[Appropriate procedure for pacemaker and ICD malfunction]

Malfunctions in implanted pacemaker and defibrillator systems can affect all components of the device (battery, capacitor, central processing unit (CPU), connector, soldering points, electrodes). The resulting problems can manifest themselves as inadequate therapy, a lack of therapy despite the need for stimulation or shock release in case of ventricular tachyarrhythmia, or as an ineffective delivery of therapy. The high number of implanted pacemaker and defibrillator systems, the increased life expectancy and the technical progress of cardiac "device" therapy mean that the treating physician is confronted with increasingly complex problems in the follow-up. In addition to the knowledge of the basic function of these devices, a structured procedure to detect and treat malfunctions in a timely manner is required. In this review, frequent malfunctions of pacemaker and defibrillators are presented, individual problems are pointed out, and solutions and treatment options are shown.

Heart rate variability and cardiac repolarization after exposure to zinc oxide nanoparticles in healthy adults

Background

Exposure to airborne zinc oxide (ZnO) particles occurs in many industrial processes, especially in galvanizing and welding. Systemic inflammation after experimental inhalation of ZnO particles has been demonstrated previously, but little is known about the impact on the cardiovascular system, particularly on the autonomic cardiac system and the risk of arrhythmias. In this study we investigated the short-term effects of ZnO nanoparticles on heart rate variability (HRV) and repolarization in healthy adults in a concentration-dependent manner at rest and during exercise in a controlled experimental set-up.

Methods

Sixteen healthy subjects were exposed to filtered air and ZnO particles (0.5, 1.0 and 2.0 mg/m³) for 4 h, including 2 h of cycling at low workloads. Parameters were assessed before, during, immediately after, and about 24 h after each exposure. For each subject, a total number of 46 10-min-sections from electrocardiographic records were analyzed. Various parameters of HRV and QT interval were measured.

Results

Overall, no statistically significant effects of controlled ZnO inhalation on HRV parameters and QT interval were observed. Additionally, a concentration-response was absent.

Conclusion

Inhalation of ZnO nanoparticles up to 2.0 mg/m³ for 4 h does not affect HRV and cardiac repolarization in healthy adults at the chosen time points. This study supports the view that cardiac endpoints are insensitive for the assessment of adverse effects after short-term inhalation of ZnO nanoparticles.

Risk stratification in patients undergoing interventional left atrial appendage occlusion-Prognostic impact of EuroSCORE II

Background

Interventional closure of the left atrial appendage (LAA) is an alternative option to stroke prophylaxis, particularly in multimorbid patients with a high risk of bleeding under oral anticoagulation. Due to the multiple comorbidities, the prognosis of patients is reduced, and the clinical benefit of the procedure is therefore questionable in the individual patient.

Hypothesis

The present study aims to identify independent preprocedural risk factors to improve risk stratification in these highly selected patients.

Methods

This study consecutively included 128 patients who received an interventional LAA occlusion with Amplatzer device (St Jude Medical, St Paul, Minnesota). The preinterventional risk assessment was performed with the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) II. The primary endpoint was all‐cause mortality. Secondary endpoints were thromboembolic events and severe bleeding.

Results

During a follow‐up of 781 ± 498 days the primary endpoint (all‐cause mortality) was reached in 35 patients (27%). The only independent predictor of mid‐term mortality was a logistic EuroSCORE II > 2% (Hazard risk [HR] 4.55, confidence interval [CI] 1.599‐12.966, P = .005). In our study, 33 patients (26%) suffered from end‐stage renal disease which was not associated with increased mortality (P = .371), increased thromboembolic events (P = .475), or severe bleeding (P = .613).

Conclusions

In patients undergoing interventional LAA occlusion, preprocedural assessment of logistic EuroSCORE II provide independent prognostic information. This parameter might help to improve risk stratification in these highly selected patients. In contrast, terminal renal failure was not associated with a significantly worse outcome.

Feasibility of the Figure-of-8-Suture as Venous Closure in Interventional Electrophysiology: One Strategy for All?

