X-ray Doses in Relation to Body Mass, Indication, and Substrate During Pediatric Electrophysiological Procedures on the Heart.

The main goal of this study is to determine typical values of dose area product (DAP) and difference in the effective dose (ED) for pediatric electrophysiological procedures on the heart in relation to patient body mass. This paper also shows DAP and ED in relation to the indication, the arrhythmia substrate determined during the procedure, and in relation to the reason for using radiation. Organ doses are described as well. The subjects were children who have had an electrophysiological study done with a 3D mapping system and X-rays in two healthcare institutions. Children with congenital heart defects were excluded. There were 347 children included. Significant difference was noted between mass groups, while heavier children had higher values of DAP and ED. Median DAP in different mass groups was between 4.00 (IQR 1.00-14.00) to 26.33 (IQR 8.77-140.84) cGycm2. ED median was between 23.18 (IQR 5.21-67.70) to 60.96 (IQR 20.64-394.04) µSv. The highest DAP and ED in relation to indication were noted for premature ventricular contractions and ventricular tachycardia-27.65 (IQR 12.91-75.0) cGycm2 and 100.73 (IQR 53.31-258.10) µSv, respectively. In arrhythmia substrate groups, results were similar, and the highest doses were in ventricular substrates with DAP 29.62 (IQR 13.81-76.0) cGycm2 and ED 103.15 (IQR 60.78-266.99) µSv. Pediatric electrophysiology can be done with very low doses of X-rays when using 3D mapping systems compared to X-rays-based electrophysiology, or when compared to pediatric interventional cardiology or adult electrophysiology.

Serum Fibrinogen and Renal Dysfunction as Important Predictors of Left Atrial Thrombosis in Patients with Atrial Fibrillation.

BACKGROUND: As has been shown previously, patients with atrial fibrillation (AF) who have left atrial thrombus (LAT) also have elevated plasma concentrations of fibrinogen. In this study, we tried to determine if this is the consequence of a genetic trait and whether elevated concentrations of fibrinogen could be used to predict LAT in patients with AF. METHODS: We recruited 181 consecutive patients scheduled for pulmonary vein isolation (PVI) or direct current cardioversion. The primary endpoint was the presence of LAT on transesophageal echocardiography (TOE). We recorded routine clinical and biochemical data as well as the polymorphism type of the fibrinogen gene for the ß chain. To control potentially interfering variables, we performed propensity score matching (PSM). Multivariable and univariable logistic regression models (LRM) were computed using the CHA2DS2-Vasc score, the fibrinogen concentration and creatinine clearance as estimated by the Cockcroft-Gault equation. RESULTS: 60 of 181 patients had LAT as detected by TOE. As expected, patients with LAT had significantly higher concentrations of fibrinogen (3.9 vs. 3.6 g/L); p = 0.01 in the unadjusted analysis. After performing PSM, there were no statistically significant differences between the groups, except for creatinine clearance (79.9 vs. 96.8 mL/min); p = 0.01. There were also no differences regarding the -455 G/A ßfibrinogen polymorphism distribution between the two groups. After constructing the LRM, we found no performance enhancement for the CHA2DS2-Vasc score by adding the fibrinogen concentration or creatinine clearance alone, but when all three variables were put together, there was a significant improvement in LAT prediction (AUC 0.64 vs. 0.72), p = 0.026. CONCLUSION: Our study found no evidence of elevated levels of circulating fibrinogen in patients with LAT or a connection between those levels and the A/A and A positive polymorphism. When used together with renal function markers such as creatinine clearance, plasma fibrinogen concentrations can provide additional power to the CHA2DS2-Vasc score for predicting LAT.

