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  • Ovid Technologies (Wolters Kluwer Health)  (10)
  • 1
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    Online Resource
    Abstract 18556: Renal Sympathetic Denervation Modulates Cardiac Repolarization in a Post Myocardial Infarction Pig Model
    Ovid Technologies (Wolters Kluwer Health) ; 2015
    In:  Circulation Vol. 132, No. suppl_3 ( 2015-11-10)
    Details
    In: Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 132, No. suppl_3 ( 2015-11-10)
    Abstract: Introduction: Changes in cardiac repolarization parameters such as QT interval and QT dispersion have been implicated in cardiac arrhythmogenesis following acute myocardial infarction (AMI). These parameters are susceptible to sympathetic modulation. We therefore hypothesized that renal sympathetic denervation (RDN) may produce potential anti-arrhythmic actions through its effects on cardiac repolarization. Methods: Fifteen pigs randomized to AMI & RDN (6 pigs), AMI & sham RDN (6 pigs) and sham MI & sham RDN (3 pigs) underwent percutaneous occlusion of the mid to distal LAD to achieve AMI. 2 weeks after infarction, the St. Jude EnligHTN® basket catheter was used to perform RDN bilaterally. Cardiac repolarization parameters were measured at 3 time points over the course of the 3 week study: baseline (immediately before MI), midpoint (2 weeks post MI; at time of RDN) and end (1 week post RDN). ECG data were acquired from limb leads. Results: In a ten beat span, the range in the durations of the QT interval was seen to increase from 18+/-7ms to 19+/-11ms in the real AMI & sham RDN group while in the real AMI & real RDN group it decreased from 17+/-5ms to 14+/-5ms (p=0.11). The mean QT interval which increased by 25% in the real AMI & sham RDN group saw only an 11% increase in the real AMI & real RDN group (p=0.048). The standard deviation of the average QT intervals post AMI, which quantifies the reduction in global dispersion of repolarization, saw a 41% decrease with RDN compared to an 8% decrease with sham RDN. The temporal dispersion of repolarization was also diminished by RDN. The dispersion of T wave peak to T wave end durations which increased in the real AMI & sham RDN group (from 15+/-6ms to 22+/-10ms), was decreased in the real AMI & real RDN group (from 19+/-7ms to 16+/-6ms) (p=0.05). T wave alternans values displayed no significant response to RDN (p=0.977). Conclusions: Adverse changes in cardiac repolarization parameters were attenuated via renal denervation in this post infarct pig model. These effects may mitigate post infarct arrhythmogenesis but require further study to evaluate the influence of local, reflex and circulating mediators.
    Type of Medium: Online Resource
    ISSN: 0009-7322 , 1524-4539
    URL: Article
    DOI: 10.1161/circ.132.suppl_3.18556
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2015
    detail.hit.zdb_id: 1466401-X
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  • 2
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    Decrement Evoked Potential Mapping : Basis of a Mechanistic Strategy for Ventricular Tachycardia Ablation
    Ovid Technologies (Wolters Kluwer Health) ; 2015
    In:  Circulation: Arrhythmia and Electrophysiology Vol. 8, No. 6 ( 2015-12), p. 1433-1442
    Details
    In: Circulation: Arrhythmia and Electrophysiology, Ovid Technologies (Wolters Kluwer Health), Vol. 8, No. 6 ( 2015-12), p. 1433-1442
    Abstract: Substrate-based mapping for ventricular tachycardia (VT) ablation is hampered by its inability to determine critical sites of the VT circuit. We hypothesized that those potentials, which delay with a decremental extrastimulus (decrement evoked potentials or DEEPs), are more likely to colocalize with the diastolic pathways of VT circuits. Methods and Results— DEEPs were identified in intraoperative left ventricular maps from 6 patients with ischemic cardiomyopathy (total 9 VTs) and were compared with late potential (LP) and activation maps of the diastolic pathway for each VT. Mathematical modeling was also used to further validate and elucidate the mechanisms of DEEP mapping. All patients demonstrated regions of DEEPs and LPs. The mean endocardial surface area of these potentials was 18±4% and 21±6%, respectively ( P =0.13). The mean sensitivity for identifying the diastolic pathway in VT was 50±23% for DEEPs and 36±32% for LPs ( P =0.31). The mean specificity was 43±23% versus 20±8% for DEEP and LP mapping, respectively ( P =0.031). The electrograms that displayed the greatest decrement in each case had a sensitivity and specificity for the VT isthmus of 29±10% and 95±1%, respectively. Mathematical modeling studies recapitulated DEEPs at the VT isthmus and demonstrated their role in VT initiation with a critical degree of decrement. Conclusions— In this preliminary study, DEEP mapping was more specific than LP mapping for identifying the critical targets of VT ablation. The mechanism of DEEPs relates to conduction velocity restitution magnified by zigzag conduction within scar channels.