Background: Venous vascular access with higher sheath size is common in interventional electrophysiology. In contrast to arterial vascular access, no dedicated closure devices exist for closure after venous access with higher sheath sizes. The Figure-of-8-Suture, an easy to apply suture, may be as a feasible approach for closure venous puncture. Our aim was to evaluate the feasibility of closure of femoral venous access. Methods: From November 2016 to February 2018, patients undergoing electrophysiological procedures, closure of left atrial appendage or patent foramen ovale were included. Until May 2017, manual compression was performed to achieve haemostasis at venous access site (control group). From May 2017, patients were treated with a Figure-of-8-Suture (treatment group, Figure 1). Turnaround time and incidence of vascular complications were compared between the two groups. Results: In total, 290 patients were included, 132 in the control group and 158 in the Figure-of-8-Suture group. Hemostasis after sheath removal was achieved in 100% of the cases in the control group by manual compression and in 98.7% of the cases with the Figure-of-8-Suture (p=0.2). Vascular complications were more common in the control group (6.8 vs. 1.3 %, p=0.01). Turnaround time was significantly lower in the Figure-of-8-Suture group (58.6 ± 14 vs. 77 ± 33.9 min, p=0.004). In a sub-analysis in obese patients with body mass index (BMI) ≥30 kg/m² (Figure-of-8 n=45, controls n=35), vascular complications were significantly more common in the control group (9.4 vs 0%, p=0.045). Conclusion: The Figure-of-8-Suture is an easy-to-apply, effective approach for venous closure after electrophysiological procedures.

Feasibility of Transfemoral Aortic Valve Implantation in Patients With Aortic Disease and Simultaneous or Sequential Endovascular Aortic Repair

OBJECTIVES

The transfemoral approach for transcatheter aortic valve implantation (TF-TAVI) is associated with a significant survival benefit for intermediate and high-risk patients. Due to the increased procedural risk, many operators avoid TF-TAVI in patients with aortic disease. Moreover, significant peri-interventional device interaction may occur in patients with previous endovascular aortic repair (EVAR). We evaluated the feasibility of TF-TAVI in patients with aortic disease in combination with simultaneous or sequential EVAR.

METHODS

Data from 15 TF-TAVI patients with concomitant aortic disease treated between 2009 and 2019 in three German heart centers representing 4410 TAVI procedures were analyzed.

RESULTS

Two patients with progressive penetrating atherosclerotic ulcers (PAUs) in the descending thoracic aorta underwent sequential and simultaneous thoracic EVAR (TEVAR), respectively. One patient with stable PAU and 4 patients with not yet relevant abdominal aortic aneurysm (AAA) underwent isolated TF-TAVI. One patient with relevant AAA underwent TF-TAVI and sequential EVAR. Seven patients with previous EVAR due to an AAA underwent TF-TAVI (5 with a bifurcated graft and 2 with a straight graft). TF-TAVI and sequential or simultaneous TEVAR were technically successful in all patients. Vascular complications occurred in 1 patient. One patient died within 30 days and 2 patients died within 12 months.

CONCLUSION

TF-TAVI can be performed successfully in patients with aortic disease or previous endovascular aortoiliac intervention. Simultaneous and sequential (T)EVAR is feasible.

Social Gradients in Myocardial Infarction and Stroke Diagnoses in Emergency Medicine

BACKGROUND

Persons of lower socio-economic status are at higher risk of disease, especially with respect to severe and chronic illnesses. To date, there have not been any studies with large case numbers regarding acute medical emergencies in this population.

METHODS

In a retrospective study, data were obtained on all cases treated by emergency physicians in Bochum, Germany, in 2014/2015, including the diagnoses that were made by the emergency physicians. There were a total of 16 767 cases. The local unemployment rate was taken as an indicator of the socioeconomic situation of a neighborhood; it was defined as the percentage of registered unemployed persons among persons aged 15 to 64 with their domicile in the neighborhood. 12 168 cases were grouped by emergency medical diagnosis and analyzed with respect to the three most heavily represented diagnostic categories (cardiovascular, neurological, and pulmonary emergencies), which accounted for nearly two-thirds of all diagnoses.

