Publications by authors named "Steven N Singh"
Background: There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly.
Objective: The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older.
Methods: Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82).
Objectives: This study sought to assess the rate and outcomes of premature ventricular contractions (PVC)-cardiomyopathy from the CHF-STAT (Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure) trial, a population with cardiomyopathy (left ventricular [LV] ejection fraction of <40%) and frequent PVCs (>10 PVCs per hour).
Background: PVCs are associated with heart failure and PVC-cardiomyopathy. The prevalence of PVC-cardiomyopathy and outcome benefits of PVC suppression are not clear.
Background: Digoxin reduces the risk of heart failure hospitalization in patients with heart failure with reduced ejection fraction. Less is known about this association in patients with heart failure with preserved ejection fraction (HFpEF), the examination of which was the objective of the current study.
Methods: In the Medicare-linked OPTIMIZE-HF registry, 7374 patients hospitalized for HF had ejection fraction ≥50% and were not receiving digoxin prior to admission.
Background: In the Studies of Left Ventricular Dysfunction (SOLVD) treatment trial, similar clinical benefits were observed between starting doses of enalapril and the target dose achieved by postrandomization up-titration. In our current analysis, protecting the randomization, we examined the early effects of starting doses of enalapril.
Methods: There were 2569 patients with mild-to-moderate chronic heart failure with reduced ejection fraction (ejection fraction ≤35%) randomized to receive starting doses (5-10 mg/day) of placebo (n = 1284) or enalapril (n = 1285).
Background: A prior hospitalization resulting from heart failure is associated with poor outcomes in ambulatory patients with heart failure. Less is known about this association in hospitalized patients with heart failure and whether it varies by ejection fraction.
Methods: Of the 25,345 hospitalized patients in the Medicare-linked OPTIMIZE-HF registry, 22,491 had known heart failure, of whom 7648 and 9558 had heart failure with preserved (≥50%) and reduced (≤40%) ejection fraction (HFpEF and HFrEF), respectively.
Background: National guidelines recommend that systolic blood pressure (SBP) in patients with heart failure with reduced ejection fraction (HFrEF) and hypertension be maintained below 130 mm Hg.
Objectives: This study sought to determine associations of SBP <130 mm Hg with outcomes in patients with HFrEF.
Methods: Of the 25,345 patients in the Medicare-linked OPTIMIZE-HF registry, 10,535 had an ejection fraction (EF) ≤40%.
Importance: Lower systolic blood pressure (SBP) levels are associated with poor outcomes in patients with heart failure. Less is known about this association in heart failure with preserved ejection fraction (HFpEF).
Objective: To determine the associations of SBP levels with mortality and other outcomes in HFpEF.
Article Synopsis
- A study focused on hospitalized patients with heart failure and preserved ejection fraction (HFpEF) aimed to investigate how discharge heart rates impact patient outcomes.
- Out of nearly 9,000 patients, those with a discharge heart rate below 70 beats per minute had a 65% mortality rate compared to 70% for patients with higher rates, suggesting a lower heart rate indicates better prognosis.
- A lower discharge heart rate also correlated with reduced risk of combined events like HF readmissions or overall mortality, but did not significantly affect readmission rates alone.
Background: Controlled clinical trial data are lacking for cardiac resynchronization therapy (CRT) outcomes in patients with advanced heart failure (HF) from reduced left ventricular ejection fraction (HFrEF) and intermittent atrial fibrillation or flutter (IAF/AFL).
Objective: The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF.
Methods: HF outcomes in patients in the COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trial with New York Heart Association class III or IV HFrEF, left ventricular ejection fraction ≤0.
Aims: We hypothesized that amiodarone (AM), unlike d-sotalol (DS) (a 'pure' Class III agent), not only prolongs the action potential duration (APD) but also causes post-repolarization refractoriness (PRR), thereby preventing premature excitation and providing superior antiarrhythmic efficacy.
Methods And Results: We tested this hypothesis in 31 patients with inducible ventricular tachycardia (VT) during programmed stimulation with the use of the 'Franz' monophasic action potential (MAP) catheter with simultaneous pacing capability. We determined the effective refractory period (ERP) for each of three extrastimuli (S2-S4) and the corresponding MAP duration at 90% repolarization (APD90), both during baseline and on randomized therapy with either DS (n = 15) or AM (n = 16).
Costs and clinical consequences of suboptimal atrial fibrillation management.
Clinicoecon Outcomes Res
October 2012
Atrial fibrillation (AF) places a considerable burden on the US health care system, society, and individual patients due to its associated morbidity, mortality, and reduced health-related quality of life. AF increases the risk of stroke, which often results in lengthy hospital stays, increased disability, and long-term care, all of which impact medical costs. An expected increase in the prevalence of AF and incidence of AF-related stroke underscores the need for optimal management of this disorder.
View Article and Find Full Text PDFArticle Synopsis
- Right ventricular pacing (RVP) is linked to worse outcomes like heart failure and death, making its reduction a key goal for treating patients with pacemakers.
- A study analyzed 7,198 veterans with pacemakers to compare survival rates based on RVP frequency, specifically looking at those with less than 20% versus more than 80% RVP.
- Results showed no significant difference in mortality rates between the two groups, yet those with less than 20% RVP had a shorter average survival time compared to those with more frequent RVP.