    Type of Medium: Online Resource
    ISSN: 1941-3149 , 1941-3084
    URL: Article
    DOI: 10.1161/CIRCEP.115.003083
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2015
    detail.hit.zdb_id: 2425487-3
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  • 3
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    Physiological Assessment of Ventricular Myocardial Voltage Using Omnipolar Electrograms
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Journal of the American Heart Association Vol. 6, No. 8 ( 2017-08-02)
    Details
    In: Journal of the American Heart Association, Ovid Technologies (Wolters Kluwer Health), Vol. 6, No. 8 ( 2017-08-02)
    Abstract: Characterization of myocardial health by bipolar electrograms are critical for ventricular tachycardia therapy. Dependence of bipolar electrograms on electrode orientation may reduce reliability of voltage assessment along the plane of arrhythmic myocardial substrate. Hence, we sought to evaluate voltage assessment from orientation‐independent omnipolar electrograms. Methods and Results We mapped the ventricular epicardium of 5 isolated hearts from each species—healthy rabbits, healthy pigs, and diseased humans—under paced conditions. We derived bipolar electrograms and voltage peak‐to‐peak (Vpps) along 2 bipolar electrode orientations (horizontal and vertical). We derived omnipolar electrograms and Vpps using omnipolar electrogram methodology. Voltage maps were created for both bipoles and omnipole. Electrode orientation affects the bipolar voltage map with an average absolute difference between horizontal and vertical of 0.25±0.18 mV in humans. Vpps provide larger absolute values than horizontal and vertical bipolar Vpps by 1.6 and 1.4 mV, respectively, in humans. Bipolar electrograms with the largest Vpps from either along horizontal or vertical orientation are highly correlated with omnipolar electrograms and with Vpps values (0.97±0.08 and 0.94±0.08, respectively). Vpps values are more consistent than bipoles, in both beat‐by‐beat (CoV, 0.28±0.19 versus 0.08±0.13 in human hearts) and rhythm changes (0.55±0.21 versus 0.40±0.20 in porcine hearts). Conclusions Omnipoles provide physiologically relevant and consistent voltages that are along the maximal bipolar direction on the plane of the myocardium.
    Type of Medium: Online Resource
    ISSN: 2047-9980
    URL: Article
    DOI: 10.1161/JAHA.117.006447
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
    detail.hit.zdb_id: 2653953-6
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  • 4
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    Sex Differences in Timeliness of Reperfusion in Young Patients With ST‐Segment–Elevation Myocardial Infarction by Initial Electrocardiographic Characteristics
    Ovid Technologies (Wolters Kluwer Health) ; 2018
    In:  Journal of the American Heart Association Vol. 7, No. 6 ( 2018-03-20)
    Details
    In: Journal of the American Heart Association, Ovid Technologies (Wolters Kluwer Health), Vol. 7, No. 6 ( 2018-03-20)
    Abstract: Young women with ST‐segment–elevation myocardial infarction experience reperfusion delays more frequently than men. Our aim was to determine the electrocardiographic correlates of delay in reperfusion in young patients with ST‐segment–elevation myocardial infarction. Methods and Results We examined sex differences in initial electrocardiographic characteristics among 1359 patients with ST‐segment–elevation myocardial infarction in a prospective, observational, cohort study (2008–2012) of 3501 patients with acute myocardial infarction, 18 to 55 years of age, as part of the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study at 103 US and 24 Spanish hospitals enrolling in a 2:1 ratio for women/men. We created a multivariable logistic regression model to assess the relationship between reperfusion delay (door‐to‐balloon time 〉 90 or 〉 120 minutes for transfer or door‐to‐needle time 〉 30 minutes) and electrocardiographic characteristics, adjusting for sex, sociodemographic characteristics, and clinical characteristics at presentation. In our study (834 women and 525 men), women were more likely to exceed reperfusion time guidelines than men (42.4% versus 31.5%; P 〈 0.01). In multivariable analyses, female sex persisted as an important factor in exceeding reperfusion guidelines after adjusting for electrocardiographic characteristics (odds ratio, 1.57; 95% CI , 1.15–2.15). Positive voltage criteria for left ventricular hypertrophy and absence of a prehospital ECG were positive predictors of reperfusion delay; and ST elevation in lateral leads was an inverse predictor of reperfusion delay. Conclusions Sex disparities in timeliness to reperfusion in young patients with ST‐segment–elevation myocardial infarction persisted, despite adjusting for initial electrocardiographic characteristics. Left ventricular hypertrophy by voltage criteria and absence of prehospital ECG are strongly positively correlated and ST elevation in lateral leads is negatively correlated with reperfusion delay.