RESULTS

The overall rates of deployment involving emergency physicians were found to be positively correlated with the unemployment rate. After adjustment for age, sex, and possible confounders, this correlation was statistically significant (p<0.01). The indirectly standardized rate ratio (IRR) for the overall case-activity rate ranged from 0.841 (95% confidence interval: [0.808; 0.875]) with less than 5% unemployment to 1.212 [1.168; 1.256] with 9.5% unemployment or higher. The same finding was obtained with respect to diagnosis-specific case activity in each of the three main diagnostic categories (cardiovascular, neurological, and pulmonary emergencies), as well as for the respective commonest individual diagnoses (acute coronary syndrome/circulatory arrest [1498 cases], transient ischemic attack/ischemic stroke/intracerebral hemorrhage [1274 cases], and asthma/chronic obstructive pulmonary disease [663 cases]).

CONCLUSION

This study shows that the case-activity rate of the emergency medical services is significantly higher in socially disadvantaged neighborhoods, both with respect to total numbers and with respect to individual diseases. It demonstrates a problem affecting society as a whole, which should be taken into account in the organization of medical rescue services.

Platelet reactivity and clinical outcomes in acute coronary syndrome patients treated with prasugrel and clopidogrel: a pre-specified exploratory analysis from the TROPICAL-ACS trial

Aims

The value of platelet function testing (PFT) in predicting clinical outcomes and guiding P2Y12-inhibitor treatment is uncertain. In a pre-specified sub-study of the TROPICAL-ACS trial, we assessed ischaemic and bleeding risks according to high platelet reactivity (HPR) and low platelet reactivity (LPR) to ADP in patients receiving uniform prasugrel vs. PFT-guided clopidogrel or prasugrel.

Methods and results

Acute coronary syndrome patients with PFT done 14 days after hospital discharge were included with prior randomization to uniform prasugrel for 12 months (control group, no treatment modification) vs. early de-escalation from prasugrel to clopidogrel and PFT-guided maintenance treatment (HPR: switch-back to prasugrel, non-HPR: clopidogrel). The composite ischaemic endpoint included cardiovascular death, myocardial infarction, or stroke, while key safety outcome was Bleeding Academic Research Consortium (BARC) 2–5 bleeding, from PFT until 12 months. We identified 2527 patients with PFT results available: 1266 were randomized to the guided and 1261 to the control group. Before treatment adjustment, HPR was more prevalent in the guided group (40% vs. 15%), while LPR was more common in control patients (27% vs. 11%). Compared to control patients without HPR on prasugrel (n = 1073), similar outcomes were observed in guided patients kept on clopidogrel [n = 755, hazard ratio (HR): 1.06 (0.57–1.95), P = 0.86] and also in patients with HPR on clopidogrel switched to prasugrel [n = 511, HR: 0.96 (0.47–1.96), P = 0.91]. In contrast, HPR on prasugrel was associated with a higher risk for ischaemic events in control patients [n = 188, HR: 2.16 (1.01–4.65), P = 0.049]. Low platelet reactivity was an independent predictor of bleeding [HR: 1.74 (1.18–2.56), P = 0.005], without interaction (Pint = 0.76) between study groups.

Conclusion

Based on this substudy of a randomized trial, selecting prasugrel or clopidogrel based on PFT resulted in similar ischaemic outcomes as uniform prasugrel therapy without HPR. Although infrequent, HPR on prasugrel was associated with increased risk of ischaemic events. Low platelet reactivity was a strong and independent predictor of bleeding both on prasugrel and clopidogrel.

Hemodynamics of paradoxical severe aortic stenosis: insight from a pressure-volume loop analysis

BACKGROUND

Controversy exists about the pathophysiology of different hemodynamic subgroups of AS. In particular, the mechanism of the paradoxical low-flow, low-gradient (PLFLG) AS with preserved ejection fraction (EF) is unclear.

METHODS

A total of 41 patients with severe, symptomatic AS were divided into the following 4 subgroups based on the echocardiographically determined hemodynamics: (1) normal-flow, high-gradient (NFHG) AS; (2) low-flow, high-gradient AS; (3) paradoxical low-flow, low-gradient (PLFLG) AS with preserved EF and (4) low-flow, low-gradient (LFLG) AS with reduced EF. As part of the comprehensive invasive examinations, the analyses of the PV loops were performed with the IntraCardiac Analyzer (CD-Leycom, The Netherlands).

