A case of short QT-interval postventricular arrhythmia arrest from Torsade De Pointes, a new phenotype, or the result of tachycardia-mediated imbalance.

INTRODUCTION: We report the case of an 18-year-old female with recurrent syncope that was discovered to have congenital long QT syndrome (LQTS) and episodes of a transiently short QT interval after spontaneous termination of polymorphic ventricular tachycardia. METHODS & RESULTS: A cardiac event monitor revealed a long QT interval and initiation of polymorphic ventricular tachycardia by a premature ventricular complex on the preceding T-wave. After 1 minute of ventricular fibrillation, her arrhythmia spontaneously terminated with evidence of a short QT interval. CONCLUSIONS: A transient, potentially artificial, short QT interval following Torsades de Pointes can occur in patients with LQTS.

Ablation Therapy for Persistent Atrial Fibrillation.

Atrial Fibrillation (AF) is the most common form of electrical disturbance of the heart and contributes to significant patient morbidity and mortality. With a better understanding of the mechanisms of atrial fibrillation and improvements in mapping and ablation technologies, ablation has become a preferred therapy for patients with symptomatic AF. Pulmonary Vein Isolation (PVI) is the cornerstone for AF ablation therapy, but particularly in patients with AF occurring for longer than 7 days (persistent AF), identifying clinically significant nonpulmonary vein targets and achieving durability of ablation lesions remains an important challenge.

Vagal milieu or electrophysiologic substrate? The link between atrial fibrillation and obstructive sleep apnea.

Atrial fibrillation is the most common cardiac arrhythmia with its prevalence expected to increase to 12.1 million people in the United States by 2030. Chronic underlying conditions that affect the heart and lungs predispose patients to develop atrial fibrillation. Obstructive sleep apnea is strongly associated with atrial fibrillation. Several pathophysiological mechanisms have been proposed to elucidate this relationship which includes electrophysiological substrate modification and the contribution of the autonomic nervous system. In this comprehensive review, we highlight important relationships and plausible causality between obstructive sleep apnea and atrial fibrillation which will improve our understanding in the evaluation, management, and prevention of atrial fibrillation. This is the most updated comprehensive review of the relationship between obstructive sleep apnea and atrial fibrillation.

Beyond Ejection Fraction: Novel Clinical Approaches Towards Sudden Cardiac Death Risk Stratification in Patients with Dilated Cardiomyopathy.

Implantable Cardioverter-Defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death due to ventricular tachyarrhythmia. The most commonly used risk stratification algorithms use Left Ventricular Ejection Fraction (LVEF) to determine which patients qualify for ICD therapy, even though LVEF is a better marker of total mortality than ventricular tachyarrhythmias mortality. This review evaluates imaging tools and novel biomarkers proposed for better risk stratifying arrhythmic substrate, thereby identifying optimal ICD therapy candidates.

Ablation Success in Various Arrhythmias: When It Is Appropriate to Recommend Ablation?

Cardiac arrhythmia is an abnormal electrical activity of the heart. It can be divided into rhythms with increased electrical activity (tachyarrhythmia) and those with reduced electrical activity (bradyarrhythmia). Ablation therapy has a role in tachyarrhythmia, but this role varies from being limited in inappropriate sinus tachycardia to being a class 1 indication in typical atrial flutter. A balanced approach in recommendation for ablation therapy for the management of tachyarrhythmias involves knowledge of the interplay between the risk, benefit, success rate, and alternatives with advances in mapping and ablation therapy.

Outcomes of transcatheter aortic valve replacement in bicuspid aortic valve stenosis.

