Search

Background: This meta-analysis assessed the relationship between obstructive sleep apnea (OSA) and echocardiographic parameters of diastolic dysfunction (DD), which are used in the assessment of heart failure with preserved ejection fraction. Methods: We searched the databases including Ovid MEDLINE, Ovid Embase, Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 26, 2020. The search was not restricted to time, publication status, or language. Two independent investigators screened the identified studies and extracted the data in duplicate. We conducted a meta-analysis using RevMan v.5. The risk of bias was assessed using Cochrane collaboration tools. Comparisons were made between patients with OSA, diagnosed in-laboratory polysomnography or home sleep apnea testing, and patients without OSA in relation to established markers of DD. Results: Primary search identified 2,512 studies. A total of 18 studies including 2,509 participants were included. The two groups were free of conventional cardiovascular risk factors. Significant structural changes were observed between the two groups. Patients with OSA exhibited greater left atrial volume index (LAVI) (3.94 95% CI [0.8, 7.07]; p = 0.000) and left ventricular mass index (11.10 95% CI [2.56, 19.65]; p = 0.000) as compared to control group. The presence of OSA was also associated with more prolonged deceleration time (10.44 ms 95% CI [0.71, 20.16]; p = 0.04), isovolumic relaxation time (IVRT) (7.85 ms 95% CI [4.48, 11.22]; p = 0.000), and a lower ratio of early to late mitral inflow velocities (E/A) ratio (−0.62 95% CI [−1, −0.24]; p = 0.001) suggestive of early DD. The early mitral inflow velocity to mitral annular early diastolic velocity (E/e′) ratio (0.94 95% CI [0.44, 1.45]; p = 0.000) was increased. Linear correlation between severity of OSA and LAVI and IVRT parameters was observed but this association did not sustain for the E/A and E/e′. The ejection fraction was not significantly different between patients with OSA and healthy controls (−0.48 95% CI [−1.18, 0.23]; p = 0.18). Conclusion: An association between OSA and echocardiographic parameters of DD was detected that was independent of conventional cardiovascular risk factors. OSA may be independently associated with DD perhaps due to higher LV mass. Investigating the role of continuous positive airway pressure therapy in reversing or ameliorating DD is recommended.

Infective endocarditis (IE) is a serious medical condition with a high morbidity and mortality rate. Staphylococcus aureus is the most common etiologic organism in IE. While echocardiography plays an important role in diagnosis and management of IE, the electrocardiogram (ECG) is helpful in determination of disease progression as well as in prognostication. We present a case of a 72-year-old man who was diagnosed with IE following methicillin resistant Staphylococcus aureus (MRSA) bacteremia. The course of hospitalization was complicated with multiple septic-embolic strokes and aortic root abscess. Serial ECG revealed PR prolongation and new onset left bundle branch block (LBBB) before the patient became terminal. Our case highlights the utility of serial ECGs monitoring in the patients with IE that may reveal subtle ECG findings, such as PR prolongation and LBBB. These findings which might serve as a clue of the presence of peri-annular extension of IE, help in prognostication and aid in the therapeutic decision-making such as early surgical intervention in these high-risk patients with poor prognosis. In this report, we also present the pathophysiologic mechanisms underlining the ECG changes in patients with aortic valve endocarditis.