RESULTS

PLFLG was characterized by small left ventricular volumes as well as a decreased cardiac index, a decreased systolic contractility and a lower stroke work, than the conventional NFHG AS. Alterations in effective arterial elastance (2.36 ± 0.67 mmHg/ml in NFHG versus 3.01 ± 0.79 mmHg/ml in PLFLG, p = 0.036) and end-systolic elastance (3.72 ± 1.84 mmHg/ml in NFHG versus 5.53 ± 2.3 mmHg/ml in PLFLG, p = 0.040) indicated impaired vascular function and increased chamber stiffness.

CONCLUSIONS

The present study suggests that the hemodynamics of PLFLG AS can be explained by two mechanisms: (1) stiffness of the small left ventricle with reduced contractility, and (2) increased afterload due to the impairment of vascular function. Both mechanisms have similarities to those of heart failure with preserved EF. This type of remodeling may explain the poor prognosis of PLFLG AS.

Comparison of perioperative strategies in ICD patients: The perioperative ICD management study (PIM study)

BACKGROUND

The prevalence of patients with implanted cardioverter defibrillators (ICDs) and the frequency of surgery on these patients are steadily on the rise. Guidelines recommend preoperative ICD reprogramming, although this is sometimes difficult in clinical practice. Placing a magnet on the ICD is a practical alternative and even no inactivation is possible in selected cases.

METHODS

In this prospective observational study, we compared different perioperative ICD management strategies depending on the location of the surgery and the type of electrocautery used. Patients undergoing surgery above the umbilicus with monopolar electrocautery had their ICD therapy inactivated by reprogramming. When surgery below the navel or surgery above the navel with bipolar electrocautery was completed, ICD inactivation was performed using a magnet. No inactivation was performed on patients undergoing lower extremity surgery with bipolar electrocautery. Only ICD patients who were not pacemaker dependent were enrolled. After surgery, the ICDs were assessed regarding documented arrhythmias and parameters.

RESULTS

Out of 101 patients included in this study, the ICD was preoperatively reprogrammed in 42 patients (41.6%), a magnet was used on 45 patients (44.5%), and ICDs were not deactivated at all in 14 patients (13.9%). No intraoperative electromagnetic interference was detected. Postoperative ICD analysis demonstrated no changes of preset parameters.

CONCLUSIONS

All three tested ICD management strategies were proved safe in this study. Keeping the location of surgery and the type of electrocautery in mind, an intraoperative magnet or even no ICD deactivation at all could be feasible alternatives in surgery on patients with ICDs.

[Radiation reduction in interventional electrophysiology : Results from operators with different levels of experience]

BACKGROUND

Radiation exposure in the catherization laboratory is associated with significant health risks. It is unclear whether a reduction of radiation exposure with the use of "near-zero fluoroscopy" protocols is possible when applied by less experienced operators.

METHODS

Consecutive ablation procedures with the use of a 3D mapping system were analyzed. Three time periods were analyzed. During the first period (standard), no specific radiation-reduction protocol was used. During the second period (initial phase of radiation reduction) a near "near-zero fluoroscopy" protocol was implemented; however, the majority of procedures were performed by an expert. During the third period (routine use of radiation reduction), less experienced operators (fellow and beginner) performed a growing number of procedures with the "near-zero fluoroscopy" protocol.

RESULTS

In all, 290 procedures were analyzed. After implementation of a radiation-reduced protocol, a significant reduction of radiation exposure was observed (standard 850 ± 831.7 vs. initial phase 197.2 ± 481.8 μGy/m², p < 0.001, and vs. routine use 283 ± 493.8 μGy/m², p < 0.001). No significant difference was observed between the initial phase and routine phase (p = 1). Over the three periods, the proportion of procedures performed by less experienced operators grew significantly for complex (fellow: 0% vs. 10% vs. 30%; p < 0.001) and noncomplex procedures (fellow: 30% vs. 39% vs. 49%; beginner: 15% vs. 38% vs. 34%; p = 0.002). Complication rates were not significantly different.

