Nickel elution properties of contemporary interatrial shunt closure devices.

OBJECTIVES: We sought to compare nickel elution properties of contemporary interatrial shunt closure devices in vitro. INTRODUCTION: There are two United States Food and Drug Administration (FDA)-approved devices for percutaneous closure of secundum atrial septal defect: the Amplatzer septal occluder (ASO; St Jude Medical Corporation) and Gore Helex septal occluder (HSO; W.L. Gore & Associates). The new Gore septal occluder (GSO) device is in clinical trials. These are also used off-label for patent foramen ovale closure in highly selected patients. These devices have high nickel content. Nickel allergy is the most common reason for surgical device explantation. Nickel elution properties of contemporary devices remain unknown. METHODS: We compared nickel elution properties of 4 devices - ASO, GSO, HSO, and sternal wire (SW) - while Dulbecco's phosphate-buffered saline (DPBS) served as control. Three samples of each device were submerged in DPBS. Nickel content was measured at 14 intervals over 90 days. RESULTS: Nickel elution at 24 hours, compared to control (0.005 ± 0.0 mg/L), was significantly higher for ASO (2.98 ± 1.65 mg/L; P=.04) and SW (0.03 ± 0.014 mg/L; P=.03). Nickel levels at 90 days, compared to control (0.005 ± 0.0 mg/L) and adjusting for multiple comparisons, were significantly higher for ASO (19.80 ± 2.30 mg/L; P=.01) and similar for HSO (P=.34), GSO (P=.34), and SW (P=.34). ASO had significantly higher nickel elution compared to HSO, GSO, and SW (P=.01). CONCLUSION: There is substantial variability in nickel elution; devices with less exposed nickel (HSO and GSO) have minimal elution. The safety of low nickel elution devices in patients with nickel allergy needs to be evaluated in prospective trials.

Intravenous electrocardiographic guidance for placement of peripherally inserted central catheters.

BACKGROUND: Correct positioning of peripherally inserted central catheters (PICCs) is essential to avoid complications. We evaluated intravenous electrocardiogram (ECG) recordings during PICC placement to assess the effectiveness of this guidance technique to reduce complications resulting from incorrect catheter placement. METHODS: Six patients undergoing PowerPICC catheter insertion were included in this pilot study. Venography through the PICC was performed to identify the superior vena cava-right atrial (SVC-RA) junction. Unipolar ECG recordings from the catheter stylet measured P-wave changes during PICC insertion. RESULTS: The peak P-wave amplitude was highest at the SVC-RA junction. With catheter insertion into the RA, P-wave amplitude decreased and eventually became negative. With catheter withdrawal into the SVC, P-wave amplitude decreased. CONCLUSIONS: P-wave amplitude was highest when the PICC catheter was in the optimal location at the SVC-RA junction. Intravenous ECG monitoring during PICC insertion seems to be a promising technique to guide catheter positioning.

Acoustic cardiographic recording during ventricular fibrillation.

This is the second case report in literature that describes the simultaneous acoustic cardiographic, electrocardiographic, and invasive hemodynamic events that occurred before, during and after ventricular fibrillation that was successfully cardioverted to sinus rhythm. The absence of heart sounds, which are linked to the lack of effective myocardial contractility, correlated well with invasive hemodynamic data, indicating the lack of perfusion during ventricular fibrillation. These observations, coupled with the challenges of pulse detection as a sign of adequate perfusion during resuscitation suggest that acoustic cardiography may be a potentially effective supplemental diagnostic tool during the resuscitation of malignant arrhythmias.