Efficacy and Safety of an Extravascular Implantable Cardioverter-Defibrillator.

BACKGROUND: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known. METHODS: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system. The primary efficacy end point was successful defibrillation at implantation. The efficacy objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients with successful defibrillation was greater than 88%. The primary safety end point was freedom from major system- or procedure-related complications at 6 months. The safety objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients free from such complications was greater than 79%. RESULTS: A total of 356 patients were enrolled, 316 of whom had an implantation attempt. Among the 302 patients in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol, the percentage of patients with successful defibrillation was 98.7% (lower boundary of the one-sided 97.5% confidence interval [CI], 96.6%; P<0.001 for the comparison with the performance goal of 88%); 299 of 316 patients (94.6%) were discharged with a working ICD system. The Kaplan-Meier estimate of the percentage of patients free from major system- or procedure-related complications at 6 months was 92.6% (lower boundary of the one-sided 97.5% CI, 89.0%; P<0.001 for the comparison with the performance goal of 79%). No major intraprocedural complications were reported. At 6 months, 25 major complications were observed, in 23 of 316 patients (7.3%). The success rate of antitachycardia pacing, as assessed with generalized estimating equations, was 50.8% (95% CI, 23.3 to 77.8). A total of 29 patients received 118 inappropriate shocks for 81 arrhythmic episodes. Eight systems were explanted without extravascular ICD replacement over the 10.6-month mean follow-up period. CONCLUSIONS: In this prospective global study, we found that extravascular ICDs were implanted safely and were able to detect and terminate induced ventricular arrhythmias at the time of implantation. (Funded by Medtronic; ClinicalTrials.gov number, NCT04060680.).

Design and deployment of the STEEER-AF trial to evaluate and improve guideline adherence: A cluster-randomised trial by the European Society of Cardiology and European Heart Rhythm Association.

AIMS: To describe the rationale, design, delivery and baseline characteristics of STEEER-AF (Stroke prevention and rhythm control Treatment: Evaluation of an Educational programme of the European Society of Cardiology [ESC] in a cluster-Randomised trial in patients with Atrial Fibrillation). METHODS & RESULTS: STEEER-AF is a pragmatic trial designed to objectively and robustly determine whether guidelines are adhered to in routine practice, and evaluate a targeted educational programme for healthcare professionals. Seventy centres were randomised in 6 countries (France, Germany, Italy, Poland, Spain and United Kingdom; 2022-2023). STEEER-AF centres recruited 1732 patients with a diagnosis of atrial fibrillation (AF), with mean age 68.9 years (SD 11.7), CHA2DS2-VASc score 3.2 (SD 1.8) and 647 (37%) women. 843 patients (49%) were in AF and 760 (44%) in sinus rhythm at enrolment. Oral anticoagulant therapy was prescribed in 1,543 patients (89%), with the majority receiving direct oral anticoagulants (1,378; 89%). Previous cardioversion, antiarrhythmic drug therapy or ablation was recorded in 836 patients (48.3%). 551 patients (31.8%) were currently receiving an antiarrhythmic drug, and 446 (25.8%) were scheduled to receive a future cardioversion or ablation. The educational programme engaged 195 healthcare professionals across centres randomised to the intervention group, consisting of bespoke interactive online learning and reinforcement activities, supported by national expert trainers. CONCLUSION: The STEEER-AF trial was successfully deployed across six European countries to investigate guideline adherence in real-world practice, and evaluate if a structured educational programme for healthcare professionals can improve patient-level care. REGISTRATION: Clinicaltrials.gov NCT04396418.

Ventricular Arrhythmias in Left Ventricular Assist Device Patients-Current Diagnostic and Therapeutic Considerations.