CONCLUSIONS

Implementation of a radiation-reduced protocol leads to a significant reduction of radiation exposure even in less experienced operators during training.

Alterations in Titin Properties and Myocardial Fibrosis Correlate With Clinical Phenotypes in Hemodynamic Subgroups of Severe Aortic Stenosis

•

The extent of myocardial fibrosis and the degree of isoform-expression and phosphorylation changes in cardiomyocyte titin were unknown in different hemodynamic subgroups of AS, including “paradoxical” low-flow, low-gradient AS with preserved ejection fraction.

•

Hemodynamic subtypes of AS were found to exhibit increased cardiac fibrosis, titin-isoform transition toward more compliant N2BA variants, and both total and site-specific titin (N2Bus) hypophosphorylation compared with donor heart controls.

•

A significant shift toward N2BA titin appeared in “paradoxical” AS, whereas alterations in total-titin phosphorylation and cardiac fibrosis were similar in all hemodynamic subtypes of AS, suggesting increased myocardial passive stiffness.

•

The unfavorable prognosis of “paradoxical” AS could be explained by the pronounced myocardial remodeling, which is no less severe than in other AS subtypes.

Titin-isoform expression, titin phosphorylation, and myocardial fibrosis were studied in 30 patients with severe symptomatic aortic stenosis (AS). Patients were grouped into “classical” high-gradient, normal-flow AS with preserved ejection fraction (EF); “paradoxical” low-flow, low-gradient AS with preserved EF; and AS with reduced EF. Nonfailing donor hearts served as controls. AS was associated with increased fibrosis, titin-isoform switch toward compliant N2BA, and both total and site-specific titin hypophosphorylation compared with control hearts. All AS subtypes revealed titin and matrix alterations. The extent of myocardial remodeling in “paradoxical” AS was no less severe than in other AS subtypes, thus explaining the unfavorable prognosis.

Soluble adenylyl cyclase: A novel player in cardiac hypertrophy induced by isoprenaline or pressure overload

Aims

In contrast to the membrane bound adenylyl cyclases, the soluble adenylyl cyclase (sAC) is activated by bicarbonate and divalent ions including calcium. sAC is located in the cytosol, nuclei and mitochondria of several tissues including cardiac muscle. However, its role in cardiac pathology is poorly understood. Here we investigate whether sAC is involved in hypertrophic growth using two different model systems.

Methods and results

In isolated adult rat cardiomyocytes hypertrophy was induced by 24 h β₁-adrenoceptor stimulation using isoprenaline (ISO) and a β₂-adrenoceptor antagonist (ICI118,551). To monitor hypertrophy cell size along with RNA/DNA- and protein/DNA ratios as well as the expression level of α-skeletal actin were analyzed. sAC activity was suppressed either by treatment with its specific inhibitor KH7 or by knockdown. Both pharmacological inhibition and knockdown blunted hypertrophic growth and reduced expression levels of α-skeletal actin in ISO/ICI treated rat cardiomyocytes. To analyze the underlying cellular mechanism expression levels of phosphorylated CREB, B-Raf and Erk1/2 were examined by western blot. The results suggest the involvement of B-Raf, but not of Erk or CREB in the pro-hypertrophic action of sAC. In wild type and sAC knockout mice pressure overload was induced by transverse aortic constriction. Hemodynamics, heart weight and the expression level of the atrial natriuretic peptide were analyzed. In accordance, transverse aortic constriction failed to induce hypertrophy in sAC knockout mice. Mechanistic analysis revealed a potential role of Erk1/2 in TAC-induced hypertrophy.

Conclusion

Soluble adenylyl cyclase might be a new pivotal player in the cardiac hypertrophic response either to long-term β₁-adrenoceptor stimulation or to pressure overload.

Implementation of a near-zero fluoroscopy approach in interventional electrophysiology: impact of operator experience

PURPOSE

Catheter ablation is performed under fluoroscopic guidance. Reduction of radiation dose for patients and staff is emphasized by current recommendations. Previous studies have shown that lower operator experience leads to increased radiation dose. On the other hand, less experienced operators may depend even more on fluoroscopic guidance. Our study aimed to evaluate feasibility and efficacy of a non-fluoroscopic approach in different training levels.