Background: The novel coronavirus disease-2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) has been a major cause of morbidity and mortality around the world Thirteen million cases have been diagnosed with approximately 570,000 deaths worldwide COVID-19 is associated with ischemia, myocarditis and eventual resulting arrhythmia Cases may present as acute thrombotic occlusion, stress cardiomyopathy, or coronary spasm Hydroxychloroquine (HCQ) was temporarily approved by FDA for COVID-19 treatment In this study, we planned to characterize the risk and degree of QTc prolongation in largely African-American population in central Brooklyn, who were hospitalized with COVID-19 infection in association with inpatient administration of HCQ and azithromycin One of the major adverse drug effects of HCQ and chloroquine is the potential prolongation of corrected QT interval (QTc) Methods: In our retrospective study, we included patients, both males and females, 18 years of age and older who were admitted at SUNY Downstate Medical Center, Brooklyn, New York, for COVID-19 infection and were treated with hydroxychloroquine Native baseline RR, QRS, and QT intervals were measured before administering the first dose of hydroxychloroquine and within 24 h of administration The RR interval was measured as a distance between the peak of the R-wave and the peak of the previous R-wave in the same lead in milliseconds and converted to a heart rate by equation, 60,000/RR For correction of the QT, we used common formulas: QTc = QT/√RR [Bazett formula], QTc = QT/∛RR [Fridericia formula], QTc = QT + 0 154 (1-RR) [Framingham formula], QTc = QT + 1 75 (heart rate-60) [Hodges formula] QTc interval prolongation was defined based on the following rules: Male Rules: 1) Baseline 450 ms;2) >15% increase over baseline post HCQ;and 3) baseline >450 ms and 500 ms;Female Rules: 1) Baseline 470 ms;2) >15% increase over baseline post HCQ;and 3) baseline >470 ms and 500 ms Statistics: Means were compared using independent sample t-tests;paired sample t-tests and proportions were compared using Chi square analysis QT correction formulas were compared using 1-way ANOVA and post hoc analysis was done with Tukey correction Binary univariate and multivariate regression were performed to determine risk factor predictors for QTc prolongation Results: We screened 444 consecutive patients with COVID-19 who were admitted to our hospital between March 10 and April 15, 2020, a total of 247 were excluded from this study because they met the exclusion criteria Thus, 197 patients were included in the analysis The mean baseline QTc interval calculated using the Bazett, Hodges, Frederica, Framingham methods were 451 0 ± 34 3, 425 1 ± 28 9, 417 2 ± 34 0, and 413 9 ± 31 ms, respectively Of the 4 correction methods, 35 5% of all patients met the criteria for prolongation using the Bazett method Of all patients included in the study 125 (63 5%) were male and 72 (36 5%) were female Subjects were predominantly African American ancestry, 179 (90 9%) The mean age of all patients was 66 1 ± 13 3 years The most common comorbidities were hypertension (74 6%), diabetes (55 3%), and hyperlipidemia (37 5%) Of all study participants, 91 7% received concomitant azithromycin;31% of patients were on home beta-blocker therapy, while 27 9% were on home calcium-channel blockers Of baseline electrocardiograms, 87 8% were sinus rhythm Total number of patients meeting prolongation criteria was less using the Hodges, Frederica, and Framingham methods Mean QTc values in both genders are presented in (Tables 1, 2, 3, and 4) All 4 methods showed statistically significant increases in QTc Bazett had the relatively largest difference between pre- and post-therapy QT interval with a mean difference of 14 48 ms The increase was present in both men and women The mean difference across sexes was largest using the Bazett method 16 43, bu this was not statistically significant Univariate analysis across all methods found that the concomitant use of azithromycin was not a significant predictor in QT prolongation across the Bazett, Hodges, Frederica, and Framingham methods However, the presence of coronary artery disease was a statistically significant predictor for QT prolongation The presence of congestive heart failure was also a predictor using the Hodges and Framingham methods (Table 5, 6, 7, and 8) (Figure 1) [Formula presented] ANOVA analysis across all subjects showed a significant difference between the four methods There were significant differences between Bazett and 3 methods The largest difference was between Bazett and Framingham, by 37 12 s There was also a smaller difference between the Hodge and Framingham methods The significant difference between the Bazzett method and the others also persisted across both men and women The difference between Hodges and Bazzett was only significant in men (Table 9, 10, and 11) QT prolongation irrespective of the method used for correction did not predict mortality [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] Conclusion: It was notable that the longest QTc prolongation seen in this study was only 14 48 ms, using the Bazett formula With other formulas, this prolongation was significantly smaller and so was the proportion of patients meeting QTc prolongation criteria Not surprisingly, the Bazett formula again overestimated extend of QT prolongation We can only speculate that the differences are perhaps related to the fact that our population was nearly exclusively African American Common channels variation has been well documented to be a factor in QT prolongation, including drug-inducted QT prolongation In the African-American ethnic subgroup, Ser1103Tyr-SCN5A is seen in approximately 8 % of population and can certainly explain our data Furthermore, frequency of CAD and CHF was slightly higher than reported in other studies and both entities were associated with QT prolongation on our population Reassuringly, the presence of QT prolongation was not found to be a predictor of mortality in our cohort Categories Other: COVID-19 Lectures

Case series Patient: Male, 80 • Female, 67 • Male, 48 Final Diagnosis: Management of difficult venous access for implantable cardiac devices Symptoms: Heart failure Medication: — Clinical Procedure: — Specialty: Cardiology Objective: Unusual clinical course Background: Cardiac implantable electronic devices (CIED) are mainstay therapy for a variety of patients with bradyarrhythmia as well as those at risk of sudden cardiac death and heart failure. At present, commonly used venous access are axillary, cephalic cutdown, and subclavian puncture. However, there are situations when these approaches cannot be employed because cannulation is not possible due to small size, spasm, absence, or occlusion of the vein. One of the alternative approaches is through an internal or external jugular vein. A jugular vein approach can be also used for upgrading CIED knowing that CIED is not commonly associated with venous occlusion. Case Report: We present 3 cases which used unusual venous access for placement of CIED using a jugular vein approach. Conclusions: Recognizing patients who have difficult venous access for CIED and using alternative approaches, like a jugular vein approach, for device insertion is important to avoid unnecessary medical and technical complications.

