How likely is the sense-B-noise to affect patients with subcutaneous implantable cardioverter-defibrillators and can we solve that problem in every case?

BACKGROUND: Sense-B-noise is a newly reported possible cause of inappropriate shocks in patients with subcutaneous implantable cardioverter-defibrillators (S-ICDs). The nature of that noise is unknown, it is not related to mechanical failure of the S-ICD system. Reprogramming to the secondary sensing vector is suggested by the producer as a possible solution. METHODS: We analyzed the medical records of S-ICD recipients from two university clinical centers (Gdansk and Szczecin, Poland). Our aim was to determine the rate of sense-B-noise, and whether the secondary sensing vector would be available for reprogramming if such a problem occurred in our patients. RESULTS: The sense-B-noise issue affected three patients in our cohort (3%), which corresponds to the incidence of 0.012 events per patient-year of follow-up. The primary vector was permanently used in 47 patients (52%), secondary in 28 (31%), and alternate in 16 (17%), respectively. Therefore, the total number of patients potentially vulnerable to sense-B noise (with the primary or alternate vector programmed permanently) was 63 (69%). Among those 63 patients, 51 individuals (81%) had also the secondary vector available for permanent use. CONCLUSION: The sense-B-noise affected 3% of patients in our cohort, with an incidence of 0.012 per patient-year of follow-up. Most patients potentially vulnerable to sense-B noise could be reprogrammed to the secondary sensing vector, if necessary. Further investigation of the sense-B-noise issue is needed.

Comparison of Preoperative ECG Screening and Device-Based Vector Analysis in Patients Receiving a Subcutaneous Implantable Cardioverter-Defibrillator.

Background and Objectives: Subcutaneous implantable cardioverter-defibrillators (S-ICDs) provide protection against sudden cardiac death from outside the cardiovascular system. ECG screening is a prerequisite for implantation, but the reproducibility of its results post-operatively in the device is only partial. We aimed to compare the results of ECG screening with device-based sensing vector analysis. Materials and Methods: We screened the hospital records of all S-ICD recipients in our clinic. All of them had pre-operative ECG screening performed (primary, secondary, and alternate vectors). The results were compared with device-based vector analysis to determine the relation of the pre- and post-operative vector availability. Results: Complete ECG screening and device-based vector analysis were obtained for 103 patients. At least two acceptable vectors were found in 97.1% of the patients pre-operatively and in 96.1% post-operatively. When comparing vectors in terms of agreement (OK or FAIL) pre- and post-operatively, in 89.3% of the patients, the result for the primary vector was the same in both situations; for the secondary, it was in 84.5%, and for the alternate, it was in 74.8% of patients, respectively. In 55.3% of patients, all three vectors were labeled the same (OK or FAIL); in 37.9%, two vectors had the same result, and in 6.8%, only one vector had the same result pre- and post-operatively. The number of available vectors was the same pre- and post-operatively in 62.1% of patients, while in 15.5%, it was lower, and in 22.3% of patients, it was higher than observed during screening. Conclusions: Routine clinical pre-operative screening allowed for a good selection of candidates for S-ICD implantation. All patients had at least one vector available post-operatively. The final number of vectors available in the device-based analysis in most patients was at least the same (or higher) than during screening. The repeatability of the positive result for a single vector was high.

Genetic testing for inherited cardiovascular diseases. A position statement of the Polish Cardiac Society endorsed by Polish Society of Human Genetics and Cardiovascular Patient Communities.

According to the latest guidelines of European and American medical societies, genetic testing (GT) is essential in cardiovascular diseases for establishing diagnosis, predicting prognosis, enabling initiation of disease-modifying therapy, and preventing sudden cardiac death. The GT result may be relevant for cascade GT in the patient's relatives, for planning his/her profession and physical activity, and for procreative counseling. This position statement has been prepared due to the scarcity of GT in cardiovascular diseases in Poland and the need to expand its availability. We give a concise description of the genetic background of cardiomyopathies, channelopathies, aortopathies, familial hypercholesterolemia, pheochromocytomas, and paragangliomas. The article discusses various aspects of GT in specific populations, such as children or athletes, and also presents prenatal genetic diagnostics. We propose recommendations for GT and counselling, which take into account Polish needs and capabilities. We give an outline of legal regulations, good clinical practice in GT with respect for patient rights, the role of cardiologists and clinical geneticists in GT planning and post-test counseling, and the requirements for laboratories performing genetic tests. The Polish Cardiac Society and Polish Society of Human Genetics experts speak with one voice with cardiovascular patient communities to underline the need for a law on GT and increasing the availability of GT for cardiovascular patients.

Application of Novel Technologies in Cardiac Electrotherapy to Prevent Complications.