METHODS

From January 2017, a near-zero fluoroscopy approach was established in two centers. Four operators (beginner, 1st year fellow, 2nd year fellow, expert) were instructed to perform the complete procedure with the use of a 3-D mapping system without fluoroscopy. A historical cohort that underwent procedures with fluoroscopy use served as control group. Dose area product (DPA), procedure duration, acute procedural success, and complications were compared between the groups and for each operator.

RESULTS

Procedures were performed in 157 patients. The first 100 patients underwent procedures with fluoroscopic guidance, the following 57 procedures were performed with the near-zero fluoroscopy approach. The results show a significant reduction in DPA for all operators immediately after implementation of the near-zero fluoroscopy protocol (control 637 ± 611 μGy/m²; beginner 44.1 ± 79.5 μGy/m², p = 0.002; 1st year fellow 24.3 ± 46.4.5 μGy/m², p = 0.001; 2nd year fellow 130.3 ± 233.3 μGy/m², p = 0.003; expert 9.3 ± 37.4 μGy/m², P < 0.001). Procedure duration, acute success, and complications were not significantly different between the groups.

CONCLUSION

Our results show a 90% reduction of DPA shortly after implementation of a near-zero fluoroscopy approach in interventional electrophysiology even in operators in training.

[Prevalence of acetylsalicylic acid (ASA) - low response in vascular surgery]

BACKGROUND

Research has revealed that a decreased antiplatelet effect (low response [LR]/high on-treatment platelet reactivity [HPR]) of acetylsalicylic acid (ASA) and clopidogrel is associated with an increased risk of thromboembolic events. There are extensive ASA low response (ALR) and clopidogrel low response (CLR) prevalence data in the literature, but there are only a few studies concerning vascular surgical patients. The aim of this study was to examine the prevalence and risk factors of ALR and CLR in vascular surgical patients.

MATERIALS AND METHODS

We examined n = 154 patients with an antiplatelet long-term therapy, who were treated due to peripheral artery occlusive disease (PAD) and/or arteria carotis interna stenosis (CVD). To detect an ALR or CLR, we examined full blood probes with impedance aggregometry (ChronoLog® Aggregometer model 590). Risk factors were examined by acquisition of concomitant disease, severity of vascular disease, laboratory test results and medication.

RESULTS

We found a prevalence of 19.3 % in the ALR group and of 21.1 % in the CLR group. Risk factors for ALR were an increased platelet and leucocyte count and co-medication with pantoprazole. We found no significant risk factors for a decreased antiplatelet effect of clopidogrel treatment.

CONCLUSION

The investigated prevalence for ALR and CLR are in the range of other studies, particularly based on cardiological patients. More investigations are needed to gain a better evaluation of the risk factors for HPR and to develop an effective antiplatelet therapy regime to prevent cardiovascular complications.

Cytochrome P450 2B6 and 2C9 genotype polymorphism – a possible cause of prasugrel low responsiveness

The cytochrome P450 (CYP) isoenzymes are essential for the metabolic activation of the prodrug prasugrel. Little is known about the impact of polymorphism of these isoenzymes on the prevalence of prasugrel low responsiveness (PLR) in patients with coronary artery disease. We investigated the frequency of PLR and the question whether PLR is associated with decreased/non-function polymorphisms of the CYP isoenzymes (2C9*2, 2C9*3, 2C19*2, 2C19*3, and 2B6*6). Our study included 355 patients who underwent percutaneous coronary stenting. The patients were initially treated with either prasugrel (n=90; 60/10 mg: loading/daily maintenance dose) or 600/75 mg clopidogrel hydrogensulfate (n=265) in combination with 500/100 mg acetylsalicylic acid (ASA). Platelet function was tested by impedance aggregometry 48 hours after taking the loading dose. Prasugrel achieved on the average significantly higher levels of platelet inhibition as compared to clopidogrel (mean 27.3 U vs 41.2 U). The frequencies of low response for prasugrel, clopidogrel and ASA were 9.8%, 35.1% and 14.9%, respectively. We identified only body mass index to be associated with PLR. PLR was not caused by a loss of ADP P2Y12-receptor function. Half of the patients with PLR were carriers of the reducedfunction allele CYP2B6*6, and 41.7% had the genetic variant CYP2C9*2. The allele CYP2C9*3 was detected in three patients with PLR (25%) and two patients with PLR (16.7%) carried the gene variant CYP2C19*2. In conclusion, the rate of low responders was significantly lower among patients treated with prasugrel than with clopidogrel. PLR are more often carriers of CYP2C9*2 (50% in PLR) than when compared to the prevalence described in literature. Also, there is a trend to an increased frequency of CYP2B6*6 in PLR. In conclusion, CYP2B6 and CYP2C9 polymorphisms seem to be associated with prasugrel low-response.