Patients with cardiomyopathy (CM) are at increased risk for sudden cardiac death (SCD), specifically, secondary to ventricular arrhythmias such as ventricular tachycardia (VT) or ventricular fibrillation (VF). Those that have CM are further stratified based on risk of death from ventricular arrhythmias. If determined high risk, implantable cardioverter-defibrillators (ICD), anti-arrhythmic medication or even ablation procedures are considered in order to minimize the risk of SCD. Ablation procedures have increased in number over the years, along with the recognition of high-risk CM patients. Along with the increase in number of ablation procedures, complications from such procedures have decreased in number and the ventricular arrhythmia ablation remains a relatively low-risk procedure. Here we describe a patient with known CM, specifically hypertrophic cardiomyopathy (HCM) with a relatively rare and high-risk complication, being ventricular aneurysm. HCM patients with ventricular aneurysm are often referred for ablation procedures as they are at a significantly higher risk for SCD due to arrhythmias. Our patient not only underwent an ablation procedure, but suffered from the rare complication of tamponade, which occurs on average

Between 2013 and 2016 there were approximately 6.2 million adults in the United States living with heart failure; nearly half had an ejection fraction that was preserved. Despite the high prevalence of heart failure with preserved ejection fraction (HFpEF), our understanding of this disease is limited and it still carries significant morbidity and mortality worldwide. At present, physicians are burdened by the inconclusive benefits of currently available treatment options. Recently the scientific community has seen an influx of new pathophysiology studies and outcome trials that have reshaped our understanding of HFpEF as a complex, multi-systemic disease. Pharmacological trials involving beta-blockers, angiotensin II receptor antagonists, aldosterone antagonists, and angiotensin-neprilysin inhibitors have demonstrated encouraging results, but have yet to reach the significance of advancements made in the treatment of heart failure with reduced ejection fraction. This review aims to summarize landmark clinical trials that have influenced current treatment guidelines, and reports on emerging evidence supporting/refuting new treatment modalities including pharmacotherapy, lifestyle modification and device therapy.

Introduction: Cryptogenic stroke comprises about 25% of all ischemic strokes. Depending on modality and duration of ECG monitoring, subclinical atrial fibrillation (AF) is detectable in 2.7-30% of cryptogenic stroke patients. Hypothesis: Extended ECG monitoring has not been studied in the African American (AA) population. This retrospective study aims to study the incidence and risk factors of subclinical AF in African-Americans. Methods: We retrospectively reviewed 96 patients who received implantable loop recorders (ILR) for detecting subclinical atrial fibrillation after cryptogenic stroke. In the vast majority of patients, the ILR was implanted during the index hospitalization. Binary univariate and multivariate analyses were performed to determine predictors for AF detection. Results: AF was detected in 29% of patients (28/96) at 1000 days. All AF that was detected was exquisitely paroxysmal and ranged in duration between 0.05-103 minutes (mean 8.4 minutes with SD= 22.1 minutes). Baseline characteristics of patients are presented (Table 1A). Binary univariate analysis revealed the use of non-dihydropyridine calcium-channel blockers to be associated with decreased odds of AF detection. (Table 1B, C). Multivariate analysis found coronary artery disease diagnosis to be associated with increased odds of AF detection. Fifty-percent of the events in the AF group were detected within the first 36 days of loop recorder implantation (Fig 1). Conclusions: AF detection in our population occurs very early after index stroke and at significantly higher rates than reported in the CRYSTAL AF trial. Baseline characteristics have a poor predictive ability for the detection of AF. These findings emphasize the need for pre-discharge ILR implantation to improve AF detection in all patients with cryptogenic stroke.

