Biventricular pacing.
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Cardiac Pacing, Artificial↗
Biomedical subjects
Charles A Henrikson
Publications and source records attributed to Charles A Henrikson.
Long-term single procedure efficacy of catheter ablation of atrial fibrillation.
BACKGROUND: Two important limitations of the data regarding the outcomes of catheter ablation of atrial fibrillation (AF) are the short-term follow-up used in most published studies and the lack of single-procedure outcomes. OBJECTIVE: The objective was to report the long-term single-procedure outcomes at our center. MATERIALS AND METHODS: The patient population was comprised of 200 consecutive patients who underwent ablation (133 men; age 56 +/- 11 years). Atrial fibrillation was paroxysmal in 92 (46%). Success was defined as absence of symptomatic AF, off antiarrhythmic drug (AAD) after a single procedure. RESULTS: After a follow-up of 26 +/- 11 months, the single-procedure long-term success rate was 28% with an additional 7% of patients demonstrating improvement. After including repeat procedures in 64 patients, the overall long-term success rate was 41% with 11% demonstrating improvement. Further subgroup analysis of 48 paroxysmal AF patients considered to be optimal candidates for the procedure, revealed a long-term success rate of 69% with an additional 4% demonstrating improvement. A major complication occurred in 7.9% of patients. CONCLUSION: The results reveal that the long-term single-procedure success rate of catheter ablation of AF in a cohort of patients with predominantly non-paroxysmal AF is less than 40%. The inclusion of redo procedures resulted in an improvement in outcomes. A much higher success rate of 69% was achieved in patients with paroxysmal AF considered to be optimal candidates for this procedure. These results make it clear that further advances in the technique of catheter ablation of AF are needed to improve the safety and efficacy of this procedure. In order to be able to compare outcomes of various techniques in differing patient populations, we urge investigators to report long-term single procedure outcomes.
Atrial Fibrillation↗
A pacemaker infection that was apparently localized to the atrial set screw.
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Electrodes, Implanted↗
Insufficient treatment of hypercholesterolemia among patients hospitalized with chest pain.
BACKGROUND: Although morbidity and mortality from coronary artery disease can be improved with a variety of pharmacologic interventions, many patients remain undertreated. HYPOTHESIS: This study sought to assess whether hospitalization for possible coronary artery disease would prompt initiation of appropriate lipid-lowering therapy. METHODS: This prospective, observational study was conducted on consecutive patients with active chest pain admitted to the Emergency Department of the hospital for suspected myocardial ischemia. Elevated cholesterol, defined as low-density lipoprotein (LDL), was >100 mg/dl with a prior history or a new diagnosis of coronary artery disease, or an LDL >130 mg/dl without known coronary artery disease. Data were recorded at the time of admission, discharge, and at 4-month follow-up. RESULTS: Of the patients with hyperlipidemia, 65% men and 55% women were on medication at the time of admission (p = 0.30), while at discharge, 79% men and 60% women were on treatment (p = 0.002), with similar rates of treatment at 4-month follow-up (p = 0.030). At discharge, two variables were independently associated with patients receiving lipid-lowering therapy: age > or =65 years (odds ratio = 2.3; 95% confidence interval 1.2-4.5) and male gender (2.7; 15-5.0). CONCLUSIONS: In patients hospitalized with chest pain, particularly in women, the initiation of treatment of hyperlipidemia frequently does not happen. This oversight represents a lost opportunity for making an impact on the health of this population.
Adult↗
Temporary placement of a defibrillating lead in the treatment of infection and ventricular tachycardia.
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Aged↗
Female sex: a protective role in suspected myocardial ischemia.
OBJECTIVE: Women are felt to have poor outcomes in coronary artery disease, largely on the basis of secondary observations in acute coronary syndrome trials. We sought to examine the neglected topic of sex differences in workup and outcomes in the general population presenting with chest pain. METHODS: We examined 439 consecutive patients admitted via the emergency department with ongoing chest pain. Cardiac testing was defined as any cardiac catheterization or stress test. Positive testing was defined as a 70% or greater stenosis in an epicardial coronary artery on catheterization, or a positive stress test result. Follow-up was obtained via telephone contact at 4 months following discharge. RESULTS: Further cardiac testing was deemed necessary in 68% (164/241) of women and 77% (153/198) of men (P=0.038). Among women undergoing further testing, only 21% (35/164) had positive tests, whereas 41% (62/153) of men had positive tests (P=0.002). At 4 months, women were less likely to have suffered the combined endpoint of subsequent myocardial infarction, revascularization, or death, than men (15 vs. 23%, P=0.027). Events were more likely to occur in patients who had further testing, and especially in those who had positive testing. CONCLUSIONS: These data suggest that women admitted with chest pain are less likely to have active coronary artery disease, and much less likely to have poor outcomes at 4 months than men. This apparent 'gender protection' effect warrants further study.
