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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 54-year-old woman had been treated under a diagnosis of cardiac sarcoidosis since 1998. She was admitted to our department because of recurrent heart failure in April 2002. A DDD pacemaker was implanted because of complete AV block in 2000, but she had always suffered from > or = New York Heart Association (NYHA) class III heart failure. To prevent recurrent heart failure, biventricular pacing was performed. The left ventricular epicardial pacing lead was newly inserted into the great cardiac vein via the left subclavian vein, and connected with the previously implanted generator. The QRS duration decreased from 200 to 140 msec. Serum brian natriuretic peptide level decreased from 321 to 226 pg/ml. Cardiac index increased from 1.93 to 2.20. Her functional class improved from NYHA class III to class II.
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PMID:[Beneficial biventricular pacing in a patient with cardiac sarcoidosis and refractory heart failure: a case report]. 1465 11

We report a prospective and descriptive study in 12 patients who had pacemaker implantation from may. 1996 and dec. 1997. Our patients benefited from complete clinical examination, ECG (12 derivations), standard laboratory tests, chest X ray. Pulsed-Doppler, two dimensional and TM echocardiography have been performed. Stimulation was achieved using endocardial lead introduced percutaneously. During the study, 12 patients over 22, representing 55% of the subjects with symptomatic conduction defects, had definitive pacemaker implantation. Mean age was 53.8 years +/- 18. Most of the patients lived in Dakar. Sex-ratio was 0.58 (7 males/5 females). Most of the patients (83%) had low socio-economical status. Before implantation mean heart rate was 47 bpm +/- 20.8. Mean blood pressure was 155 mmHg +/- 26.7 (systolic) and 71.6 +/- 20.8 mmHg (diastolic). Heart failure was present in 5 patients/12. Others symptoms were mainly syncope (83%). Mean cardiothoracic ratio was 0.56 +/- 0.09. Over a 14 months period we have implanted 7 double chamber stimulators (DDD) and 5 monochamber (VVI). Over a 210 days follow-up, main problems are infection of the pocket in 2 patients. In one of them culture was positive. In Senegal, it is necessary to develop cardiac stimulation. Pacemakers should be available for all patients with symptomatic conduction defects. A national center for electrophysiologic studies and pacemaker implantation is a priority.
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PMID:[Permanent cardiac stimulation in Senegal: preliminary experience at the Cardiology Clinic of Dakar]. 1466 2

Several observational studies have indicated that selection of pacing mode may be important for the clinical outcome in patients with symptomatic bradycardia, affecting the development of atrial fibrillation (AF), thromboembolism, congestive heart failure, mortality and quality of life. In this paper we present and discuss the most recent data from six randomized trials on mode selection in patients with sick sinus syndrome (SSS). In pacing mode selection, VVI(R) pacing is the least attractive solution, increasing the incidence of AF and-as compared with AAI(R) pacing, also the incidence of heart failure, thromboembolism and death. VVI(R) pacing should not be used as the primary pacing mode in patients with SSS, who haven't chronic AF. AAIR pacing is superior to DDDR pacing, reducing AF and preserving left ventricular function. Single site right ventricular pacing-VVI(R) or DDD(R) mode-causes an abnormal ventricular activation and contraction (called ventricular desynchronization), which results in a reduced left ventricular function. Despite the risk of AV block, we consider AAIR pacing to be the optimal pacing mode for isolated SSS today and an algorithm to select patients for AAIR pacing is suggested. Trials on new pacemaker algorithms minimizing right ventricular pacing as well as trials testing alternative pacing sites and multisite pacing to reduce ventricular desynchronization can be expected within the next years.
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PMID:Selecting the appropriate pacing mode for patients with sick sinus syndrome: evidence from randomized clinical trials. 1507 Dec 65