Introduction: This meta-analysis assessed the effect of chronic non-invasive positive airway pressure (> 6 weeks) on moderate to severe OSA with diastolic dysfunction based on echocardiographic parameters. Hypothesis: chronic use of non-invasive positive airway pressure (> 6 weeks) on moderate to severe OSA improves diastolic dysfunction based on echocardiographic parameters. Methods: We searched the databases for randomized clinical trials including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 20th, 2019. The search was not restricted to time, publication status or language. Two independent investigators screened the identified studies and extracted the data, in duplicate. Risk of bias was assessed using Cochrane collaboration tools. Results: A total of 2753 results were identified. A total of 9 studies including 808 participants were included. Results showed improvement in deceleration time (-39.49ms CI[-57.24,-21.74]; p=0.000), isovolumic relaxation time (-9.32 ms CI[-17.08, -1.57]; p=0.02) and the ratio of early mitral inflow velocity to mitral annular early diastolic velocity (E/E’) (-1.38 CI[-2.6, -0.16]; p=0.03). However, improvement in left atrial volume index, the ratio of early to late mitral inflow velocities (E/A) was not statistically significant. The risk of bias is mild to moderate. Conclusions: Our results suggest that chronic treatment of moderate to severe OSA with non-invasive positive airway pressure is associated with improvement in diastolic dysfunction.

Background Vitamin K antagonists (VKAs) have been regarded as the therapy of choice for intracardiac thrombosis for decades based mostly on observational data. The advent of direct oral anticoagulants (DOACs) has displaced VKAs as the first-line therapy for multiple thrombotic disorders but not for intracardiac thrombosis. Although limited, there is growing evidence that DOACs are effective for intracardiac thrombosis and some data suggest that thrombus resolution might be superior to that with warfarin. Case summary Here, we present a series of six patients with left atrial appendage thrombi were treated with a venous thromboembolic dose of DOACs with resolution within 2–6 months with no reported complications. Discussion This case series adds to the accumulating evidence supporting the efficacy of DOACs in the treatment of intracardiac thrombi.

Hydroxychloroquine and Chloroquine are commonly used for the treatment of malaria and autoimmune conditions. Most recently, hydroxychloroquine has been implicated in the treatment armamentarium of Severe acute respiratory syndrome (SARS) caused by SARS-associated coronavirus-2. A rare, underreported side effect of hydroxychloroquine and chloroquine is cardiotoxicity. The cardiomyopathy occurs as a result of inhibition of lysosomal enzymes causing lysosomal dysfunction and intra-cellular accumulation of metabolic byproducts in the myocardium, leading to hypertrophy with or without restrictive physiology and resultant conduction abnormalities. Based on our review of 57 reported cases of hydroxychloroquine or chloroquine induced cardiomyopathy, dyspnea was the most common associated symptom. The most common rhythms seen on EKG were as follows: complete heart block (18.75%), right bundle branch block (RBBB) (18.75%). The most common findings on echocardiography were left ventricular hypertrophy (LVH) (54%), systolic dysfunction (48%) and diastolic dysfunction (32%). A definitive diagnosis is established by endomyocardial biopsy which demonstrates the presence of curvilinear inclusion bodies. The outcome following cessation of the offending agent ranges from complete reversal in 45% of the cases to continued progression with need for cardiac transplantation or even death in 17.5% of the cases.

This meta-analysis assessed the relationship between Obstructive Sleep Apnea (OSA) and echocardiographic parameters suggesting diastolic dysfunction, which is a well-recognized finding in Heart Failure with Preserved Ejection Fraction (HFpEF). We searched the databases including Ovid MEDLINE, Ovid

Obstructive sleep apnea (OSA) is associated with various types of cardiovascular disorders. The aim of the present meta-analysis was to investigate the relationship between OSA severity and echocardiographic measures of diastolic dysfunction (DD). We searched the databases since inception up to

Myocardial infarction (MI) due to coronary artery disease is a leading cause of mortality in the USA. ST-segment elevation myocardial infarction (AMI) is defined as myocardial injury with evidence of cell necrosis in the form of cardiac troponin elevation greater than the 99th percentile of upper reference limit, in a clinical setting. With wider application of early reperfusion therapy, there is significant improvement in the management of myocardial infarction, with a significant resulting decrease of 30-day mortality (Anderson and Morrow, N Engl J Med;376(21):2053–64, 2017).

Background: Cardiac resynchronization therapy (CRT) has a proven role in improving mortality in patients with heart failure and ventricular dyssynchrony. However, the effects of biventricular pacing (CRT) on ventricular arrhythmia susceptibility have not been definitely established, and data regarding the risk of ventricular arrhythmias (VA) with CRT has been limited and conflicting.The aim of this study was to compare the burden of VA in the short term before and after an upgrade to a cardiac resynchronization device in order to avoid the long term effects of myocardial remodeling.Methods: We analyzed 44 consecutive patients with severe LV systolic dysfunction who underwent an upgrade from a single chamber defibrillator to biventricular defibrillator due to worsening heart failure status.Results: CRT was associated with a decrease in VA in patients with high arrhythmic burden, in women and in patients older than 65.Conclusion: In this study we provide convincing evidence that in patients with identical electrophysiological substrate, biventricular pacing alone is associated with a decrease in VA burden.

