Point-of-care ultrasound for assessing arteriovenous fistula maturity in outpatient hemodialysis.

BACKGROUND: Point-of-care ultrasound in end-stage renal disease is on the rise. Presently the decision to cannulate an arteriovenous fistula is based on its duration since surgery and physical exam. This study examines the effects of point-of-care ultrasound on decreasing the time to arteriovenous fistula cannulation, time spent with a central venous catheter, and the complications and infections that arise. METHODS: Prospective point-of-care ultrasound patients were recruited between January 2015 and January 2018, while retrospective data (non-point-of-care ultrasound) were collected via chart review from patients who had fistula creation between November 2011 and May 2014. Patients had point-of-care ultrasound within 3 weeks after arteriovenous fistula creation and were followed for 1 year. Arteriovenous fistula cannulation was initiated when the following parameters were met: diameter > 6 mm (with no depreciable narrowing of more than 20% throughout), depth < 6 mm, and length > 6 cm. Demographic data, as well as time to cannulation and central venous catheter removal, number of infections, complications, and interventions were compared between point-of-care ultrasound and non-point-of-care ultrasound groups using unpaired t-test, chi-square, and Fisher exact test statistical analysis. RESULTS: A total of 37 patients with new arteriovenous fistulas were followed by point-of-care ultrasound compared to 29 non-point-of-care ultrasound patients. Point-of-care ultrasound patients had earlier cannulations (35.5 vs 63.3 days, p < 0.05), shorter central venous catheter duration (68.2 vs 98.3 days, p < 0.05), and less infections (12 vs 19) without differences in complication compared to the non-point-of-care ultrasound. CONCLUSION: Point-of-care ultrasound facilitates early and safe arteriovenous fistula cannulation leading to a reduction in central venous catheter time and risk of infection. Point-of-care ultrasound may also aid in earlier identification of complications and difficult cannulations.

Electrocardiographic comparison of ventricular arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy and right ventricular outflow tract tachycardia.

OBJECTIVES: The purpose of this study was to evaluate whether electrocardiographic characteristics of ventricular arrhythmias distinguish patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) from those with right ventricular outflow tract tachycardia (RVOT-VT). BACKGROUND: Ventricular arrhythmias in RVOT-VT and ARVD/C-VT patients can share a left bundle branch block/inferior axis morphology. METHODS: We compared the electrocardiographic morphology of ventricular tachycardia or premature ventricular contractions with left bundle branch block/inferior axis pattern in 16 ARVD/C patients with that in 42 RVOT-VT patients. RESULTS: ARVD/C patients had a significantly longer mean QRS duration in lead I (150 ± 31 ms vs. 123 ± 34 ms, p = 0.006), more often exhibited a precordial transition in lead V(6) (3 of 17 [18%] vs. 0 of 42 [0%] with RVOT-VT, p = 0.005), and more often had at least 1 lead with notching (11 of 17 [65%] vs. 9 of 42 [21%], p = 0.001). The most sensitive characteristics for the detection of ARVD/C were a QRS duration in lead I of ≥120 ms (88% sensitivity, 91% negative predictive value). QRS transition at V(6) was most specific at 100% (100% positive predictive value, 77% negative predictive value). The presence of notching on any QRS complex had 79% sensitivity and 65% specificity of (55% positive predictive value, 85% negative predictive value). In multivariate analysis, QRS duration in lead I of ≥120 ms (odds ratio [OR]: 20.4, p = 0.034), earliest onset QRS in lead V(1) (OR: 17.0, p = 0.022), QRS notching (OR: 7.7, p = 0.018), and a transition of V(5) or later (OR: 7.0, p = 0.030) each predicted the presence of ARVD/C. CONCLUSIONS: Several electrocardiographic criteria can help distinguish right ventricular outflow tract arrhythmias originating from ARVD/C compared with RVOT-VT patients.