Incidence of asymptomatic oesophageal lesions after atrial fibrillation ablation using an oesophageal temperature probe with insulated thermocouples: a comparative controlled study

Aims

Oesophageal probes to monitor luminal oesophageal temperature (LET) during atrial fibrillation (AF) catheter ablation have been proposed, but their effects remain unclear. Aim of this study is to evaluate the effects of an oesophageal temperature probe with insulated thermocouples.

Methods and results

Patients with symptomatic, drug-refractory paroxysmal or persistent AF who underwent left atrial radiofrequency (RF) catheter ablation were prospectively enrolled. Patients were ablated using a single-tip RF contact force ablation catheter. An intraluminal oesophageal temperature probe was used in Group 1. In Group 2, patients were ablated without LET monitoring. Assessment of asymptomatic endoscopically detected oesophageal lesions (EDEL) was performed by oesophagogastroduodenoscopy (EGD) in all patients. Eighty patients (mean age 63.7 ± 10.7 years; men 56%) with symptomatic, drug-refractory paroxysmal (n = 28; 35%) or persistent AF were included. Group 1 and Group 2 patients (n = 40 in each group) were comparable in regard to baseline characteristics, but RF duration on the posterior wall was significantly shorter in Group 1 patients. Overall, seven patients (8.8%) developed EDEL (four ulcerations, three erythema). The incidence of EDEL in Group 1 and Group 2 patients was comparable (7.5 vs. 10%, P = 1.0). No major adverse events were reported in both groups.

Conclusion

According to these preliminary results, the use of oesophageal temperature probes with insulated thermocouples seems to be feasible in patients undergoing AF RF catheter ablation. The incidence of post-procedural EDEL when using a cut-off of 39°C is comparable to the incidence of EDEL without using a temperature probe.

Cardiac mapping and pulmonary vein isolation using a novel ablation catheter with tip minielectrodes

BACKGROUND

Pulmonary vein isolation (PVI) is a standard treatment for atrial fibrillation (AF). Identification of gaps in the ablation line is difficult. Tip-ring electrograms from ablation catheters represent relative large areas of myocardial tissue. Recently, an ablation catheter with three minielectrodes (ME) on the catheter tip with closer interelectrode spacing was introduced. The aim of our study was to evaluate the novel electrodes during PVI.

METHODS

PVI was performed with an irrigated ablation catheter equipped with conventional electrodes and three additional radial tip electrodes. Detection of pulmonary vein potentials (PVPs), local signal amplitude, amplitude reduction during ablation, and loss of capture after ablation were compared between the ME and the conventional tip-ring electrodes.

RESULTS

Thirty-one patients (mean age 67.8 ± 10.3 years, 45.2 % men) were included. A total of 306 mapping/lesion points were analyzed. A PVP was significantly more often obtained with the ME compared to the conventional tip-ring electrodes (99.2% vs 83.5%, P < 0.001). Local amplitude was significantly higher on the ME (0.8 ± 0.6 mV vs 0.67 ± 0.46 mV, P  =  0.003). Amplitude reduction during 1 RF pulse was significantly greater on the ME (82.9 ± 19.5% vs. 61.8 ± 26.9%, P < 0.001). During pace mapping, loss of capture after 1 RF pulse was observed significantly more often on ME (98.3% vs 63.3%, P < 0.001).