Immediate recognition of cardiovascular emergencies leads to less delays in treatment and a lower risk of morbidity and mortality. In this chapter, we will focus on complications of acute myocardial infarction (arrhythmia, inflammatory, and mechanical), symptomatic bradycardia, and cardiac arrest. Detailed discussion on tamponade, aortic dissection, and symptomatic tachyarrhythmia can be found in separate, dedicated chapters in this pocket manual.

Objectives: ST-segment elevation myocardial infarction (STEMI) can be associated with many conduction disturbances including complete atrioventricular block (CAVB). CAVB complicating STEMI resulted in an increased mortality before the modern era of primary percutaneous coronary intervention (PCI). The aim of this study was to ascertain the rate and risk factors for CAVB in STEMI patients undergoing rapid reperfusion with PCI. Methods: We analyzed 223 patients presenting with STEMI. Patient characteristics, procedural characteristics, and in-hospital data were compared between patients with and without CAVB. Results: Out of 223 patients, 174 underwent PCI; the majority (87%) was African-American. CAVB was present in 8 patients (4.6%), and 6 of them had RCA occlusion. Independent predictors of CAVB included diabetes mellitus, female gender, lower systolic and diastolic blood pressure, and inferior-lateral/lateral STEMI. Ten patients (5.7%) required temporary pacing at presentation; only 1 patient required permanent pacing before discharge. No patient with anterior STEMI developed CAVB. Conclusions: The incidence and in-hospital mortality rate of CAVB in patients with STEMI who underwent primary PCI was reduced when compared to data from the thrombolytic era. This may be due to faster flow recovery in the infarct-related artery achieved with PCI.

BACKGROUND Barbed suture use in surgical fields such as gynecology and orthopedic surgery has been associated with faster wound closure, improved cosmesis, increased cost-effectiveness and potentially decreased rates of infection. However, the use of barbed suture in electrophysiology device procedures has not been reported. OBJECTIVE This study aims to (1) investigate the safety and effectiveness of barbed suture in wound closure in patients after EP implantable cardioverter defibrillators and loop recorders (CIED) procedures, (2) to determine whether these sutures have an advantage in device implant procedures by improving incision integrity, (3) and to find out whether these sutures would potentially lead to lower rates of infections compared to non-barbed sutures. METHODS We retrospectively compared the closure success and complications in 413 patients undergoing CIED procedures without Quill sutures and with Quill sutures. The primary outcome was closure success and pocket infection/dehiscence within 3 months of CIED. RESULTS Of the 413 patients who were followed up in 3 months, there was a non-significant trend toward a lower infection rate with barbed versus non-barbed suture 1.31%, vs 1.63% p= 0.78. CONCLUSION This study confirms the safety and usefulness of barbed suture material for wound closure during CIED procedures.

Background The aim of this study was to ascertain whether individual atrioventricular delay (AVD) optimization using impedance cardiography (ICG) offers beneficial hemodynamic effects as well as improved exercise tolerance and quality of life in patients with requiring constant right ventricular pacing. Methods There were 37 patients with advanced AV block included in the study. Several examinations were performed at the beginning. Next, the optimization of AVD by ICG was done. The next step of the study patients have been randomized into optimal AVD group (AVDopt) or factory setting group (AVDfab). After 3 months, the follow-up all data were collected again and crossover was performed. After another 3 months, during the final follow-up all these measures were repeated. Results In 87.5% patients, AVDopt were different than factory value. Cardiac output (CO), cardiac index (CI), and stroke volume (SV) were significantly (P < 0.001) higher in AVDopt group than in AVDfab group (CO: 6.0 ± 1.4 L/minute vs. 5.3 ± 1.2 L/minute; SV: 85.8 ± 25.7 mL vs.76.9 ± 22.5 mL; CI: 3.2 ± 0.7 L/minute/m2 vs. 2.7 ± 0.6 L/minute/m2). There was a statistical significant (P < 0.05) reduction of proBNP and NYHA class in patients with AVDopt compared to AVDfab (proBNP: 196.4 ± 144.7pg/mL vs. 269.4 ± 235.8 pg/mL; NYHA class: 1.7 ± 0.5 vs. 2.3 ± 0.6). Six-minute walking test was significantly (P < 0.05) higher in AVDopt group (409 ± 90 m) than in AVDfab group (362 ± 93 m). There were no statistically significant differences in echocardiographic parameters between AVDopt and AVDfab settings. Conclusion Our study results suggest that AVD optimization in patients with DDD pacemaker with ICG improves hemodynamic when compared to the default factory settings. Furthermore, optimally programmed AVD reduces BNP and improves exercise tolerance and functional class.

