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1.
Clin Anat ; 37(1): 43-53, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37337379

ABSTRACT

Outflow tract ventricular arrhythmias are the most common type of idiopathic ventricular arrhythmia. A systematic understanding of the outflow tract anatomy improves procedural efficacy and enables electrophysiologists to anticipate and prevent complications. This review emphasizes the three-dimensional spatial relationships between the ventricular outflow tracts using seven anatomical principles. In turn, each principle is elaborated on from a clinical perspective relevant for the practicing electrophysiologist. The developmental anatomy of the outflow tracts is also discussed and reinforced with a clinical case.


Subject(s)
Arrhythmias, Cardiac , Catheter Ablation , Humans , Heart Ventricles , Electrophysiology , Catheter Ablation/methods , Electrocardiography/methods
2.
J Cardiovasc Electrophysiol ; 34(1): 229-230, 2023 01.
Article in English | MEDLINE | ID: mdl-35946395

ABSTRACT

A 70-year-old woman with longstanding persistent atrial fibrillation underwent Micra leadless pacemaker implantation and atrioventricular nodal ablation. No postprocedural complications were noted. She subsequently underwent surgical mitral valve replacement 4 years later. During the surgery, Micra tine perforation of the right ventricular free wall was seen. No device revision was performed due to her asymptomatic status and stable pacemaker position/function. Pericardial effusion is a known complication of Micra implantation. The incidence of tine perforation is unknown as many patients may be asymptomatic. The clinical consequences regarding adverse events, device functionality, and explantation/extraction risk profile remain to be determined.


Subject(s)
Atrial Fibrillation , Cardiac Surgical Procedures , Pacemaker, Artificial , Humans , Female , Aged , Treatment Outcome , Pacemaker, Artificial/adverse effects , Atrial Fibrillation/diagnosis , Atrial Fibrillation/therapy , Cardiac Surgical Procedures/adverse effects , Atrioventricular Node
3.
Curr Opin Ophthalmol ; 31(2): 91-100, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31904596

ABSTRACT

PURPOSE OF REVIEW: Current recommendations for glaucoma screening are decidedly neutral. No studies have yet documented improved long-term outcomes for individuals who undergo glaucoma screening versus those who do not. Given the long duration that would be required to detect a benefit, future studies that may answer this question definitively are unlikely. Nevertheless, advances in artificial intelligence and telemedicine will lead to more effective screening at lower cost. With these new technologies, additional research is needed to determine the costs and benefits of screening for glaucoma. RECENT FINDINGS: Using optic disc photographs and/or optical coherence tomography, deep learning systems appear capable of diagnosing glaucoma more accurately than human graders. Eliminating the need for expert graders along with better technologies for remote imaging of the ocular fundus will allow for less expensive screening, which could enable screening of individuals with otherwise limited healthcare access. In India and China, where most glaucoma remains undiagnosed, glaucoma screening was recently found to be cost-effective. SUMMARY: Recent advances in artificial intelligence and telemedicine have the potential to increase the accuracy, reduce the costs, and extend the reach of screening. Further research into implementing these technologies in glaucoma screening is required.


Subject(s)
Artificial Intelligence , Deep Learning , Diagnostic Techniques, Ophthalmological , Economics, Medical , Glaucoma/diagnosis , Telemedicine , Cost-Benefit Analysis , Humans , Tomography, Optical Coherence/methods
4.
Ophthalmology ; 126(5): 702-711, 2019 05.
Article in English | MEDLINE | ID: mdl-30529130

