Metal artefact reduction algorithms prevent false positive results when assessing patients for cardiac implantable electronic device infection.

Software-based metal artefact reduction (MAR) techniques are available to reduce artefacts from cardiac implantable electronic devices (CIED) in the CT data. The impact of disabling MAR techniques on quantification of 18F-FDG uptake around the CIED has not been examined. We consider the importance of enabling MAR in patients with suspected CIED infection to prevent inaccuracies in quantification of tissue tracer uptake on the attenuation-corrected PET images.

Pacing-induced cardiomyopathy: pathophysiological insights through matrix metalloproteinases.

Pacing-induced ventricular dysfunction and pacing-induced cardiomyopathy (PiCMP) are recognized complications of chronic right ventricular pacing. Alterations in myocardial perfusion and sympathetic innervation contribute to the development of pacing-induced heart disease. However, it is unlikely that these are the only processes involved. Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade the collagenous extracellular matrix and play a central role in left ventricular remodelling during the development of heart failure. While the pathophysiological mechanisms and altered MMP expression that occur in chronic pressure overload, ischaemic and non-ischaemic dilated cardiomyopathy have been defined, those that occur in the clinical setting of pacing-induced ventricular dysfunction and PiCMP have not been reported. Here we review the clinical epidemiology of pacing-induced ventricular dysfunction and discuss how data derived from animal models provide insight into how changes in MMP expression and function contribute to the development of PiCMP. The review concludes by exploring pacing strategies that may be used to prevent pacing-induced ventricular dysfunction.

Ambulatory intravenous furosemide for decompensated heart failure: safe, feasible, and effective.

AIMS: This study aims to establish the feasibility, safety, and efficacy of outpatient intravenous (IV) diuretic treatment for the management of decompensated heart failure (HF) for patients enrolled in the HeartFailure@Home service. METHODS AND RESULTS: We retrospectively analysed the clinical episodes of decompensated HF for patients enrolled in the HeartFailure@Home service, managed by ambulatory IV diuretic treatment either at home or on a day-case unit. A control group consisting of HF patients admitted to hospital for IV diuretics (standard-of-care) was also evaluated. In total, 203 episodes of decompensated HF (n = 154 patients) were evaluated. One hundred and fourteen episodes in 79 patients were managed exclusively by the ambulatory IV diuretic service-78 (68.4%) on a day-case unit and 36 (31.6%) domiciliary; 84.1% of patient episodes under the HF@Home service were successfully managed entirely in an out-patient setting without hospitalization. Eleven patients required admission in order to administer higher doses of IV diuretics than could be provided in the ambulatory setting. During follow-up, there were 20 (17.5%) 30 day re-admissions with HF or death in the ambulatory IV group and 29 (32.6%) in the standard-of-care arm (P = 0.02). There was no difference in 30 day HF readmissions between the two groups (14.9% ambulatory vs. 13.5% inpatients, P = 0.8), but 30 day mortality was significantly lower in the ambulatory group (3.5% vs. 21.3% inpatients, P < 0.001). CONCLUSIONS: Outpatient ambulatory management of decompensated HF with IV diuretics given either on a day case unit or in a domiciliary setting is feasible, safe, and effective in selected patients with decompensated HF. This should be explored further as a model in delivering HF services in the outpatient setting during COVID-19.

Performance of first pacemaker to use smart device app for remote monitoring.

BACKGROUND: High adherence to remote monitoring (RM) in pacemaker (PM) patients improves outcomes; however, adherence remains suboptimal. Bluetooth low-energy (BLE) technology in newer-generation PMs enables communication directly with patient-owned smart devices using an app without a bedside console. OBJECTIVE: To evaluate the success rate of scheduled RM transmissions using the app compared to other RM methods. METHODS: The BlueSync Field Evaluation was a prospective, international cohort evaluation, measuring the success rate of scheduled RM transmissions using a BLE PM or cardiac resynchronization therapy PM coupled with the MyCareLink Heart app. App transmission success was compared to 3 historical "control" groups from the Medtronic de-identified CareLink database: (1) PM patients with manual communication using a wand with a bedside console (PM manual transmission), (2) PM patients with wireless automatic communication with the bedside console (PM wireless); (3) defibrillator patients with similar automatic communication (defibrillator wireless). RESULTS: Among 245 patients enrolled (age 64.8±15.6 years, 58.4% men), 953 transmissions were scheduled through 12 months, of which 902 (94.6%) were successfully completed. In comparison, transmission success rates were 56.3% for PM manual transmission patients, 77.0% for PM wireless patients, and 87.1% for defibrillator wireless patients. Transmission success with the app was superior across matched cohorts based on age, sex, and device type (single vs dual vs triple chamber). CONCLUSION: The success rate of scheduled RM transmissions was higher among patients using the smart device app compared to patients using traditional RM using bedside consoles. This novel technology may improve patient engagement and adherence to RM.