Purpose Little is known about the usefulness and safety of vascular closure devices (VCDs) in electrophysiological procedures. We present a retrospective analysis of our experience assessingtheutilityandoutcomesofcollagenvascularclosure device (Angioseal) in patients that required periprocedural anticoagulation and multiple vascular access sites. Methods An retrospective chart review of patients who have undergone the deployment of VCD following electrophysiological procedures. Results In 26 patients (16 males, age 57±15 years, weight 96 ±21 kg), a total of 76 VCD were deployed. Seventy-three VCDs in femoral veins (right or left) and three in femoral artery. The mean number of VCD per patient was 3 (range, 2–4). VCD was successfully deployed in 75 out of 76 access sites.Onepatientwasnotedtohaveecchymosisinbothgroins during follow-up visit. No other complications were noted. Conclusions We provide evidence that a collagen plug-based VCD designed for arterial closure can be safely and effectively used to close multiple venous accesses even in the same vein. This can be accomplished with a venotomy size up to 2 Fr larger than the size of the closure device.

Objectives: The purpose of this study was to prospectively evaluate the feasibility and diagnostic value of right ventricular overdrive pacing (RVOP) during supraventricular tachycardia (SVT) using a 2-catheter approach with automatic pacing from the right ventricular inflow (RVIT) and outflow tract (RVOT). Methods: One hundred and thirty-six consecutive patients (with 138 arrhythmias, mean age 36 ± 20 years, range 4-95) were enrolled in this study. Only coronary sinus and ablation catheters were used. RVOP was delivered from RVIT and then from RVOT. Each attempt consisted of 10 synchronized beats delivered at a cycle length of 10-40 ms longer than the tachycardia cycle length. Results: RVOP was sufficient to confirm the transition zone within the first 9 beats in the majority of SVTs. Atrial perturbation (acceleration, delayed) in the transition zone was detected in all patients with orthodromic atrioventricular (AV) reentry. Patients with typical AV nodal reentry, atypical AV nodal reentry and atrial tachycardia did not show atrial timing perturbation during fusion complexes of RVOP. Conclusions: Synchronized RVOP from RVIT or RVOT is an easy and accurate method for the quick and reliable differential diagnosis of SVT in various clinical settings, particularly when only a limited number of catheters are used.

Background: Nonsustained ventricular tachycardia (VT), frequent in unoperated severe mitral regurgitation (MR), confers mortality risk [sudden death (SD) and cardiac death (CD)]. The prognostic value of VT after mitral valve surgery (MVS) is unknown; we aimed to define this prognostic value and to assess its modulation by left (LV) and/or right (RV) ventricular ejection fraction (EF) for mortality after MVS. Methods: In 57 patients (53% females, aged 58 ± 12 years) with severe MR prospectively followed before and after MVS, we performed 24-hour ambulatory electrocardiograms approximately annually. LVEF and RVEF were determined within 1 year after MVS by radionuclide cineangiography. Results: During 9.52 ± 3.49 endpoint-free follow-up years, late postoperative CD occurred in 11 patients (7 SD, 4 heart failures). In univariable analysis, >1 VT episode after MVS predicted SD (p < 0.01) and CD (SD or heart failure; p < 0.04). Subnormal postoperative RVEF predicted CD (p < 0.04). When adjusted for preoperative age, gender, etiology or antiarrhythmics, both postoperative VT and RVEF predicted CD (p ≤ 0.05). When postoperative VT and RVEF were both in the multivariable model, only subnormal RVEF predicted CD (p < 0.04). Among those with normal RVEF, VT >1 episode predicted SD (p = 0.03). Conclusion: Postoperative VT and subnormal RVEF predict late postoperative deaths in nonischemic MR. Their assessment may aid patient management.