    Type of Medium: Online Resource
    ISSN: 2047-9980
    URL: Article
    DOI: 10.1161/JAHA.117.007021
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2018
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  • 5
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    Effects of Renal Artery Denervation on Ventricular Arrhythmias in a Postinfarct Model
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Circulation: Cardiovascular Interventions Vol. 10, No. 3 ( 2017-03)
    Details
    In: Circulation: Cardiovascular Interventions, Ovid Technologies (Wolters Kluwer Health), Vol. 10, No. 3 ( 2017-03)
    Abstract: The therapeutic potential of renal denervation (RDN) for arrhythmias has not been fully explored. Detailed mechanistic evaluation is in order. The objective of the present study was to determine the antiarrhythmic potential of RDN in a postinfarct animal model and to determine whether any benefits relate to RDN-induced reduction of sympathetic effectors on the myocardium. Methods and Results— Pigs implanted with single-chamber implantable cardioverter defibrillators to record ventricular arrhythmias (VAs) were subjected to percutaneous coronary occlusion to induce myocardial infarction. Two weeks later, a sham or real RDN treatment was performed bilaterally using the St Jude EnligHTN basket catheter. Parameters of ventricular remodeling and modulation of cardio–renal sympathetic axis were monitored for 3 weeks after myocardial infarction. Histological analysis of renal arteries yielded a mean neurofilament score of healthy nerves that was significantly lower in the real RDN group than in sham controls; damaged nerves were found only in the real RDN group. There was a 100% reduction in the rate of spontaneous VAs after real RDN and a 75% increase in the rate of spontaneous VAs after sham RDN ( P =0.03). In the infarcted myocardium, presence of sympathetic nerves and tissue abundance of neuropeptide-Y, an indicator of sympathetic nerve activities, were significantly lower in the RDN group. Peak and mean sinus tachycardia rates were significantly reduced after RDN. Conclusions— RDN in the infarcted pig model leads to reduction of postinfarction VAs and myocardial sympathetic effectors. This may form the basis for a potential therapeutic role of RDN in postinfarct VAs.
    Type of Medium: Online Resource
    ISSN: 1941-7640 , 1941-7632
    URL: Article
    DOI: 10.1161/CIRCINTERVENTIONS.116.004172
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
    detail.hit.zdb_id: 2450801-9
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  • 6
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    Hemodynamic Management of Patients During Endovascular Treatment of Acute Ischemic Stroke Under Conscious Sedation: A Retrospective Cohort Study
    Ovid Technologies (Wolters Kluwer Health) ; 2019
    In:  Journal of Neurosurgical Anesthesiology Vol. 31, No. 3 ( 2019-07), p. 299-305
    Details
    In: Journal of Neurosurgical Anesthesiology, Ovid Technologies (Wolters Kluwer Health), Vol. 31, No. 3 ( 2019-07), p. 299-305
    Abstract: Anesthetic modality and hemodynamic management during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are potential contributors to the success of revascularization. The aims of our study were to review the hemodynamic management by anesthesiologists and clinical outcomes in patients undergoing MT under conscious sedation. Methods: Retrospective cohort study of patients with anterior circulation AIS from January 2012 to March 2016. Primary outcome was hemodynamic intervention, defined as administration of vasoactive drugs to maintain systolic blood pressure (BP) between 140 and 180 mm Hg. The secondary outcome was poor hemodynamic control, defined as BP outside target for 〉 15 minutes despite hemodynamic intervention. We performed regression analysis to determine the predictors of hemodynamic intervention and poor hemodynamic control. Results: A total of 126 patients were included in this study; 92% (116) receiving conscious sedation and 8% (10) no sedation. Upon arrival to the neuroradiology suite, systolic BP was 〈 140 mm Hg in 30.2% of the patients and 〉 180 mm Hg in 14.3%. Hemodynamic intervention was required in 38.9% of patients; 15.1% for hypotension and 19.8% for hypertension. In the multivariate analysis, systolic BP on hospital admission (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P =0.019) constituted a predictor for hemodynamic intervention. Poor hemodynamic control occurred in 12.7% of patients, with lower baseline systolic BP being associated with higher risk of intraprocedural hypotension (odds ratio, 0.92; 95% confidence interval, 0.89-0.96; P 〈 0.001). In-hospital mortality was 13.6%. Conclusions: Hemodynamic intervention is frequent during MT under conscious sedation. The routine presence of anesthesiologists during MT may be helpful in maintaining hemodynamic stability and allow rapid treatment of emergent complications. An individualized approach with tailored hemodynamic targets is required during management of patients undergoing MT for AIS.