Left ventricular assist devices (LVAD) are used in the treatment of advanced left ventricular heart failure. LVAD can serve as a bridge to orthotopic heart transplantation or as a destination therapy in cases where orthotopic heart transplantation is contraindicated. Ventricular arrhythmias are frequently observed in patients with LVAD. This problem is further compounded as a result of diagnostic difficulties arising from presently available electrocardiographic methods. Due to artifacts from LVAD-generated electromagnetic fields, it can be challenging to assess the origin of arrhythmias in standard ECG tracings. In this article, we will review and discuss common mechanisms, diagnostics methods, and therapeutic strategies for ventricular arrhythmia treatment, as well as numerous problems we face in LVAD implant patients.

Magnetic resonance imaging in patients with implanted cardiac electrotherapy devices: a statement from experts of the Polish Medical Society of Radiology, the Polish Society of Cardiology, and the Polish Society of Electroradiology.

The year 2023 marks 60 years since the first pacemaker was implanted in Poland. The number of implantable cardiac electrotherapy devices (CIEDs), including pacemakers, cardioverter-defibrillators, and resynchronization therapy systems, has been systematically increasing in the subsequent decades. It is estimated that nearly 500,000 Poles have an implanted cardiac electrotherapy device, making optimal diagnostic imaging with the use of magnetic resonance imaging (MRI) a clinically and epidemiologically important issue. MRI has become a gold diagnostic standard in many disease states. In this situation, it is believed that 50-70% of patients who have a cardiac electrotherapy device may have indications for an MRI examination later in life. For many years, an implanted cardiac electrotherapy device was considered a definite contraindication to MRI. However, MRI has become possible in most patients with CIED if certain procedures and precautions are followed. In these guidelines, we describe the basic rules that should be followed in order to perform a safe MRI examination in patients with different CIEDs. Despite all the risks and organizational factors described in the text, it seems that for many MRI departments, MRI in patients with CIEDs is achievable and should be implemented immediately. A second important issue is the need for dedicated financial support for these procedures from public health insurance.

Diagnostic electrocardiographic trap: A case of conduction system pacing.

His-bundle pacing (HBP) is a relatively new method of cardiac pacing, with recent studies showing an association between HBP and a lower risk of developing right ventricular heart failure compared to classical pacing methods. However, HBP is also associated with a higher risk of lead dislodgement, undersensing, and loss of capture. As such, a detailed assessment of pacing effectiveness in pacemaker patients is vital. In the presented case, an electrocardiogram (ECG) recording seems to present successful selective His-bundle pacing, while pacemaker follow-up demonstrated the loss of ventricular capture. In conclusion, patients receiving HBP should undergo ECG alongside pacing parameter analysis and pacing electrograms, as differences in successful and unsuccessful pacing ECG can be very subtle.

Rate-Responsive Cardiac Pacing: Technological Solutions and Their Applications.

Modern cardiac pacemakers are equipped with a function that allows the heart rate to adapt to the current needs of the patient in situations of increased demand related to exercise and stress ("rate-response" function). This function may be based on a variety of mechanisms, such as a built-in accelerometer responding to increased chest movement or algorithms sensing metabolic demand for oxygen, analysis of intrathoracic impedance, and analysis of the heart rhythm (Q-T interval). The latest technologies in the field of rate-response functionality relate to the use of an accelerometer in leadless endocavitary pacemakers; in these devices, the accelerometer enables mapping of the mechanical wave of the heart's work cycle, enabling the pacemaker to correctly sense native impulses and stimulate the ventricles in synchrony with the cycles of atria and heart valves. Another modern system for synchronizing pacing rate with the patient's real-time needs requires a closed-loop system that continuously monitors changes in the dynamics of heart contractions. This article discusses the technical details of various solutions for detecting and responding to situations related to increased oxygen demand (e.g., exercise or stress) in implantable pacemakers, and reviews the results of clinical trials regarding the use of these algorithms.

Glasgow Coma Scale score of more than four on admission predicts in-hospital survival in patients after out-of-hospital cardiac arrest.