BACKGROUND: Due to abnormal valve geometry, patients with bicuspid aortic valve (BAV) have been excluded in many transcatheter aortic valve replacement (TAVR) trials resulting in very limited data with regards to its safety and efficacy. METHODS: We searched electronic databases including Cochrane Database of Systematic Reviews, MEDLINE and EMBASE for all studies including case series, and original reports published before December 2018 that assessed outcomes following TAVR in BAV stenosis. We also included studies that had patients with TAV for comparison. Pooled effect size was calculated with a random-effect model and weighted for the inverse of variance, to compare outcomes post-TAVR between BAV and TAV. The heterogeneity of effect estimates across the studies was assessed using I2. Publication bias was assessed with funnel plots. Statistical analysis was performed using SPSS version 24 (IBM Corp., SPSS Statistics for Windows, Version 24.0. Armonk, NY.). RESULTS: A total of 19 studies describing 1,332 patients with BAV and 3,610 with TAV. There was no significant difference in the30-day mortality between patients with BAV and TAV [odds ratio (OR): 1.18, 95% confidence interval (CI): 0.7-1.7, P=0.41, I2=0]. One-year mortality rate in the BAV population was 13.1% compared to 15.4% in the TAV patients (P=0.75). Patients with BAV had significantly more moderate to severe paravalvular leak (PVL) post TAVR (PVL ≥3) 8.8% vs. 4.2% in TAV patients (OR: 1.478, 95% CI: 1.000-2.184, P=0.050, I2=0. Device success was significantly higher in TAV patients compared to BAV patients 93.5% vs. 87% (OR: 0.63, 95% CI: 0.49-0.86, P=0.003). CONCLUSIONS: TAVR in patients with BAV is associated with a high incidence of paravalvular regurgitation with a comparable 30-day mortality rate to TAV patients. The use of newer generation valve prosthesis improved outcomes.

Ticagrelor or prasugrel vs. clopidogrel in combination with anticoagulation for treatment of acute coronary syndrome in patients with atrial fibrillation.

For patients with atrial fibrillation (AF) and acute coronary syndrome (ACS), it is often challenging to find the optimal balance between the risk for ischemic and hemorrhagic complication when using both antiplatelet therapy and oral anticoagulation (OAC) with vitamin K antagonist (VKA) or direct oral anticoagulants (DOACs). Current guidelines recommended: (I) double therapy with a P2Y12 inhibitor and dose adjusted VKA is reasonable post-stenting; (II) double therapy with clopidogrel and low-dose rivaroxaban (15 mg daily) may be reasonable post-stenting; (III) double therapy with a P2Y12 inhibitor and dabigatran 150 mg twice daily is reasonable post-stenting. In the AUGUSTUS trial, most patients were given clopidogrel as part a DAPT regimen, however prasugrel and ticagrelor use allowed albeit in a small percentage of the trial population, underestimating its effect. Ticagrelor and prasugrel are known to have a stronger antiplatelet effect compared to clopidogrel, however randomized studies have not been adequately powered to date allowing comparisons between ticagrelor, prasugrel and clopidogrel together in the setting of anticoagulation for the treatment of patients with ACS and AF. Careful consideration should be given to this scenario to avoid falling into the concept of sacrificing efficacy for safety.

Cocaine Positivity in ST-Elevation Myocardial Infarction: A True or False Association.

INTRODUCTION: Every year, more than 500,000 US Emergency Department visits are associated with cocaine use. People who use cocaine tend to have a lower incidence of true ST-elevation myocardial infarction (STEMI). OBJECTIVE: To identify the factors associated with true STEMI in patients with cocaine-positive (CPos) findings. METHODS: We retrospectively analyzed 1144 consecutive patients with STEMI between 2008 and 2013. True STEMI was defined as having a culprit lesion on coronary angiogram. Multivariate and univariate analyses were used to identify risk factors and create a predictive model. RESULTS: A total of 64 patients with suspected STEMI were CPos (mean age 53.1 ± 11.2 years; male = 80%). True STEMI was diagnosed in 34 patients. Patients with CPos true STEMI were more likely to be uninsured than those with false STEMI (61.8% vs 34.5%, p = 0.03) and have higher peak troponin levels (21.1 ng/mL vs 2.12 ng/mL, p = < 0.01) with no difference in mean age between the 2 groups (p = 0.24). In multivariate analyses, independent predictors of true STEMI in patients with CPos findings included age older than 65 years (odds ratio [OR] = 19.3, 95% confidence iterval [CI] = 1.2-318.3), lack of health insurance (OR = 4.9, 95% CI = 1.2-19.6), and troponin level higher than 0.05 (OR = 24.0, 95% CI = 2.6-216.8) (all p < 0.05). A multivariate risk score created with a C-statistic of 82% (95% CI = 71-93) significantly improved the identification of patients with true STEMI. CONCLUSION: Among those with suspected STEMI, patients with CPos findings had a higher incidence of false STEMI. Older age, lack of health insurance, and troponin levels outside of defined limits were associated with true STEMI in this group.