ABSTRACT

PURPOSE: To describe variations in retinal nerve fiber layer (RNFL) thickness based on spectral-domain (SD) OCT in a multiethnic Asian population. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Ethnic Chinese, Malay, and Indian adults older than 48 years without glaucoma who were recruited from the Singapore Epidemiology of Eye Diseases Study. METHODS: All participants underwent standardized systemic and ocular examinations. Retinal nerve fiber layer thickness was measured using SD OCT. Participants with poor-quality scans were excluded. Linear regression models were used to investigate the associations of ocular and systemic factors with average RNFL thickness. Generalized estimating equation models were used to account for correlation between both eyes. MAIN OUTCOME MEASURE: Average RNFL thickness. RESULTS: Four thousand four hundred seventy-five participants (8178 eyes) consisting of 1371 Chinese, 1303 Malay, and 1801 Indian adults contributed to this analysis. Average RNFL thickness measured was 95.7±9.6 µm in Chinese participants, 94.9±10.6 µm in Malay participants, and 87.3±10.6 µm in Indian participants (P < 0.001). Multivariate analysis adjusted for age, gender, and ethnicity revealed a reduction in RNFL thickness with increased intraocular pressure and axial length (P < 0.001 for both), as well as a diagnosis of diabetes (P = 0.04); greater RNFL thickness was associated with increased disc area (P < 0.001), signal strength (P < 0.001), and low-density lipoprotein cholesterol (P = 0.02). When these significant variables were taken into account, the average RNFL thickness of Indian participants was significantly thinner compared with Chinese participants (7.45 µm thinner on average [95% confidence interval, 6.75-8.15 µm; P < 0.001]), whereas there was no significant difference in average RNFL thickness between Malay and Chinese participants (P = 0.15). CONCLUSIONS: Average and regional RNFL thicknesses were significantly thinner in Indian eyes compared with Chinese and Malay eyes. Results of the study highlight the need to acquire more refined normative data for the comparison of individual patients with others of similar ethnic background while accounting for ocular factors that could influence RNFL thickness. This in turn may improve the sensitivity and specificity of glaucoma detection.


Subject(s)
Retinal Ganglion Cells/cytology , Tomography, Optical Coherence/methods , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Glaucoma/diagnosis , Glaucoma/epidemiology , Humans , Male , Middle Aged , Nerve Fibers , Prevalence , Reference Values , Singapore/epidemiology
5.
Curr Opin Ophthalmol ; 30(2): 89-96, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30562243

ABSTRACT

PURPOSE OF REVIEW: Optic nerve head (ONH) changes such as tilt and torsion are associated with the progression of myopia, and may in turn predispose toward glaucoma. At the same time, these ONH deformations also make the structural assessment for glaucoma difficult. Here, we review the mechanisms and changes to the myopic optic disc, and the advances in structural imaging to better evaluate the ONH in myopia. RECENT FINDINGS: The distance, depth, and angle between the optic disc and the deepest point of the elongated eyeball may be related to the degree and direction of optic disc tilt and torsion. It is hypothesized that as the eyeball grows axially, the disc is pulled toward its most protruded point. These ONH deformations in myopia are thought to induce strain on the lamina cribrosa and the axons passing through it. Recent studies have shown unique characteristics of the lamina cribrosa in myopia that may account for susceptibility toward glaucoma. New developments in imaging the ONH in myopia, including the use of optical coherence tomography-angiography may also further our understanding of the relationship between myopia and glaucoma. SUMMARY: Optic disc changes in myopia are secondary to the configuration of the posterior globe. These ONH deformations may predispose toward glaucoma, although the causative relationship between myopia and glaucoma remains to be further clarified.


Subject(s)
Glaucoma/physiopathology , Myopia/physiopathology , Optic Disk/pathology , Optic Nerve Diseases/physiopathology , Disease Progression , Humans , Tomography, Optical Coherence/methods
6.
Eur Heart J ; 39(21): 1970-1977a, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29315367

