New Frontiers in Electrocardiography, Cardiac Arrhythmias, and Arrhythmogenic Disorders.

In recent decades, diagnosing, risk-stratifying, and treating patients with primary electrical diseases, as well as heart rhythm disorders, have improved substantially [...].

Stereotactic management of arrhythmia - radiosurgery in treatment of ventricular tachycardia (SMART-VT). Results of a prospective safety trial.

BACKGROUND AND PURPOSE: Despite its increasing popularity, there are limited prospective data on stereotactic arrhythmia radioablation (STAR). In this trial, we assessed the safety and efficacy of STAR in patients with ventricular tachycardia (VT), focusing on early treatment-related grade ≥ 3 adverse events (AE). MATERIALS AND METHODS: This prospective trial was designed for adults with VT recurrence following catheter ablation (CA) despite adequate pharmacotherapy, or contraindications to CA. A single dose of 25 Gy was delivered to the arrhythmia substrate defined on electro-anatomic mapping and cardiac-gated CT. The primary endpoint was safety, defined as two or fewer treatment-related grade ≥ 3 AEs during the first three months in 11 patients. Additional endpoints included treatment efficacy, clinical and biological markers of cardiac injury, and quality of life. RESULTS: Eleven patients with a median age of 67 years, structural heart disease, and a clinically significant recurrence of VT despite adequate pharmacotherapy and 1-4 previous CAs were enrolled between 2020/09 and 2022/10. Following the treatment, one patient developed a possibly treatment-related grade ≥ 3 AE, a grade 4 heart failure exacerbation at 87 days, which resolved after conservative treatment. There was a total 84.3% reduction in VT burden in 10 evaluable patients; however, VT recurrence was eventually observed in eight, and three patients required additional CAs. Three deaths due to unrelated causes were recorded. CONCLUSIONS: STAR appears to be safe and efficient. It is a promising treatment for selected patients; however, long-term outcomes remain to be evaluated, and controlled trials comparing STAR with standards of care are missing.

Histopathological Examination of an Explanted Heart in a Long-Term Responder to Cardiac Stereotactic Body Radiotherapy (STereotactic Arrhythmia Radioablation).

Cardiac stereotactic body radiotherapy is an emerging treatment method for recurrent ventricular tachycardia refractory to invasive treatment methods. The single-fraction delivery of 25 Gy was assumed to produce fibrosis, similar to a post-radiofrequency ablation scar. However, the dynamics of clinical response and recent preclinical findings suggest a possible different mechanism. The data on histopathological presentation of post-radiotherapy hearts is scarce, and the authors provide significantly different conclusions. In this article, we present unique data on histopathological examination of a heart explanted from a patient who had a persistent anti-arrhythmic response that lasted almost a year, until a heart failure exacerbation caused a necessity of a heart transplant. Despite a complete treatment response, there was no homogenous transmural fibrosis in the irradiated region, and the overall presentation of the heart was similar to other transplanted hearts of patients with advanced heart failure. In conclusion, our findings support the theorem of functional changes as a source of the anti-arrhythmic mechanism of radiotherapy and show that durable treatment response can be achieved in absence of transmural fibrosis of the irradiated myocardium.

Radiosurgery in Treatment of Ventricular Tachycardia - Initial Experience Within the Polish SMART-VT Trial.

Background: Stereotactic Arrhythmia Radioablation (STAR) is an emerging treatment modality for patients with sustained ventricular tachycardia (VT) and refractory to treatment with drugs and radiofrequency catheter ablation (RFA). It is believed that up to 12-17% of patients experience recurrence of VT within 1 year of follow-up; thus, novel therapeutic options are needed. The aim of this article is to present initial experience within a novel treatment modality for VT. Case Summary: Two patients with a medical history of coronary artery disease and heart failure with reduced left ventricle (LV) ejection fraction, after implantation of cardioverter-defibrillator (ICD) and previous unsuccessful RFAs owing to sustained VT were admitted to the cardiology department due to recurrence of sustained VT episodes. With electroanatomical mapping (EAM), the VT substrate in LV has been confirmed and specified. In order to determine the target volume for radioablation, contrast-enhanced computed tomography was performed and the arrhythmia substrate was contoured using EAM data. Using the Volumetric Modulated Arc Therapy technique and three 6 MeV flattening filter-free photon beam fields, a single dose of 25 Gy was delivered to the target volume structure located in the apex and anterior apical segments of LV in the first patient and in the apex, anterolateral and inferior apical segments of the second patient. In both cases, volumes of the target structures were comparable. Interrogation of the implanted ICD at follow-up visits throughout 6 months after the treatment revealed no VT episodes in the first patient and sudden periprocedural increase in VT burden with a subsequent gradual decrease of ventricular arrhythmia to only two non-sustained episodes at the end of the follow-up period in case of the second patient. A significant reduction in premature ventricular contractions burden was observed compared to the pre-treatment period. No noticeable deterioration in LV function was noted, nor any adverse effects of radiosurgery associated with the implanted device. Conclusion: The early response to STAR can be unpredictable and probably does not reflect the final outcome of irradiation. Close monitoring of patients, especially in the early period after irradiation is crucial to properly handle potentially harmful early reactions to STAR.