We tested the hypothesis that optimized biventricular pacing (BiVP) enhances cardiac output (CO) during critical pulmonary stenosis (PS) by attenuating distortions in left ventricular (LV) geometry. Following median sternotomy in six anesthetized pigs, heart block was induced by ethanol ablation. During epicardial, DDD BiVP, atrioventricular delay (AVD) was varied from 60 ms to 180 ms in 30 ms increments. At the AVD with the highest CO right-left delay (RLD) was varied from (+) 80 ms (RV first) to (-) 80 ms (LV first) in 20 ms increments. At each pacing setting, aortic flow, ECG, and LV diameter were measured in the control state (CON) and during PS, created by snaring the pulmonary artery until CO decreased 50%. Short axis LV echocardiograms were obtained at (+) and (-) 80 ms. In CON, RLD had no effect on function or geometry. During PS optimum BiVP resulted in significant increases in CO (1.12 L/min +/- 0.13 SEM at RLD =+ 40 ms versus 0.92 +/- 0.12 at RLD = 0 and 0.73 +/- 0.08 at RLD =-80), and LV fractional shortening (8.97%+/- 0.51% at RLD =+ 40 ms versus 7.34%+/- 0.58% at RLD = 0 and 6.21%+/- 0.66% at RLD =-80). In addition, LV eccentricity with (-) RLD was significantly different versus CON at both end-diastole (0.79 +/- 0.07 vs 1.02 +/- 0.03, P = 0.011 Student's t-test) and end-systole (0.83 +/- 0.05 vs 1.00 +/- 0.02, P = 0.017). However, with (+) RLD differences versus CON were not significant at either end-diastole (0.88 +/- 0.06 vs 0.99 +/- 0.03) or end-systole (0.92 +/- 0.03 vs 1.01 +/- 0.03). In swine hearts with PS, optimized BiVP increases CO, fractional shortening, and LV symmetry. BiVP warrants further study as treatment for acute postoperative heart failure.
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PMID:Mechanisms of optimized biventricular pacing in pulmonary stenosis: effects on left ventricular geometry in swine. 1530 53

A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing.
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PMID:[Assessment of regional wall motion using strain Doppler imaging during right ventricular bifocal pacing in a patient with severe congestive heart failure: a case report]. 1537 39

Newer indications for permanent cardiac stimulation include the prevention of paroxysmal atrial fibrillation (AF) and cardiac resynchronisation in patients suffering from advanced heart failure. Direct comparisons between VVI and DDD or AAI pacing showed an advantage conferred by physiological pacing on the risk of developing AF during long-term follow-up in patients with sinus node dysfunction, AV block, or both. Furthermore, in patients with conventional pacing indications and paroxysmal atrial tachyarrhythmias, a high percentage of atrial pacing was associated with a lighter AF burden. This article reviews several important issues involved in the optimisation of cardiac pacing with a view to prevent paroxysmal AF by new, dedicated pacing algorithms. The AF Suppression trade mark algorithm significantly reduced the rates of symptomatic paroxysmal AF. This algorithm, which confers its benefit by maintaining the atrial pacing rate slightly above the spontaneous sinus rate, should be activated in patients with a history of atrial tachyarrhythmia. Implanting the lead in the low atrial septum seems to reduce further the frequency of tachyarrhythmic events. Future indications for this mode of pacing may be extended to patients at high risk of new-onset or recurrent AF, such as candidates for cardiac resynchronisation therapy or implantable cardioverter/defibrillator recipients.
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PMID:Contributions of permanent cardiac pacing in the treatment of atrial fibrillation. 1545 Feb 78

Implantable cardioverter defibrillators (ICDs) reduce sudden arrhythmic death risk but when these devices are programmed DDD and pace in the right ventricle (RV), they can be associated with increased mortality and heart failure morbidity compared to an ICD programmed to back-up RV. An ideal ICD would provide effective treatment for life-threatening tachyarrhythmias, reduce unnecessary RV pacing and maintain AV synchrony. The Inhibition of Unnecessary RV Pacing with AV Search Hysteresis (AVSH) in ICDs (INTRINSIC RV) study will assess whether an ICD programmed to DDDR with AVSH is equal to an ICD programmed to VVI with regard to mortality, heart failure hospitalizations, and several predefined secondary enpoints. AVSH allows intrinsic AV conduction beyond the programmed AV delay to help minimize ventricular pacing. INTRINSIC RV, a multi-center, randomized, prospective trial will enroll >1,200 participants who receive a Guidant VITALITY AVT ICD. ICDs are programmed initially to DDDR AVSH 60-130. Then, after a week, if the %RV pacing <20%, patients are randomized to VVI-40 or DDDR 60-130 with AVSH. Those with RV pacing > or =20% are placed in an obvservational arm and programmed ad libitum by the treating physician. Patients are followed for one year. This large, randomized, controlled, clinical trial will address whether DDDR with AVSH programming is equivalent to VVI programming in an ICD with regard to mortality and heart failure hospitalization.
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PMID:Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs (INTRINSIC RV): design and clinical protocol. 1566 Aug 5