(1) Background: Cardiac electrotherapy is developing quickly, which implies that it will face a higher number of complications, with cardiac device-related infective endocarditis (CDRIE) being the most frequent, but not the only one. (2) Methods: This is a retrospective case study followed by a literature review, which presents a patient with a rare but dangerous complication of electrotherapy, which could have been prevented if modern technology had been used. (3) Results: A 34-year-old female was admitted with suspicion of CDRIE based on an unclear echocardiographic presentation. However, with no signs of infection, that diagnosis was not confirmed, though an endocardial implantable cardioverter-defibrillator (ICD) lead was found folded into the pulmonary trunk. The final treatment included transvenous lead extraction (TLE) and subcutaneous ICD (S-ICD) implantation. (4) Conclusions: With the increasing number of implantations of cardiac electronic devices and their consequences, a high index of suspicion among clinicians is required. The entity of the clinical picture must be thoroughly considered, and various diagnostic tools should be applied. Lead dislocation into the pulmonary trunk is an extremely rare complication. Our findings align with the available literature data, where asymptomatic cases are usually effectively treated with TLE. Modern technologies, such as S-ICD, can effectively prevent lead-related problems and are indicated in young patients necessitating long-term ICD therapy.

Left Ventricle Segmental Longitudinal Strain and Regional Myocardial Work Index Could Help Determine Mitral Valve Prolapse Patients with Increased Risk of Ventricular Arrhythmias.

Mitral valve prolapse (MVP) could associate with malignant ventricular arrhythmias (VAs). Mitral annular disjunction, a putative mechanism for an arrhythmic substrate, leads to excessive mobility, stretch, and damage of some segments. Speckle tracking echocardiography (STE), with particular attention to the segmental longitudinal strain and myocardial work index (MWI), could be an indicator of the segments we aimed to check. Seventy-two MVP patients and twenty controls underwent echocardiography. Complex VAs documented prospectively after the enrollment was qualified as the primary endpoint, which was noticed in 29 (40%) patients. Pre-specified cut-off values for peak segmental longitudinal strain (PSS) and segmental MWI for basal lateral (-25%, 2200 mmHg%), mid-lateral (-25%, 2500 mmHg%), mid-posterior (-25%, 2400 mmHg%), and mid-inferior (-23%, 2400 mmHg%) segments were accurate predictors of complex VAs. A combination of PSS and MWI increased the probability of the endpoint, reaching the highest predictive value for the basal lateral segment: odds ratio 32.15 (3.78-273.8), p < 0.001 for PSS ≥ -25% and MWI ≥ 2200 mmHg%. STE may be a valuable tool for assessing the arrhythmic risk in MVP patients. Excessively increased segmental longitudinal strain with an augmented regional myocardial work index identifies patients with the highest risk of complex VAs.

Comprehensive Echocardiography of Left Atrium and Left Ventricle Using Modern Techniques Helps in Better Revealing Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy.

Atrial fibrillation (AF) is an important arrhythmia in hypertrophic cardiomyopathy (HCM). We aimed to explore whether a complex evaluation of the left ventricle (LV) using modern echocardiography techniques, additionally to the left atrium (LA) boosts the probability of AF diagnosis. Standard echocardiography, 2D and 3D speckle tracking, were performed for LA and LV evaluation in HCM patients and healthy volunteers. Of 128 initially qualified HCM patients, 60 fulfilled included criteria, from which 43 had a history of AF, and 17 were without AF. LA volume index and peak strain, LV ejection fraction, and strains were significant predictors of AF. In addition, 2D global longitudinal strain (GLS) for LV at cut off -16% turned out to be the most accurate predictor of AF (OR 48.00 [95% CI 2.68-859.36], p = 0.001), whereas the combination of LA peak strain ≤ 22% and LV GLS ≥ -16% had the highest discriminatory power (OR 76.36 [95% CI 4.13-1411.36], p = 0.001). AF in HCM patients seems to be LA as well as LV disease. Revealing lower strain for LV, in addition to lower LA strain, may have an important impact on accurate characteristics of HCM patients with AF history.

Segmental longitudinal strain as the most accurate predictor of the patchy pattern late gadolinium enhancement in hypertrophic cardiomyopathy.

BACKGROUND: The prognostic value of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) has been well-established. Although cardiac magnetic resonance (CMR) is the method of choice in its revealing as the presence of late gadolinium enhancement (LGE), this technique still has limited availability in daily clinical practice. Two-dimensional speckle tracking echocardiography (2D STE) seems to be helpful in verification which HCM patient has the highest probability of LGE presence and hence needs to be qualified to CMR. While the majority of HCM patients have a patchy pattern of myocardial fibrosis, the aim of this study was to evaluate whether segmental rather than global longitudinal strain is more accurate in the identification of the presence of LGE. METHODS: Forty-six HCM patients had transthoracic echocardiography and CMR imaging performed. Each patient had global longitudinal strain and rotation parameters calculated, as well as segmental analyses for wall thickness, longitudinal strain, and LGE presence based on 736 segments of the left ventricle (LV). The presence of LGE in CMR was confirmed on a per-segment basis, which was similar to LV segments in the echocardiographic examination. All patients were divided into two groups according to the CMR result: LGE (+) and LGE (-). RESULTS: Receiver-operating characteristic analyses identified peak global longitudinal strain and peak twisting velocity with the cut-off values -14.4% and 116°/s respectively as the accurate predictors of LGE presence in CMR, whereas segmental longitudinal strain of -12.5% cut-off value had the highest area under the curve value (87.4%, confidence interval 84.5-90.3%), with 93.7% sensitivity, 86.5% negative predictive value, and 55% specificity. CONCLUSIONS: Segmental longitudinal strain with the cut-off value of -12.5% has the highest discriminatory power for LGE presence and seems to be more adequate than global speckle tracking parameters in identification of HCM patients with strong indications for CMR for more accurate risk stratification.

