Abstract:
:Currently available internal cardiac defibrillators use a uniphasic, truncated exponential waveform morphology of about 6 msec in duration at an energy level of 23 to 33 joules. To determine if improved defibrillation could be achieved with a different waveform morphology, we implanted 4.5 cm2 titanium patches to the left and right ventricle of 28 dogs. After ventricular fibrillation was induced, defibrillation was attempted using 7, 12, 13, or 17 joules. A 5 msec rectangular uniphasic waveform morphology was compared with a 10 msec rectangular biphasic waveform with the lagging 5 msec pulse of half the amplitude of the leading 5 msec. In an additional seven dogs, a transvenous bipolar catheter was placed with the distal electrode in the right ventricular apex and the proximal electrode in the superior vena cava. Biphasic and uniphasic shocks were compared at 14 joules. In the patch-patch system, the biphasic waveform was superior to the uniphasic waveform at 7 joules (67% versus 35%, p less than 0.001) and at 12 joules (93% versus 78%, p less than 0.001). No statistically significant differences were achieved at 13 joules or 17 joules. In the catheter electrode system with a delivered energy of 14 joules, the biphasic waveform was more effective than the uniphasic waveform (87% versus 27%, p less than 0.001). Manufacturers of automatic implantable defibrillators should consider this information in the design of future automatic implantable defibrillators.
journal_name
Am Heart Jjournal_title
American heart journalauthors
Flaker GC,Schuder JC,McDaniel WC,Stoeckle H,Dbeis Mdoi
10.1016/0002-8703(89)90187-7subject
Has Abstractpub_date
1989-08-01 00:00:00pages
288-91issue
2eissn
0002-8703issn
1097-6744pii
0002-8703(89)90187-7journal_volume
118pub_type
杂志文章abstract:BACKGROUND:Technetium Tc 99m gated single photon emission computed tomography (SPECT) has become the cornerstone of noninvasive risk stratification in patients with ischemic heart disease, but its role in patients with heart failure is not as well established. STUDY DESIGN:This study is a substudy of the Heart Failure...
journal_title:American heart journal
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.ahj.2007.03.045
更新日期:2007-07-01 00:00:00
abstract:BACKGROUND:The conventional use of 16-slice multidetector computed tomography (MDCT) remains somewhat limited for evaluating stenoses in vein graft distal anastomotic sites and in coronary arteries. We investigated the diagnostic accuracy of 64-slice MDCT for assessment of both grafts and coronary arteries in patients ...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/j.ahj.2007.04.054
更新日期:2007-09-01 00:00:00
abstract::The conducting tissue of the heart was studied in 25 human cases of Chagas' myocarditis with a method which employs complete serial sections mounted on continuous transparent plastic tape. The pathological changes were correlated with electrocardiographic findings. The inflammation of the acute phase of Chagas' myocar...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(78)90362-9
更新日期:1978-03-01 00:00:00
abstract:OBJECTIVE:The study aimed to determine the impact on eptifibatide-associated bleeding by implementing a computerized dosing algorithm in the cardiac catheterization suite. BACKGROUND:Excessive dosing of eptifibatide is associated with increased bleeding rates and hospital mortality. Although dosing adjustments based o...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/j.ahj.2009.10.006
更新日期:2009-12-01 00:00:00
abstract::The antihypertensive effects of the renin inhibitor enalkiren were compared with those of the angiotensin-converting enzyme inhibitor enalaprilat in 17 hypertensive patients (14 white, 3 black; mean age 57 years), whose renin systems had been stimulated by diuretic pretreatment. Patients were studied on 3 separate in-...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(91)90477-y
更新日期:1991-10-01 00:00:00
abstract::We examined intraindividual variability in serum TC in 2912 men and women having TC measured at each of biennial examinations 2 through 7 of the FHS. RMSE described variability around the linear slope of an individual's TC during the baseline decade. Average biennial difference +/- SD was +3.7 +/- 6.7 mg/dl in men, +6...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(94)90393-x
更新日期:1994-06-01 00:00:00
abstract:BACKGROUND:Diastolic dysfunction is common immediately after coronary artery bypass surgery (CABG). The duration of this phenomenon is unknown. Intravenous calcium is frequently administered during separation from cardiopulmonary bypass (CPB). We sought to determine whether intravenous calcium influences perioperative ...