COVID-19 pandemic: Impact on the cardiac implantable electronic devices' implantation rates in Croatia.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) pandemic has influenced health-care organization worldwide, including management of non-communicable diseases. The aim of this study was to determine the impact of COVID-19 pandemic on cardiac implantable electronic devices' (CIEDs) implantation rates in Croatia. METHODS: A retrospective, observational, national study was conducted. The data on CIEDs' implantation rates from 20 Croatian implantation centres, between January 2018 and June 2021, were extracted from the national Health Insurance Fund registry. Implantation rates before and after COVID-19 pandemic started, were compared. RESULTS: The overall numbers of CIED implantations in Croatia during COVID-19 pandemic were not different in comparison to 2 years pre-COVID-19 time (2618 vs. 2807, p = .081). The pacemaker implantation rates decreased significantly (by 45%) during April (122 vs. 223, p < .001) and May 2020 (135 vs. 244, p = .001), as well as during November 2020 (177 vs. 264, p = .003), but significantly increased during summer months 2020 comparing to 2018 and 2019 (737 vs. 497, p<0.001). The ICD implantation rates decreased significantly by 59% in April 2020 (26 vs. 64, p = .048). CONCLUSION: To the authors best knowledge this is a first study including complete national data on CIED implantation rates and COVID-19 pandemic impact. A significant reduction in number of both pacemaker and ICD implants during specific months of the COVID-19 pandemic was determined. However, afterwards compensation in implants resulted in similar total number when the complete year was evaluated.

Differences in activated clotting time and total unfractionated heparin dose during pulmonary vein isolation in patients on different anticoagulation therapy.

BACKGROUND: Periprocedural pulmonary vein isolation (PVI) anticoagulation requires balancing between bleeding and thromboembolic risk. Intraprocedural anticoagulation is monitored by activated clotting time (ACT) with target value >300 s, and there are no guidelines specifying an initial unfractionated heparin (UFH) dose. METHODS: We aimed to assess differences in ACT values and UFH dosage during PVI in patients on different oral anticoagulants. We conducted an international, multi-center, registry-based study. Consecutive patients with atrial fibrillation (AF) undergoing PVI, on uninterrupted anticoagulation therapy, were analyzed. Before transseptal puncture, UFH bolus of 100 IU/kg was administered regardless of the anticoagulation drug. RESULTS: Total of 873 patients were included (median age 61 years, IQR 53-66; female 30%). There were 248, 248, 189, 188 patients on warfarin, dabigatran, rivaroxaban, and apixaban, respectively. Mean initial ACT was 257 ± 50 s, mean overall ACT 295 ± 45 s and total UFH dose 158 ± 60 IU/kg. Patients who were receiving warfarin and dabigatran compared to patients receiving rivaroxaban and apixaban had: (i) significantly higher initial ACT values (262 ± 57 and 270 ± 48 vs. 248 ± 42 and 241 ± 44 s, p < .001), (ii) significantly higher ACT throughout PVI (309 ± 46 and 306 ± 44 vs. 282 ± 37 and 272 ± 42 s, p < .001), and (iii) needed lower UFH dose during PVI (140 ± 39 and 157 ± 71 vs. 171 ± 52 and 172 ± 70 IU/kg). CONCLUSION: There are significant differences in ACT values and UFH dose during PVI in patients receiving different anticoagulants. Patients on warfarin and dabigatran had higher initial and overall ACT values and needed lower UFH dose to achieve adequate anticoagulation during PVI than patients on rivaroxaban and apixaban.

Sudden Cardiac Death-A New Insight Into Potentially Fatal Genetic Markers.

Sudden cardiac death (SCD) is an unexpected and dramatic event. It draws special attention especially in young, seemingly healthy athletes. Our scientific paper is based on the death of a young, 23-year-old professional footballer, who died on the football field after a two-year history of cardiac symptoms. In this study we analyzed clinical, ECG and laboratory data, as well as results of genetic testing analysis in family members. To elucidate potential genetic etiology of SCD in this family, our analysis included 294 genes related to various cardiac conditions.

Delayed radiofrequency ablation efficacy in slow pathway ablation: a case report.

BACKGROUND: The delayed effect of radiofrequency (RF) ablation was described in cases of accessory pathway and premature ventricular contraction ablation, as well as delayed atrioventricular (AV) block after slow pathway ablation. CASE SUMMARY: We report a case of a female patient with AV nodal re-entry tachycardia (AVNRT), in whom the first electrophysiology study ended with acute failure of slow pathway ablation, despite using long steerable sheath, both right and left-sided ablation with >15 min of RF energy application and repeatedly achieving junctional rhythm. Six weeks afterwards, during scheduled three-dimensional electroanatomical mapping procedure, there was no proof of dual AV nodal conduction nor could the tachycardia be induced. Also, the patient did not have palpitations between the two procedures nor during the 12-month follow-up period. DISCUSSION: This case illustrates that watchful waiting for delayed RF ablation efficacy in some cases of AVNRT ablation could be reasonable, in order to reduce the risk of complications associated with slow pathway ablation.