ABSTRACT

Aims: Ventricular dysfunction or structural alteration of either ventricle is a well-established risk factor for sudden death (SD). Ebstein anomaly (EA) can present with both right and left heart abnormalities; however, predictors of SD have not been described. We therefore sought to characterize the incidence and risk factors of SD among a large cohort of patients with EA. Methods and results: All EA patients who underwent evaluation at a high-volume institution over a 4-decade period were retrospectively reviewed. Clinical variables, cardiovascular surgical procedure(s), and cause of death were recorded. Sudden death incidence from birth and following tricuspid valve (TV) surgery were estimated using the Kaplan-Meier method. Cox regression analysis was used to identify clinical and surgical predictors of SD. The cohort comprised of 968 patients [mean age 25.3 years, 41.5% male; 79.8% severe EA, 18.6% accessory pathway, 0.74% implantable cardioverter-defibrillator (ICD) placement]. The 10-, 50-, and 70-year cumulative incidences of SD from birth were 0.8%, 8.3%, and 14.6%, respectively. Prior ventricular tachycardia [hazard ratio (HR) 6.37, P < 0.001)], heart failure (HR 5.64, P < 0.001), TV surgery (HR 5.94, P < 0.001), syncope (HR 2.03, P = 0.019), pulmonic stenosis (HR 3.42, P = 0.001), and haemoglobin > 15 g/dL (HR 2.05, P = 0.026) were multivariable predictors of SD. In a similar subgroup analysis of patients who underwent TV surgery, all of the above factors except syncope were significantly associated with post-operative SD on multivariable analysis. Conclusion: Patients with EA are at significant risk for SD. Key clinical SD predictors identified can aid in risk stratification and potentially guide primary prevention ICD implantation.


Subject(s)
Death, Sudden/epidemiology , Ebstein Anomaly/epidemiology , Heart Failure/epidemiology , Pulmonary Valve Stenosis/epidemiology , Syncope/epidemiology , Tachycardia, Ventricular/epidemiology , Adolescent , Adult , Aged , Cardiac Surgical Procedures/statistics & numerical data , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Proportional Hazards Models , Risk Factors , Tricuspid Valve/surgery , Young Adult
7.
Ophthalmology ; 125(1): 15-21, 2018 01.
Article in English | MEDLINE | ID: mdl-28863943

ABSTRACT

PURPOSE: To quantitatively determine how the reliability indices in standard automated perimetry (SAP) affect the global indices of visual field (VF) results in nonglaucomatous eyes. DESIGN: Observational, cross-sectional study. PARTICIPANTS: A total of 830 adults aged 40 to 80 years, without visual impairment, glaucoma, significant cataract, and major eye diseases, were selected from the population-based Singapore Chinese Eye Study (SCES). METHODS: Study participants underwent a comprehensive and standardized ocular examination and VF assessment using a Humphrey Field Analyzer II (Carl Zeiss Meditec, Inc., Dublin, CA). The effects of the test reliability, as indicated by the false-negative (FN), false-positive (FP), and fixation loss (FL) rates, on global indices, as indicated by the mean deviation (MD) and pattern standard deviation (PSD), were analyzed with multivariable regression models. MAIN OUTCOME MEASURES: The MD and PSD. RESULTS: A total of 1828 VF results from 1235 normal eyes of 830 study subjects were included in the analyses. The multivariable regression analyses adjusted for age, gender, best-corrected visual acuity, and test duration showed that at lower frequencies of false answers (<15%), FNs decreased the MD (ß [change in decibels {dB} per 5% increment in false answers] = -0.71 dB; P < 0.001), whereas FPs increased the MD (ß = 0.65 dB; P < 0.001). At higher frequencies (≥15%), the false answers influenced the MD to a greater extent, where the ß for the associations with FN and FP rates was -1.15 and 1.26 dB, respectively (both P < 0.001). We also found that when FN rate was <15%, higher FN rate increased the PSD (ß = 0.51 dB; P < 0.001), and the effect was slightly larger when FN rate was ≥15% (ß = 0.71 dB; P < 0.001). The effect of FPs on PSD was observed only when FP rate was <15% (ß = -0.22 dB; P < 0.001). The FL had no associations with the MD, and had minimal effects on the PSD. CONCLUSIONS: We quantified the effect of unreliable responses on the MD and PSD in SAP. Our study may allow clinicians to estimate how VF results are affected by varying degrees of unreliability, instead of relying on cutoff values for reliability indices.


