A 31‐year‐old male patient with an implantable cardioverter defibrillator (ICD) experienced ventricular fibrillation. After resuscitation, no communication between the device and an ICD programmer ...was possible. The ICD was explanted, no signs of destruction were visible, and the ICD leads revealed normal values. A new ICD was implanted, interrogation values were stable. However, immediately after defibrillation testing the connection between programmer and ICD was interrupted and could not be established again. The device showed burn marks and a hole in the can. Analysis revealed an isolation defect of the ICD lead, which was not detectable with standard interrogation.
Background and aims
Antiscatter grids improve image contrast by absorbing scattered x‐ray beams, although by removing the antiscatter grid patient dose can be reduced as more x‐ray beams reach the ...image receptor. Additionally, there is a trend toward ultra‐low frame rates for radiation dose reduction during various electrophysiology procedures. As for most cardiac device implantations (CIED) image quality demands are usually modest, the purpose of this study was to assess the safety and efficacy of an ultra‐low frame rate and scatter grid‐less radiation protocol.
Methods/results
A total of 140 patients undergoing CIED implantation between 2014 and 2017 were included in the study. Seventy patients (50%) implanted after implementation of the antiscatter grid‐less and ultra‐low frame rate protocol were matched to controls before the dose‐reduction protocol was established. Forty patients (28.6%) had a one‐chamber pacemaker or one‐chamber implantable cardioverter defibrillator (ICD) implantation/revision, 60 (42.9%) had a two‐chamber pacemaker or two‐chamber ICD implantation/revision, and 40 (28.6%) patients had a cardiac resynchronization therapy device implantation/revision. Removing the antiscatter‐grid and lowering the frame rate led to a 73% reduction of the overall dose area product (1,206 ± 2,015 vs 324 ± 422 μGym, P < 0.001). Procedural duration (95 ± 51 minutes vs 82 ± 44 minutes, P = 0.053) and rate of complications were not significantly different between the two groups.
Conclusion
The use of an ultra‐low frame rate and antiscatter grid‐less radiation protocol significantly reduced radiation dose for implantation of CIED and led to very low average patient doses, while procedural duration and complication rates did not increase.
Background
Implantable loop recorders (ILR) are valuable tools for the investigation of patients with suspected arrhythmias. The BioMonitor 2‐AF is a novel insertable ILR with enhanced atrial ...fibrillation (AF) detection algorithm and remote monitoring capability.
Objective
The objective of this first‐in‐human study with the BioMonitor 2‐AF was to analyze course of P‐wave sensing performance and R‐wave amplitude, prevalence of false and correctly sensed and classified episodes, and effectiveness of remote monitoring.
Methods
All 19 patients who underwent ILR insertion were included in the BIOTRONIK Home Monitoring® system (BIOTRONIK GmbH, Berlin, Germany). Daily changes in P‐wave and R‐wave sensing were analyzed over 6 weeks. A breathing test (in‐ and expiration) was performed in two different body positions at baseline and during a 6‐week in‐house follow‐up to investigate alterations of P‐wave and R‐wave sensing.
Results
R‐wave amplitude and the high P‐wave visibility (94.4%) remained unchanged during the follow‐up period. In most patients both an increase and decrease of R‐wave amplitude, and in some cases a complete R‐wave vector change (31.6%), was documented during the “breathing test.” Change of body position did not alter R‐wave sensing amplitude mostly. “Breathing test” and change of body position had no effect on P‐wave sensing performance. In 15.8% of the patients, misclassification of episodes as AF or high ventricular rates due to P‐wave oversensing occurred. No ILR‐related complication occurred. Automatic transmission via BIOTRONIK Home Monitoring® was successful 100% of the time.
Conclusion
This study demonstrates that the BioMonitor 2‐AF is a safe and effective tool for continuous cardiac monitoring.