AIM: The aim of the study was to assess the usefulness of the Glasgow Coma Scale (GCS) score assessed by EMS team in predicting survival to hospital discharge in patients after out-of-hospital cardiac arrest (OHCA). METHODS: Silesian Registry of OHCA (SIL-OHCA) is a prospective, population-based regional registry of OHCAs. All cases of OHCAs between the 1st of January 2018 and the 31st of December 2018 were included. Data were collected by EMS using a paper-based, Utstein-style form. OHCA patients aged ≥18 years, with CPR attempted or continued by EMS, who survived to hospital admission, were included in the current analysis. Patients who did not achieve return of spontaneous circulation (ROSC) in the field, with missing data on GCS after ROSC or survival status at discharge were excluded from the study. RESULTS: Two hundred eighteen patients with OHCA, who achieved ROSC, were included in the present analysis. ROC analysis revealed GCS = 4 as a cut-off value in predicting survival to discharge (AUC 0.735; 95%CI 0.655-0.816; p < 0.001). Variables significantly associated with in-hospital survival were young age, short response time, witnessed event, previous myocardial infarction, chest pain before OHCA, initial shockable rhythm, coronary angiography, and GCS > 4. On the other hand, epinephrine administration, intubation, the need for dispatching two ambulances, and/or a physician-staffed ambulance were associated with a worse prognosis. Multivariable logistic regression analysis revealed GCS > 4 as an independent predictor of in-hospital survival after OHCA (OR of 6.4; 95% CI 2.0-20.3; p < 0.0001). Other independent predictors of survival were the lack of epinephrine administration, previous myocardial infarction, coronary angiography, and the patient's age. CONCLUSION: The survival to hospital discharge after OHCA could be predicted by the GCS score on hospital admission.

Use of an exercise test to enhance sensing vector assessment and prevent inadequate subcutaneous implantable cardioverter-defibrillator discharges.

Subcutaneous implantable cardioverter-defibrillators are a modern alternative to classic cardioverter-defibrillators. Prior to implantation of the device, qualification based on assessment of the heart's specific rhythm shape during a resting electrocardiogram examination must be performed. In the presented case, a patient with a subcutaneous implantable cardioverter-defibrillator experienced numerous discharges during exercise. An exercise test was performed, which revealed a bundle branch block that appeared during exercise. The wide QRS complex was double- or triple-counted by the device, resulting in an inaccurate heart rate estimation and multiple discharges. Optimising the sensing vectors during exercise solved this problem.

How to deliver personalized cardiac resynchronization therapy through the precise measurement of the acute hemodynamic response: Insights from the iSpot trial.

INTRODUCTION: New pacing technologies offer a greater choice of left ventricular pacing sites and greater personalization of cardiac resynchronization therapy (CRT). The effects on cardiac function of novel pacing configurations are often compared using multi-beat averages of acute hemodynamic measurements. In this analysis of the iSpot trial, we explore whether this is sufficient. MATERIALS AND METHODS: The iSpot trial was an international, prospective, acute hemodynamic trial that assessed seven CRT configurations: standard CRT, MultiSpot (posterolateral vein), and MultiVein (anterior and posterior vein) pacing. Invasive and noninvasive blood pressure, and left ventricular (LV) dP/dtmax were recorded. Eight beats were recorded before and after an alternation from AAI to the tested pacing configuration and vice-versa. Eight alternations were performed for each configuration at each of the five atrioventricular delays. RESULTS: Twenty-five patients underwent the full protocol of eight alternations. Only four (16%) patients had a statistically significant >3 mm Hg improvement over conventional CRT configuration (posterolateral vein, distal electrode). However, if only one alternation was analyzed (standard multi-beat averaging protocol), 15 (60%) patients falsely appeared to have a superior nonconventional configuration. Responses to pacing were significantly correlated between the different hemodynamic measures: invasive systolic blood pressure (SBP) vs noninvasive SBP r = 0.82 (P < .001); invasive SBP vs LV dP/dt r = 0.57, r2 = 0.32 (P < .001). CONCLUSIONS: Current standard multibeat acquisition protocols are unfortunately unable to prevent false impressions of optimality arising in individual patients. Personalization processes need to include distinct repeated transitions to the tested pacing configuration in addition to averaging multiple beats. The need is not only during research stages but also during clinical implementation.