Subject(s)
Algorithms , Vision Disorders/diagnosis , Visual Field Tests/methods , Visual Fields/physiology , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Vision Disorders/physiopathology
9.
Europace ; 20(3): 535-540, 2018 03 01.
Article in English | MEDLINE | ID: mdl-28340054

ABSTRACT

Aims: Atrial arrhythmias are common in patients with Ebstein's anomaly (EA) despite cardiac surgical repair and concomitant Maze procedures. We aimed to evaluate the outcome of radiofrequency catheter ablation in this group of patients. Methods and results: All patients with EA and atrial arrhythmias who underwent catheter ablation for atrial arrhythmias between 1/1999 and 1/2016 were included. Atrial arrhythmia recurrence was identified as the primary outcome; secondary outcomes included repeat ablation, need for antiarrhythmic medications after ablation, and death. Predictors of recurrence were sought using univariate analysis. 22 patients (median age 42 years, 54.5% male) were included. Atrial flutter was the most common presenting arrhythmia (n = 14 patients, 63.5%), whereas focal atrial tachycardia (FAT) and atrial fibrillation were identified in 5 (22.7%) and 2 patients (9.1%), respectively, with both atrial flutter/fibrillation evident in a single patient 1 (4.5%). 8 patients (36.4%) had a history of right-sided maze procedures. Cavotricuspid isthmus atrial flutter (CTI-AFl) was the most commonly induced arrhythmia (n = 13, 59.1%), followed by incisional intra-atrial re-entrant tachycardia (IART; n = 4, 18.2%), and FAT (n = 4, 18.2%); 3 patients also underwent left-side ablation with concomitant pulmonary vein isolation (13.6%). 1-year and 5-year atrial arrhythmia recurrence rates were 10.0% and 41.2%, respectively. 7 patients (31.8%) underwent redo ablations, and anti-arrhythmic medication was utilized in 8 patients (36.4%) post-ablation. Neither ablation location nor echocardiographic parameters were found to be predictors of arrhythmia recurrence. Conclusion: Catheter ablation of atrial arrhythmias in patients with EA has a favorable outcome overall with an acceptable recurrence and safety profile; left-sided ablations are rarely necessary. Despite prior Maze and catheter ablation procedures, CTI-AFl and IART recurrences predominate.


Subject(s)
Atrial Fibrillation/surgery , Catheter Ablation , Ebstein Anomaly/complications , Heart Atria/surgery , Adolescent , Adult , Aged , Anti-Arrhythmia Agents/therapeutic use , Atrial Fibrillation/diagnosis , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Atrial Function, Left , Atrial Function, Right , Catheter Ablation/adverse effects , Child , Ebstein Anomaly/diagnosis , Ebstein Anomaly/physiopathology , Female , Heart Atria/physiopathology , Humans , Male , Middle Aged , Recurrence , Reoperation , Retrospective Studies , Risk Factors , Time Factors , Treatment Outcome , Young Adult
10.
Phys Chem Chem Phys ; 19(44): 30039-30047, 2017 Nov 15.
Article in English | MEDLINE | ID: mdl-29094742

ABSTRACT

The fundamental origins surrounding the dynamics of disordered solids near their characteristic glass transitions continue to be fiercely debated, even though a vast number of materials can form amorphous solids, including small-molecule organic, inorganic, covalent, metallic, and even large biological systems. The glass-transition temperature, Tg, can be readily detected by a diverse set of techniques, but given that these measurement modalities probe vastly different processes, there has been significant debate regarding the question of why Tg can be detected across all of them. Here we show clear experimental and computational evidence in support of a theory that proposes that the shape and structure of the potential-energy surface (PES) is the fundamental factor underlying the glass-transition processes, regardless of the frequency that experimental methods probe. Whilst this has been proposed previously, we demonstrate, using ab initio molecular-dynamics (AIMD) simulations, that it is of critical importance to carefully consider the complete PES - both the intra-molecular and inter-molecular features - in order to fully understand the entire range of atomic-dynamical processes in disordered solids. Finally, we show that it is possible to utilise this dependence to directly manipulate and harness amorphous dynamics in order to control the behaviour of such solids by using high-powered terahertz pulses to induce crystallisation and preferential crystal-polymorph growth in glasses. Combined, these findings provide compelling evidence that the PES landscape, and the corresponding energy barriers, are the ultimate controlling feature behind the atomic and molecular dynamics of disordered solids, regardless of the frequency at which they occur.