Development and advances in heart pacing over the last nearly half a century allowed to save numerous lives by providing pacing support in bradycardia and complete heart block. Nevertheless, long-term follow up of patients with implanted pacemaker showed unfavorable remodeling of the heart, both from hemodynamic as well as electrical standpoint. The optimal programmed pacemaker setting, apart from the optimal place for ventricular stimulation, is essential to obtain the best hemodynamic and the clinical after-effects of the stimulation of the heart and to minimize potential unfavorable effects. In patients with dual-chamber pacemaker (DDD) the correct function of the left ventricle of the heart depends mainly on the electric delays between the stimulated chambers. Atrio-ventricular delay (AVD) during dual-chamber pacing influences left ventricle contraction function through preload modulation. Improperly programmed AVD in the DDD pacemaker can have unfavorable hemodynamic results. Various methods have been developed during last few decades (right heart catheterization, ventriculography, peak endocardial acceleration, echocardiography, and impedance cardiography), however only echocardiography and reocardiography are currently in general use. There should be noticed too, that also the application of special algorithms present in modern pacemakers allowing for dynamic changes of the time of the delay represents certain alternative to individual AVD optimization.

The implantable cardioverter defibrillator (ICD) has become the primary therapy for the treatment of potentially lethal ventricular arrhythmias. Ventricular arrhythmias encompass a spectrum of rhythm disturbances ranging from the occasional monomorphic ventricular premature complex to the almost universally fatal ventricular fibrillation. Our understanding of the mechanisms of ventricular fibrillation and defibrillation is still in evolution. At present, the most common ICD configuration consists of a pectoral pulse generator (active-can) with a bipolar transvenous dual coil lead. A transvenous system with an active-can has improved defibrillation thresholds and the ease of implantation. However, there are various clinical scenarios in which patients with high defibrillation threshold (DFT) are encountered. Although the incidence of high DFT patients is low, it is of significant concern since it may account for sudden cardiac death in patients with ICDs. At present, there are few clinical trials that are rigorous and well designed, and which can define a perfect methodology for the treatment of high DFT patients. In this review, in the context of commonly encountered clinical scenarios, we discuss therapeutic strategies to help manage patients with high DFT.

Long QT syndrome (LQTS) is one of several primary electrical disorders or hereditary arrhythmia syndromes along with the short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Since its initial recognition in 1957 by Jervell and Lange-Nielsen ( Am Heart J. 1957;54:59-68), LQTS has been intimately associated with risk for sudden cardiac death. The implantable defibrillator was developed by Morowski et al ( N Engl J Med. 1980;303:322-4) as a treatment to prevent sudden cardiac death. Consequently, implanted cardioverter-defibrillator therapy deserves serious consideration as an important therapy for LQTS.

BACKGROUND: The aim of this study was to ascertain whether individual atrioventricular delay (AVD) optimization using impedance cardiography (ICG) offers beneficial hemodynamic effects as well as improved exercise tolerance and quality of life in patients with requiring constant right ventricular pacing. METHODS: There were 37 patients with advanced AV block included in the study. Several examinations were performed at the beginning. Next, the optimization of AVD by ICG was done. The next step of the study patients have been randomized into optimal AVD group (AVDopt) or factory setting group (AVDfab). After 3 months, the follow‐up all data were collected again and crossover was performed. After another 3 months, during the final follow‐up all these measures were repeated. RESULTS: In 87.5% patients, AVDopt were different than factory value. Cardiac output (CO), cardiac index (CI), and stroke volume (SV) were significantly (P < 0.001) higher in AVDopt group than in AVDfab group (CO: 6.0 ± 1.4 L/minute vs. 5.3 ± 1.2 L/minute; SV: 85.8 ± 25.7 mL vs.76.9 ± 22.5 mL; CI: 3.2 ± 0.7 L/minute/m(2) vs. 2.7 ± 0.6 L/minute/m(2)). There was a statistical significant (P < 0.05) reduction of proBNP and NYHA class in patients with AVDopt compared to AVDfab (proBNP: 196.4 ± 144.7pg/mL vs. 269.4 ± 235.8 pg/mL; NYHA class: 1.7 ± 0.5 vs. 2.3 ± 0.6). Six‐minute walking test was significantly (P < 0.05) higher in AVDopt group (409 ± 90 m) than in AVDfab group (362 ± 93 m). There were no statistically significant differences in echocardiographic parameters between AVDopt and AVDfab settings. CONCLUSION: Our study results suggest that AVD optimization in patients with DDD pacemaker with ICG improves hemodynamic when compared to the default factory settings. Furthermore, optimally programmed AVD reduces BNP and improves exercise tolerance and functional class.

