repeated ileocolonoscopy with biopsies performed during follow-up evaluation revealed CD in 5 and ulcerative colitis (UC) in 1 patient. UC was found in a seventh case at colectomy performed just after WCE. Eighteen patients remained with a diagnosis of IBDU 16 months on average after WCE. CONCLUSIONS: WCE is a potentially clinically useful technique for categorizing a subgroup of patients with IBDU, although negative WCE does not exclude further diagnosis of CD. Patients with negative WCE who remain IBDU at follow-up evaluation may belong to an original subgroup of IBD.     

Ventricular arrhythmia is predicted by sum absolute QRST integralbut not by QRS width

Background

There is a controversy regarding the association between QRS width and ventricular arrhythmias (VAs). We hypothesized that predictive value of the QRS width could be improved if QRS width were considered in the context of the sum magnitude of the absolute QRST integral in 3 orthogonal leads sum absolute QRST integral (SAI QRST). We explored correlations between QRS width, SAI QRST, and VA in primary prevention implantable cardioverter-defibrillator (ICD) patients with structural heart disease.

Methods

Baseline orthogonal electrocardiograms were recorded at rest in 355 patients with implanted primary prevention ICDs (mean age, 59.5 ± 12.4 years; 279 male [79%]). Patients were observed prospectively at least 6 months; appropriate ICD therapies because of sustained VA served as end points. The sum magnitude of the absolute QRST integral in 3 orthogonal leads (SAI QRST) was calculated.

Results

During a mean follow-up of 18 months, 48 patients had sustained VA and received appropriate ICD therapies. There was no difference in baseline QRS width between patients with and those without arrhythmia (114.9 ± 32.8 vs 108.9 ± 24.7 milliseconds; P = .230). SAI QRST was significantly lower in patients with VA at follow-up than in patients without VA (102.6 ± 27.6 vs 112.0 ± 31.9 mV·ms; P = 0.034). Patients with SAI QRST (≤145 mV·ms) had a 3-fold higher risk of ventricular tachycardia (VT)/ventricular fibrillation (VF) (hazard ratio [HR], 3.25; 95% confidence interval [CI], 1.59-6.75; P = .001). In the univariate analysis, QRS width did not predict VT/VF. In the bivariate Cox regression model, every 1 millisecond of incremental QRS widening with a simultaneous 1 mV·ms SAI QRST decrease raised the risk of VT/VF by 2% (HR, 1.02; 95% CI, 1.01-1.03; P = .005).

Conclusion

QRS widening is associated with ventricular tachyarrhythmia only if accompanied by low SAI QRST.     

Actinomyces graevenitzii pulmonary abscess mimicking tuberculosis in a healthy young man

Pulmonary actinomycosis is a rare disease that is often misdiag-nosed as tuberculosis or lung cancer. Actinomyces graevenitzii is a relatively new recognized Actinomyces species isolated from various clinical samples. The authors report a case of pulmonary actinomycosis caused by A graevenitzii. A computed tomography examination revealed an excavated consolidation in the middle right lobe of a previously healthy young man who presented with a long history of moderate cough. Cultures of the bronchoalveolar lavage fluid confirmed the diagnosis of pulmonary abscess caused by A gravenitzii. At the three-month follow-up consultation and, after six weeks of high-dose amoxicillin, the pulmonary lesion had completely disappeared.     

Complications of catheter ablation for atrial fibrillation: incidence and predictors

Introduction: Pulmonary vein (PV) isolation by catheter ablation is an increasingly used strategy to treat atrial fibrillation (AF). Complication rates from AF ablation reported in different case series vary widely. We conducted a retrospective analysis of 641 consecutive ablation procedures to assess complication rates, temporal trends, and clinical predictors of adverse outcomes.
Methods: All patients (n = 517) undergoing catheter ablation for AF at Johns Hopkins Hospital between February, 2001 and June, 2007 were prospectively enrolled in a database. Data from 641 consecutive procedures were analyzed and complications considered if they occurred within 30 days of ablation. Major complications were defined as those that required intervention, resulted in long-term disability, or prolonged hospitalization.
Results: Thirty-two major complications occurred in 641 procedures (5%). Among the patients with major complications, seven had cerebrovascular accident (CVA), eight had tamponade, one had PV occlusion with hemoptysis, and 11 had vascular injury requiring surgical repair and/or transfusion. No periprocedural deaths occurred, and no instances of esophageal injury were seen. Complication rates were higher during the first 100 cases (9.0%) than during the subsequent 541 (4.3%). Major adverse clinical events were associated with age > 70 years (P = 0.007; odds ratio 3.7, 95% confidence interval 1.4–9.6) and female gender (P = 0.014; odds ratio 3.0, 95% confidence interval 1.3–7.2). No other clinical or procedural predictors of complication were identified.
Conclusions: Complication rates from AF ablation remain significant, despite improved techniques and increased awareness of procedural risks. Both advanced age and female gender predict major adverse events, suggesting careful consideration of the risk/benefit profile in these patients prior to ablation.     

Tyrosinemia type 1 in pediatric nephrology: Not always straightforward

The main clinical features of tyrosinemia type 1 usually appear in the first months of life, including fever, diarrhea, vomiting, liver involvement, growth failure, and renal proximal tubulopathy with subsequent hypophosphatemic rickets. An early diagnosis is crucial in order to provide specific management and to prevent complications. Here, we report on two cases referred primarily to pediatric nephrologists for the diagnosis of “neonatal tubulopathy” and management of “X-linked hypophosphatemia (XLH),” respectively. Our aim is to emphasize that (1) even a mixed tubulopathy can reveal tyrosinemia, and (2) tyrosinemia is a classic differential diagnosis of XLH that should not be forgotten, especially in the era of the anti-FGF23 burosumab.     

Bullous pemphigoid induced by vildagliptin: a report of three cases

To report three cases of bullous pemphigoid in patients treated with vildagliptin. Case 1: An 86‐year‐old woman presented with bullous pemphigoid after 1 month of treatment with vildagliptin and metformin. After introduction of clobetasol, the symptoms resolved although vildagliptin was continued. However, the skin lesions reappeared 3 months later. Sustained remission was achieved only after definitive withdrawal of vildagliptin. Case 2: A 79‐year‐old man presented with bullous pemphigoid after 37‐month treatment with gliclazide, vildagliptin and metformin. The disease at first responded to clobetasol but 3 months later the lesions reappeared. They finally regressed when the gliptin was discontinued. Case 3: A 77‐year‐old woman, treated with gliclazide and vildagliptin for 26 months, presented with bullous pemphigoid, which responded well to discontinuation of the gliptin and topical clobetasol. Gliptins are new molecules for treatment of type 2 diabetes mellitus, which have been suspected of implication in bullous pemphigoid. Such cases have been described in the literature (seven with vildagliptin and three with sitagliptin). In nine of these cases, the gliptin was associated with metformin, but the latter had never been considered responsible. The mechanism implicated in the development of bullous pemphigoid has not yet been clearly identified, but may involve a modified immune response or alteration of the antigenic properties of the epidermal basement membrane. These reports support the risk of bullous pemphigoid in patients exposed to gliptins.