The long term risk of lead failure in patients with cardiovascular implantable electronic devices undergoing catheter ablation.

Objectives. The aim of the study was to assess the long-term influence of catheter ablation (CA) of different arrhythmias on cardiovascular implantable electronic devices (CIED) endocardial leads durability. Design. This was a retrospective case-control study. Ablation protocols and in- or outpatient medical records were reviewed to identify and extract data on adult patients with CIED undergoing a CA. A cohort of patients with hypertrophic cardiomyopathy and implantable cardioverter-defibrillators (ICD) served as a historical control group. The primary endpoint was the diagnosis of lead damage defined as permanent loss of proper function demanding replacement or removal. Results. Among 145 patients n = 177 catheter ablations were performed. Patients' mean age was 66.4 ± 10.5, 66.1% had an ICD or ICD with cardiac resynchronization function (CRT-D), 18.1% had >1 CA. During median 812 days [IQR 381-1588] of follow-up, there were 11 (6.2%) cases of lead damage in the examined and 13 cases (13%) in the control group, p = 0.054. None of the technical aspects of the CA (indication, type of catheter, transseptal sheath) influenced the primary outcome. Both the number of leads and observation time after CA were significantly related to the risk of endocardial lead damage. Conclusion. This study did not find any significant influence of CA on the long-term durability of CIED endocardial leads. Reported risk factors were consistent with general population of CIED patients.

Statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of implantable cardiac monitors in patients after ischaemic embolic stroke of undetermined source.

INTRODUCTION: Stroke remains one of the main causes of death and the most common cause of long-term disability in adults. Embolic strokes of undetermined source (ESUS) amount to a significant proportion of all ischaemic strokes. Detection of atrial fibrillation (AF) in this group of patients would allow for a major therapeutic decision to switch from antiplatelets to oral anticoagulants and therefore significantly reduce the risk of recurrence. STATE OF THE ART: Current technology allows long-term continuous ECG monitoring with different systems, including implantable cardiac monitors (ICM). However, in Poland lack of reimbursement does not allow their use in everyday clinical practice. CLINICAL IMPLICATIONS: This is a statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of ICM in patients after ischaemic embolic strokes of undetermined source. The aim was to develop reasonable and comprehensive guidance on how to select and manage candidates for ICM in order to obtain the maximum benefit for Polish public health. FUTURE DIRECTIONS: This expert opinion is not intended as a guideline but it provides advice as to how to optimise the potential use of ICM in patients after ESUS in the Polish setting.

Fifteen years' experience of implantable cardioverter defibrillator in children and young adults: Mortality and complications study.

BACKGROUND: Young implantable cardioverter defibrillator (ICD) recipients have a high rate of complications, some of which seem to be underestimated. We report our clinical experience with ICD therapy in children and young adults during a 15 year follow up. METHODS: We reviewed the database of ICD recipients at the present institution and chose 73 consecutive patients who underwent implantation at age 6-21 years. We analyzed intervention rate, mortality, rate and characteristics of complications and treatment options. RESULTS: A total of 20/73 patients (27.4%) received ≥1 episode of appropriate therapy (AT) for ventricular tachycardia/ventricular fibrillation (anti-tachycardia pacing or shock) and 24/73 patients (32.8%) had one or multiple episodes of inappropriate therapy (IT). Eight patients (11%) had both interventions: AT + IT. A total of 15/73 patients (20.5%) had ventricular lead dysfunction, with 13 re-implantations (17.8%) of a new system. Four of 73 patients (5.5%) had infection: endocarditis or device pocket infection. A total of 2/73 patients (2.7%) died due to ventricular lead dysfunction, while 22/73 patients (30.1%) needed elective device replacement, five of them twice (6.8%). CONCLUSION: Endocardial ICD implantation in children and young adults is a feasible and life-saving procedure, according to the present 15 year follow up. The rate of complications including IT was high: 72.8% in the young ICD recipients. Re-implantation of a new system was often required due to ventricular lead dysfunction or infection in 25% of the patients.