Atrial appendages' mechanics assessed by 3D transoesophageal echocardiography as predictors of atrial fibrillation recurrence after pulmonary vein isolation.

BACKGROUND: Although there are numerous studies reflecting predictors of atrial fibrillation (AF) recurrence (AFR) after pulmonary vein isolation (PVI), data on atrial appendages' mechanics is scarce. This study aimed to assess atrial appendages' mechanics by 2-dimensional (2D) and 3-dimenssional (3D) transoesphageal echocardiography (TEE) and to explore its value to predict AFR after PVI. METHODS: Consecutive patients with paroxysmal AF undergoing first PVIwere analysed. 3D and 2D-TEE with tissue Doppler imaging (TDI) and strain analysis was obtained prior to the PVI, including: left atrial appendage (LAA) TDI and strain analysis, LAA ostium surface area, right atrial appendage's TDI velocity and superior vena cava (SVC) ostium surface area. The primary end-point was freedom from any documented recurrence of atrial arrhythmia lasting > 30 s. RESULTS: This single-centre, prospective study included 74 patients with paroxysmal AF (median age 59 years; 36% female; BMI 27.4 ±â€¯4.1 kg/m2, LA volume index 32 ±â€¯11 mL/m2). After a median follow-up of 14 (IQR 10-22) months, 21 (28%) patients had AFR. In a univariate and multivariate Cox-regression analysis LAA TDI velocity (HR 1.48, 95%CI 1.28-1.62, p < 0.001) and LAA ostium surface area(HR 1.58, 95%CI 1.06-1.81, p = 0.033) both independently predicted AFR after single PVI. RAA TDI velocity and SVC ostium surface area were not correlated to AFR. CONCLUSION: Paroxysmal AF patients with lower LAA TDI tissue velocity and LAA ostium surface area have higher risk of developing AFR after PVI. To our knowledge, this is the first study assessing atrial appendages' mechanics in predicting AFR after PVI.Clinical trial registration: www.drks.de(Identifier: DRKS00010495).

MANAGEMENT OF PATIENTS WITH CARDIAC IMPLANTABLE ELECTRONIC DEVICES UNDERGOING MAGNETIC RESONANCE IMAGING - PROPOSAL FOR UNIFIED HOSPITAL PROTOCOL: CROATIAN WORKING GROUP ON ARRHYTHMIAS AND CARDIAC PACING.

For many years, magnetic resonance imaging (MRI) was contraindicated in patients with cardiac implantable electronic devices (CIED). Today, there is a growing amount of evidence that MRI can be performed safely in the majority of patients with CIEDs. Firstly, there are devices considered MRI conditional by manufacturers that are available on the market and secondly, there is clear evidence that even patients with MRI non-conditional devices can also undergo MRI safely. Protocols have been developed and recommendations from different cardiac and radiologic societies have been published in recent years. However, the majority of physicians are still reluctant to refer these patients to MRI. Therefore, this document is published as a joint statement of the Croatian Working Group on Arrhythmias and Cardiac Pacing and Department of Radiology, Sestre milosrdnice University Hospital Centre to guide and ease the management of patients with CIED undergoing MRI. Also, we propose a unified protocol and checklist that could be used in Croatian hospitals.

LEFT VENTRICULAR LEAD PLACEMENT FOR PACING AND SENSING IN A PATIENT WITH ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY UNDERGOING ICD IMPLANTATION.

We present a case of a 64-year-old female patient scheduled for implantable cardioverter defibrillator (ICD) implantation due to arrhythmogenic right ventricular cardiomyopathy (ARVC). Dual coil, active fixation ICD lead was introduced through the axillary vein. More than 20 positions were changed in the right ventricle (RV) (outflow tract, high, mid and apical septum, infero-basal, apical and lateral wall). Maximum R wave amplitude was 2 mV with pacing threshold of 0.5 V. Since the sensing was inappropriate, we decided to place the pace/sense lead of the ICD in the coronary sinus. The lead was placed in the basal part of the lateral vein. The pacing threshold was 1.0 V/0.40 ms and R wave was 9 mV. The lead was connected to the ICD sense-pace port and high voltage coils were connected in the usual way. The RV sense-pace lead was capped off. The device sensed an R wave of 7.0 mV 48 hours later. The purpose of this report is to show a possible solution of sensing problems during an ICD implantation in a patient with ARVC.