11.
J Cardiovasc Electrophysiol ; 27(10): 1167-1173, 2016 10.
Article in English | MEDLINE | ID: mdl-27422772

ABSTRACT

BACKGROUND: Cardiac amyloidosis (CA) is associated with increased atrial arrhythmias risk. The efficacy/safety of catheter-based ablation therapy in patients with CA has not been adequately assessed. METHODS AND RESULTS: All diagnosed CA patients who underwent atrial arrhythmia ablation therapy from 1995 to 2015 were reviewed. Arrhythmia recurrence, NYHA symptoms, and mortality were recorded. A total of 26 patients with CA and atrial arrhythmias were included; there were 7 light-chain (AL), 17 wild-type transthyretin (ATTRwt), and 2 mutated transthyretin (ATTRm) amyloidosis patients in total. Of which 13 underwent atrial arrhythmia ablation (CA-A) and 13 underwent AV nodal ablation (CA-AVN). In the CA-A group, there were: 3 with atrial fibrillation (AF); 6 with atrial flutter (AFL); 2 with AF/AFL; and 2 with atrial tachycardia (AT). One-year and 3-year recurrence-free survival were 75% and 60%, respectively. NYHA symptom improvement 6 months postablation was observed in both CA-A and CA-AVN groups: 7/10 (70%) and 4/8 (50%), respectively. Eleven patients with CA died (8 in CA-AVN group vs. 3 in CA-A group). CONCLUSIONS: Catheter-based ablation for patients with CA appears to provide important symptomatic relief. However, mortality from the underlying disease remains a significant issue for the amyloid light-chain subtype.


Subject(s)
Amyloidosis/complications , Atrial Fibrillation/surgery , Atrial Flutter/surgery , Cardiomyopathies/complications , Catheter Ablation , Heart Atria/surgery , Tachycardia, Supraventricular/surgery , Action Potentials , Aged , Amyloidosis/mortality , Atrial Fibrillation/etiology , Atrial Fibrillation/mortality , Atrial Fibrillation/physiopathology , Atrial Flutter/etiology , Atrial Flutter/physiopathology , Cardiomyopathies/mortality , Catheter Ablation/adverse effects , Catheter Ablation/mortality , Disease-Free Survival , Female , Heart Atria/physiopathology , Heart Rate , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Minnesota , Recurrence , Retrospective Studies , Risk Factors , Tachycardia, Supraventricular/etiology , Tachycardia, Supraventricular/mortality , Tachycardia, Supraventricular/physiopathology , Time Factors , Treatment Outcome
12.
Mol Pharm ; 12(3): 810-5, 2015 Mar 02.
Article in English | MEDLINE | ID: mdl-25615410

ABSTRACT

Simvastatin is known to exist in at least three polymorphic forms. The nature of polymorphism in simvastatin is ambiguous, as the crystal structures of the polymorphs do not show any significant change in crystal packing or molecular conformation. We utilize terahertz time-domain spectroscopy to characterize each of the polymorphs and probe the phase transitions in the range of 0.2-3.0 THz and for temperatures ranging from 90 to 390 K. In form III, vibrational modes are observed at 1.0, 1.25, and 1.7 THz. For form I, we find that the spectrum is dominated by a baseline corresponding to libration-vibration motions coupled to the dielectric relaxations, which is characteristic of a disordered hydrogen bonding material but with additional broad vibrational modes at 0.8 and 1.4 THz. In addition, the baseline shifts with temperature similar to that observed in disordered materials. This background absorption exhibits pronounced changes around the phase transition temperatures at 232 and 272 K. The results are in agreement with molecular dynamics simulations, which indicate that changes in the rotational freedom of the ester tail in the molecule govern the polymorphism in simvastatin.