Association between the geographic region and the risk of familial atrioventricular nodal reentrant tachycardia in the Polish population.

Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common regular supraventricular arrhythmias referred for catheter ablation (CA). In Poland, several families with familial AVNRT (FAVNRT) were reported in Podkarpacie Province (PP). Objectives: We aimed to determine the frequency of FAVNRT in PP compared with other south-eastern provinces of Poland. Patients and methods: Clinical data of 1544 patients with AVNRT diagnosed by invasive electrophysiological study between 2010 and 2019 were screened for FAVNRT. From January 2017 to June 2019, patients were asked to provide details on family history and origin to obtain 3-generation pedigrees. Families with at least 2 members with previous CA of AVNRT were divided into those from south-eastern provinces (SEPs; including PP and bordering provinces [BPs]) and the remaining parts of Poland (RPP). Results: There were 932 patients from SEPs and 612 from RPP. FAVNRT was reported in 45 patients (2.91%) from 27 families, with a higher frequency in SEPs than RPP (4.02% vs 1.17%; P = 0.002) and the highest frequency in PP (6.33% vs 2.47% in BPs; P = 0.004). The risk of FAVNRT was higher in PP compared with BPs (odds ratio, 2.67; 95% CI, 1.36­5.23; P = 0.004) and similar in BPs compared with RPP (odds ratio, 2.14; 95% CI, 0.86­5.34; P = 0.1). Conclusions: A relationship exists between the geographic region and frequency of FAVNRT. A greater distance from PP was associated with less frequent FAVNRT. International cooperation and genetic testing are needed to confirm the genetic impact of FAVNRT in this part of Central Europe.

Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1.

BACKGROUND: Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. OBJECTIVES: This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. METHODS: Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. RESULTS: We enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). CONCLUSIONS: Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1.

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.

The Phenotypic Spectrum of a Mutation Hotspot Responsible for the Short QT Syndrome.

OBJECTIVES: This study sought to evaluate the phenotypic and functional expression of an apparent hotspot mutation associated with short QT syndrome (SQTS). BACKGROUND: SQTS is a rare channelopathy associated with a high risk of life-threatening arrhythmias and sudden cardiac death (SCD). METHODS: Probands diagnosed with SQTS and their family members were evaluated clinically and genetically. KCNH2 wild-type (WT) and mutant genes were transiently expressed in HEK293 cells, and currents were recorded using whole-cell patch clamp and action potential (AP) clamp techniques. RESULTS: KCNH2-T618I was identified in 18 members of 7 unrelated families (10 men; median age: 24.0 years). All carriers showed 100% penetrance with variable expressivity. Eighteen members in 7 families had SCD. The average QTc intervals of probands and all carriers was 294.1 ± 23.8 ms and 313.2 ± 23.8 ms, respectively. Seven carriers received an implantable cardioverter-defibrillator. Quinidine with adequate plasma levels was effective in prolonging QTc intervals among 5 cases, but 3 cases still had premature ventricular contraction or nonsustained ventricular tachycardia. Bepridil successfully prevented drug-refractory ventricular fibrillation in 1 case with 19-ms prolongation of the QTc interval. Functional studies with KCNE2 revealed a significant increase of IKr (rapidly activating delayed rectifier potassium channel) tail-current density in homozygous (119.0%) and heterozygous (74.6%) expression compared with WT. AP clamp recordings showed IKr was larger, and peak repolarizing current occurred earlier in mutant versus WT channels. CONCLUSIONS: We reported the clinical characteristics and biophysical properties of the highly frequent mutation that contributes to genetically identified SQTS probands. These findings extend our understanding of the spectrum of KCNH2 channel defects in SQTS.

The world's largest family with familial atrio-ventricular nodal reentry tachycardia.

We report a three-generation family coming from southeastern region of Poland (Podkarpackie voivodship) with 6 women having normal hearts and presenting with a history of paroxysmal tachycardia with onset of symptoms in the adulthood. Recordings of clinical SVT, dual AVN electrophysiology, induction of typical AVNRT and results of RFCA are available. The history of this family shows the significance of a careful and detailed collection of medical history, and point towards the importance of family screening in AVNRT patients.