Prevalence of Arrhythmia in Adults after Fontan Operation.

Structural, hemodynamic, and morphological cardiac changes following Fontan operation (FO) can contribute to the development of arrhythmias and conduction disorders. Sinus node dysfunction, junction rhythms, tachyarrhythmias, and ventricular arrhythmias (VAs) are some of the commonly reported arrhythmias. Only a few studies have analyzed this condition in adults after FO. This study aimed to determine the type and prevalence of arrhythmias and conduction disorders among patients who underwent FO and were under the medical surveillance of the John Paul II Hospital in Krakow. Data for the study were obtained from 50 FO patients (mean age 24 ± 5.7 years; 28 men (56%)). The median follow-up time was 4 (2-9) years. Each patient received a physical examination, an echocardiographic assessment, and a 24 h electrocardiogram assessment. Bradyarrhythmia was diagnosed in 22 patients (44%), supraventricular tachyarrhythmias in 14 patients (28%), and VAs in 6 patients (12%). Six patients required pacemaker implantation, and three required radiofrequency catheter ablation (6%). Arrythmias is a widespread clinical problem in adults after FO. It can lead to serious haemodynamic impairment, and therefore requires early diagnosis and effective treatment with the use of modern approaches, including electrotherapy methods.

Clinical Evidence behind Stereotactic Radiotherapy for the Treatment of Ventricular Tachycardia (STAR)-A Comprehensive Review.

The electrophysiology-guided noninvasive cardiac radioablation, also known as STAR (stereotactic arrhythmia radioablation) is an emerging treatment method for persistent ventricular tachycardia. Since its first application in 2012 in Stanford Cancer Institute, and a year later in University Hospital Ostrava, Czech Republic, the authors from all around the world have published case reports and case series, and several prospective trials were established. In this article, we would like to discuss the available clinical evidence, analyze the potentially clinically relevant differences in methodology, and address some of the unique challenges that come with this treatment method.

Implantable cardioverter-defibrillators in patients with long QT syndrome: a multicentre study.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy has been proven effective in the prevention of sudden cardiac death, but data on outcomes of ICD therapy in the young and otherwise healthy patients with long QT syndrome (LQTS) are limited. AIM: We sought to collect data on appropriate and inappropriate ICD discharges, risk factors, and ICD-related complications. METHODS: All LQTS patients implanted with an ICD in 14 centres were investigated. Demographic, clinical, and ICD therapy data were collected. RESULTS: The study included 67 patients (88% female). Median age at ICD implantation was 31 years (12-77 years). ICD indication was based on resuscitated cardiac arrest in 46 patients, syncope in 18 patients, and malignant family history in three patients. During a median follow-up of 48 months, 39 (58%) patients received one or more ICD therapies. Time to first appropriate discharge was up to 55 months. Inappropriate therapies were triggered by fast sinus rhythm, atrial fibrillation, and T-wave oversensing. No predictors of inappropriate shocks were identified. Risk factors for appropriate ICD therapy were: (1) recurrent syncope despite b-blocker treatment before ICD implantation, (2) pacemaker therapy before ICD implantation, (3) single-chamber ICD, and (4) noncompliance to b-blockers. In 38 (57%) patients, at least one complication occurred. CONCLUSIONS: ICD therapy is effective in nearly half the patient population; however, the rates of early and late complica-tions are high. Although the number of unnecessary ICD shocks and reimplantation procedures may be lowered by modern programming and increased longevity of newer ICD generators, other adverse events are less likely to be reduced.

Asymmetric Dimethylarginine versus Proton Pump Inhibitors Usage in Patients with Stable Coronary Artery Disease: A Cross-Sectional Study.