Subject(s)
Simvastatin/chemistry , Biopharmaceutics , Humans , Hydrogen Bonding , Hydroxymethylglutaryl-CoA Reductase Inhibitors/chemistry , Models, Molecular , Molecular Conformation , Molecular Dynamics Simulation , Motion , Phase Transition , Temperature , Terahertz Spectroscopy , Vibration
13.
Phys Chem Chem Phys ; 17(8): 5999-6008, 2015 Feb 28.
Article in English | MEDLINE | ID: mdl-25642466

ABSTRACT

Terahertz time-domain spectroscopy is used to explore hydrogen bonding structure and dynamics in binary liquid mixtures, spanning a range of protic-protic, protic-aprotic and aprotic-aprotic systems. A direct absorption coefficient analysis is compared against more complex Debye analysis and we observed good agreement of the two methods in determining the hydrogen bonding properties when at least one of the mixture components is protic. When both components are aprotic, we show that the trend in absorption coefficients match well with the theoretical trend in strength of hydrogen bond interactions predicted based on steric and electronic properties of the components.


Subject(s)
Terahertz Spectroscopy , Hydrogen Bonding , Methanol/chemistry , Solvents/chemistry , Water/chemistry
14.
Mayo Clin Proc Innov Qual Outcomes ; 8(4): 396-405, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39100655

ABSTRACT

Objective: To review the salient features of multimodality cardiovascular imaging in patients with disseminated Mycobacterium chimaera (MC) infections after exposure to contaminated heater-cooler units during cardiopulmonary bypass. Patients and Methods: Twelve patients with confirmed MC infection were retrospectively identified after a review from January 1, 2010, to April 30, 2021. The electronic medical records were examined with a focus on transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography (CT), cardiac magnetic resonance imaging, and positron emission tomography-CT. Results: Three (27.3%) patients had diagnostic findings of endocarditis on transthoracic echocardiography, with most patients having nonspecific abnormalities including elevated prosthetic valve gradients or prosthetic leaflet thickening. Transesophageal echocardiography identified 4 (36.7%) patients with vegetations and 3 (27.3%) with aortic root abscess or pseudoaneurysm, with more common findings such as mild aortic root or prosthetic leaflet thickening. Six (50%) patients underwent cardiac CT imaging, which found aortic root pseudoaneurysms or abscesses, prosthetic ring dehiscence, and leaflet thickening. Three (25%) patients underwent cardiac magnetic resonance imaging demonstrating prosthetic valve vegetations, leaflet thickening, and abnormal myocardial delayed enhancement in a noncoronary distribution, suggesting myocarditis. Ten (83%) patients underwent positron emission tomography-CT, 4 (40%) had an abnormal fluorodeoxyglucose uptake around the cardiac prosthetic material, and 7 (70%) had a fluorodeoxyglucose uptake in other organs, suggesting concomitant multiorgan involvement. Conclusion: Multimodality cardiovascular imaging is central to the management of patients with disseminated MC and can help establish a preliminary diagnosis while awaiting confirmatory microbiological data, potentially reducing the time to diagnosis. Imaging findings are subtle and atypical, not always meeting classically modified Duke's criteria for infectious endocarditis. Clinicians should have a high index of suspicion for the disease and a low threshold for repeat imaging when initial testing is equivocal.