ROUTINELY AVAILABLE BIOMARKERS AS LONG-TERM PREDICTORS OF DEVELOPING SYSTOLIC DYSFUNCTION IN COMPLETELY REVASCULARIZED PATIENTS WITH ACUTE ST ELEVATION MYOCARDIAL INFARCTION.

The aim of this study was to assess the efficacy of high-sensitivity C-reactive protein (hsCRP), cardiac troponin T (cTnT) and creatine kinase (CK) as long-term predictors of reduced systolic function in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) with complete revascularization. This prospective study evaluated consecutive patients with acute STEMI who had normal left ventricular ejection fraction (LVEF ≥50%) at admission with single-vessel disease and underwent complete revascularization. Blood samples were collected from admission to day 7. The primary endpoint was reduction of LVEF <50% after 12 months. The study included 47 patients, median age 59±10 years, 74.5% of them men. Patients who developed systolic dysfunction (LVEF <50%) had significantly higher mean values of cTnT after 24 hours (5.11 vs. 2.82 µg/L, p=0.010) and peak values of CK (3375.5 vs. 1865 U/L, p=0.008). There was no significant relation between hsCRP and development of reduced LVEF (p=0.541). In conclusion, cTnT and CK could serve as long-term predictors of reduced left ventricular systolic function (<50%) in acute STEMI patients with normal systolic function at admission, single-vessel coronary disease and complete revascularization during primary PCI.

High prevalence of hyperlipidaemia in patients with AV re-entry tachycardia and AV nodal re-entry tachycardia.

Diet rich in lipids and hyperlipidaemia increases incidence of atrial premature beats and all supraventricular arrhythmias. The aim of the study was to investigate the prevalence of hyperlipidaemia in patients with AV re-entry tachycardia (AVRT) and AV nodal re-entry tachycardia (AVNRT). We conducted a retrospective, cross-sectional, case-control study that included all consecutive patients for whom AVRT or AVNRT was confirmed during electrophysiology study. Age and gender-matched patients admitted to hospital or outpatient clinic for various reasons were randomly included and served as a control group. Hyperlipidaemia was defined according to 2016 European Society of Cardiology guidelines. A total of 1448 subjects were included: 725 patients with AVRT/AVNRT and 723 controls. AVRT/AVNRT patients had high hyperlipidaemia prevalence, which was significantly higher when compared to the control group (50.1 vs. 35.8%, p < 0.001). AVRT patients, with median age of 37.5 years, had hyperlipidaemia prevalence of 45.7%. In a multivariate analysis, hyperlipidaemia was independently associated with AVRT/AVNRT (OR 2.128, p < 0.001), both with AVNRT (OR 1.878, p < 0.001) and AVRT (OR 2.786, p < 0.001). Hypercholesterolemia was significantly more prevalent in patients with AVNRT and AVRT, while this was not the case for hypertriglyceridemia. There were no differences between the AVRT and AVNRT patients regarding hyperlipidaemia prevalence (51.9 vs. 45.7%, p = 0.801), even though AVRT patients were significantly younger (37.5 vs. 48.5, p < 0.001). In conclusion, this is the first study that investigated hyperlipidaemia prevalence in patients with AVRT or AVNRT. AVRT/AVNRT patients had higher prevalence of hyperlipidaemia and higher total and LDL cholesterol levels.

Noninvasive Recanalization of a Coronary Chronic Total Occlusion.

BACKGROUND: Spontaneous recanalization of a chronically occluded artery is rare and reported anecdotally. CASE SUMMARY: We report a case of a patient with a chronically occluded right coronary artery, found on a coronary angiography performed due to acute ST elevation myocardial infarction with an occluded circumflex artery as a culprit lesion. Three months later, a follow-up angiography was performed and a recanalization of the occluded right coronary artery was detected. DISCUSSION: There is a possibility that intrinsic fibrinolytic mechanisms with the additional effect of standard antithrombotic drugs administrated after the acute coronary event led to the recanalization.