Procedural Variations in Performing Primary Percutaneous Coronary Intervention in Patients With ST-Elevation Myocardial Infarction.

Multiple variations exist in performing a primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) among various cardiologists. These variations range from the choice of peripheral access artery (radial vs femoral), performance or time of complete angiography including left ventriculography, and nonculprit vessel angiography before or after intervening on the culprit vessel. The reasons for such variations include emphasis on door-to-balloon time, knowledge of cardiac anatomy before proceeding with pPCI, physician expertise, and the level of comfort with radial approach. Over the last 2 decades, the field of interventional cardiology has changed dynamically leading to marked improvements in the clinical outcomes of patients with STEMI. This includes upstreaming of pPCI along with technical advancements ranging from radial artery catheterization to culprit lesion-guided approach. Increased comfort with use of radial access approach by cardiologists and availability of multiuse guide catheters would both reduce door-to-balloon time and enable complete coronary angiography before performance of percutaneous coronary intervention. There are no clear guidelines or consensus dictating on cardiologists a correct sequence of action during STEMI, or even suggesting what the preferred approach is. Lack of guidelines results in a substantive variation in methodology. This review aims to highlight and to better understand the variations in the current practice, and to emphasize the advantages as well as the disadvantages of each approach. It is also perhaps a call out for guidelines that direct cardiologists to the best practice.

Impact of Pre-existing Kidney Dysfunction on Outcomes Following Transcatheter Aortic Valve Replacement.

BACKGROUND: Pre-existing chronic kidney disease (CKD) portends adverse outcomes following heart valve surgery. However, only limited and conflicting evidence is available on the impact of CKD on outcomes following transcatheter aortic valve replacement (TAVR). The objective of this review was to evaluate the effect of pre-existing CKD on TAVR outcomes. METHODS: We performed a systematic electronic search using the PRISMA statement to identify all randomized controlled trials and observational studies investigating the effect of pre-existing CKD on outcomes following TAVR. 30-day and long-term outcomes were measured comparing patients with Glomerular filtration rate (GFR) ≥60 to those with GFR <60. RESULTS: Ten studies were analyzed comprising of 8688 patients. Compared to patients with GFR ≥60, those with GFR < 60 had worse 30-day all cause mortality (OR 1.40, 95% CI: 1.13-1.73), cardiovascular mortality (OR 1.66, 95% CI: 1.04-2.67), strokes (OR 1.39, 95% CI: 1.05-1.85), acute kidney injury (OR 1.42, 95% CI: 1.21-1.66) and the risk for dialysis (OR 2.13, 95% CI: 1.07-4.22). There was no difference in device success (p=0.873), major or life threatening bleeds (p = 0.302), major vascular complications (p=0.525), need for pacemaker implantation (p = 0.393) or paravalvular leaks (p = 0.630). All-cause mortality at 1 year was also significantly higher in patients with GFR <60 (OR 1.80, 95% CI: 1.26-2.56). CONCLUSION: Pre-existing CKD defined as GFR <60 is a strong predictor of worse short and longterm outcomes following TAVR. Active measures should be taken to mitigate the postprocedure risk in these group of patients.

Complete Revascularization of Simultaneous Multiple Culprit Lesions in a Septuagenarian with ST-Elevation Myocardial Infarction.

BACKGROUND ST-elevation myocardial infarction (STEMI) is usually caused by rupture of unstable plaque with thrombus formation and abrupt cessation of blood flow through a single coronary artery that is deemed the culprit. The simultaneous thrombotic occlusions of multiple coronary arteries in the setting of STEMI is a rare occurrence with implications for patient management and outcome not fully addressed in the current STEMI guidelines, although more recent studies suggest a benefit of complete revascularization compared to culprit vessel-only treatment in the setting of STEMI. CASE REPORT A 74-year-old female presented with STEMI. Coronary angiography revealed simultaneous multiple coronary thrombotic occlusions involving the right coronary, left circumflex, and ramus intermedius arteries successfully treated with primary percutaneous revascularization at the same setting with good outcome and short hospital length of stay. CONCLUSIONS Although the most appropriate timing to treat simultaneous multiple culprit lesions has yet to be definitively defined, multi-vessel percutaneous coronary intervention in the setting of a STEMI with multiple culprit lesions is feasible with good outcome as shown by our index case.