Clinical factors affecting long term survival in patients with systolic heart failure and cardiac resynchronization therapy in advanced age.

Identification of demographic and clinical factors which influence prognosis is crucial in patients with heart failure and cardiac resynchronization therapy (CRT). MATERIALS AND METHODS: The study included 223 patients with CRT (177 males), mean age 64.6±9.7 years, including 98 patients (43.9%) with defibrillation function (CRT-D) and 58 (26.0%) with permanent atrial fibrillation (AF). Of 223, n=72 patients (32.3%) had CRT implanted after the age of 70. The mean follow-up was 37±19 months. Mortality rates and other clinical factors according to age were assessed in multivariable analysis of CRT patients follow-up. RESULTS: Total mortality was 30.9%. Mortality rate was similar in subjects aged ≤70 and >70 (HR:1.41, 95%CI:0.70-2.82). The female gender was the strongest clinical factor of best prognosis (HR:0.12,95%CI:0.03-0.59, p=0.0088). Lower mortality was also associated with higher left ventricular ejection fraction (HR:0.94,95%CI:0.90-0.98, p=0.0031). Coronary disease (HR:2.09,95%CI:1.10-3.99, p=0.0245), chronic kidney disease (HR:3.00, 95%CI:1.47-6.12, p=0.0024)and higher NYHA class (HR:2.28, 95%CI:1.18-4.40, p=0.0137) were factors of increased mortality. For patients >70 years old, gender was not a survival determining factor and mortality was lower in regard to hypertension or permanent AF. Only chronic kidney disease was significantly associated with higher mortality in patients >70 years old (HR:6.74, 95%CI:1.90-23.9). The use of defibrillation function had no influence on survival rate at any age. CONCLUSIONS: In patients with cardiac resynchronization therapy female gender was not associated with mortality and was the factor of better prognosis. For subjects aged >70 a worse prognosis was related to renal insufficiency.

Biventricular Paced QRS Area Predicts Acute Hemodynamic CRT Response Better Than QRS Duration or QRS Amplitudes.

INTRODUCTION: Vectorcardiographic (VCG) QRS area of left bundle branch block (LBBB) predicts acute hemodynamic response in cardiac resynchronization therapy (CRT) patients. We hypothesized that changes in QRS area occurring with biventricular pacing (BV) might predict acute hemodynamic CRT response (AHR). METHODS AND RESULTS: VCGs of 624 BV paced electrocardiograms (25 LBBB patients with 35 different pacing configurations) were calculated according to Frank's orthogonal lead system. Maximum QRS vector amplitudes (XAmpl , YAmpl , ZAmpl , and 3DAmp ) and QRS areas (XArea , YArea , ZArea , and 3DArea ) in the orthogonal leads (X, Y, and Z) and in 3-dimensional projection were measured. Volume of the 3D vector loop and global QRS duration (QRSD) on the surface electrocardiogram were assessed. Differences (Δ) in VCG parameters between BV paced and LBBB QRS complexes were calculated. An increase of 10% in dP/dt max was considered as AHR. LBBB conduction is characterized by a large ZArea (109 µVs, interquartile range [IQR]:75;135), significantly larger than XArea (22 µVs, IQR:10;57) and YArea (44 µVs, IQR:32;62, P < 0.001). Overall, QRS duration, amplitudes, and areas decrease significantly with BV pacing (P < 0.001). Of all VCG parameters, 3DAmpl , Δ3DAmpl , ZArea, ΔZArea , Δ3DArea , and ΔQRSD differentiate AHR response from nonresponse (P < 0.05). ΔZArea predicted best positive AHR (area under the curve = 0.813) and outperformed any other VCG parameter or QRSD measurement. CONCLUSION: Of all VCG parameters, reduction in QRS area, calculated in Frank's Z lead, predicts acute hemodynamic response best. This method might be an easy, noninvasive tool to guide CRT implantation and optimization.

Utility of automated template matching for the interpretation of pace mapping in patients ablated due to outflow tract ventricular arrhythmias.