15.
Heart Rhythm ; 2024 May 24.
Article in English | MEDLINE | ID: mdl-38797305

ABSTRACT

BACKGROUND: Despite effectiveness of the implantable cardioverter-defibrillator (ICD) in saving patients with life-threatening ventricular arrhythmias (VAs), the temporal occurrence of VA after ICD implantation is unpredictable. OBJECTIVE: The study aimed to apply machine learning (ML) to intracardiac electrograms (IEGMs) recorded by ICDs as a unique biomarker for predicting impending VAs. METHODS: The study included 13,516 patients who received Biotronik ICDs and enrolled in the CERTITUDE registry between January 1, 2010, and December 31, 2020. Database extraction included IEGMs from standard quarterly transmissions and VA event episodes. The processed IEGM data were pulled from device transmissions stored in a centralized Home Monitoring Service Center and reformatted into an analyzable format. Long-range (baseline or first scheduled remote recording), mid-range (scheduled remote recording every 90 days), or short-range predictions (IEGM within 5 seconds before the VA onset) were used to determine whether ML-processed IEGMs predicted impending VA events. Convolutional neural network classifiers using ResNet architecture were employed. RESULTS: Of 13,516 patients (male, 72%; age, 67.5 ± 11.9 years), 301,647 IEGM recordings were collected; 27,845 episodes of sustained ventricular tachycardia or ventricular fibrillation were observed in 4467 patients (33.0%). Neural networks based on convolutional neural networks using ResNet-like architectures on far-field IEGMs yielded an area under the curve of 0.83 with a 95% confidence interval of 0.79-0.87 in the short term, whereas the long-range and mid-range analyses had minimal predictive value for VA events. CONCLUSION: In this study, applying ML to ICD-acquired IEGMs predicted impending ventricular tachycardia or ventricular fibrillation events seconds before they occurred, whereas midterm to long-term predictions were not successful. This could have important implications for future device therapies.

16.
Circ Arrhythm Electrophysiol ; 17(2): e012377, 2024 02.
Article in English | MEDLINE | ID: mdl-38288627

ABSTRACT

BACKGROUND: The incidence and prognosis of right bundle branch block (RBBB) following transcatheter aortic valve replacement (TAVR) are unknown. Hence, we sought to characterize the incidence of post-TAVR RBBB and determine associated risks of permanent pacemaker (PPM) implantation and mortality. METHODS: All patients 18 years and above without preexisting RBBB or PPM who underwent TAVR at US Mayo Clinic sites and Mayo Clinic Health Systems from June 2010 to May 2021 were evaluated. Post-TAVR RBBB was defined as new-onset RBBB in the postimplantation period. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. RESULTS: Of 1992 patients, 15 (0.75%) experienced new RBBB post-TAVR. There was a higher degree of valve oversizing among patients with new RBBB post-TAVR versus those without (17.9% versus 10.0%; P=0.034). Ten patients (66.7%) with post-TAVR RBBB experienced high-grade atrioventricular block and underwent PPM implantation (median 1 day; Q1, 0.2 and Q3, 4), compared with 268/1977 (13.6%) without RBBB. Following propensity score adjustment for covariates (age, sex, balloon-expandable valve, annulus diameter, and valve oversizing), post-TAVR RBBB was significantly associated with PPM implantation (hazard ratio, 8.36 [95% CI, 4.19-16.7]; P<0.001). No statistically significant increase in mortality was seen with post-TAVR RBBB (hazard ratio, 0.83 [95% CI, 0.33-2.11]; P=0.69), adjusting for age and sex. CONCLUSIONS: Although infrequent, post-TAVR RBBB was associated with elevated PPM implantation risk. The mechanisms for its development and its clinical prognosis require further study.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Pacemaker, Artificial , Transcatheter Aortic Valve Replacement , Humans , Transcatheter Aortic Valve Replacement/adverse effects , Bundle-Branch Block/diagnosis , Bundle-Branch Block/epidemiology , Bundle-Branch Block/etiology , Aortic Valve Stenosis/surgery , Incidence , Cardiac Pacing, Artificial/adverse effects , Treatment Outcome , Risk Factors , Aortic Valve/surgery
17.
Ophthalmology ; 125(8): e55, 2018 08.
Article in English | MEDLINE | ID: mdl-30032800
18.
Front Cardiovasc Med ; 10: 1143409, 2023.
Article in English | MEDLINE | ID: mdl-37273874