Aspirin↗
Laser recanalization of the subclavian vein.
We report the use of a long wire and introducer as a rail for the laser recanalization of a chronically occluded subclavian vein following extraction of a fractured permanent pacing lead. This allowed new pacing leads to be placed through the previously occluded vessel.
Child↗
Computed tomography to assess possible cardiac lead perforation.
BACKGROUND: Chest radiography and echocardiography are standard techniques to evaluate possible extracardiac migration of pacemaker and defibrillator leads, but computed tomography (CT) scanning may be a helpful adjunct. METHODS: Chest CT using a 64-detector helical scanner was performed in three cases of lead perforation where standard techniques did not yield a definitive diagnosis. In two patients, a cardiac CT protocol was followed, the primary indication for which was to assess the lead tip location. On one patient, persistent chest pain several days after the implant led to a chest CT to rule out a pulmonary embolism, and the extracardiac lead was found fortuitously. RESULTS: In all cases, CT scan images resulted in a definitive diagnosis of extracardiac migration of pacemaker or defibrillator leads. One patient had an extracardiac atrial lead which was dysfunctional but not associated with symptoms. The risks of repositioning were felt to outweigh potential benefits in this patient with chronic obstructive pulmonary disease, and treatment was conservative. The other two patients had extracardiac ventricular leads and were symptomatic with pleuritic chest pain. These patients were treated by lead revision with no evidence of bleeding into the pericardial space. All patients did well and none have suffered any further complications. CONCLUSION: CT images aid in the diagnosis of lead perforation when other modalities are nondiagnostic. Recent advances in CT technology have been associated with increased use of this technique for evaluation of chest pain, analysis of which should now include location of intracardiac leads.
Aged↗
Opportunistic access: Successful retrograde guide wire advancement to the pocket through a track created by laser lead extraction.
Obtaining vascular access can be difficult following lead extraction if a wire is not retained within the vessel. We describe a unique situation in which retrograde passage of a guidewire to the explanted internal cardioverter/defibrillator pocket facilitated regaining subclavian venous access.
Adult↗
Symptomatic and asymptomatic atrial fibrillation in patients undergoing radiofrequency catheter ablation.
INTRODUCTION: The goals of this study were to (i) evaluate the feasibility and results of monitoring patients prior to and following catheter ablation of AF with the mobile cardiac outpatient telemetry (MCOT) system and to (ii) correlate symptoms and the presence or absence of atrial fibrillation (AF). METHODS AND RESULTS: A total of 19 consecutive patients (12 men [63%]; age 60 +/- 6 years) with highly symptomatic drug refractory AF underwent catheter ablation. Each was provided with a MCOT monitor (CardioNet, USA) and asked to wear it 5 days immediately before the ablation, and 5 days per month starting with the ablation for 6 consecutive months. When patients experienced any symptoms, they were asked to activate the system and to record associated symptoms. A total of 494 days (11,856 hours) were monitored. Out of the total 390 events triggered by patient's symptoms, 40% were confirmed as AF events (156) and 60% were confirmed as non-AF events (234). Only shortness of breath and chest discomfort were highly associated with AF (P < 0.05). At the end of 6 months of follow-up, out of 10 patients that completed the study, 7 (70%) patients were free of symptomatic AF recurrences whereas only 5 (50%) patients achieved success when asymptomatic AF recurrences were included in the outcome. CONCLUSIONS: The results of this study demonstrate the potential utility of wireless monitoring systems in the follow-up of AF ablation patients, while also identifying poor patient compliance with an intensive monitoring protocol as an important limitation.