AIMS: One of the disadvantages of classic pace mapping (PM) is the operator's subjective interpretation. The aim of this single-centre retrospective study was to evaluate the value of automated template matching (AMT) in patients ablated due to ventricular outflow tract arrhythmias (OTAs). METHODS AND RESULTS: From an overall group of 105 patients with OTA who were scheduled for transcatheter ablation (TA), AMT was accessible in 42 patients [21 right ventricular outflow tract (RVOT), 21 left ventricular outflow tract (LVOT), 28 women, aged 51.5 ± 12.7 years]. We used AMT to compare spontaneous arrhythmia ORS (spontQRS) with paced QRS complexes during PM in sites where radiofrequency (RF) applications were successful and in sites where RF applications were unsuccessful. The concordance was presented in per cents as objective matching scores (OMS). Then, at the successful ablation sites, we examined the relationship between OMS and the visual interpretation of PM was presented as electrophysiologists matching scores (EMS). The OMS of PM at sites of successful ablation varied from 78 to 99% (mean 94.1 ± 3.8) and from 47 to 95% (mean 80.2 ± 12.6%) at sites of unsuccessful ablation. Pace mapping in unsuccessful RF sites was significantly less similar to spontQRS morphologies than in successful RF sites (P = 0.0001). There was a significant correlation between OMS and EMS (r = 0.82; P < 0.0001). The OMS that indicated optimal ablation site was 89% (sensitivity = 95%; specificity = 80%). The mean OMS for successful sites at RVOT (95.1 ± 1.8%) and LVOT (93.1 ± 4.9%) were not different (P = 0.0551). CONCLUSION: This analysis revealed that AMT is a valuable technique for the interpretation of PM and for the identification of successful ablation sites in OTA.

The use of 1.5 T magnetic resonance imaging for therapeutic decisions in patients with cardiac implantable electronic devices and significant neurological, neurosurgical and neuro-oncology diagnostic indications.

UNLABELLED: Between September 2009 and May 2014 the classification of 36 patients with cardiac implantable electronic devices (CIEDs) in terms of the feasibility of MRI scanning due to strong clinical indications was carried out. Finally MRI examinations were performed in 20 patients, of whom 27 studies were conducted and a total number of 35 anatomical regions were scanned. Neurological, neurosurgical and neuro-oncology indications for MRI were reported in 19 patients (95%) in whom 26 MRI studies (96.3%) were performed, and 34 anatomical regions (97.1%) were scanned. One patient had indications for MRI in the field of cardiology. Medical information obtained from 27 MRI studies allowed decisions to be made regarding the treatment in all patients. After 8 studies (29.6%), patients were classified into 9 different neurosurgical procedures. In the case of the remaining 19 studies (70.4%), there were no indications for surgical treatment and the decisions to implement conservative treatment were made. There were no complications related to the implanted CIEDs observed: neither immediate nor in the follow-up.

Potential prevention of pacing-induced heart failure using simple pacemaker programming algorithm.

INTRODUCTION: Right ventricular pacing (RVP) causes ventricular desynchronization and may lead to the development of heart failure (HF). Prolongation of atrioventricular delay (AVD) in DDDR pacemakers reduces unnecessary RV stimulation. The aim of the study was to verify the influence of RVP reduction on HF symptoms. METHODS: The study comprised 31 patients (17 men, mean age: 71.6 ± 8 yrs) with DDDR pacemaker implanted due to sinus node dysfunction (SND). At baseline, 28 patients did not present any symptoms of HF. Three patients were in NYHA class II. Patients were randomized either to 150 ms AVD or to minimizing right ventricular pacing (MRVP). Crossing over to the alternate mode took place after 4 months. Cardiopulmonary exercise test (CPX), echocardiography (ECHO) and BNP measurements were done before pacemaker implantation, after 4 and 8 months. RESULTS: The percentage of RVP was significantly higher in 150 ms AVD than in MRVP: 81.7 ± 22.6 versus 14.2±20.5%, P < 0.0001. Patients with 150 ms mode had worse CPX parameters than those with MRVP mode: peak oxygen uptake was 14.2±4.3 versus 19.9±6.3 ml/kg per min, P = 0.0001, higher BNP concentrations: 72.3±48.3 versus 49.4±43.9 pg/ml, P = 0.001 and worse left ventricle [LV] function: ejection fraction: 53.2±6.7 versus 57.3±5.5%, P < 0.0001; LV diastolic diameter: 4.86±0.52 versus 4.66±0.5 cm, P < 0.01. CONCLUSION: Predominant RVP in patients without symptoms of HF at baseline may be responsible for worse performance in cardiopulmonary exercise test, higher BNP concentrations and impairment of LV function. Specific DDDR pacemaker programming promotes intrinsic AV conduction and may prevent the development of pacing-induced HF.