Nutritional Considerations of Cardiovascular Diseases and Treatments.

Nutritional considerations of many chronic diseases are not fully understood or taken into consideration in everyday clinical practice. Therefore, it is not surprising that high proportion of hospitalized patients with cardiovascular diseases remains underdiagnosed with malnutrition. Malnourished patients have increased risk of poor clinical outcomes, complications rate, prolonged hospital stay, more frequent rehospitalizations, and lower quality of life. The purpose of this review is to recapitulate recent data on nutritional considerations in cardiovascular medicine.

Recommendations for Perioperative Management of Patients with Cardiac Implantable Electronic Devices.

Four thousand cardiac implantable electronic devices (CIED) are implanted yearly in Croatia with constant increase. General anesthesia and surgery carry some specific risk for the patients with implanted CIEDs. Since most of the surgical procedures are performed in institutions without reprogramming devices available, or in the periods when they are unavailable, these guidelines aim to standardize the protocol for perioperative management of these patients. With this protocol, most of the procedures can be performed easily and, more importantly, safely in the majority of surgical patients.

An uncommon case of spontaneous conversion from AV re-entry tachycardia to AV nodal re-entry tachycardia in a patient with dual tachycardia.

We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontaneously and repeatedly converted to the typical slow-fast AV node reentry tachycardia (AVNRT). Both accessory and AV nodal slow pathways were ablated, due to the finding that both AVRT and AVNRT were independently inducible during the EP study.

Transcatheter patent foramen ovale closure and radiofrequency ablation of right atrial tachycardia.

Patent foramen ovale (PFO) can be found in approximately 25% of adult population. Transcatheter closure of PFO is a potential option in selected patients with PFO. We report a case of a female patient that underwent mapping and catheter ablation of atrial tachycardia and PFO closure in the same procedure.

Persistent Left Superior Vena Cava in Patients Undergoing Cardiac Device Implantation: Clinical and Long-Term Data.

BACKGROUND: Persistent left superior vena cava (LSVC) is a rare congenital venous anomaly that may be found at the time of cardiac device lead insertion. METHODS: In this case series, we present clinical and long-term data of five patients with LSVC who underwent pacemaker (PM) or cardioverter defibrillator (ICD) implantation during the period of 10 years. RESULTS: Left-sided venous approach was used for device implantation in 3 patients with standard PM indications, whereas a right-sided venous approach and an epicardial approach had to be used in 2 patients who needed an ICD and biventricular PM, respectively. In post implantation period of 44 ± 29 months, one patient died due to stroke, one underwent heart transplantation, and 3 had atrial fibrillation. CONCLUSION: The long-term outcome of patients with persistent LSVC and implanted cardiac devices is mostly influenced by the presence of underlying heart disease.

Persistent atrial fibrillation is associated with a poor prognosis in patients with atrioventricular block and dual-chamber pacemaker.

BACKGROUND: The prognostic significance of development of persistent atrial fibrillation (AF) in patients with atrioventricular (AV) block and dual chamber (DDD) pacemakers has not been separately investigated. We sought to determine whether persistent AF influences clinical outcome in these patients. METHODS: Three hundred-eight consecutive patients with second- or third-degree AV block and implanted a DDD pacemaker were followed for 36 ± 20 months and retrospectively divided into two groups. Thirty-four patients who developed persistent AF formed persistent AF group, and 278 patients who remained free of this arrhythmia control group. Clinical and outcome data of the two groups were compared. The primary outcome was cardiovascular death. RESULTS: The primary outcome occurred more often among the patients in the persistent AF group (6.8% per year) than among those in the control group (2.9% per year; P = 0.028). This difference was primarily because of higher rate of heart failure-related deaths in the persistent AF group (P = 0.009). Secondary outcomes, hospitalization for heart failure and paroxysmal AF episode ≥5 minutes, occurred also more often among the patients in the persistent AF group (P = 0.008 and P < 0.001, respectively), although the risk of nonfatal stroke was similar in both groups (P = 0.628). CONCLUSION: In patients with second- or third-degree AV block and DDD pacemaker, the development of persistent AF is associated with an increased risk of cardiovascular death and heart failure.