journal_title:American heart journal
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/S0002-8703(02)94786-1
更新日期:2003-05-01 00:00:00
abstract::Fasting mongrel dogs underwent hyperbaric oxygen treatment (HBOT), recombinant tissue plasminogen activator (rt-PA) treatment, and simultaneous HBOT and rt-PA treatment following prior experimental left anterior descending coronary artery occlusion for 2 hours. Thrombosis in and around a copper coil was recorded angio...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(90)90194-3
更新日期:1990-10-01 00:00:00
abstract:BACKGROUND:In a previous study from a single center, radionuclide measures of collateral flow with technetium 99m sestamibi have been shown to be significantly associated with angiographic residual (antegrade and collateral) flow and independent predictors of final infarct size in acute myocardial infarction. This stud...
journal_title:American heart journal
pub_type: 杂志文章,多中心研究
doi:10.1016/s0002-8703(97)70046-2
更新日期:1997-10-01 00:00:00
abstract:BACKGROUND:Statins (3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors) are known to reduce mortality and cardiac events in patients with coronary artery disease who have not progressed to left ventricular systolic dysfunction (LVSD) and/or heart failure (HF). This study investigated the effect of changes in s...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/j.ahj.2007.01.029
更新日期:2007-04-01 00:00:00
abstract:BACKGROUND:The relationship of changes in weight to outcomes in patients after myocardial infarction (MI) is controversial. METHODS:From the ENRICHD trial data, we assessed weight change, and the associations of baseline weight and change at follow-up with outcomes and interactions between psychosocial factors. RESUL...
journal_title:American heart journal
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.ahj.2007.10.026
更新日期:2008-03-01 00:00:00
abstract:BACKGROUND:Chronic periodontal infection is associated with an increased risk of coronary heart disease. Although the mechanism responsible for the relationship between periodontal disease and cardiovascular events is not fully understood, it is hypothesized that the chronic inflammatory burden of periodontal disease m...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/j.ahj.2005.10.002
更新日期:2006-01-01 00:00:00
abstract::We studied 56 right ventricular papillary muscles isolated from cats to determine whether the direct mechanical effects of contrast media are due to their pharmacologic action or to the hyperosmolality caused by them. A 10% solution of Renografin-76 abruptly decreased force 22% below control, then slowly increased it ...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(84)90550-7
更新日期:1984-07-01 00:00:00
abstract::Although the Doppler mitral flow velocity pattern changes in accordance with the degree of left ventricular diastolic dysfunction, it is "normalized" in the presence of heart failure. In this study the pulmonary venous flow velocity pattern was characterized in 43 hypertensive patients with and without heart failure t...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(92)90982-2
更新日期:1992-10-01 00:00:00
abstract:BACKGROUND:Enhanced external counterpulsation (EECP) reduces angina and extends time to exercise-induced ischemia in patients with symptomatic coronary disease. One- and two-center studies and a retrospective case series reported that EECP improves myocardial perfusion in stable angina pectoris. We sought to critically...
journal_title:American heart journal
pub_type: 杂志文章,多中心研究
doi:10.1016/j.ahj.2005.01.054
更新日期:2005-11-01 00:00:00
abstract:BACKGROUND:Parasympathetic dysautonomia is an established feature of advanced Chagas cardiomyopathy. However, in the absence of cardiac involvement, the presence of vagal dysfunction remains controversial. In a cross-sectional study, we compared patients with Chagas disease without cardiac involvement and healthy indiv...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1067/mhj.2001.111406
更新日期:2001-02-01 00:00:00
abstract:BACKGROUND:Atrial fibrillation (AF) in the setting of heart failure (HF) is linked to embolic stroke and exacerbation of HF. The rate of new-onset AF in patients with left ventricular dysfunction and mild to moderate HF enrolled in the SoLVD trials was significantly lower with enalapril than with placebo (5.4% vs 24% o...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/j.ahj.2005.07.027
更新日期:2005-11-01 00:00:00
abstract::Twenty-six patients with Ebstein's anomaly were classified into three types according to their clinical features, heart catheterization data, angiocardiographic and anatomical findings which were obtained on surgery or autopsy. The hemodynamics in each type were discussed. 1. Tricuspid Stenosis Dominant Type. Eight pa...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(78)90458-1
更新日期:1978-02-01 00:00:00
abstract::We report the angiographic studies of 53 consecutive patients with angiographic coronary artery disease (CAD) and recurrent sustained ventricular tachycardia occurring at least 6 weeks remote from an acute myocardial infarction. Triple-vessel disease was present in 25 patients (47%), double-vessel disease in 19 patien...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(83)90392-7