We report a rare case of inadvertent reversal of the defibrillator shock coils during generator change which then resulted in both intermittent, recurrent "noise" on both the rate sensing and the shock electrogram leads and multiple inappropriate shocks.

formed and inferences were drawn only from plasma measurements. In a recent issue of Cardiology, Wang et al. [8] provide evidence that increased left atrial tissue expression of MMP-2 is associated with recurrence of AF in patients undergoing mitral valve replacement and surgical AF ablation. The assessment of recurrent AF was not robust yet the early postoperative period was censored to avoid influence of surgery itself on AF recurrence. In addition to the expression of ECM proteins, the size of the left atrium predicted the recurrence of AF in this study. This is consistent with the earlier finding that the extent of atrial scars assessed with MRI is associated with success of ablative therapy for AF [9] . This further supports the notion that there is a threshold of left atrial damage/remodeling beyond which rhythm maintenance strategies are unlikely to provide sustained success. The gap between the pathogenesis of AF and evidence of structural atrial remodeling appears to be narrowing. Thus, atrial remodeling, whether measured macroscopically by echocardiography through left atrial size or at the cellular level by measuring the expression of ECM proteins, has predicted AF recurrence. Certainly, the expression of the ECM markers is a very promising path to understanding the pathophysiology of AF. Indeed, it may help identify patients who will benefit from ablative therapy. Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Its prevalence is increasing as the population ages. Among the various mechanisms putatively responsible for the development of AF, structural atrial remodeling appears to be an important element. In 2004, Xu et al. [1] studied the structure of atrial extracellular matrix (ECM) in explanted hearts from patients with end-stage heart failure. He showed that, in the atrium, the selective downregulation of tissue inhibitors of metalloproteinases (TIMP-2) along with upregulation of metalloproteinases (MMP-2) and collagen type I volume fraction (CVF-1) are associated with the development of sustained AF. Several other studies have demonstrated alterations in MMP and TIMP expression in patients with AF [2–4] . In addition, abnormal levels of serum MMP and subnormal levels of TIMP seem to predict the outcome of rhythm control therapy for AF. Thus, an abnormal serum MMP-2 level predicted AF recurrence in 102 patients after pharmacological or electrical cardioversion [5] . Similar results were found more recently with elevated MMP9 and low TIMP-4 [6] . Furthermore, abnormal serum MMP-2 levels predicted AF recurrence in 50 patients who underwent catheter ablation for drug-resistant AF [7] . Interpretation of some of these studies is limited by the fact that tissue assessment of MMP and TIMP were not perReceived: July 16, 2013 Accepted: July 19, 2013 Published online: November 13, 2013

The aim of this study was to determine whether defibrillation waveform duration adjustment with single-coil defibrillation leads can be used to increase the proportion of patients with satisfactory defibrillation thresholds (DFTs). A retrospective analysis of the DFT levels for 105 patients with implantable cardioverter-defibrillator devices and a single-coil defibrillation lead was performed. Two groups of patients were compared: 34 patients who had undergone waveform tuning (group A) and 71 patients with a fixed-tilt waveform (group B). Additional data including demographics, etiology, New York Heart Association functional class, left ventricular ejection fraction, high-voltage lead impedance and medications were gathered to determine what effect these variables had on the DFT levels. Of the 34 patients who had undergone waveform adjustment (group A), 27 (79%) were found to have satisfactory DFTs, while 41 (58%) of the 71 patients with fixed-tilt devices (group B) had satisfactory DFTs. Waveform duration adjustment was found to significantly increase the proportion of patients with satisfactory DFTs (p = 0.03).

Cardiac perforation due to a pacemaker or defibrillator lead occurs at a rate of 0.4–2.0%. Since first described [1], the overall incidence has decreased significantly. The reported incidence of this complication has been as low as < 1 % to as high as 15% [2-4]. Of 4,280 permanent pacemaker (PPM) implants only 50 (1.2%) patients developed a significant effusion and symptoms consistent with a perforation [5]. The incidence of this complication from the time of surgery decreases over time. By convention, a perforation detected within 24 hours, is classified as acute. If detected within 30 days of implantation (usually 5 days4 weeks), it is referred to as early (sub-acute); and, those detected after 30 days referred to as late, delayed or chronic perforation. The majority of perforations manifest within a year but rarely cases have been reported as late as five years following implantation. [6]

A 65 year-old woman developed tachycardia and hypotension during haemodialysis. The non-contact mapping system was used to localise the origin of focal atrial tachycardia, and showed a remote from the endocardium focus. We discuss techniques that are helpful in identifying the origin, the area of preferential conduction, and the endocardial breakthrough of tachycardia.