Pulmonary arterial hypertension (PAH) is a fatal disease with limited therapeutic options. Pathophysiological changes comprise obliterative vascular remodelling of small pulmonary arteries, elevated ...mean pulmonary arterial systolic pressure (PASP) due to elevated resistance of pulmonary vasculature, adverse right ventricular remodelling, and heart failure. Recent findings also indicate a role of increased inflammation and insulin resistance underlying the development of PAH. We hypothesized that treatment of this condition with the peroxisome proliferator-activated receptor-γ (PPARγ) activator pioglitazone, known to regulate the expression of different genes addressing insulin resistance, inflammatory changes, and vascular remodelling, could be a beneficial approach. PAH was induced in adult rats by a single subcutaneous injection of monocrotaline (MCT). Pioglitazone was administered for 2 weeks starting 3 weeks after MCT-injection. At day 35, hemodynamics, organ weights, and -indices were measured. We performed morphological and molecular characterization of the pulmonary vasculature, including analysis of the degree of muscularization, proliferation rates, and medial wall thickness of the small pulmonary arteries. Furthermore, markers of cardiac injury, collagen content, and cardiomyocyte size were analyzed. Survival rates were monitored throughout the experimental period. Pioglitazone treatment improved survival, reduced PASP, muscularization of small pulmonary arteries, and medial wall thickness. Further, MCT-induced right ventricular hypertrophy and fibrosis were attenuated. This was accompanied with reduced cardiac expression of brain natriuretic peptide, as well as decreased cardiomyocyte size. Finally, pulmonary macrophage content and osteopontin gene expression were attenuated. Based on the beneficial impact of pioglitazone, activation of PPARγ might be a promising treatment option in PAH.
Despite the use of 3D mapping systems and new developments of non-fluoroscopic options, most centres still rely at least in part on fluoroscopy for catheter visualization during catheter ablations. ...The purpose of this study was to assess the feasibility of using an ultra-low frame rate and antiscatter grid-less radiation protocol during complex left atrial ablations to minimize radiation exposure for the patient and staff.
A total of 150 consecutive patients undergoing left atrial ablations in our hospital were included in the analysis. The procedures were performed between January 2015 and November 2016. Of the included patients 75 (50%) underwent ablation before and 75 (50%) after the ultra-low frame rate (reduced from 4 to 2 FPS) and antiscatter grid-less radiation protocol was established. Procedures performed after the dose reduction protocol was established showed a 64% reduction of the dose area product (630.28 ± 550.96 vs. 226.44 ± 277.44 µGym2, P < 0.001), while fluoroscopy duration (14.22 ± 4.47 vs. 13.62 ± 7.11 min, P = 0.066) and procedural duration (1:48 ± 0:28 vs. 1:53 ± 0:34 min, P = 0.525) were not prolonged. Acute procedural success was achieved in all procedures. Two complications occurred before and one complication after the protocol was established. During four procedures, operators decided to re-introduce the antiscatter grid. This was due to impaired visibility in morbidly obese patients (n = 2) or technically difficult transseptal puncture (n = 2).
The use of an ultra low framerate and antiscatter grid-less radiation protocol effectively reduced radiation dose for complex left atrial ablation procedures and lead to very low average patient doses. Reduced image quality did not impair procedural and fluoroscopy duration or acute procedural success.
BACKGROUND: Contact force (CF)-sensing catheters are commonly used in the field of radiofrequency (RF) ablation to treat atrial fibrillation (AF). Increasing ablation power (e.g., 50 W) has been ...suggested as a method to reduce procedure times whilst creating safe and lasting lesions. METHODS: We report the first clinical evidence of a 50 W point-by-point RF ablation in 25 consecutive patients with symptomatic AF using a novel CF-sensing catheter with a gold tip (AlCath Force, Biotronik). We collected and analyzed procedural and ablation parameters. The safety and efficacy of the catheter were evaluated. RESULTS: Altogether, 985 RF lesions in 25 patients were created with a mean number of 39.4 ± 16.3 lesions per patient. The total skin-to-skin procedure time was 116.1 ± 35.1 min, and the mean total area dose product was 10.9 ± 5.1 Gy*cm2. The mean RF time per procedure was 13.2 ± 6.6 min. The mean RF time per lesion was 20.2 ± 8.4 s. The mean CF was 15.7 ± 7.6 g. We observed a mean force time integral of 274.7 ± 11.1 gs (range: 53 to 496 gs). Acute procedural success, defined as entrance and exit block in all pulmonary veins, could be obtained in all cases. No procedure- or device-related serious adverse events were observed. No audible steam pops occurred. Optical inspection of the catheter after the procedure showed neither charring nor clotting. CONCLUSIONS: We provide the first evidence for the safety and efficacy of 50 W ablation using the AlCath Force gold-tip catheter. These data must be supported by a larger multi-center study.
In persistent atrial fibrillation (AF), left atrial low-voltage areas and complex fractionated atrial electrograms (CFAEs) have been thoroughly discussed as critical substrate points for AF ...perpetuation. Thus, in patients undergoing pulmonary vein isolation, these sites are often considered additional ablation targets. Currently, mapping techniques for these substrate indicators are still under discussion. The aim of this study was to evaluate the impact of different mapping catheters on the detection of low-voltage areas and CFAE.