Exercise-Induced Arrhythmia or Munchausen Syndrome in a Marathon Runner?

A 36-year-old professional marathon runner reported sudden irregular palpitations occurring during competitions, with heart rates (HR) up to 230 bpm recorded on a sports HR monitor (HRM) over 4 years. These episodes subsided upon the cessation of exercise. Electrocardiograms, echocardiography, and cardiac magnetic resonance imaging results were borderline for athlete's heart. Because an electrophysiology study and standard exercise tests provoked no arrhythmia, doctors suspected Munchausen syndrome. Ultimately, an exercise test that simulated the physical effort of a competition provoked tachyarrhythmia consistent with the HRM readings. This case demonstrates the diagnostic difficulties related to exercise-induced arrhythmia and the diagnostic usefulness of sports HRMs.

Position of the Polish Cardiac Society on therapeutic targets for LDL cholesterol concentrations in secondary prevention of myocardial infarctions.

Cardiovascular diseases account for 43% of deaths in Poland. The COVID-19 pandemic increased the number of cardiovascular deaths by as much as 16.7%. Lipid metabolism disorders are observed in about 20 million Poles. Lipid disorders are usually asymptomatic, they cause a significant increase in the risk of cardiovascular diseases. Up to 20% of patients who experience an acute coronary syndrome (ACS) may experience a recurrence of a cardiovascular event within a year, and up to 40% of these patients may be re-hospitalized. Within 5 years after a myocardial infarction, 18% of patients suffer a second ACS and 13% have got a stroke. Lipid-lowering therapy is an extremely important element of comprehensive management, both in primary and secondary prevention, and its main goal is to prevent or extend the time to the onset of heart or vascular disease and reduce the risk of cardiovascular events. A patient with a history of ACS belongs to the group of a very high risk of a cardiovascular event due to atherosclerosis. In this group of patients, low-density lipoprotein cholesterol levels should be aimed below 55 mg/dl (1.4 mmol/l). Many scientific guidelines define the extreme risk group, which includes not only patients with two cardiovascular events within two years, but also patients with a history of ACS and additional clinical factors: peripheral vascular disease, multivessel disease (multilevel atherosclerosis), or multivessel coronary disease, or familial hypercholesterolemia, or diabetes with at least one additional risk factor: elevated Lp(a) >50 mg/dl or hsCRP >3 mg/l, or chronic kidney disease (eGFR <60 ml/min/1.73 m²). In this group of patients, the LDL-C level should be aimed at below 40 mg/dl (1.0 mmol/l). Achieving therapeutic goals in patients after ACS should occur as soon as possible. For this purpose, a high-dose potent statin should be added to the therapy at the time of diagnosis, and ezetimibe should be added if the goal is not achieved after 4-6 weeks. Combination therapy may be considered in selected patients from the beginning. After 4-6 weeks of combination therapy, if the goal is still not achieved, adding a proprotein convertase subtilisin/kexin type 9 protein inhibitor or inclisiran should be considered. In order to increase compliance with the recommendations, Polish Cardiac Society and Polish Lipid Society propose to attach in the patient's discharge letter a statement clearly specifying what drugs should be used and what LDL-C values should be achieved. It is necessary to cooperate between the patient and the doctor, to follow the recommendations and take medicines regularly, to achieve and maintain therapeutic goals.