Background: Spontaneous coronary artery dissection (SCAD) is a rare condition that commonly presents as an acute coronary event in the younger population, especially in females of childbearing age. Generally, there is no consensus on the etiology, prognosis, and treatment of SCAD.
Methods: The Medline database was searched for "spontaneous coronary artery dissection" between 1931 and 2008.
Intrathoracic impedance preceding ventricular tachyarrhythmia episodes.
Pacing Clin Electrophysiol
August 2010
Article Synopsis
- Heart failure can lead to serious heart rhythm issues (VT/VF), and fluid buildup may trigger these episodes; researchers aimed to see if changes in intrathoracic impedance could predict VT/VF occurrences.
- Data from 121 patients with implanted Medtronic defibrillators showed a decline in intrathoracic impedance before 64% of VT/VF episodes, though the changes were small.
- A new measure called DeltaTI, which quantifies impedance changes, was negative before 66% of the episodes and significantly lower than expected, indicating a potential link between impedance and arrhythmia.
Article Synopsis
- * The VA's adherence to clinical treatment guidelines has resulted in better patient outcomes, including lower risks of morbidity, mortality, and stroke-related rehospitalizations compared to Medicare, Medicaid, and university hospitals.
- * Factors contributing to the VA's success include a more closed system that ensures administrative discipline, continuity of care, and a focus on quality of care rather than incentivizing the volume of medical services.
Article Synopsis
- A study investigated the necessary energy levels for electrocardioversion in patients with persistent atrial fibrillation (AF) and the effects of antiarrhythmic medications.
- The research involved 665 patients who were given either amiodarone, sotalol, or a placebo, with 504 patients undergoing electrocardioversion if they didn't reach sinus rhythm after 28 days.
- Results showed a 71.6% success rate in electrocardioversion, with amiodarone and sotalol significantly increasing the likelihood of success compared to placebo, while calcium channel blockers had no impact on the outcome.
Background: Many patients receiving amiodarone therapy are male. The long-term risk for amiodarone-induced thyroid dysfunction in these patients has not been systematically and prospectively investigated. The purpose of this study was to determine the extent of amiodarone-induced thyroid dysfunction in a large male cohort.
View Article and Find Full Text PDFArticle Synopsis
- Therapy for chronic atrial fibrillation (AF) can focus on either controlling the heart rate or maintaining a regular rhythm, but its impact on exercise tolerance is not well understood.
- A study with 655 patients evaluated the effects of medications and cardioversion on their exercise capacity over a year. Significant findings included that younger, non-obese individuals with worse initial exercise capacity benefited most from cardioversion, which led to better heart rates and a 15% improvement in exercise capacity at 8 weeks that persisted over time.
- Overall, cardioversion provided lasting enhancements in exercise ability for both those who maintained a regular heart rhythm and those with recurring AF, highlighting its effectiveness in certain patient demographics.
Background: Heart failure complicated by atrial fibrillation (AF) is associated with excessive mortality and morbidity. The aim of the study was to determine the role of amiodarone or implantable cardioverter/defibrillator (ICD) in patients with AF and heart failure.
Methods: Patients were determined to be in sinus rhythm (SR) or AF on the baseline electrocardiogram.
Objectives: The purpose of this study was to determine quality of life (QOL) and exercise performance (EP) in patients with persistent atrial fibrillation (AF) converted to sinus rhythm (SR) compared with those remaining in or reverting to AF.
Background: Restoration of SR in patients with AF improving QOL and EP remains controversial.
Methods: Patients with persistent AF were randomized double-blind to amiodarone, sotalol, or placebo.
In patients with structural heart disease, ventricular arrhythmias are associated with an increased risk of overall mortality and sudden cardiac death (SCD). Nonsustained ventricular tachycardia (NSVT) is common in patients with dilated cardiomyopathy of both ischemic and nonischemic origin. Recent studies suggest that NSVT may be a marker, but not a significant predictor, of mortality and SCD in that suppression of NSVT in these patients using antiarrhythmic drugs is of questionable benefit.
View Article and Find Full Text PDFBackground: The optimal pharmacologic means to restore and maintain sinus rhythm in patients with atrial fibrillation remains controversial.
Methods: In this double-blind, placebo-controlled trial, we randomly assigned 665 patients who were receiving anticoagulants and had persistent atrial fibrillation to receive amiodarone (267 patients), sotalol (261 patients), or placebo (137 patients) and monitored them for 1 to 4.5 years.
Background: Atrial fibrillation (AF) in heart failure (HF) is generally considered a negative prognostic factor. Recent studies indicate that the incidence of AF might be decreased by renin angiotensin aldosterone system inhibitors. The identification of a treatment to prevent its occurrence is likely to improve patients outcome.
View Article and Find Full Text PDFArticle Synopsis
- Both supraventricular and ventricular arrhythmias increase the risk of mortality and morbidity, leading to efforts to develop antiarrhythmic drugs to improve survival and quality of life.
- Certain antiarrhythmics can worsen arrhythmias, so they should be used with caution, especially in patients with pre-existing heart conditions.
- Beta blockers are the only antiarrhythmics proven to reduce sudden arrhythmic death, while specific drugs like ibutilide, propafenone, and amiodarone are recommended based on the type of arrhythmia and presence of heart disease.