Atrial Fibrillation↗
Initial experience in the use of integrated electroanatomic mapping with three-dimensional MR/CT images to guide catheter ablation of atrial fibrillation.
INTRODUCTION: No prior studies have reported the use of integrated electroanatomic mapping with preacquired magnetic resonance/computed tomographic (MR/CT) images to guide catheter ablation of atrial fibrillation (AF) in a series of patients. METHODS AND RESULTS: Sixteen consecutive patients with drug-refractory AF underwent catheter ablation under the guidance of a three-dimensional (3D) electroanatomic mapping system (Carto, Biosense Webster, Inc., Diamond Bar, CA, USA). Gadolinium-enhanced MR (n = 8) or contrast-enhanced high-resolution CT (n = 8) imaging was performed within 1 day prior to the ablation procedures. Using a novel software package (CartoMerge, Biosense Webster, Inc.), the left atrium (LA) with pulmonary veins (PVs) was segmented and extracted for image registration. The segmented 3D MR/CT LA reconstruction was accurately registered to the real-time mapping space with a combination of landmark registration and surface registration. The registered 3D MR/CT LA reconstruction was successfully used to guide deployment of RF applications encircling the PVs. Upon completion of the circumferential lesions around the PVs, 32% of the PVs were electrically isolated. Guided by a circular mapping catheter, the remaining PVs were disconnected from the LA using a segmental approach. The distance between the surface of the registered 3D MR/CT LA reconstruction and multiple electroanatomic map points was 3.05 +/- 0.41 mm. No complications were observed. CONCLUSIONS: Three-dimensional MR/CT images can be successfully extracted and registered to anatomically guided clinical AF ablations. The display of detailed and accurate anatomic information during the procedure enables tailored RF ablation to individual PV and LA anatomy.
Atrial Fibrillation↗
Long-term safety and efficacy of circumferential ablation with pulmonary vein isolation.
BACKGROUND: Each of the two main approaches to catheter ablation of atrial fibrillation (AF, segmental and circumferential) is associated with moderate long-term efficacy. OBJECTIVE: To report the long-term outcomes of a modified technique that combines circumferential ablation with pulmonary vein (PV) isolation, determined by a circular mapping catheter and to determine the relationship between complete PV isolation and long-term efficacy. METHODS: The patient population was composed of 64 consecutive patients (47 men [73%]; age 59 +/- 11 years) with AF who underwent catheter ablation. AF was paroxysmal in 29 (45%) and nonparoxysmal in 35 (55%). Each patient was followed for a minimum of 12 months. RESULTS: After a mean follow-up of 13 +/- 1 months, the long-term single-procedure success rate was 45% (n = 29) with an additional 4% (n = 3) of patients demonstrating improvement. With repeat procedures in 19 patients, the overall long-term success rate was 62% (n = 40) with 9% (n = 6) demonstrating improvement. All the patients who underwent repeat ablations had recovered PV conduction. Incomplete PV isolation was the only independent predictor of failure. A major complication occurred in four (6%) patients, including three patients with vascular complications and one with cardiac tamponade. CONCLUSION: Our results suggest that the long-term single-procedure efficacy of circumferential ablation with PV isolation in a cohort of patients with predominantly nonparoxysmal AF approaches 50%. Repeat procedures involving re-isolation of the PVs result in a significant improvement in outcomes. Complete electrical isolation of the PVs has a significant impact on the long-term efficacy of the procedure.
Atrial Fibrillation↗
Antiarrhythmic engineering of skeletal myoblasts for cardiac transplantation.
Skeletal myoblasts are an attractive cell type for transplantation because they are autologous and resistant to ischemia. However, clinical trials of myoblast transplantation in heart failure have been plagued by ventricular tachyarrhythmias and sudden cardiac death. The pathogenesis of these arrhythmias is poorly understood, but may be related to the fact that skeletal muscle cells, unlike heart cells, are electrically isolated by the absence of gap junctions. Using a novel in vitro model of myoblast transplantation in cardiomyocyte monolayers, we investigated the mechanisms of transplant-associated arrhythmias. Cocultures of human skeletal myoblasts and rat cardiomyocytes resulted in reentrant arrhythmias (spiral waves) that reproduce the features of ventricular tachycardia seen in patients receiving myoblast transplants. These arrhythmias could be terminated by nitrendipine, an l-type calcium channel blocker, but not by the Na channel blocker lidocaine. Genetic modification of myoblasts to express the gap junction protein connexin43 decreased arrhythmogenicity in cocultures, suggesting a specific means for increasing the safety (and perhaps the efficacy) of myoblast transplantation in patients.