Two bipolar voltage maps and two CFAE left atrial maps were obtained each in 30 patients undergoing catheter ablation of AF using the following two different catheters: A four-pole ablation catheter (MAP, mapping and ablation catheter) (electrode size: tip: 4 mm, band: 1 mm; inter-electrode spacing: 0.5-5-2 mm) and a 10-pole circular pulmonary vein mapping catheter (CMC) (electrode size: 1 mm; inter-electrode spacing: 7-7-7 mm). Successively, low-voltage and CFAE area sizes were then compared between the two catheters. Areas with a bipolar voltage of <0.5 mV were significantly smaller when obtained with the CMC compared with the MAP (8.9 ± 8.9 vs. 17.4 ± 11.7 cm², P < 0.001). This was also significantly different for a bipolar voltage of <0.2 mV (2.3 ± 4.6 vs. 6.2 ± 9.6 cm², P < 0.001). Complex fractionated atrial electrogram area sizes were significantly larger when obtained with the CMC compared with the MAP group (14.6 ± 10.9 vs. 19.4 ± 9.4 cm², P = 0.011).
Low-voltage and CFAE area size varies significantly between different mapping catheters. Mapping electrode settings have to be taken into consideration for the assessment of electroanatomical substrate of AF.
Atrial and ventricular arrhythmias significantly contribute to morbidity and mortality of patients with cardiac disease. Ablation of these arrhythmias has shown to improve clinical outcomes, yet ...targeted ablation strategies rely on proper mapping capabilities. In the present study, we compare different modes of high-resolution mapping in clinically relevant arrhythmias using HD grid.
Using the Advisor™ HD Grid Mapping Catheter in either the standard, the wave (bipolar along spline and bipolar orthogonal) or the wave diagonal setting, low-voltage areas were determined. Low-voltage was defined as local electrograms with an amplitude <0.5 mV (bipolar; atria/ventricle) or <4 mV (unipolar; ventricle). Ultra high-density mapping in 47 patients with ventricular tachycardia, ventricular premature beats, atrial fibrillation and atrial tachycardia provided reliable information for the understanding of the arrhythmia mechanism resulting in safe ablation procedures. Regions of low voltage were significantly decreased by 14 ± 2% and 31 ± 3% with wave and wave diagonal settings as compared to standard settings, respectively.
Substrate mapping and risk stratification relies on proper low voltage discrimination. Even though the Advisor™ HD Grid Mapping Catheter was safely used in all cases, the extent of low voltage areas was mapping-mode dependent.
Patients with COVID-19 seem to be prone to the development of arrhythmias. The objective of this trial was to determine the characteristics, clinical significance and therapeutic consequences of ...these arrhythmias in COVID-19 patients requiring intensive care unit (ICU) treatment.
A total of 113 consecutive patients (mean age 64.1 ± 14.3 years, 30 (26.5%) female) with positive PCR testing for SARS-CoV2 as well as radiographically confirmed pulmonary involvement admitted to the ICU from March to May 2020 were included and observed for a cumulative time of 2321 days. Fifty episodes of sustained atrial tachycardias, five episodes of sustained ventricular arrhythmias and thirty bradycardic events were documented.
Sustained new onset atrial arrhythmias were associated with hemodynamic deterioration in 13 cases (35.1%). Patients with new onset atrial arrhythmias were older, showed higher levels of Hs-Troponin and NT-proBNP, and a more severe course of disease.
The 5 ventricular arrhythmias (two ventricular tachycardias, two episodes of ventricular fibrillation, and one torsade de pointes tachycardia) were observed in 4 patients. All episodes could be terminated by immediate defibrillation/cardioversion. Five bradycardic events were associated with hemodynamic deterioration. Precipitating factors could be identified in 19 of 30 episodes (63.3%), no patient required cardiac pacing. Baseline characteristics were not significantly different between patients with or without bradycardic events.
Relevant arrhythmias are common in severely ill ICU patients with COVID-19. They are associated with worse courses of disease and require specific treatment. This makes daily close monitoring of telemetric data mandatory in this patient group.
•Relevant arrhythmias are common in severely ill ICU patients with COVID-19.•New onset atrial arrhythmias are associated with worse courses of COVID-19 disease.•Daily close monitoring of telemetric data is mandatory in patients with COVID-19 on intensive care unit.•Specific treatment are required.
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