ABSTRACT

A 70-year-old female presented with incessant supraventricular tachycardia that was refractory to metoprolol and sotalol. ECG revealed a narrow complex tachycardia with a rate of 163 beats per minute with a short RP relationship. She had salvos of atrial tachycardia which led to a severe reduction in ejection fraction as noted on echocardiography and hemodynamic instability. An electrophysiological study was performed, and findings suggested this to be an atrial tachycardia with earliest activation in the perinodal area. Radiofrequency ablation was carried out along the septum and associated structures to surround this region including the right atrium, non-coronary sinus of Valsalva, and the left atrium (anterior wall outside of the right superior pulmonary vein) to isolate this area and surround the focus with ablation lesions. The patient has done well post-procedure and continues to do well without any recurrence on low-dose flecainide at 8 months.

19.
Front Cardiovasc Med ; 10: 1328898, 2023.
Article in English | MEDLINE | ID: mdl-38169814

ABSTRACT

Background: Pathogenic/Likely pathogenic variants in DSP-encoded desmoplakin are strongly associated with arrhythmogenic cardiomyopathy (ACM). However, their contribution towards sinus node dysfunction has not been well-delineated. Case summary: A 74-year-old man with a pathogenic variant of DSP-encoded desmoplakin (c.478C >T; p.Arg160X) but no evidence of ACM presented with one episode of syncope in the setting of a gastrointestinal illness. Workup including echocardiography, cardiac magnetic resonance imaging, and Holter monitor did not show evidence of ACM or significant arrhythmias. One month later, he experienced several closely-spaced episodes of syncope associated with long sinus pauses and sinus arrest documented on telemetry. He underwent urgent dual chamber pacemaker implantation, during which a ventricular programmed stimulation study was performed and was negative for sustained ventricular arrhythmias. His syncopal episodes resolved and he had no recurrent events on three-month follow-up. Discussion: As highlighted here, DSP-encoded desmoplakin pathogenic/Likely pathogenic variants may contribute to isolated sinus node dysfunction. This clinical link should be further explored in larger studies involving patients with DSP variants.

20.
JACC CardioOncol ; 5(2): 203-212, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37144110

ABSTRACT

Background: The prevention of stroke in patients with atrial fibrillation (AF) and cancer is challenging because patients are at increased bleeding and thrombotic risk. Objectives: The authors sought to assess left atrial appendage occlusion (LAAO) as a safe and effective strategy for reducing stroke at no increased bleeding risk in cancer patients with AF. Methods: We reviewed patients with nonvalvular AF who underwent LAAO at Mayo Clinic sites from 2017 to 2020 and identified those who had undergone prior or current treatment for cancer. We compared the incidence of stroke, bleeding, device complications, and death with a control group who underwent LAAO without malignancy. Results: Fifty-five patients were included; 44 (80.0%) were male, and the mean age was 79.0 ± 6.1 years. The median CHA2Ds2-VASc score was 5 (Q1-Q3: 4-6), with 47 (85.5%) having a prior bleeding event. Over the first year, ischemic stroke occurred in 1 (1.4%) patient, bleeding complications in 5 (10.7%) patients, and death in 3 (6.5%) patients. Compared with controls who underwent LAAO without cancer, there was no significant difference in ischemic stroke (HR: 0.44; 95% CI: 0.10-1.97; P = 0.28), bleeding complication (HR: 0.71; 95% CI: 0.28-1.86; P = 0.19), or death (HR: 1.39; 95% CI: 0.73-2.64; P = 0.32). Conclusions: Within our cohort, LAAO in cancer patients was achieved with good procedural success and offered a reduction in stroke at no increased bleeding risk similar to noncancer patients.

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