Action Potentials↗
Troponin and outcomes.
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Angina Pectoris↗
Images in cardiovascular medicine. "Shrink-wrapped" permanent pacemaker.
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Adrenal Cortex Hormones↗
A practical and evidence-based approach to cardiovascular disease risk reduction.
Implementation of the numerous lifestyle and medical management options for secondary prevention of cardiovascular disease remains a daunting goal for primary care physicians and cardiologists alike. Despite the existence of expert consensus guidelines on cardiovascular prevention by the American College of Cardiology and the American Heart Association, therapies known to improve patient care and decrease morbidity and mortality remain underutilized. This review attempts to simplify cardiovascular risk reduction by summarizing key clinical trials in an "ABC" format. We believe that if health care providers and patients use such a format, important lifestyle and pharmacologic options will more likely be addressed.
Anticoagulants↗
Prognostic usefulness of marginal troponin T elevation.
Marginal elevations of troponin T among patients with chest pain are often considered to be insignificant. We sought to define the prognostic value of marginal troponin T elevations in patients presenting to the emergency department with suspected myocardial ischemia. Four hundred twenty-eight consecutive patients presenting to the emergency department with ongoing chest pain were evaluated, followed through their hospital course, and contacted for follow-up 4 months after discharge. Two hundred ninety-nine patients had undetectable troponin T levels (<0.01 microg/L), 76 had marginal troponin T elevations (0.01 to 0.09 microg/L), and 53 had frank troponin T elevations (> or =0.1 microg/L). Patients with either marginally or frank elevated troponin levels were older and more likely to be men, but did not differ from patients with undetectable troponin levels with regard to the prevalence of coronary artery disease risk factors, history of coronary disease, or race. While in the hospital, the undetectable and marginal troponin groups were referred for cardiac testing in equal proportions (58% and 59%, respectively), whereas 87% of the elevated group underwent further testing. After adjustment for possible confounders, a significantly increased rate of death/myocardial infarction/revascularization was observed in the marginal troponin group compared with the undetectable troponin group (p = 0.004). Marginal elevations of troponin T identified a currently underevaluated high-risk subgroup of patients with suspected myocardial ischemia who are more likely to have adverse clinical outcomes than those with undetectable troponin levels.
Adult↗
Treatment of hyperlipidemia in cardiac transplant recipients.
Of the 60,000 patients receiving heart transplants between 1982 and 2001, approximately 12,000 are currently alive. The high incidence of hyperlipidemia and coronary disease (also known as accelerated graft atherosclerosis, or AGA) in these patients warrants early prophylaxis soon after transplantation with 3-hydroxy-3-methylglutaryl (HMG) Co-A reductase inhibitors (statins). Immunosuppressive agents such as prednisone, cyclosporine, mycophenylate mofetil, and sirolimus are associated with hyperlipidemia. Statins, in addition to lowering cholesterol levels, also benefit cardiac transplant recipients via effects on the immune system and endothelial function. Recent data have demonstrated that statins decrease AGA and mortality rates. Furthermore, greater benefits are seen when statins are started early. The 2 statins shown to decrease mortality in patients after cardiac transplantation are pravastatin and simvastatin, which differ in their metabolism (pravastatin is the only statin with non-cytochrome metabolism) and lipophilicity (pravastatin is less lipophilic). Although the benefit of simvastatin has been shown to extend to 8 years after transplantation, increased adverse effects in other studies with higher doses of simvastatin have resulted in new prescribing recommendations, which state that the dose of simvastatin should probably not exceed 10 mg with cyclosporine or gemfibrozil and 20 mg with amiodarone or verapamil. The evidence for potential benefits, interactions, and adverse effects of other potential lipid-lowering drugs for this patient population, such as fibrates, niacin, fish oil, cholestyramine, and ezetimibe, are also discussed. A summary algorithm is proposed, including approaches to patients with statin-associated musculoskeletal symptoms and patients with inadequate results after initial statin therapy.
Algorithms↗