A recent experimental study suggested that proton pump inhibitors (PPI), widely used to prevent gastroduodenal complications of dual antiplatelet therapy, may increase the accumulation of the endogenous nitric oxide synthesis antagonist asymmetric dimethylarginine (ADMA), an adverse outcome predictor. Our aim was to assess the effect of PPI usage on circulating ADMA in coronary artery disease (CAD). Plasma ADMA levels were compared according to PPI use for ≥1 month prior to admission in 128 previously described non-diabetic men with stable CAD who were free of heart failure or other coexistent diseases. Patients on PPI tended to be older and with insignificantly lower estimated glomerular filtration rate (GFR). PPI use was not associated with any effect on plasma ADMA (0.51 ± 0.11 (SD) vs. 0.50 ± 0.10 µmol/L for those with PPI (n = 53) and without PPI (n = 75), respectively; p = 0.7). Additionally, plasma ADMA did not differ between PPI users and non-users stratified by a history of current smoking, CAD severity or extent. The adjustment for patients' age and GFR did not substantially change the results. Thus, PPI usage does not appear to affect circulating ADMA in non-diabetic men with stable CAD. Whether novel mechanisms of adverse PPI effects on the vasculature can be translated into clinical conditions, requires further studies.

Management of Patients with Atrial Fibrillation: Focus on Treatment Options.

Atrial fibrillation (AF) is leading cardiac arrhythmia with important clinical implications. Its diagnosis is usually made on the basis on 12-lead ECG or 24-hour Holter monitoring. More and more clinical evidence supports diagnostic use of cardiac event recorders and cardiovascular implantable electronic devices (CIED). Treatment options in patients with atrial fibrillation are extensive and are based on chosen rhythm and/or rate control strategy. The use and selected contraindications to AF related pharmacotherapy, including anticoagulants are shown. Nonpharmacological treatments, comorbidities and risk factors control remain mainstay in the treatment of patients with AF. Electrical cardioversion consists important choice in rhythm control strategy. Much progress has been made in the field of catheter ablation and cardiac surgery methods. Left atrial appendage occlusion/closure may be beneficial in patients with AF. CIED are used with clinical benefits in both, rhythm and rate control. Pacemakers, implantable cardioverter-defibrillators and cardiac resynchronization therapy devices with different pacing modes have guaranteed place in the treatment of patients with AF. On the other hand, the concepts of permanent leadless cardiac pacing, atrial dyssynchrony syndrome treatment and His-bundle or para-Hisian pacing have been proposed. This review summarizes and discusses current and novel treatment options in patients with atrial fibrillation.

[Reasons of recurrence and subjective arrhythmia feelings after successful RF AVNRT ablation].

Aim of the study was analysis of electrophysiological and clinical parameters related to increasement of recurrence risk of AVNRT and subjective heart feelings after successful RF ablation. Materials and methods: Retrospective analysis was made among patients after successful RF AVNRT ablation. Study group was 93 patients (F=63), mean age 46.7+15.9 (from 18 to 80y). Electrophysiological and physical parameters achieved during electrophysiological study was analysed. Using telephone monitoring and question survey patients were divided into 3 subgroups A ­ without symptoms, B ­ with subjective arrhythmia feelings and C with documented arrhythmia recurrence. Results: 6.4% patients (n=6) had documented arrhythmia recurrence AVNRT (subgroup C); women 100% (n=6), mean age 43.5±14 years. 43% of patients (n=40) after successful RF ablation had subjective feelings of heart palpitations of a different kind (subgroup B); women 68% (n=32), mean age 42.8±14 years. 51% (n=47) of patients didn't feel any arrhythmia (subgroup A); women 64% (n=36), mean age 50.7±17 years. Conclusions: Factors related to increased risk of arrhythmia recurrence was: atypical forms of tachycardia, shorter tachycardia cycle, slow pathway modification, low mean power during RF ablation. Among patients without documented arrhythmia recurrence: lower age, higher time from the beginning arrhythmia until ablation procedure and Wenckebach Point cycle length shorter predispose to inadequate subjective arrhythmia feelings after successful RF ablation.

Fulminant heart failure due to giant cell myocarditis affecting the left ventricle.

A 56-year-old woman, previously healthy, was hospitalized after an episode of ventricular tachycardia in the course of infection. In view of the fulminant course of heart failure the patient was connected to an extracorporeal membrane oxygenation (ECMO) system. After 3 weeks of treatment with ECMO the patient received a heart transplant. A histopathological examination of the tissues of the explanted heart revealed giant cell myocarditis. The patient was treated with immunosuppression based on induction therapy followed by a standard regimen with steroids. Currently, the patient remains in good general condition with an left ventricular ejection fraction of 60%.