Recent observations suggest that frequent dual-chamber pacing in recipients of implantable cardioverter defibrillators (ICD) may adversely influence clinical outcomes. This prospective, multicenter study examined the relationship between the frequency of atrial (%AP) and ventricular pacing (%VP) and the incidence of atrial (AT) and/or ventricular tachyarrhythmias (VT) in a standard ICD population. A total of 141 consecutive patients with primary and secondary ICD indications were studied. Continuous arrhythmia detection with a dual-chamber ICD revealed paroxysmal AT in 60 (43%) and VT in 72 (51%) patients within 6 months of device implantation. Far-field oversensing of ventricular signals occurred in 13% of all "atrial tachy response" mode switches. Without adjustment for covariates, a higher %AP was associated with an increased incidence of AT (P < 0.05). However, this association remained only weakly significant after adjustment for covariates using a multivariate model. High New York heart failure functional classes correlated significantly with AT (P = 0.02) and VT (P = 0.007). Rate-modulated pacing, programmed in 1/3 of patients, correlated with occurrence of AT (P = 0.006), but not with occurrence of VT. With respect to dual-chamber pacing, a %AP >/= 48% combined with a %VP > 40% was associated with an increased probability for VT. In conclusion, AT and VT occurred frequently within 6 months after dual-chamber ICD implantation. High rates of DDD/R stimulation were associated with a trend toward higher incidence of AT, VT, or both.
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PMID:Impact of dual chamber pacing on the incidence of atrial and ventricular tachyarrhythmias in recipients of implantable cardioverter defibrillators. 1568 8

COMBAT is a prospective, multicenter, randomized, blinded clinical study, with crossover design. The main objective is the comparative evaluation of atrio-biventricular versus conventional atrioventricular stimulation (atrio and right ventricle) in patients with heart failure and bradycardia as the primary indication for pacemaker implantation. After successful atrio-biventricular system implantation, patients will be randomized into two groups: group A--atrioventricular conventional pacing and group B--atrio-biventricular pacing. Both groups will be programmed in DDD mode with AV delay optimized by echocardiogram. After 3 months, New York Heart Association functional class, ventricular arrhythmia density and complexity, echocardiography outcomes, 6-min hall walk distance, quality of life and peak oxygen consumption will be assessed in all patients. Then, all patients will crossover to the other pacing regimen, with an additional AV delay adjustment by echo. Patients will be followed up for another 3 months at the end of which all evaluations will be repeated. Patients will then crossover back to their original pacing regimen for a further 3 months. At the end of this 9-month period, patients will be reprogrammed according to their optimal pacing regime. In an extended follow-up, patient survival will be evaluated after 24 months of the optimal pacing therapy.
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PMID:COMBAT--conventional versus multisite pacing for bradyarrhythmia therapy: rationale of a prospective randomized multicenter study. 1570 70

Evidence from randomized trials indicates that the clinical benefits of dual-chamber (DDD) pacing are modest: (i) no significant differences exist between physiological pacing and single-chamber pacing in mortality and stroke; (ii) ventricular desynchronization resulting from chronic right-ventricular pacing in DDD mode, induces a significantly increased incidence of atrial fibrillation (AF) and heart failure hospitalizations; (iii) AF pacing prevention and therapy algorithms have shown a modest to minimal or absent efficacy; (iv) the widespread use of physiological pacemakers is not an economically attractive strategy. Thus, these data provide a reliable body of evidence on which to make more rationale clinical decisions for individual patients and policy decisions for health costs saving. The cheaper single-chamber AAI(R) or VVI(R) has been shown to satisfy both conditions in most cases of sinus node disease and AV block.
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PMID:Pacemaker selection: time for a rethinking of complex pacing systems? 1620 37


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