Early diagnosis of cardiac implantable electronic device generator pocket infection using ¹8F-FDG-PET/CT.

AIMS: To examine the utility of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the early diagnosis of cardiac implantable electronic device (CIED) generator pocket infection. METHODS AND RESULTS: A total of 86 patients with CIEDs were evaluated with (18)F-FDG PET/CT imaging: 46 with suspected generator pocket infection and 40 without any history of infection. (18)F-FDG activity in the region of the generator pocket was expressed as a semi-quantitative ratio (SQR)-defined as the maximum count rate around the CIED divided by the mean count rate between normal right and left lung parenchyma. All patients underwent standard clinical management, independent of the PET/CT result. Patients with suspected generator pocket infection that required CIED extraction (n = 32) had significantly higher (18)F-FDG activity compared with those that did not (n = 14), and compared with controls (n = 40) [SQR: 4.80 (3.18-7.05) vs. 1.40 (0.88-1.73) vs. 1.10 (0.98-1.40), respectively; P < 0.001]. On receiver operator characteristic analysis, SQR had a high diagnostic accuracy (area under curve = 0.98) for the early identification of patients with confirmed infection (i.e. those ultimately needing extraction)-with an optimal SQR cut-off value of >2.0 (sensitivity = 97%; specificity = 98%). CONCLUSION: This study highlights the potential benefits of evaluating patients with suspected CIED generator pocket infection using (18)F-FDG PET/CT. In this study, (18)F-FDG PET/CT had a high diagnostic accuracy in the early diagnosis of CIED generator pocket infection, even where initial clinical signs were underwhelming.

Early Durata lead failure caused by rib-clavicular crush.

The patented Optim coating was designed to prevent insulation abrasions on the Durata lead (St Jude Medical, St Paul, Minnesota) and avoid the problems that had afflicted its predecessor, the Riata silicone lead (St Jude Medical). We report a case of external insulation failure 8 months after implantation of a dual-coil Durata lead and consider the potential causes of the failure.

Safety and acceptability of implantation of internal cardioverter-defibrillators under local anesthetic and conscious sedation.

BACKGROUND: Implantation and testing of implantable defibrillators (ICDs) using local anesthetic and conscious sedation is widely practiced; however, some centers still use general anesthesia. We assessed safety and patient acceptability for implantation of defibrillators using local anesthetic and conscious sedation. METHODS: The records of 500 consecutive device implants from two UK cardiac centers implanted under local anesthetic and conscious sedation from January 1996 to December 2004 were reviewed. Procedure time, left ventricular ejection fraction (LVEF) sedative dosage (midazolam), analgesic dosage (fentanyl or diamorphine), requirement for drug reversal, and respiratory support were recorded. Patient acceptability of the procedure was also assessed. RESULTS: Of 500 implants examined, 387 were ICDs, 88 were biventricular ICDs, and 25 were generator changes. Patients with biventricular-ICDs had significantly longer (mean +/- SD) procedure times 129.7 +/- 7.6 minutes versus 63.3 +/- 32.3 minutes; P < 0.0001 and lower LVEF 24.4 +/- 8.4% versus 35.7 +/- 15.4%; P < 0.0001. There were no differences in the doses (mean +/- SD) of midazolam 8.9 +/- 3.5 mg versus 8.0 +/- 3.1 mg; P = NS, diamorphine 4.3 +/- 2.0 mg versus 3.8 +/- 1.7 mg; P = NS or fentanyl 94.4 +/- 53.7 mcg versus 92.2 +/- 48.6 mcg; P = NS, between the two groups. There were no deaths or tracheal intubations in either group. Acceptability was available for 373 of 500 (75%) patients, 41 of 373 (11%) described "discomfort," but from these 41 patients only 14 of 373 (3.8%) declined a second procedure under the same conditions. CONCLUSIONS: Implantation of defibrillators under local anesthetic and sedation is safe and acceptable to patients. General anesthesia is no longer routinely required for implantation of defibrillators.