[The effectiveness of RF ablation of ventricular ectopic beats made using selected mapping techniques]. / Skutecznosc ablacji RF ekstrasystolii komorowej wykonanej z uzyciem wybranych technik mapowania.

UNLABELLED: Only several world-leading centers have summarized outcomes of invasive therapy of ventricular arrhythmia. AIM: The aim of the work is to compare the effectiveness of RF ablation of ventricular arrhythmia. MATERIALS AND METHODS: 183 patients (111 males, mean age 50 ± 17) underwent RF ablation of ventricular ecopic beats (VEB). Retrospective analysis of procedural protocols, in- and outpatient medical records was performed. RF ablation was done using electroanatomical CARTO system, Pacemapping or both methods (CARTO + Pacemapping). RESULTS: Long-term ablation effectiveness was as follows: CARTO - success rate assessed during the ablation procedure was 84,4%; during post operation period follow-up 70,3%, and in long term followup 71,1%; Pacemaping-success rate assessed during the ablation procedure was 91,7%; during post operation period follow-up 83,3%, and in long term follow-up 75,0%; CARTO + Pacemaping - success rate assessed during the ablation procedure was 85,4%; during post operation period follow-up 70,8%, and in long term follow-up 77,1%. Mean amount of VEBs per day before ablation was 18750 ± 12560 (2435 to 50000) and after ablation 575 ± 428 (0 to 1550), p<0.001. Best results were achieved in cases where both mapping techniques were used in combination. Among clinical parameters affecting long-term ablation effectiveness, only hypertension was found to significantly decrease long-term effectiveness of VEB ablation. Only ablation temperature and energy affected long-term therapy effect significantly (p<0,0014; HR=0,84). After the ablation, there was improvement of the left-ventricular end-diastolic diameter and ejection fraction. CONCLUSIONS: Long-term success of ventricular extrasystoly ablation in combined method (CARTO+Pacemapping) was slightly higher compared in CARTO technique and in Pacemapping technique. Classic RF ablation is effective and safe, therefore it can be considered as first-line therapy. In ablation, precise localization of arrhythmic focus is the most important factor. Ablation temperature and energy were significantly correlated to long-term ablation effectiveness. After ventricular extrasystoly ablation, left ventricle ejection fraction increased and left ventricle end-diastolic diameter decreased. Hypertension significantly decreased long-term effectiveness of ventricular extrasystoly ablation.

Depressed Systemic Arterial Compliance is Associated with the Severity of Heart Failure Symptoms in Moderate-to-Severe Aortic Stenosis: a Cross-Sectional Retrospective Study.

BACKGROUND: Patients with aortic stenosis (AS) may develop heart failure even in the absence of severe valve stenosis. Our aim was to assess the contribution of systemic arterial properties and the global left ventricular afterload to graded heart failure symptoms in AS. METHODS: We retrospectively reviewed medical records of 157 consecutive subjects (mean age, 71±10 years; 79 women and 78 men) hospitalized owing to moderate-to-severe degenerative AS. Exclusion criteria included more than mild aortic insufficiency or disease of another valve, atrial fibrillation, coronary artery disease, severe respiratory disease or anemia. Heart failure symptoms were graded by NYHA class at admission. Systemic arterial compliance (SAC) and valvulo-arterial impedance (Zva) were derived from routine echocardiography and blood pressure. RESULTS: Sixty-one patients were asymptomatic, 49 presented mild (NYHA II) and 47 moderate-to-severe (NYHA III-IV) heart failure symptoms. Mild symptoms were associated with lower SAC and transvalvular gradients, while more severe exercise intolerance coincided with older age, lower systolic blood pressure, smaller aortic valve area and depressed ejection fraction. By multiple ordinal logistic regression, the severity of heart failure symptoms was related to older age, depressed ejection fraction and lower SAC. Each decrease in SAC by 0.1 ml/m² per mmHg was associated with an increased adjusted odds ratio (OR) of a patient being in one higher category of heart failure symptoms graded as no symptoms, mild exercise intolerance and advanced exercise intolerance (OR: 1.16 [95% CI, 1.01-1.35], P=0.045). CONCLUSIONS: Depressed SAC may enhance exercise intolerance irrespective of stenosis severity or left ventricular systolic function in moderate-to-severe AS. This finding supports the importance of non-valvular factors for symptomatic status in AS.

