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Heart Rhythm Jun 2024
PubMed: 38936450
DOI: 10.1016/j.hrthm.2024.06.042 -
Herzschrittmachertherapie &... Jun 2024
PubMed: 38935120
DOI: 10.1007/s00399-024-01027-9 -
Journal of the American Heart... Jun 2024Anterior-posterior electrode placement is preferred in electrical cardioversion of atrial fibrillation. However, the optimal anterior-posterior electrode position in...
BACKGROUND
Anterior-posterior electrode placement is preferred in electrical cardioversion of atrial fibrillation. However, the optimal anterior-posterior electrode position in relation to the heart is not studied.
METHODS AND RESULTS
We performed a prospective observational study on patients presenting for cardioversion of atrial fibrillation. Electrodes were placed in the anterior-posterior position and shock was delivered in a step-up approach (100 J→200 J→360 J). Fluoroscopic images were obtained, and distances were measured from points A, midanterior electrode; and B, midposterior electrode, to midpoint of the cardiac silhouette. Patients requiring one 100 J shock for cardioversion success (group I) were compared with those requiring >1 shock/100 J (group II). Logistic regression was used to determine the impact of electrode distance on low energy (100 J) cardioversion success. Computed tomography scans from this cohort were analyzed for anatomic landmark correlation to the cardiac silhouette. Of the 87 patients included, 54 (62%) comprised group I and 33 (38%) group II. Group I had significantly lower distances from the mid-cardiac silhouette to points A (5.0±2.4 versus 7.4±3.3 cm; <0.001) and B (7.3±3.0 versus 10.0±3.8 cm; =0.002) compared with group II. On multivariate analysis, higher distances from the mid-cardiac silhouette to point A (odds ratio, 1.33 [95% CI, 1.07-1.70]; =0.01) and B (odds rsatio, 1.24 [95% CI, 1.05-1.50]; =0.01) were independent predictors of low energy (100 J) cardioversion failure. Based on review of computed tomography scans, we suggest that the xiphoid process may be an easy landmark to guide proximity to the myocardium.
CONCLUSIONS
In anterior-posterior electrode placement, closer proximity to the cardiac silhouette predicts successful 100 J cardioversion irrespective of clinical factors.
PubMed: 38934869
DOI: 10.1161/JAHA.123.034817 -
Cureus May 2024Left ventricular non-compaction cardiomyopathy (LVNC), or non-compaction cardiomyopathy (NCCM), is defined by pronounced left ventricular trabeculations and deep...
Left ventricular non-compaction cardiomyopathy (LVNC), or non-compaction cardiomyopathy (NCCM), is defined by pronounced left ventricular trabeculations and deep intertrabecular recesses connecting with the ventricular cavity. Patients with NCCM can be asymptomatic or have severe complications, including heart failure, arrhythmias, thromboembolism, and sudden cardiac death. Our case discusses a patient with shortness of breath who was found to have a newly decreased ejection fraction. The workup revealed non-ischemic cardiomyopathy and cardiac MRI showed hyper-trabeculations consistent with NCCM. The patient was started on oral anticoagulation and guideline-directed medical therapy (GDMT) and discharged with an event monitor. NCCM stands as a relatively rare and enigmatic condition, often veiled in ambiguity. The absence of standardized diagnostic and management protocols further complicates its clinical landscape. While echocardiography is the primary diagnostic tool, its tendency for under-diagnosis poses a significant challenge. Conversely, advanced imaging modalities like cardiac MRI may lead to instances of overdiagnosis. Treatment approaches are non-specific, incorporating GDMT, anticoagulation, implantable cardioverter-defibrillator placement, and genetic testing paired with counseling. Prioritizing genetic research is crucial to uncover tailored therapeutic interventions. Establishing consensus guidelines and refining diagnostic accuracy are pivotal steps toward mitigating the risks associated with under and over-diagnosis.
PubMed: 38933642
DOI: 10.7759/cureus.61142 -
Polymers Jun 2024The 6935M Sprint Quattro Secure S and 6947M Sprint Quattro Secure are high voltage leads designed to administer a maximum of 40 joules of energy for terminating...
The 6935M Sprint Quattro Secure S and 6947M Sprint Quattro Secure are high voltage leads designed to administer a maximum of 40 joules of energy for terminating ventricular tachycardia or ventricular fibrillation. Both leads utilize silicone insulation and a polyurethane outer coating. The inner coil is shielded with polytetrafluoroethylene (PTFE) tubing, while other conductors are enveloped in ethylene tetrafluoroethylene (ETFE), contributing to the structural integrity and functionality of these leads. Polyurethane is a preferred material for the outer insulation of cardiac leads due to its flexibility and biocompatibility, while silicone rubber ensures chemical stability within the body, minimizing inflammatory or rejection responses. Thirteen implantable cardioverter defibrillator (ICD) leads were obtained from the Wright State University Anatomical Gift Program. The as-received devices exhibited varied in vivo implantation durations ranging from less than a month to 89 months, with an average in vivo duration of 41 ± 27 months. Tests were conducted using the Test Resources Q series system, ensuring compliance with ASTM Standard D 1708-02a and ASTM Standard D 412-06a. During testing, a load was applied to the intact lead, with careful inspection for surface defects before each test. Results of load to failure, percentage elongation, percentage elongation at 5 N, ultimate tensile strength, and modulus of elasticity were calculated. The findings revealed no significant differences in these parameters across all in vivo exposure durations. The residual properties of these ICD leads demonstrated remarkable stability and performance over a wide range of in vivo exposure durations, with no statistically significant degradation or performance changes observed.