    Type of Medium: Online Resource
    ISSN: 0898-4921
    URL: Article
    DOI: 10.1097/ANA.0000000000000514
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2019
    detail.hit.zdb_id: 2047474-X
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  • 7
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    Resolving Bipolar Electrogram Voltages During Atrial Fibrillation Using Omnipolar Mapping
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Circulation: Arrhythmia and Electrophysiology Vol. 10, No. 9 ( 2017-09)
    Details
    In: Circulation: Arrhythmia and Electrophysiology, Ovid Technologies (Wolters Kluwer Health), Vol. 10, No. 9 ( 2017-09)
    Abstract: Low-voltage–guided substrate modification is an emerging strategy in atrial fibrillation (AF) ablation. A major limitation to contemporary bipolar electrogram (EGM) analysis in AF is the resultant lower peak-to-peak voltage (V pp ) from variations in wavefront direction relative to electrode orientation and from fractionation and collision events. We aim to compare bipole V pp with novel omnipolar peak-to-peak voltages (V max ) in sinus rhythm (SR) and AF. Methods and Results: A high-density fixed multielectrode plaque was placed on the epicardial surface of the left atrium in dogs. Horizontal and vertical orientation bipolar EGMs, followed by omnipolar EGMs, were obtained and compared in both SR and AF. Bipole orientation has significant impact on bipolar EGM voltages obtained during SR and AF. In SR, vertical values were on average 66±119% larger than horizontal ( P =0.004). In AF, vertical values were on average 31±96% larger than horizontal ( P =0.07). Omnipole V max values were 99.9±125% larger than both horizontal (99.9±125%; P 〈 0.001) and vertical (41±78%; P 〈 0.0001) in SR and larger than both horizontal (76±109%; P 〈 0.001) and vertical (52±70%; P value 〈 0.0001) in AF. Vector field analysis of AF wavefronts demonstrates that omnipolar EGMs can account for collision and fractionation and record EGM voltages unaffected by these events. Conclusions: Omnipolar EGMs can extract maximal voltages from AF signals which are not influenced by directional factors, collision or fractionation, compared with contemporary bipolar techniques.
    Type of Medium: Online Resource
    ISSN: 1941-3149 , 1941-3084
    URL: Article
    DOI: 10.1161/CIRCEP.117.005018
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
    detail.hit.zdb_id: 2425487-3
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  • 8
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    Incidence, Diagnosis, and Management of QT Prolongation Induced by Cancer Therapies: A Systematic Review
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Journal of the American Heart Association Vol. 6, No. 12 ( 2017-12-02)
    Details
    In: Journal of the American Heart Association, Ovid Technologies (Wolters Kluwer Health), Vol. 6, No. 12 ( 2017-12-02)
    Abstract: The cardiovascular complications of cancer therapeutics are the focus of the burgeoning field of cardio‐oncology. A common challenge in this field is the impact of cancer drugs on cardiac repolarization (ie, QT prolongation) and the potential risk for the life‐threatening arrhythmia torsades de pointes. Although QT prolongation is not a perfect marker of arrhythmia risk, this has become a primary safety metric among oncologists. Cardiologists caring for patients receiving cancer treatment should become familiar with the drugs associated with QT prolongation, its incidence, and appropriate management strategies to provide meaningful consultation in this complex clinical scenario. Methods and Results In this article, we performed a systematic review (using Preferred Reporting Items of Systematic Reviews and Meta‐Analyses (PRISMA) guidelines) of commonly used cancer drugs to determine the incidence of QT prolongation and clinically relevant arrhythmias. We calculated summary estimates of the incidence of all and clinically relevant QT prolongation as well as arrhythmias and sudden cardiac death. We then describe strategies to prevent, identify, and manage QT prolongation in patients receiving cancer therapy. We identified a total of 173 relevant publications. The weighted incidence of any corrected QT ( QT c) prolongation in our systematic review in patients treated with conventional therapies (eg, anthracyclines) ranged from 0% to 22%, although QT c 〉 500 ms, arrhythmias, or sudden cardiac death was extremely rare. The risk of QT c prolongation with targeted therapies (eg, small molecular tyrosine kinase inhibitors) ranged between 0% and 22.7% with severe prolongation ( QT c 〉 500 ms) reported in 0% to 5.2% of the patients. Arrhythmias and sudden cardiac death were rare. Conclusions Our systematic review demonstrates that there is variability in the incidence of QT c prolongation of various cancer drugs; however, the clinical consequence, as defined by arrhythmias or sudden cardiac death, remains rare.