CONCLUSION

Signal amplitude is higher and sensitivity during PVP mapping and ablation is increased when ME are used. ME may facilitate catheter ablation of AF in the future.

Hypothermia induced alteration of repolarization - impact on acute and long-term outcome: a prospective cohort study

BACKGROUND

The effects of target temperature management (TTM) on the heart aren't thoroughly studied yet. Several studies showed the prolongation of various ECG parameters including Tpeak-Tend-time under TTM. Our study's goal is to evaluate the acute and long-term outcome of these prolongations.

METHODS

In this study we included patients with successful resuscitation after cardiac arrest who were admitted to the Charité Virchow Klinikum Berlin or the Heart and Vascular Centre of the Ruhr University Bochum between February 2006 and July 2013 (Berlin) or May 2014 to November 2015 (Bochum). For analysis, one ECG during TTM was recorded after reaching the target temperature (33-34 °C) or in the first 6 h of TTM. If possible, another ECG was taken after TTM. The patients were being followed until February 2016. Primary endpoint was ventricular arrhythmia during TTM, secondary endpoints were death and hospitalization due to cardiovascular diseases during follow-up.

RESULTS

One hundred fifty-eight patients were successfully resuscitated in the study period of which 95 patients had usable data (e.g. ECGs without artifacts). During TTM significant changes for different parameters of ventricular de- and repolarization were noted: QRS (103.2 ± 23.7 vs. 95.3 ± 18.1; p = 0.003),QT (405.8 ± 76.4 vs. 373.8 ± 75.0; p = 0.01), QTc (474.9 ± 59.7 vs. 431.0 ± 56.8; p < 0.001), JT (302.8 ± 69.4 vs. 278.5 ± 75.2; p = 0.043), JTc (354.3 ± 60.2 vs. 318.7 ± 59.1; p = 0.001). 13.7% of the patients had ventricular arrhythmias during TTM, however these patients showed no difference regarding their ECG parameters in comparison to those were no ventricular arrhythmias occurred. We were able to follow 69 Patients over an average period of 35 ± 31 months. The 14 (21.5%) patients who died during the follow-up had significant prolongations of the TpTe-time in the ECGs without TTM (103.9 ± 47.2 vs. 75.8 ± 28.6; p = 0.023).

CONCLUSION

Our results show a significant prolongation of ventricular repolarization during TH. However, there was no significant difference between the ECG parameters of those who developed a ventricular arrhythmia and those who did not. The temporary prolongation of the repolarization during TTM seems to be less important for the prognosis of the patient. Whereas the prolongation of the repolarization in the basal ECG is associated with a higher mortality in our study.

[Catheter ablation of ventricular extrasystoles and ventricular tachycardia in the elderly]

BACKGROUND

The prevalence of structural heart disease increases with higher age, and thereby the basis for ventricular arrhythmias is created. Catheter ablation has been shown to be an effective therapy option that is very safe and achieves good long-term results in patients with recurrent ventricular tachycardia (VT). Data regarding ablation in patients older than 75 years is sparse, although this patient group was included as a minority in most published VT ablation studies. Data from younger patient collectives may not be transferable to older patient cohorts due to differences in patient comorbidities and baseline characteristics.

METHODS

Studies with patient collectives ≥75 years or even ≥80 years show comparable efficacy of catheter ablation for VT; however, the complication rate is higher, mainly due to groin complications, increases. Catheter ablation of ischemic VT appears effective and safe even in ≥75 year olds; however, extensive data for other structural heart diseases are lacking. Epicardial procedures are also possible and safe in older patients (≥80 years). Due to the significant challenges of VT ablation in older patients, including the consideration of complex comorbidities, these should be performed in specialized centers with high expertise.

CONCLUSION

The aim of catheter ablation in older patients is, above all, to improve quality of life and morbidity. Long-term survival is significantly lower due to the "near end of life" situation than in younger patients. Careful consideration of alternative therapy options, chances for success of the catheter ablation, and their risks, taking into account specific patient conditions and symptoms, is crucial in these patients.