PubMed: 38932072
DOI: 10.3390/polym16121722 -
Biomedicines Jun 2024Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator...
Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator (ICD) should be considered in patients with an estimated 5-year risk of malignant ventricular arrhythmia (MVA) of ≥10%. The risk prediction score for MVA includes non-missense LMNA mutations, despite their role as an established risk factor for sudden cardiac death (SCD) has been questioned in several studies. The purpose of this study is to investigate cardiac features and find gene-phenotype correlations that would contribute to the evidence on the prognostic implications of non-missense vs. missense mutations in a cohort of LMNA mutant patients. An observational, prospective study was conducted in which 54 patients positive for a Lamin A/C mutation were enrolled, and 20 probands (37%) were included. The median age at first clinical manifestation was 41 (IQR 19) years. The median follow-up was 8 years (IQR 8). The type of gene mutation was distributed as follows: missense in 26 patients (48%), non-frameshift insertions in 16 (30%), frameshift deletions in 5 (9%), and nonsense in 7 (13%). Among the missense mutation carriers, two (8%) died and four (15%) were admitted onto the heart transplant list or underwent transplantation, with a major adverse cardiovascular event (MACE) rate of 35%. No statistically significant differences in MACE prevalence were identified according to the missense and non-missense mutation groups ( value = 0.847). Our data shift the spotlight on this considerable topic and could suggest that some missense mutations may deserve attention regarding SCD risk stratification in real-world clinical settings.
PubMed: 38927500
DOI: 10.3390/biomedicines12061293 -
Journal of Veterinary Emergency and... 2024To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps.
OBJECTIVE
To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps.
DESIGN
Standardized, systematic evaluation of literature pertinent to ALS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by ALS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.
SETTING
Transdisciplinary, international collaboration in university, specialty, and emergency practice.
RESULTS
Seventeen questions pertaining to vascular access, vasopressors in shockable and nonshockable rhythms, anticholinergics, defibrillation, antiarrhythmics, and adjunct drug therapy as well as open-chest CPR were reviewed. Of the 33 treatment recommendations formulated, 6 recommendations addressed the management of patients with nonshockable arrest rhythms, 10 addressed shockable rhythms, and 6 provided guidance on open-chest CPR. We recommend against high-dose epinephrine even after prolonged CPR and suggest that atropine, when indicated, is used only once. In animals with a shockable rhythm in which initial defibrillation was unsuccessful, we recommend doubling the defibrillator dose once and suggest vasopressin (or epinephrine if vasopressin is not available), esmolol, lidocaine in dogs, and/or amiodarone in cats.
CONCLUSIONS
These updated RECOVER ALS guidelines clarify the approach to refractory shockable rhythms and prolonged CPR. Very low quality of evidence due to absence of clinical data in dogs and cats continues to compromise the certainty with which recommendations can be made.
Topics: Animals; Dogs; Cats; Dog Diseases; Cardiopulmonary Resuscitation; Cat Diseases; Veterinary Medicine; Heart Arrest
PubMed: 38924633
DOI: 10.1111/vec.13389 -
Journal of Cardiovascular... Jun 2024The dST-Tiso is a newly proposed electrocardiographic (ECG) marker during Brugada (BrS) type I pattern, that predicts the likelihood of ventricular arrhythmia (VA)...
INTRODUCTION
The dST-Tiso is a newly proposed electrocardiographic (ECG) marker during Brugada (BrS) type I pattern, that predicts the likelihood of ventricular arrhythmia (VA) inducibility in patients with ajmaline-induced pattern. The objective of this study was to validate the effectiveness of this criterion using an independent data set.
METHODS
Consecutive patients exhibiting a BrS type I ECG pattern following ajmaline administration underwent programmed ventricular stimulation (PVS). dST-Tiso interval was measured in all patients and tested as a predictor for positive VA inducibility.