    Type of Medium: Online Resource
    ISSN: 2047-9980
    URL: Article
    DOI: 10.1161/JAHA.117.007724
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
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  • 9
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    Letter by Jackson et al Regarding, “PR Interval Identifies Clinical Response in Patients With Non-Left Bundle Branch Block: A Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy Substudy” by Kutyifa et al
    Ovid Technologies (Wolters Kluwer Health) ; 2014
    In:  Circulation: Arrhythmia and Electrophysiology Vol. 7, No. 6 ( 2014-12), p. 1279-1279
    Details
    In: Circulation: Arrhythmia and Electrophysiology, Ovid Technologies (Wolters Kluwer Health), Vol. 7, No. 6 ( 2014-12), p. 1279-1279
    Type of Medium: Online Resource
    ISSN: 1941-3149 , 1941-3084
    URL: Article
    DOI: 10.1161/CIRCEP.114.002279
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2014
    detail.hit.zdb_id: 2425487-3
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  • 10
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    Mortality Implications of Appropriate Implantable Cardioverter Defibrillator Therapy in Secondary Prevention Patients: Contrasting Mortality in Primary Prevention Patients From a Prospective Population‐Based Registry
    Ovid Technologies (Wolters Kluwer Health) ; 2017
    In:  Journal of the American Heart Association Vol. 6, No. 8 ( 2017-08-02)
    Details
    In: Journal of the American Heart Association, Ovid Technologies (Wolters Kluwer Health), Vol. 6, No. 8 ( 2017-08-02)
    Abstract: We sought to examine the mortality impact of appropriate implantable cardioverter defibrillator ( ICD ) therapy between patients who received ICD for primary versus secondary prevention purposes. Methods and Results From a prospective, population‐based registry, we identified 7020 patients who underwent de novo ICD implantation between February 2007 and May 2012 in Ontario, Canada. The primary outcome was all‐cause mortality. We used multivariable Cox proportional hazard modeling to adjust for differences in baseline characteristics and analyzed the mortality impact of first appropriate ICD therapy (shock and antitachycardia pacing [ ATP ]) as a time‐varying covariate. There were 1929 (27.5%) patients who received ICD s for secondary prevention purposes. The median follow‐up period was 5.02 years. Compared with those with secondary prevention ICD s, patients with primary prevention ICD s had more medical comorbidities, and lower ejection fraction. Patients who experienced appropriate ICD shock or ATP had greater risk of death compared with those who did not, irrespective of implant indication. In the primary prevention group, the adjusted hazard ratios of death for appropriate shock and ATP were 2.00 (95% CI : 1.72–2.33) and 1.73 (95% CI : 1.52–1.97), respectively. In the secondary prevention group, the adjusted hazard ratios of death for appropriate ICD shock and ATP were 1.46 (95% CI : 1.20–1.77) and 1.38 (95% CI : 1.16–1.64), respectively. Conclusions Despite having a more favorable clinical profile, occurrence of appropriate ICD shock or ATP in patients with secondary prevention ICD s was associated with similar magnitudes of mortality risk as those with primary prevention ICD s. A heightened degree of care is warranted for all patients who experience appropriate ICD shock or ATP therapy.
    Type of Medium: Online Resource
    ISSN: 2047-9980
    URL: Article
    DOI: 10.1161/JAHA.117.006220
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2017
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