[Electrocardiologic opportunities for the treatment of recurrent ventricular tachycardia on the example of a patient with arrhythmogenic right ventricular dysplasia]. / Elektrokardiologiczne mozliwosci leczenia nawracajacych czestoskurczów komorowych na przykladzie pacjenta z arytmogenna dysplazja prawej komory.

Arrhythmogenic right ventricular dysplasia is a genetic disease, in which pathologic fibrofatty tissue occurs mainly in the right ventricle of the heart. Changes in heart muscle predispose to arrhythmias such as ventricular tachycardia or ventricular fibrillation, so these patients are candidates for implantation of implantable cardioverter-defibrillator. Furthermore, depending on the indication, RF-ablation is performed, which, due to changes in morphology of the heart muscle, are often difficult and of uncertain efficacy. In this paper we present a case of a patient with implanted cardioverter-defibrillator for primary prevention of sudden cardiac death. Initially, the patient experienced only complications related to the possession of the device, but due to the significant progression of the disease and symptoms, the device turned out to be necessary. In addition, the patient underwent complex electrophysiology procedures to control recurrent episodes of ventricular tachycardia. Treatment of cardiac arrhythmias in arrhythmogenic right ventricular dysplasia is problematic both because of the inability to predict the course of disease in asymptomatic patients, as well as due to the difficulty of carrying out effective ablation of arrhythmia foci in morphologically altered myocardium.

The effects of LAA ligation on LAA electrical activity.

BACKGROUND: The arrhythmic role of the left atrial appendage (LAA) has been implicated in the maintenance of persistent atrial fibrillation. LAA isolation with catheter ablation has been successful but is limited by the risk of tamponade and electromechanical dissociation with the potential for LAA thrombus formation. OBJECTIVE: To assess whether LAA ligation results in LAA electrical isolation. METHODS: A total of 68 patients with contraindication or intolerance to oral anticoagulation therapy underwent LAA ligation with the LARIAT suture delivery device. Patients had unipolar [n = 30(44%)] or bipolar [n = 38(56%)] voltage measurements pre- and post-LAA ligation. RESULTS: All 68 patients underwent successful LAA ligation. There was a statistically significant reduction in the mean LAA voltage from pre-ligation (unipolar pre-ligation voltage 1.1 ± 0.53 mV; bipolar pre-ligation voltage 4.7 ± 2.83 mV) to post-ligation (unipolar post-ligation voltage 0.3 ± 0.38 mV; bipolar post-ligation voltage 0.6 ± 0.27 mV). Ninety-four percent of the patients had a reduction in the LAA voltage after the closure of the snare, with 10 of 30 (33%) of the patients having complete elimination of LAA voltage with the initial tightening of the suture. Pacing from the LAA after the closure of the snare resulted in lack of capture of the left atrium in 28 of 31 patients. CONCLUSIONS: The snare closure of the LAA using the LARIAT device produces an acute reduction in the LAA voltage and inhibits the capture of the left atrium during LAA pacing. Future studies are needed to determine whether LAA ligation affects atrial fibrillation burden.

Implantable intravascular defibrillator: defibrillation thresholds of an intravascular cardioverter-defibrillator compared with those of a conventional ICD in humans.

BACKGROUND: A percutaneous intravascular cardioverter-defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC)-brachiocephalic vein (BCV) region and the inferior vena cava (IVC). OBJECTIVE: To compare defibrillation thresholds (DFTs) of the PICD with those of a conventional ICD in humans. METHODS: Ten patients with ischemic cardiomyopathy and ejection fraction ≤35% were randomized to initial testing with either PICD or conventional ICD. A standard dual-coil lead was positioned in the RV apex. If randomized to PICD, the device was placed into the vasculature such that 1 titanium electrode was positioned in the SVC-BCV region and the second in the IVC. For PICD DFTs, the RV coil of the conventional ICD lead was connected to the PICD mandrel [shock vector: RV (+) to SVC-BCV (-) + IVC (-)]. When testing the conventional ICD, a subcutaneous pocket was formed in the left pectoralis region and the ICD was connected to the lead system and positioned in the pocket [shock vector: RV (+) to SVC (-) + active can (-)]. Each device was removed before testing with the other. A step-down binary search protocol determined the DFT, with the initial shock being 9 J. RESULTS: The mean PICD DFT was 7.6 ± 3.3 J, and the conventional ICD system demonstrated a mean DFT of 9.5 ± 4.7 J (N = 10; paired t test, P = .28). CONCLUSION: The intravascular defibrillator has DFTs similar to those of commercially available ICDs.