RESULTS
Among 128 patients (median age 43 years, 59% male) with drug-induced BrS type I ECG pattern who underwent PVS, 32 (25.0%) had VA inducibility that required defibrillation. Compared to noninducible subjects, those with positive PVS were more commonly male (81% vs. 51%, p = 0.003), had longer PQ (165 vs. 160 ms, p = 0.016) and dST-Tiso (310 vs. 230 ms, p < 0.001) intervals, and shorter QT interval (412 vs. 420 ms, p = 0.022). When treated as a continuous variable, dST-Tiso confirmed significant association with VA inducibility, with an adjusted odds ratio of 1.02 (95% confidence interval: 1.01-1.03, p < 0.001) for each 1 ms increase in duration. A dST-Tiso interval >300 ms yielded a sensitivity of 75%, a specificity of 86%, and positive and negative predictive values of 69% and 91%, respectively.
CONCLUSION
The validation of the model based on the dST-Tiso interval >300 ms confirmed its high accuracy in predicting VA inducibility in drug-induced BrS type I pattern. This straightforward ECG marker might be linked to the extent of the electrical substrate of the disease.
PubMed: 38923783
DOI: 10.1111/jce.16348 -
Journal of Cardiovascular... Jun 2024Pacemaker-mediated tachycardia is a known arrhythmia in patients with dual chamber pacemakers and defibrillators and intact ventriculoatrial (VA) conduction. We report a...
INTRODUCTION
Pacemaker-mediated tachycardia is a known arrhythmia in patients with dual chamber pacemakers and defibrillators and intact ventriculoatrial (VA) conduction. We report a case of pacemaker-mediated reentrant arrhythmia (PMRA) in a patient with an atrioventricular (AV) synchronous leadless pacemaker.
METHODS AND RESULTS
A 91-year-old female presented with 2:1 AV conduction and received an AV synchronous leadless pacemaker. She had atrial mechanical sense-ventricular paced beats between heart rates of 80-100 bpm more than 80% of the time. She was found to have a new cardiomyopathy and was referred for placement of biventricular pacemaker. At the time of device implantation, her electrocardiogram showed ventricular pacing with a short RP interval and superiorly directed P waves. Changes in the ventricular pacing rate resulted in changes in the atrial rate. Following device placement, her heart rate decreased to the lower rate limit of her pacemaker. The atrial mechanical sense impulse most likely was generated by a retrograde conducted P wave resulting in near incessant PMRA.
CONCLUSION
PMRA may occur in patients who receive an AV synchronous leadless pacemaker with intact VA conduction and sinoatrial node dysfunction. Due to the lower rates of PMRA, this arrhythmia may be underrecognized. Interventions for and implications of PMRA need further investigation.
PubMed: 38923693
DOI: 10.1111/jce.16350 -
Journal of Cardiovascular Development... Jun 2024(1) Introduction: Digitalis use in patients with severe heart failure is controversial. We assessed the effects of digitalis therapy on mortality in a large,...
(1) Introduction: Digitalis use in patients with severe heart failure is controversial. We assessed the effects of digitalis therapy on mortality in a large, observational study in recipients of cardiac resynchronization therapy (CRT). (2) Methods: Consecutive patients receiving a CRT-defibrillator in three European tertiary referral centers were enrolled and followed-up for a mean 37 months ± 28 months. Digitalis use was assessed at the time of CRT implantation. A multivariate Cox-regression model and propensity score matching were used to determine all-cause mortality as the primary endpoint. CRT-response (defined as improvement of ≥1 NYHA class), echocardiographic improvement (defined as improvement of LVEF of ≥ 5%) and incidence of ICD shocks and rehospitalization were assessed as secondary endpoints in a subgroup of patients. (3) Results: The study comprised 552 CRT-recipients with standard indications, including 219 patients (40%) treated with digitalis. Compared to patients without digitalis, they had more often atrial fibrillation, poorer LVEF and a higher NYHA class (all ≤ 0.002). Crude analysis of all-cause mortality demonstrated a similar relative risk of death for patients with and without digitalis (HR = 1.14; 95% CI 0.88-1.5; = 0.40). After adjustment for independent predictors of mortality, digitalis therapy did not alter the risk for death (adjusted HR = 1.04; 95% CI 0.75-1.45; = 0.82). Furthermore, in comparison to 286 propensity-score-matched patients, mortality was not affected by digitalis intake (propensity-adjusted HR = 1.11; 95% CI 0.72-1.70; = 0.64). A CRT-response was predominant in digitalis non-users, concerning both improvement of HF symptoms and LVEF (NYHA < 0.01; LVEF < 0.01), while patients on digitalis had more often ventricular tachyarrhythmias requiring ICD shock ( = 0.01); although, rehospitalization for cardiac reasons was significantly lower among digitalis users compared to digitalis non-users (HR = 0.58; 95% C. I. 0.40-0.85; = 0.01). (4) Conclusions: Digitalis therapy had no effect on mortality, but was associated with a reduced response to CRT and increased susceptibility to ventricular arrhythmias requiring ICD shock treatment. Although, digitalis administration positively altered the likelihood for cardiac rehospitalization during follow-up.
PubMed: 38921673
DOI: 10.3390/jcdd11060173