更新日期:1983-06-01 00:00:00
abstract:BACKGROUND:Vascular wall shear stress (WSS) has been implied in the pathogenesis of atherosclerosis and vascular remodeling. Our aim was to calculate WSS after balloon angioplasty and evaluate its predictive value for long-term outcome. METHODS:WSS was calculated proximal to, in, and distal to the lesion after angiogr...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1067/mhj.2002.123110
更新日期:2002-07-01 00:00:00
abstract::The relationship between myocardial sites with late activation during sinus rhythm and sites critical for the initiation and sustentation of reentrant ventricular tachycardia was systematically examined in the 4-day-old postinfarction canine heart. The critical sites for prevention of the initiation of reentry and for...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/s0002-8703(05)80230-3
更新日期:1990-05-01 00:00:00
abstract::The duration of intravenous heparin therapy required to maintain patency of the infarct-related artery after intravenous streptokinase is uncertain. Twenty-eight patients were prospectively treated with 1.5 million units of intravenous streptokinase within 4 hours of onset of chest pain. Intravenous heparin was begun ...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(88)90870-8
更新日期:1988-04-01 00:00:00
abstract::The Magnum/Magnarail system consists of "over-the-wire" balloon catheters and a 0.021 inch (0.53 mm) guide wire with a 1 mm olive-shaped tip. To compare it to conventional systems, 100 consecutive unselected patients with chronic total coronary occlusions were randomly assigned to one of two groups. If the balloon cou...
journal_title:American heart journal
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/0002-8703(92)91020-2
更新日期:1992-05-01 00:00:00
abstract::To determine the factors relating to prognosis, the records of 15 neonates with persistent prolongation of the QT interval on the electrocardiogram after the fourth day of life were reviewed. Patients were admitted for symptoms (syncope, cardiac failure, or seizures), abnormal auscultation with an irregular heart rate...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(92)90940-w
更新日期:1992-07-01 00:00:00
abstract:BACKGROUND:Low-molecular weight heparins have different pharmacokinetic and pharmacodynamic characteristics and may vary in efficacy. We compared the efficacy of enoxaparin with that of tinzaparin in the management of non-ST-segment elevation acute coronary syndromes (NSTACS). METHODS:A total of 438 patients with NSTA...
journal_title:American heart journal
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/S0002-8703(03)00179-0
更新日期:2003-08-01 00:00:00
abstract:BACKGROUND:Optimal antithrombotic treatment after transcatheter aortic valve replacement (TAVR) is unknown and determined empirically. The direct factor Xa inhibitor rivaroxaban may potentially reduce TAVR-related thrombotic complications and premature valve failure. DESIGN:GALILEO is an international, randomized, ope...
journal_title:American heart journal
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.ahj.2016.10.017
更新日期:2017-02-01 00:00:00
abstract::Electrical ablation techniques (ECT) have had limited success in achieving control of arrhythmias originating in the right atrial free wall (RAFW). To ascertain determinants for successful ECT, we studied the clinical and cellular electrophysiologic effects of electrical ablation of the RAFW. After performing electric...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(87)90655-7
更新日期:1987-06-01 00:00:00
abstract::To assess the relation between myocardial ischemia, ventricular arrhythmias (VA), and left ventricular (LV) dysfunction, we evaluated 74 patients with coronary artery disease (CAD) using radionuclide angiography (to determine the resting ejection fraction [EF]), resting thallium-201 scintigraphy (to ascertain the exte...
journal_title:American heart journal
pub_type: 杂志文章
doi:10.1016/0002-8703(85)90588-5
更新日期:1985-02-01 00:00:00
abstract:BACKGROUND:Half of patients with hypertension have poor blood pressure (BP) control. Recent models for treating hypertension have integrated disease monitoring and telephone-based interventions delivered in patients' homes. This study evaluated the costs of the Hypertension Intervention Nurse Telemedicine Study (HINTS)...
journal_title:American heart journal
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.ahj.2012.03.016
更新日期:2012-06-01 00:00:00
abstract:BACKGROUND:Anxiety is highly prevalent among patients with coronary heart disease (CHD), and there is growing evidence that high levels of anxiety are associated with worse prognosis. However, few studies have evaluated the efficacy of treating anxiety in CHD patients for reducing symptoms and improving clinical outcom...
journal_title:American heart journal
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.ahj.2016.03.003
更新日期:2016-06-01 00:00:00